Proceedings
Plenary
Latin American Sustainability and Trade
Jorge Buhler-Vidal, Polyolefins Consulting LLC
Latin America and the Caribbean is a medium income region representing the largest land mass joined by two major common languages. Its more than 600 million inhabitants are the world's fourth largest economy. Its 20 countries, which are far from being a single, monolithic market, can be grouped in five polyolefin commercial regions. Geography, logistics, development and trading patterns define five sub regions: Mexico, Central America and Caribbean, Northern South America, Brazil and Southern Cone. Fortunately, awareness of the problems created by improperly disposed plastics has increased in the region, as it has in the rest of the world, but control measures are sometimes poorly thought out and have undesirable consequences. Legislation addressing single use plastics has resulted in total or partial bans in some countries and cities. Industry has generally been reactive rather than leading. Brazil is a substantial producer of sugarcane bio polyethylene, that captures CO2 rather than releasing it as does petrochemical based polyethylene. The region has several polyolefin resins producing countries, but while there are plans for new projects, almost none of the projects are active because sufficient raw materials are not available. Argentina could justify a new olefins and polyolefins complex because it has the regional demand, and it may soon have enough natural gas. The regional lack of new capacity continues to provide opportunities for outside producers to import polymers for local processors. The situation is not likely to change in the near future.
Sustainable Nano-Fibril Technology for Polyolefins with Superior Properties and Foaming Ability
Chul Park, University of Toronto
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This plenary speech will explain the details of the sustainable nanofibril technology for the PE and PP resins that will enhance the mechanical properties and/or the foaming ability dramatically. Nanofibril composites are thermoplastic resins including nanofibrils with a high aspect ratio over 100. The processing technology for creating nanofibrils inside the PE and PP matrix will be presented. The processing, equipment, and materials requirements for the PE and PP resins will be presented in detail. The structure and morphology of the nanofibrils will be presented. With the dispersed nanofibrils in the PO matrix, the mechanical properties and the foaming/film-blowing ability of the PO resins are improved. This talk will address the impact of the nanofibrils and the details of the nanofibril processing technology for PO resins. First off, the enhanced sustainability of the PO foams with nanofibrils will be discussed. I will address the critical issues about (i) the costs, the energy, and the environment, (ii) broadening of the processing window with the introduction of the nanofibrils. The increased mechanical properties including the stiffness, the ductility, the strength, and the impact strength will be presented as a function of the nanofibril content. The addition of reinforcing fillers such as talc, glass fibers, etc. typically increases the stiffness of the resin with a sacrifice to the ductility and the impact strength. But our nanofibrils will increase both of the stiffness and the ductility. The increased barrier properties with the presence of nanofibrils will be discussed with the changed crystal morphology. The increased foaming ability of the PE and PP with inherently low melt strength will also be presented, which is related to the modern foaming technologies using crystals to control foam processing. First, the effects of crystals on cell nucleation and cell growth will be discussed. Next, I will discuss the gas's effect on crystallization kinetics. We found that the crystallization temperature decreased because of the gas's plasticizing effect through increased dilation of the polymer. A high-pressure DSC analysis showed that the dissolved gas significantly promoted crystal nucleation. I will show how crystallization is controlled and how crystals affect the foaming behaviors in the processes of bead foaming, extrusion foaming and foam injection molding, using nanofibrils in the PE and PP matrix.
Dow's Sustainability Journey
Mukund Parthasarathy, The Dow Chemical Company
Market drivers of product protection, resource efficiency and circular economy continue to impact the world of packaging applications. This presentation will relate how these market drivers are leading to advances in the materials and package design, especially for recyclability. The presentation will describe how Dow is collaborating globally across the value chain to provide sustainable packaging solutions. Finally, the presentation will focus on the challenges in packaging particularly with regard to developing meaningful end of life solutions to enable a circular economy and Dow's effort in driving sustainability.
Ocean Plastics: Industry-Led Initiatives to End Plastics Waste
Steven Russell, American Chemistry Council
Plastics enable health, safety, sustainability and convenience benefits that have revolutionized society. However, plastic waste in the environment, particularly the ocean, is a serious challenge. While progress has been made to increase plastic recycling and recovery, the scale of the problem is immense and will only increase on our current path. CEOs from along the plastic value chain have created a new, business-driven, results-oriented entity to eliminate plastic waste in the environment. The initiative will address: Waste Management Infrastructure and Systems, Innovation, Education and Engagement, and Clean Up. Members will invest in technical solutions such as improved optical sorting and packaging formats, as well as optimized products and designs. Looking ahead, deployment of innovative technologies to create value from used plastics through new business models will play an increasingly important role in designing waste management infrastructure to prevent major leakage areas, including in the Asia-Pacific region.
Tutorial
Fundamentals and Applications of Metallocene Polyethylenes
Rajen Patel, The Dow Chemical Company
Polyethylene is the largest volume thermoplastics used today and has a very broad range of properties enabling wide variety of applications including packaging. Metallocene polyethylene were commercially launched starting from early 1990's including Polyolefin Plastomer (POP), Polyolefin Elastomer (POE) and mLLDPE. This tutorial will focus on metallocene polyethylene resins covering structure-properties relationships in metallocene polyethylene, various processes to make them and key applications of metallocene polyethylene. The presentation will also cover additives used in polyethylene.
Sustainable Nano-Fibril Technology for Polyolefins with Superior Properties and Foaming Ability
Chul B Park, University of Toronto
This plenary speech will explain the details of the sustainable nanofibril technology for the PE and PP resins that will enhance the mechanical properties and/or the foaming ability dramatically. Nanofibril composites are thermoplastic resins including nanofibrils with a high aspect ratio over 100. The processing technology for creating nanofibrils inside the PE and PP matrix will be presented. The processing, equipment, and materials requirements for the PE and PP resins will be presented in detail. The structure and morphology of the nanofibrils will be presented. With the dispersed nanofibrils in the PO matrix, the mechanical properties and the foaming/film-blowing ability of the PO resins are improved. This talk will address the impact of the nanofibrils and the details of the nanofibril processing technology for PO resins. First off, the enhanced sustainability of the PO foams with nanofibrils will be discussed. I will address the critical issues about (i) the costs, the energy, and the environment, (ii) broadening of the processing window with the introduction of the nanofibrils. The increased mechanical properties including the stiffness, the ductility, the strength, and the impact strength will be presented as a function of the nanofibril content. The addition of reinforcing fillers such as talc, glass fibers, etc. typically increases the stiffness of the resin with a sacrifice to the ductility and the impact strength. But our nanofibrils will increase both of the stiffness and the ductility. The increased barrier properties with the presence of nanofibrils will be discussed with the changed crystal morphology. The increased foaming ability of the PE and PP with inherently low melt strength will also be presented, which is related to the modern foaming technologies using crystals to control foam processing. First, the effects of crystals on cell nucleation and cell growth will be discussed. Next, I will discuss the gas's effect on crystallization kinetics. We found that the crystallization temperature decreased because of the gas's plasticizing effect through increased dilation of the polymer. A high-pressure DSC analysis showed that the dissolved gas significantly promoted crystal nucleation. I will show how crystallization is controlled and how crystals affect the foaming behaviors in the processes of bead foaming, extrusion foaming and foam injection molding, using nanofibrils in the PE and PP matrix.
Rheology with Application to Polyolefins
Teresa Karjala | Sylvie Vervoort, The Dow Chemical Company
Rheology, or the science of deformation and flow of materials, is very important in both polyolefin polymer processing as well as product design. In this tutorial, the basics of polymer rheology will be addressed along with specific examples primarily focused on polyethylenes. Fundamental rheological properties will be explained as well as basic relationships with polyolefin molecular properties. The practical examples will show how rheological measurements help with resin selection and process optimization.
Solutions for Protective Packaging: Enhanced Expanded Polyethylene Foam
Todd Hogan, The Dow Chemical Company
Polyolefin foams are utilized in a wide variety of applications ranging from protective packaging, sports and leisure, construction, to automotive and others. Foams are utilized in these applications as they provide the key performance properties such as cushioning, energy absorption, sound insulation, and thermal insulation. Polyolefin foams derive their performance in large part from the polyolefin-based resins used in their composition, as well as the processing conditions used to fabricate the foam. Selection of the appropriate polyolefin resin for a given application is critical in order to achieve the desired foam performance. Historically, the primary resin used in expandable polyethylene (EPE) foaming application are 2-4 g/10 min melt index LDPE as it has suitable melt strength and appropriate processing conditions. The foaming ratio is regulated by the loading level of blowing agent, nucleating agent (talc, amount and size), permeation agent, processing conditions, and resin properties. With LDPE as the base resin, the mechanical properties of produced foam sheet or plank (e.g. tensile strength, tear resistance, compression set, compressive strength, and creep resistance) are mainly determined by foaming ratio. Unfortunately, higher foaming ratios typically result in lower mechanical properties, and therefore, a limit is reached with pure LDPE. Through extensive R&D development, Dow has developed a tailored LDPE/LLDPE blend solution to overcome the foaming ratio limit for LDPE and reduce packaging weight or volume while maintaining the required level of protection. Previously, a heavy item or an object that is shock-sensitive would require heavier or thicker foam, resulting in larger overall packaging weight. The new lightweight and sustainable solution achieves equivalent packaging integrity.
Additives
Compatibilizing PP and PET - an approach for recycling of unseparable plastic streams
Christoph Burgstaller, TCKT
Recycling of various post-industrial and post-consumer materials is currently a very intense research topic in Europe, as EU-legislation puts out mandatory quotes for recyclable packaging, and also China has stopped importing plastic waste streams. The paper will give an introduction on the different waste streams in industry and their recyclability, as well as some overview about activities going on in the scope of this topic. In packaging applications, nowadays typically multilayer films are applied to fulfil a variety of requirements like tenacity, printability, barrier properties and food contact approval. These multilayer films show one main problem, which is their recycling, even as low contaminated post-industrial waste, which is present as start-up materials and edge-trim, as the different layers are usually incompatible, thus re-melting results in degraded properties, which are insufficient for most applications. Therefore, the aim of this work was to investigate composition effects of polypropylene based formulations with polyethylene terephthalate and approaches to compatibilize these. The different formulations were melt blended, with or without compatibilisation, in a twin-screw extruder. The materials were further processed via injection moulding to retrieve universal test specimen for mechanical testing (tensile and impact tests). Further characterisation, via scanning electron microscopy or rheology (represented her by melt flow rate determination), was carried out to investigate the correlations between composition, morphology and properties. We found, that the morphology is formulation dependent, and, that it is possible to compatibilise such formulations by applying maleic anhydride grafted polypropylene, but also proper processing in terms of vacuum degassing and pre-drying is crucial to yield reasonable properties. These findings can help in the mechanical recycling of multilayer film based on PP and PET.
Effect of HALS against photo degradation of greenhouse PO film under severe sulfur fumigation
Yota Tsuneizumi, ADEKA Corporation
Polyolefins such as polyethylene and polypropylene are used in a wide variety of applications ranging from greenhouse films, automotive parts and building & construction materials. Articles exposed to sunlight, however, must be stabilized to prevent the degradation induced by the ultraviolet light on the polymer backbone. HALS (Hindered Amine Light Stabilizers) are generally added to prevent the degradation in polyolefins. For greenhouse film application, 3-5 years life-time can be achieved by addition of HALS. But it many cases, chlorine type, phosphorus type or sulfur type pesticides are used and especially with sulfur fumigation causes salt formation with conventional high basicity HALS, resulting in the inhibition of the stabilization mechanism. For this reason, in greenhouse films, use of low basicity NO-Alkyl type HALS is preferred. An advanced NO-Alkyl HALS-1 system was developed which provides remarkable weathering resistance in terms of the transparency and mechanical properties of the film under sulfur fumigation compared to conventional high basicity HALS. In addition, the initial color of film after processing can also be improved by HALS-1 compared to NO-Alkyl HALS-2. This paper describes the influence of sulfur content in the greenhouse film application and the appropriate usage of HALS for the application with a number of desired improvements under sulfur fumigation.
Solid Phase Extraction for Additive Analysis in Polyolefins
Robert Bruell, Fraunhofer
"The rapid development in the area of stabilizing additives creates the need for appropriate analytical techniques. These shall address the aspect of quantitatively separating the stabilizer from the matrix and, in succesively, to discriminate between various structurally similar stabilizers. Various approaches like Soxhlet extraction and precipitation, are state of the art, yet regularly cannot satisfy the analytical requirements of novel and complex additive packages. Solid phase extraction, SPE, is a powerful approach to isolate low molecular weight analytes from matrices, and has been widely used in environmental analysis or food analysis. In this presentation we will show how SPE can be applied to the analysis of additives in polyolefins. The effect of stationary and mobile phase on the process of desorption and adsorption for representative stabilizing additives will be shown."
Development of a Polyolefin Stabilizer Blend with Predefined Properties and Food Contact Status
Robert Sherman, Baerlocher
Development of a new additive or additive blend is a complex, time intensive process. Baerlocher has introduced Baeropol Resin Stabilization Technology (RST) as a synergistic stabilizer blend for polyolefins. A discussion of the work necessary to develop a new blend including regulatory, performance, and properties will be discussed.
Innovative Solutions for Film Antiblocking
Estelle Lagache, Imerys
Unfilled polymer films will stick together or block when, for example, tightly pressed together or wound onto a reel. Various additives are used to reduce or prevent blocking and are known as antiblocks. Imerys is offering a wide range of mineral including Diatomaceous Earth like Celite and Super Floss which provide excellent clarity together with high blocking at very low addition rates. Thanks to its thorough knowledge within the plastic industry, and to answer to the most demanding requirements, Imerys is developing a new range of engineered products with a large choice of particles size, particle shape and mineralogy. In this paper, Imerys will present the optical, mechanical and blocking results obtained with this new portfolio of minerals at different loading rates in a typical LLDPE resin.
Selecting Metal Soaps for Optimum Acid Scavenging Performance in Polyolefins
Leonard Walp, Norac Additives
Calcium stearate is know as an acid scavenger for polyolefins. This paper gives in in depth study on the effect of changing calcium levels, calcium sources, and fatty acid types on the neutralization effectiveness. It investigates corrosion effects of the calcium stearates. It also investigates the effect of calcium stearate on filter plugging.
On the Mitigation of Threats to “Business as Usual” in the World of Polymer Additives
Rob Lorenzini, Maroon Group
From tariffs, to regulatory changes, and raw material shortages, the world of polymer additives has recently been in a state of heightened flux. Because of these challenges, many buyers and formulators are operating in previously uncharted territory, with rumors and half-truths abound. This talk will be a journey through various topics du jour, including regulatory threats to the UV absorber market, practical impacts of China's "Blue Sky Initiative" and various formulation strategies using historical products that perhaps deserve a second look.
Phosphite Antioxidant Kinetics and in-Polymer Performance: Part 2
Hayder Zahalka, Addivant
Reaction kinetics of model hydroperoxides with solid phosphites was monitored by 31P NMR and reaction rate constants were calculated from 31P NMR spectrum. The kinetic study data will be complemented with in polymer performance for high performance solid phosphite and compared to a commodity solid phosphite.
Simultaneously Extending Impact, Melt Flow, and Stiffness of Polypropylene Impact Copolymers
Nicolas Treat, Milliken and Co.
Milliken's recent developmental additives for polypropylene impact copolymers enable resin manufacturers to extend the performance of their materials to better meet customer needs. These additives go beyond conventional nucleating agents and rheology modifiers to enable a higher performing class of polypropylene resin that has not existed without the use of impact modifiers and fillers. The end result is better toughness characteristics and improved processability resulting in improved profitability and more sustainable solutions for converters.
Investigating the use of polymeric phosphites to improve processing, melt fracture and thermal stability.
Michael Jakupca, Dover Chemical
Phosphites are widely used to improve the thermal stability of polymers during melt processing. However, phosphites also have ancillary effects which can be both positive and negative. This paper will address several benefits of a new class of polymeric phosphite stabilizers that include improved processing, thermal stability and unique melt fracture synergy with process aids.
Minerals Solutions for Various Modes of Noise Reduction in Polyolefins
Prasad Raut, Imerys
Minerals have been an integral part of polyolefin applications. Traditionally minerals are used for increased reinforcement and/or reduced compound cost in thermoplastic applications. In this paper new mineral solutions focusing on applications targeting noise reduction in injection molded PP articles will be discussed. Guide on optimum mineral choice for various modes of noise mitigation in PP formulation will be presented along with the benefits of a specific mineral type in mechanical, thermal and rheological properties.
Optimizing Stabilization Systems for Polyolefins Using Traditional and Specialty Antioxidants
Rick King, BASF Corporation
Phenolic antioxidants and phosphite based stabilizers are traditional cornerstones of a generic polyolefin stabilization system. The phenolic antioxidant provides long term thermal stability, and the phosphite provides melt processing stability. Using a judicious selection process for the components, the base stabilization system can then be further optimized using various loadings, ratios, along with other co-additives to meet the desired performance targets for a given end use application. These traditional antioxidant systems can then be further optimized using hyperactive stabilizer chemistries, that allow for specific performance characteristic that afford improved processability under demanding condition, and/or remarkable discoloration resistance, both during and after processing. Representative examples for how to optimize selected polyolefins will be presented in this paper.
Twenty-five Years of Light Stabilizer Applications and Development for Polyolefins
Joseph Fay, BASF Corporation
The wide-spread use of polyolefins in outdoor applications has been made possible by the development of high performance light stabilizer chemistries. Over the years, formulation technologies have improved with not only the addition of new stabilizer chemistries, but also with advances in how both new and older stabilizers are used together. While challenges remain with respect to commercialization of new chemistries and will limit new introductions, the current portfolio of products has enabled the polyolefins market to continue to grow in both size and number of products and applications. Light stabilizers have played a critical role in many of these applications, especially those in which outdoor UV exposure is intended. A review of light stabilizer technologies, with an emphasis on products and technologies introduced over the last twenty-five years, will help demonstrate how these cost-effective products have helped advance the utility of polyolefins and how they will continue to advantage polyolefin applications in the future.
High Performance Stabilizers for Colour Protection and Melt Flow Stabilization
Hartmut Siebert, Clariant
AddWorks LXR 568 is a high performance stabilizer that provides outstanding colour protection and excellent melt flow stabilization. It is highly compatible with a broad range of thermoplastic polymers and brings substantial resin improvements in numerous applications, such as films or moulded articles, automotive compounds, pressure pipes. AddWorks LXR 568 makes the polymer more lasting, more sustainable and more suitable for recycling. AddWorks LXR 568 is resistant to hydrolysis, thermally stable and produced in free-flowing pills and micro-pills, making it very easy to handle and to use on plastic processing lines. AddWorks LXR 568 shows a deferred formation of non-intentionally added substance (NIAS).
New Catalyst Neutralizer Polymer Protector Additive for Polyolefin Polymers
Donald Beuke, Mitsui Plastics Inc.
For many decades' metallic oxides, metallic stearates and Hydrotalcites have been used to scavenge acids from the 1st - 4th generation TiCl4 catalysts spanning 1955-1995. Metallic oxides and stearates form Lewis Acids which reduce antioxidant efficiency resulting in polymer degredation. Hydrotalcite results in reduced OIT and increased color; thus, limiting to a few polyolefin applications. Mitsui with our in depth knowledge of catalysts, Hydrotalcites, antioxidants and lubricants, have discovered new 5th + generation catalyst neutralizer. This new discovery solves the problem of current acid scavengers with modern day Ziegler-Natta catalysts. Results are improved quality which results in a significant increase in; LLDPE and PP tensile strength, and HDPE flexural modulus. Three take-a ways:
- Mitsui Plastics new proprietary catalyst neutralizer protects the polymer resulting in improved quality and performance.
- Quality: 50-60% increase in antioxidant retention, increased OIT and up to 95% less polyolefin degredation per FTIR analysis.
- Performance: 1-5 extruder passes no yellow color, significant increase in LLDPE and PP tensile strength.
New Nano Additives Patented and Recently Produced for Engineering Plastics Upgrade
Howard Paul, America P & G Co.
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A major obstacle to the application of plastics in engineering is the mechanical strength, toughness, wear and tear resistance. One way to improve engineering plastics is to enhance the mechanical strength by the addition of Nano composite whiskers. SiC Nano whiskersand Al2O3 Nano whiskers therefore have been aimed by bonding with raw pellets and other additives as composite reinforcing materials for conventional engineering plastics upgrade. Concentrated efforts have recently commercially produced by our USA Patent technology # US8426328 for two new Nano additives "silicon carbide (SiC) whiskers and alumina (Al2O3) whiskers". Two new Nano additives can be utilized as a process drop-in technology to achieve an overall solution for commercial engineering plastics upgrade. The new Nano additives can upgrade engineering plastics, specialty plastics and thermoplastics for application areas included aerospace, automotive parts, transportation, engineering accessory parts, construction heavy duty equipment, and explosion-proof safety.
New Opportunities for Stabilizers Through Circular Economy
Rudolf Pfaendner, Fraunhofer LBF
Circular economy will change our way to design plastic products to provide greater durability, reuse and high-quality recycling. The European Union will considerably reduce landfill, introduce economic incentives to put greener products on the market and drive investments and innovation to circular solutions. In addition to improve design to make plastic products easier to recycle, collection and sorting will be expanded and viable markets for recycled and renewable plastics will be created [1]. In any case recycling of plastics will grow and the quality of recyclates has to be improved to replace pristine polymers. Additives play an important role to enhance and to maintain the quality of recyclates and the performance of plastics from nature. The most used additives for recyclates are stabilizers, repair additives, compatibilizers and odor neutralizing agents [2]. Recyclate stabilizers fulfil the same function as in virgin material namely to protect the polymer from oxidative degradation during processing and to maintain the properties during use. Consumed stabilizers of the first application have to be replaced at least and/or adjusted to the requirements of the second application. For example a recyclate from a short-time packaging application is not sufficiently stabilized for a long-term service life. Specific recyclate stabilizers were developed in the past, however mainly as a variation of standard virgin stabilizer systems. Selected combinations of phenolic antioxidants, phosphites and antiacids in optimized ratio prove that the best cost/performance stabilizer combination for recyclates is different from the one for virgin material [3]. Recycled plastics show usually predamage through oxidation from the first service life e.g. an increased carbonyl group content versus virgin material is found in polyolefins. Moreover the oxidized molecular structures act as an initiator site and prodegradant accelerating further degradation [4, 5]. A novel stabilizer system beyond virgin stabilizers interacts directly with the carbonyl groups and neutralizes the initiator sites resulting in improved recyclate protection. The newly developed components are environmentally friendly, are derived from natural resources and, in addition, may act as hydroperoxide decomposer and metal deactivator. Results are shown for post consumer PP recyclate from battery cases and for other polyolefin applications. For the further development of the technology an industrial partnership is established.
Effect of Mold Temperature and Additive on Scratch Behavior of TPOs at Elevated Temperatures
Hung-Jue Sue, Polymer Technology Center - Texas A&M University
Scratch performance of TPOs is now being treated as one of the most important properties of engineering polymers for automotive applications. In order to enhance the scratch-resistance of TPOs, slip additives such as mono-unsaturated fatty acid amides are commonly used. When TPOs are injection molded, the mold temperature affects not only the migration of the slip additive toward the surface of TPOs but also the crystallinity of the matrix polymer, which is one of the factors influencing scratch-resistance. In this research, the ASTM/ISO linearly increasing normal load scratch test methodology was performed to evaluate the effect of the mold temperature and erucamide on scratch performance. Furthermore, the scratch tests were carried out at 25°C, 50°C and 75°C to learn about how and why the testing temperature affects the scratch performance. The present study offers a comprehensive understanding on the effects of mold temperature, slip additive, elevated testing temperature, and thermal aging on scratch behavior of TPOs.
Enhancing the Properties of Polyolefins to Accelerate Market Adoption
Jian-Yang Cho, Solvay
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As the use of polyolefins continues to increase in new markets and applications, resin producers, compounders, masterbatchers and molders must keep pace with complex, changing technical requirements. Leveraging its experience in polyolefin stabilization, Solvay is helping companies throughout the plastics value chain deliver exceptional performance and improve operational efficiencies. This presentation will highlight our technical innovations to meet demanding requirements in the building and construction as well as molding markets.
Low VOC Stabilization Systems for PP Automotive Applications
JungDu Kim, SONGWON International Americas
Emissions from polypropylene are gaining more and more attention. In automotive interior applications in particular, emissions can be generated by the quality (purity) of the polyolefin, the degradation of the polyolefin, and the solubility and inertness of the additives used. For a few years, reduction of Volatile Organic Content (VOC) for automotive interior compounds has been a major topic with norms becoming more and more stringent. In response to this new trend, resin producers have introduced low VOC grades. One way to improve VOC is to slow down the pelletization step after the polymerization of the PP, but this increases the cost of the automotive resin. In the compound market, different additive packages potentially can influence the emission levels, and new advanced stabilizer solutions can reduce emission levels for exterior and interior PP-based TPO automotive applications. This paper presents solutions for reduction of VOC in the value chain (from resin producers to OEMs). Our idea is special additives, which contribute to lessening VOC.
Enhanced Dispersion and Properties in Polypropylene Composites Processed Employing Extensional Mixing Elements
Chaitanya Danda, Case Western Reserve University
Dispersing fillers in polymer composites is necessary to harvest the enhanced behavior the filler brings in. Depending on the nature and geometry of the filler, dispersion demands energy that need to be delivered by the processes involved in making composites. The work encompassed involves the study of nature of flow type during processing on the extent of filler dispersion. Polymer systems investigated are polypropylene composites with Carbon Black (CB), Graphene Nano Platelets (GNP) and Carbon Nano Tubes (CNT). Process conditions are kept identical with the exception of changing a mixing element of interest on the screw of a twin strew extruder. A mixing element quoted here as an Extensional Mixing Element (EME) imparts extension dominated flows on the polymer melt. Several EMEs with varying degrees of aggressiveness are compared alongside a Kneading Block (KB) in their ability to break up filler agglomerates. Dispersion analysis of filler agglomerates indicate EMEs deliver improved dispersion over KB. This enhancement in dispersion in translated into improved mechanical behavior. A significant increase in biaxial stretch behavior alongside improved tensile properties are observed with composites processed through EMEs.
New Hydrogenated Styrenic Block Copolymers for PP Modification
Bing Yang | Aparajita Bhattacharya | Richard Ma | Yonghua Zhou, Kraton Polymers
Hydrogenated styrenic block copolymers (HSBC) are soft thermoplastic elastomers that have good compatibility with polyolefins. Blends of HSBC polymers with polypropylenes at low ratios can enhance impact performance while maintain high clarity of random copolypropylene. Blends of HSBC with random copolypropylenes at high ratios can be melt processed into flexible parts for many different applications. The latest polymer development from Kraton Polymers demonstrates improved performance and processability in applications such as medical tubing and bag due to their high clarity, flexibility, kink resistance and toughness. The polymer can also be processed at lower temperature to expand the operating window of common processes.
Insuring Plastic Additives which are used in Sensitive Applications are Fit for Use
David Horst, BASF Corporation
Plastic Additives are often applied in food contact, water pipe or other sensitive applications. Regulations have established requirements for suitable purity for these products. Over the years, focus on identification and evaluation on migrating substances have increased and Good Manufacturing Practice requirements for plastic additives during synthesis and blending have become more explicit. Many plastic additives, especially antioxidants and light stabilizers, undergo chemical transformations as they perform their functions during plastic fabrication and use. Non-intentionally added substances (NIAS) that originate from various sources must be assessed and controlled. Authorities and others are investigating NIAS and questions can be expected. We will discuss BASF's programs to identify and mitigate risks in this area and comment on the current state of affairs.
Loan Doan
Thi Thu Loan Doan, University of Science and Technology, The University of Danang
Mechanism of Discoloration of Polyolefins Melt index change and discoloration are the main factors to determine the degradation of polyolefin. The main mechanisms of discoloration of polyolefin including the discoloration of polyolefin them self by oxidation to form poly conjugated double bonds, the residue of catalyst, and oxidation of hindered phenol antioxidant have been studied. The discoloration of polyolefin and the effects of structure of hindered phenols on the discoloration have also been investigated. The results of the study on the discoloration will be reported in this talk.
Automotive
Lightweight Design for Future Mobility Concepts
Maurits van Tol, Borealis Polyolefine GmbH
Making cars lighter has been in the focus of the automobile industry for a long time. First to ensure that (racing) cars would be faster, but over time the emphasis changed for the mass produced cars from increasing the speed to reducing fuel consumption. Even so, with our increasing demand for safety- and comfort-enhancing features, the curb weight of comparable cars has significantly increased…this despite the fact that a massive amount of metals has been replaced by lightweight performance plastics already. Combustions engines have been refined at a high speed to deliver more power at lower fuel consumption, but still, the increasing legal requirements on reduced CO2 emissions become more and more a challenge if curb weight continues to increase at the same time. For cars with electric engines plus (heavy!) batteries, curb weight reduction is important as at this stage in their development the distance they can be driven between recharging cycles needs to be increased to help mass adoption. Borealis is a significant and innovative player in the production of polyolefins, in particular polyethylene and polypropylene. These plastics have a competitive CO2-footprint, can be designed on a molecular level to match performance criteria, they can be easily recycled, and they are very versatile in that they can be compounded (mixed with other ingredients) for the production of (structural) foams, fiber-reinforced materials, etc. In the presentation we will show some examples of how Borealis and its value chain partners in the automotive industry tackle the industry challenges by developing polyolefin-based solutions. They find their way in the all types of vehicles with the full width of drive trains and will continue to play a significant role in keeping the planet mobile and safe at an as low as possible energy consumption.
Lightweighting Strategies with Talc in Automotive TPOs
Piergiovanni Ercoli Malacari, IMI Fabi Spa
Automotive plastics market is a very demanding and growing business. Talc is a functional mineral for polymer modifications in this market where it plays a relevant role in TPOs where the very unique final performances can be achieved. IMI Fabi has developed a full range of products to fulfil the most demanding request in this area with a global presence, to satisfy the main automotive requirements. In this paper, some specific examples how to approach lightweighting by using IMI Fabi Talc grades will be showed.
Electron Transport in Conductive PP Polymer Nanocomposites
Zhanhu Guo, University of Tennessee
To make inert polyolefin possess properties like electrical conductivity, heat conductivity or magnetic properties will broaden its applications. Carbon nanotube is commonly used as conductive nanofiller to improve the electric conductivity of hosting polymer matrix. However, the conductivity of the polymer nanocomposite depends on the network formation of carbon nanotubes (CNTs) in the polymer matrix, and high CNTs content was required to accomplish the conduction network in polymer matrix. To enhance the conductivity of the composite, certain extra treatments such as chemically functionalized through acid, amine and heat treatment were used to improve the dispersion of CNTs in polymer matrix. However, these treatments would cause some negative effect on the conductivity of the pristine CNTs by influence the connection. In order to make a more efficient network formation of CNTs in polymer matrix, polypropylene/carbon nanotubes (PP/CNTs) nanocomposites were fabricated by both solvent and microwave radiation methods to coat CNTs on the surface of PP pellet, respectively; and after hot pressing CNTs between the PP pellets would connect together and easily form network structure in the polymer matrix. CNTs have successfully served as nanofillers for obtaining highly electrical conductive PP resin polymer nanocomposites (PNCs). The effects of nanofiller loading levels and the processed temperature on the rheological behaviors, crystal structure, electrical conductivity, optical properties and dielectric properties were systematically studied. The crystalline structures of PNCs, that are crystal structure, crystallization temperature and crystalline fraction, were obviously affected by CNTs loading levels and processing temperatures. The electrical conductivity was observed to depend on the pressing temperature and CNT loading levels, which are main factors on network formation. Variable range hopping (VRH) mechanistic study will be used to study the electron transport mechanism. The applications of these materials will be presented as well.
Building and Infrastructure (inc. Pipe and Geomembranes)
Kinetics of Slow Crack Growth in HDPE Pipes
Jung-Wook Wee, Korea University
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In case of the pipe grade high-density polyethylene (HDPE), the slow crack growth (SCG) occurs in the continuous, discontinuous, or mixed manner depending on the applied stress and temperature. The accurate lifetime estimation requires the appropriate model which describes such unique SCG kinetics. The crack layer (CL) model was proposed as a promising way to describe the uncommon SCG based on the theoretical backgrounds. The CL is a system of main crack and the surrounding process zone (PZ), and the CL theory concerns the thermodynamic interactions between them. Indeed, the discontinuous SCG kinetics in HDPE have been successfully simulated by the CL theory for the several test specimens. For the HDPE pipes, it has been observed that the crack propagates from the pre-existing internal defects such as voids, gels, dusts, and so on. Thus the CL models from the internal initial crack is required to describe the realistic brittle fracture scenario. Also, because the size of the initial defect is random, the stochastic analysis regarding the defect size is required to assess the reliability. In this study, the CL growth model from the internal initial crack was developed, and the discontinuous SCG from the internal crack was successfully simulated. Further, the probabilistic lifetime distribution from the randomly generated initial crack sizes were analyzed. The diagrams for the stress-lifetime distributions with regard to the various initial crack locations and sizes were also constructed.
Microwave Interaction with Polyethylene and Its Use in Inspection of Joints
Bob Stakenborghs, ILD/Evisive
This presentation will describe the theory of microwave inspection in general and then discuss the interaction of microwave energy with various materials. Then we will explore how microwaves specifically interact with materials under inspection. The specifics of microwave interaction with polyethylene will be described and how it is used for inspection. Finally, we will look at the current state of the art in inspection technologies and codification status of microwaves as a tool for inspection.
Elevated Temperature Testing and Validation of Long-Term Performance for Polyolefin Piping Materials
Tom Walsh, Plastic Pipeline Integrity, LLC
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In order to design for thermoplastic, composite or multilayer piping applications, the long-term strength of the particular thermoplastic material or composite or combination of materials needs to be established. This is necessary because thermoplastic and many composite and multilayer piping products demonstrate time dependent strength properties due to their viscoelastic responses. To properly design using such materials and to ensure adequate service life for the plastic piping, some type of long-term testing method must be used. This testing method, along with some type of mathematical analysis of the resulting data must allow a projection of the estimated long-term strength at or near the projected service life limits required for the particular application.
Qualifying a Masterbatch for Use with a Pressure Pipe Resin to Meet PE 4710 Pipe Requirements
Taha Abdulla, Sasol
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High density polyethylene (HDPE) resins or compounds used in the production of various pressure piping system components (solid wall HDPE pipe, fabricated or injection molded fittings, composite pipe, etc.) are required to meet or exceed certain minimum long-term performance requirements as specified in many application standards. HDPE resin producers, pipe manufacturers, and additive/masterbatch producers must adhere to these standards (including but not limited to ASTM, ISO, PPI, NSF, CSA, etc.) in order to participate in the pressure pipe market. In this paper presentation, we take a deep dive into what it takes to qualify masterbatch/additive producers that will be utilized in the production of the pressure piping system components. While there are official standards, published papers and a host of knowledge in understanding HDPE pipe masterbatches, the intention of this document is to specifically outline the step-by-step process of how one could obtain qualification of a masterbatch with a specific HDPE resin for production of HDPE piping system components. This document will address when one begins the process and the tests one conducts during the qualification period. It will also highlight some potential barriers that could render a masterbatch supplier from meeting qualification requirements.
Microwave Inspection of Composites and other Dielectric Materials
Donald McNicol, Sonomatic Inc.
A review of practical application of the microwave inspection technique applied to a range of non-metallic materials, suitable and proven in field deployment
The Performance Requirements for Recycled HDPE Materials in Various Pipe Applications
John Kurdziel, ADS
The engineering requirements for recycled HDPE materials in corrugated pipe varies depending on the end user’s applications. Requirements for agricultural drainage to sanitary sewer installations will be presented.
Catalysis
Borealis Sirius Catalyst Technology - Enabling Factor for Sustainable Growth
Nora Vaarne, Borealis Polymers Oy
Borealis has developed a proprietary Ziegler-Natta catalyst based on our own Borealis Sirius manufacturing technology. Our non-phthalate donor in combination with the ability to tailor the morphology and kinetic properties of the catalyst to the needs of our Borstar™ process is a key enabler for the production of a wide variety of products with superior operational performance. Combining this catalyst with Borealis' Borstar™ PP process provides access to broad range of specialty PP products including random co-/terpolymers and impact modified reactor blends. The catalyst is being produced in our Borealis Sirius catalyst manufacturing asset in Europe and commercialized in our PP production since 2015 for the full range of our PP polymers including specialties.
LyondellBasell Technology: Advancing Possible
Steve Davis, LyondellBasell
Plastics have been selected in the last 50 years due to their low environmental footprint, their versatility, as well as being a very competitive material. The challenge our industry faces today is to work on their life after use and ensure it is not going into the environment. The polyolefin industry is continuously evolving in response to global megatrends of population and environment. Specifically highlighted in this presentation will be advances in product performance enabled by LyondellBasell's proprietary multizone circulating reactor (MZCR) - the heart of our innovative Spherizone and Hyperzone processes for the production of polypropylene (PP) and multi-modal high density polyethylene (HDPE). Also discussed will be recent developments in the area of catalysts for PP which are improving product performance and plant operations. Innovation in process design and catalysis, combined with operational excellence, is driving LyondellBasell's unique technology portfolio to deliver differential performance, creating value for the user and positioning them for long term success in response to a constantly changing environment.
Developing Sustainable Solutions in a Time of Unprecedented Growth
Jon Ratzlaff, Chevron Phillips Chemical Company LP
Today is an exciting time to be in plastics industry. With an ample supply of low cost feedstock, North America has seen unprecedented increases in plastics production. Polyethylene in particular has seen the highest production growth in the history of North America. But in spite of high growth coupled with strong worldwide consumer demand, plastics have come under fire in the public's eye with increased attention being placed on mishandled plastics entering our waterways and oceans. Some have proposed plastics bans, but the truth is these materials are needed by a growing middle class to meet basic human needs for safe food, safe water and energy efficient homes and transportation. In response, a range of programs are under development to address post consumer plastics mismanagement around the world while continuing to meet the needs of a growing middle class. This presentation will highlight drivers behind this unprecedented industry growth, the challenges faced by our industry and the illustrate examples of programs under development to deliver sustainable solutions globally.
SMOLEFIN and SWILE - Paradigm Shift in Polyolefin R&D and Quality Control
Michael Schneider, Chemspeed Technologies AG
We have made a significant breakthrough that will change how you run Polyolefin R&D and Quality Control. Despite all the technology that exists today, selective catalysis, particularly reflected by polyolefin synthesis, is still operationally challenging due to the extreme sensitivity of the reactants and catalysts in low amounts. Chemspeed's revolutionary solution makes the use of even the most difficult to handle homogeneous and heterogeneous catalysts known today very straight forward indeed. It is both an easy to evaluate and extremely easy to apply technology - making selective catalysis as easy to execute as any standard synthesis. The SMOLEFIN technology, together with our scalable reactor and robotic technology solves all the technical challenges from catalyst synthesis, reformatting with SWILE, testing, and characterization, to storage in a globally standardized way without impacting the chemistry at all. The lecture will show state-of-the-art case studies about automated (standardized, accelerated) synthesis of e.g. single-site and Ziegler-Natta catalysts, reformatting and subsequent screening, optimization / scale-up, and will address the challenges in experimentation (e.g. handling of sensitive catalysts in small amounts) with the paradigm shifting SMOLEFIN and SWILE.
Advanced Molecular Polyolefin Catalysis: Enabling Growth and Sustainability
Philip Fontaine, Dow Chemical Company
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The advent of molecular catalysis has fueled the development of new polyolefin materials with improved properties. In particular, the use of molecular catalysts affords an exquisite level of synthetic control, facilitating the tailoring of polyolefin microstructures. This in turn imparts new flexibility into the product design space, allowing for the production of materials with superior performance characteristics. With each year, new catalytic advances are made, further expanding the boundaries of the design space, and enabling the economical synthesis of novel polyolefins at the industrial scale. Our research makes use of state-of-the-art high throughput instrumentation, and high level computational modeling, to arrive at unique combinations of catalytic properties. Sustainability is a key market driver for several of our recent commercial innovations, which include: resins with superior stiffness/toughness balance for light-weighting applications, and new olefin block copolymers (OBCs) for improved compatibilization and recycling.
Solutions for the Circular Economy: Designing for Recyclability
Barry Morris | Jill Martin, Dow
Growth in the plastic packaging market has been fueled by the benefits of plastics over alternative materials such as glass, metal, and paper. The plastics industry has continually innovated to maximize the efficiency of materials to minimize the weight of packaging while maintaining performance standards. Despite these benefits, the increased focus on leakage of plastic into the environment has put pressure on the industry to define solutions that not only build off of these benefits but provide solutions that enable further use of the materials. Multiple agencies in the geographies have been working to define guidelines for recyclability of flexible packaging, in particular. Using these guidelines as well as Dow’s broad portfolio of polyethylene and ethylene copolymers, capabilities within our global PackStudios locations, and reach within the industry, Dow has developed and implemented solutions across a number of market segments. We will discuss advancements in polymers for film orientation for packaging simplification, compatabilization strategies, and challenges associated with mechanically recycled materials.
A Holistic View of the Role of Flexible Packaging in a Sustainable World
Todd Bukowski, PTIS Global
The presentation will highlight the sustainability benefits that flexible packaging offers, provide foresight into future sustainability implications for flexible packaging as well as lifecycle case study examples looking at the benefits of flexible packaging through a lifecycle approach. Todd's presentation will also provide a view on some of the hot button topics related to sustainability that flexible packaging providers will need to consider as part of their environmental initiatives.
State of the Flexible Packaging Industry
Alison Keane, Flexible Packaging Association
This presentation from the Flexible Packaging Association will address the state of the industry and the influence of public policy and public perception.
Investigating & Improving Mao Activation Efficiency of Metallocenes for olefin Polymerization
Matthew Thorn, WR Grace
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Group 4 transition metal-based molecules, particularly the metallocene dichlorides [Cp2MCl2], are industrially important as single-site catalyst precursors for alpha-olefin polymerization. To be useful catalysts for polymerization the dichlorides require activation via alkylation/ionization chemistry in order to form the catalytically active ion pair {[Cp2M-R]+[A]-}. Typical activators include methylaluminoxanes (MAO), borates {e.g. [B(C6F5)3]} and boranes {e.g. [Ph3C][B(C6F5)4]} in combination with organoaluminum compounds such as trimethyl-, triethyl- and triisobutyl-aluminum. While the MAO activation mechanism is not fully understood recent studies have suggested several plausible pathways.1-4 The use of boron-based activators can often provide useful discrete molecular models to aid in this understanding. However, the structures of the activator and the metallocene must still be taken into account. Recent experiments suggest potential differences in MAO- vs. B-based activation mechanisms. Through these types of fundamental studies it's now believed to be better understood how to improve the overall activation efficiency of single-site catalysts with MAO. Furthermore, in combination with high-throughput (~ 1 gram) and lab-scale (~100 gram) polymerization methods, these improvements can be tested, refined and advanced in scale such as, for example, Grace's proprietary ActivCat® portfolio.
Highly Branched Polyethylene Oligomers via Group 4-Catalyzed Polymerization in Very Nonpolar Media
Yanshan Gao, Northwestern University
Early transition metal catalysts produce high-density and linear low-density polyethylenes with spectacular efficiency. Nevertheless, these catalysts are ineffective in producing low-density polyethylene homopolymers with large -(CH2)xCH3 branch densities (x ‚â• 5), or low molecular mass (Mn <1200 g/mol) highly branched polyethylenes (HBPEs). The latter are potential alternative synthetic lubricants which have eluded efficient catalytic synthesis. Here we report the synthesis of low-Mn HBPEs with 61-93 branches/1000 carbon atoms from abundant ethylene as the primary feedstock using a soluble, highly active ion-paired organozirconium catalyst in a saturated hydrocarbon solvent. The unprecedented activity and branch-selectivity reflect heretofore unrecognized aspects of the cationic catalyst-counteranion pairing in non-polar media and are characterized spectroscopically and quantum mechanically. The HBPE products are rheologically and tribologically attractive candidates for synthetic lubricants.
Characterization and Analysis
Characterization of Nickel-Coated Carbon Fiber-Reinforced Polypropylene Composites: Effects of Extrusion Processing Method
Donghwan Cho, Kumoh National Institute of Technology
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In this study, nickel-coated carbon fiber-reinforced polypropylene (NiCF/PP) composites with various NiCF loadings were fabricated using extrusion and injection processes. NiCF/PP pellets were produced by two different feeding methods of NiCF and PP, hopper feeding (H) and side feeding (S), respectively. The effects of extrusion processing method on the electromagnetic, electrical, mechanical, and thermal properties of the composites were characterized in terms of electromagnetic interference shielding effectiveness, electrical resistivity, tensile, flexural, impact, thermal stability, heat deflection temperature, fiber length distribution, and fracture surfaces. The S-NiCF/PP composites exhibit improved electromagnetic, electrical, mechanical, and thermal properties, compared to those of the H-NiCF/PP composites. The improved properties of the S-NiCF/PP composites can be explained by that the S-NiCF/PP composite has a higher aspect ratio of NiCF remaining in the composite than the H-NiCF/PP counterparts, due to less shear stress and fiber damages occurring during the twin-screw extrusion compounding. However, the improvement effect is more or less restricted due to peel-off phenomenon of the nickel-coated layer found in the resulting composites during the process, as expected. The characterization results were agreed with each other.
Scratch Resistance of PP as a Function of MFR and fiber content
Jungsub Lee, Korea University
Polymer blending is an easy and useful technic to improve various properties of polymeric materials. It mixes two or more polymers physically to form a new type of material. The blend can resist chemicals and heat more effectively or show better processability. Improved mechanical properties can be observed as well. For polypropylene (PP), it is desirable to add elastomers to improve its impact strength. Another way to modify the properties of polymers is adding fillers. The additive can be inorganic fillers such as talc or glass fiber. It can increase tensile modulus, yield or tensile strength. The properties of polymer blends and composites are strongly related to their structures. Chemical parameters are good indices to understand the structure of the material. In this study, scratch resistances of PP with various melt indices and glass fiber compositions were investigated. Test specimens were prepared using the principles of DOE. After obtaining the scratch properties, statistical modeling was conducted using chemical parameters. Regression and neural network models were used.
Revealing the Chemical Composition Distribution of Polyolefins Using Crystallization Based Techniques and Interactive Chromatography
Priya Garg, SABIC
Polyolefins (PE and PP) are an important class of industrial polymers that are used in a variety of end applications. Typical fields of application are packaging, building and construction, agricultural, industrial and consumer goods. Incorporating a comonomer during polymerization gives rise to a chemical composition distribution (CCD) which is interrelated with the molar mass distribution (MMD). This resulting CCD is dependent on the type of catalyst as well as reactor conditions. Revealing the CCD will give information about the polymerization (incorporation). On the other hand, the recurring chain irregularity is crucial for understanding the structure-property relationships of that material. A number of analytical techniques such as TREF/CEF are typically employed to investigate the CCD. This group of techniques is based on crystallizability of the polymer. Another approach for determining the CCD is interaction chromatography. However, each technique has certain drawbacks. In this presentation, we would like to discuss the use of various analytical techniques for the elucidation of the CCD of polyolefins as well as their potential drawbacks. Examples from LLDPEs and POEs will be shown. Additionally, the theoretical CCD based on the Stockmayer distributions will be compared to the experimentally obtained ones.
Asymmetric Flow Field Flow Variant (AF4)--An Alternative to SEC-MALS
Robert Bruell, Fraunhofer
Size exclusion chromatography coupled with multi-angle light scattering (SEC-MALS) is widely used to analyze the molar mass distribution and long-chain branching (LCB) of polyolefins. In SEC the fractionation is based on the exclusion of macromolecules from a porous stationary phase according to their hydrodynamic volume. This mechanism imposes limitations, which cannot be overcome. Specifically the aspects of peculiar co-elution, shear degradation and the exclusion limit of the column. The family of field flow fractionation techniques offers an alternative separation principle, with the asymmetric flow field flow variant (AF4) showing most promise. As AF4 does not require a stationary phase, ultra-high molar mass fractions can be analyzed with good precision. Due to the absence of peculiar co-elution reliable information on the degree of long-chain branching along the molar mass distribution and architecture becomes available. The separation principle of AF4 offers the possibility to tailor experimental protocols for specific materials. The design of suitable flow programs has to take the flow specifics in a narrow channel into account. We will show how flow profiles can be designed for ultra-high molar mass materials and how long chain branching in polyolefins of commercial relevance can be analyzed. These experimental results will be supported by evidence from theoretical modelling.
Hierarchical Multivariate Analysis to Map Structure-Process-Property Relationships
David Fiscus, Exxon Mobil
The properties of polymeric materials depend on their composition and the molecular architectures of each of the components. Simultaneous changes to these material factors, along with fabrication conditions alter the balance of properties of formed parts. Understanding these multivariate structure-process-property relationships can guide material development. We present the application of hierarchical multivariate analysis to establishing the structure-process-property relationships of commercial polyethylene blown film resins and interpret the result to the development of new resins with targeted film performance.
Simple and Fast Methodology for Determination of Additives in Polyolefins using Dissolution/Re-precipitation and Gas and Liquid Chromatographic Analyses
Shayne Green, The Dow Chemical Company
Methodology for determination of additives in polyolefin resins was developed over ten years ago and it has been successfully practiced in our laboratory since this time. Using this method the resin is dissolved in hot o-xylene followed by precipitation with methanol. Once the precipitated polymer is allowed to settle, an aliquot of solution is removed for immediate analysis by liquid chromatography (LC) with a UV/Vis absorbance detector and/or gas chromatography (GC) with a flame ionization detector (FID). The conditions used in this methodology completely dissolves polyolefins, hence it is called the Total Dissolution Method (TDM)1. TDM offers equivalent or improved accuracy and precision compared to Soxhlet, reflux, and other solid-liquid extraction techniques. Since many of these methods do not completely dissolve the resin, the extraction process is lengthy and the extraction efficiency for additives can be low. TDM is capable of achieving high throughput and it can be easily implemented in small labs with very little equipment cost. Multiple samples can be prepared for analysis in about six hours. Because of the simplicity of this methodology, the preparation procedure can be automated using commercial robotic systems. This presentation will discuss TDM, analysis of additives by GC and LC, and the automation of the methodology to achieve high throughput."
Making Sense of Polyolefin Products through Sensory Science
Tanya Fry, Dow Chemical
Taste, Smell, Touch, Sight and Hearing; The five human senses are what help us make sense of the world, and the products, around us. As polymer scientists, we easily measure physical and analytical properties of plastics. But to measure what consumers think about your product, you need human input. Sensory Science can help identify how polymers affect the taste of food, determine the different odor characteristics of polymer, evaluate how something feels which influences consumer perception, and improve visual appeal of your product on the grocery store shelf. Sensory Science can deliver customer solutions.
Accelerated Slow Crack Growth Resistance Tests For Characterization of High-Performance Bimodal HDPE Pipe Materials
Cliff Mure, Univation Technologies/Dow
New generations of PE100 and PE4710 pressure pipe materials exhibit a superior balance of mechanical properties. The slow crack growth performance of these materials measured by traditional tests such as PENT and FNCT can exceed one year. These high performance materials deliver significant advantages to the end uses, especially to challenging installation techniques such as horizontal directional drilling which may cause damage to the pipes during installation. However, these exceptional material properties present some challenges for the raw material suppliers during product development. First, the product development cycle for new polymer structures becomes very long since the evaluation of SCGR performance may take one year or longer. Additionally, quality control of the materials cannot be conducted with traditional methods. The pipe industry is developing and implementing new accelerated test methods for the characterization of SCGR performance. These new techniques include the strain hardening modulus (SHM), accelerated FNCT (ACT), cracked round bar (CRB), and the accelerated point loading test (PLT). Although these tests significantly reduce the time-to-failure of the improved HDPE resins, the mechanisms of polymer deformation may be different. These differences must be considered when establishing correlations (or lack thereof) between results from different tests and their ability to rank resins consistently. This paper presents preliminary results from PENT, ACT, SHM, PLT, and CRB of various resins and discusses relationships between time-to-failure, molecular design and deformation mechanisms.
Study of the effect of ASTM and ISO testing conditions on mechanical properties of polypropylene
Jing Zhong, W.R. Grace & Co
As two commonly used standards, ASTM and ISO have similarities and distinctions in measurement of polypropylene mechanical properties. The four major differences between ISO and ASTM protocols are specimen dimensions, melt temperature, mold temperature and cycle time. Some injection molding studies were carried out in this presentation to address the effect of injection molding on mechanical properties of HPP and ICP. Multiple simulations were also done to gather information during the injection molding process that could not be measured experimentally. In addition, several grades of HPP and ICP with different MFR and composition were measured and compared under strict ASTM and ISO protocols. The test included flexural modulus, yield stress and IZOD. For the same PP material, ISO and ASTM standards may or may not provide similar test results depending on many factors. In general, yield stress and flex modulus are relatively comparable between ISO and ASTM results. However, more differences were seen in IZOD especially when ICP samples were compared. All the differences and similarities could be explained from the injection molding standpoint. The understanding gained during this study will help understand and translate mechanical properties as measured using one standard into the other.
Compounding and Extrusion
New Involute Extruder Screw Elements for Improved Productivity and Quality
Paul Andersen, Coperion
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The co-rotating fully intermeshing twin-screw extruder has evolved significantly in the 60 years since it was commercialized in 1957. While this equipment might be considered a “mature” technology, it has not experienced a decline in new developments as might be expected, but rather a significant number of advancements. The technology continues to evolve. For example in the last 20 years several significant developments have been introduced. These include a) the implementation of high torque (power) designs, b) the use of increased screw rpm in conjunction with high torque for improved operating flexibility and productivity, and c) a breakthrough technology for feeding difficult to handle low bulk density materials. However, one area of twin-screw technology that has not evolved as much is screw elements geometry. Conveying elements and kneading blocks have remained essentially the same since the original Erdmenger design patents filed in the late 1940's and early 1950's. However, to take advantage of increased torque and power transmission capacity introduced in the newest generation of twin-screw compounding extruders, solids feed conveying and melt/mixing capacity in, for example, some highly filled compounds, had to be improved. Coperion has developed special involute screw and kneading elements with a new (Patent: EP 2 483 051 B1) cross section design to help achieve this objective. This paper will focus on the comparison of standard kneading blocks vs new involute kneading elements, specifically looking at some significant aspects related to performance.
Options to Aid Extruder Screw Removal and Cleaning
John Presa, DowDupont
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All extruder screws will have to be removed at some time for various reasons. These reasons can include periodic screw and barrel maintenance, screw type change, or to simply clean your extrusion system. This paper will compare and contrast different materials to aid in the removal and cleaning of your extruder and screw by measuring ease of pulling screw, ease of cleaning, price of material and time to clean.
Optimized Extrusion Process for developing High Performance TPOs & Lightweight Polyolefin Composites.
Tanmay Pathak, A.Schulman-Lyondellbasell
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Advanced technology in compounding thermoplastic polyolefin composites brings outstanding performance characteristics that make them highly valuable to automotive markets. Light weighting, high impact performance, low emissions are some of the key attributes that today's automotive market demands out of these TPOs and filled polyolefin compounds. However, it becomes highly challenging to make such a universal composite that shows a great balance of properties with equally high impact and high stiffness, low density and low emissions. The work presented here focusses on the development of a mineral filled polypropylene composite that exhibits high stiffness along with high impact properties and at the same time has a much lower density. This development included not only a balanced formulation approach but also an improved process design on twin screw extrusion (TSE) technology to achieve the desired balance of properties. The improved extrusion process was also utilized to convert certain batch process TPOs to a continuous TSE process while maintaining or enhancing the product properties.
Effect of Processing on the Performance of Waterborne Heat Seal Coating
Carlos Escobar, The Dow Chemical Company
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Aqueous polyolefin dispersions represent a new class of waterborne polymeric material produced by a proprietary continuous, mechanical dispersion process utilizing BLUEWAVE® Technology. These dispersions are commercially available for use in various coating applications and have characteristics similar to other water-based dispersions/emulsions (e.g., final solids content from 40 to 50%, particle size from 0.15 to 2.5 ¬µm, viscosity from 300 to 3500 cP, and pH ranging from 7 to 11). The wide variety of olefin chemistries and crystallinities available from The Dow Chemical Company enable the tailoring of the polyolefin dispersion (POD) composition for a specific application and performance requirements. This paper describes the effect that the type of process, batch mixing versus continuous BLUEWAVE® Technology, on the final performance of a water based heat seal coating. The results obtained from the application tests of the heat seal coating produced using the continuous BLUEWAVE® Technology show improved properties (appearance, shelf stability, aging, hot tack, and heat seal bonds) over that produced in a batch process.
Managing Melt Temperature in a Twin Screw Extruder
Charlie Martin, Leistritz Extrusion
Managing Melt Temperature in a Twin Screw Extruder: The melt temperature in a twin screw extruder must be managed to avoid degradation of the polymer. Various factors will be considered, including operating conditions, screw geometries, barrel design and machine system configuration. Test results will be presented for various type polyolefins.
In-Line Compounding for Production of Filaments for (Fused Filament Fabrication) FFF Printing
Steve Post, Thermo Fisher Scientific
The majority of filaments for FFF process are produced via single screw extruders. This technology is suitable for many applications, but poses issues with coalescence when combining non-compatible materials. The direct or "in-line" compounding process has proven itself to be a more effective way of producing filaments for challenging applications where small percentages of non-compatible or "difficult to feed" materials are being utilized.
Design Optimization of Maddock Mixers
Xiaofei Sun, Dow Chemical
Maddock-style mixers are used extensively on single-screw extruder screws to disperse materials into the molten resin matrix. Since the time LeRoy invented the device and Maddock perfected and commercialized it, the device has undergone several innovations. The goal of this paper is to describe the optimal flute geometry and mixing undercut dimension for a Maddock mixer with the goal of mitigating degradation gels and maximizing dispersive mixing efficiency.
Foams
Effect of Processing Techniques on the Insulation Properties of Amorphous PLA Foams
Kayode Oluwabunmi, MEEN Dept. University of North Texas, Denton.
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Microcellular foams were produced from amorphous polylactic acid (PLA) with 12 % d-lactide content using the physical foaming technique. Solubility over a temperature and pressure range of (23 - 70) oC and (300-1200) psi respectively was determined. A sub-critical method of CO2 absorption at room temperature followed by CO2 release above its glass transition was evaluated (thermal soak). This was compared to directly soaking the polymer in supercritical CO2 above the glass transition followed by cooling to room temperature or holding it just below the glass transition temperature to promote nucleation and growth (decompression). It was observed that the thermal soak technique produced foams with more closely packed cells and more uniform sizes in their cellular architecture compared to any of the decompression foams. Maximum values of 81 % and 21 % was recorded for percentage open porosity and percentage void fraction respectively. This was lower than the maximum values obtained in the decompression foams. These properties contributed to their excellent thermal insulation properties compared to the other two types of foams. Foams made through the decompression technique at foaming temperature of 55 oC were rigid in nature and had a better mix of cellular architecture due to the bimodal cellular structure compared to the foams made at foaming temperature of 75 o C. This in addition to the generally higher percentage open porosity, with maximum value of 60 % contributed majorly to their excellent sound absorption properties and good thermal resistance values. With a range thermal conductivity values of (0.027 - 0.06) W/mK recorded for the PLA foams ~ (0.03 - 0.06) W/mK for petroleum based extruded polystyrene (EPS) and expanded polystyrene (XPS) foams. The PLA foams can be said to be potential eco-friendly substitutes for the petroleum-based building insulation foams.
Structure-Property Relationships of Polyolefin Foams
Colin Li Pi Shan, Dow
Polyolefin foams offer the industry a number of versatile options to create resilient and light weight solutions. Through proper resin selection and formulation, a variety of moldable and extruded foams can be tailored for use in protective and industrial insulation, comfort matting, and other consumer goods. Elastomeric polyolefin foams can be formulated with ethylene-vinyl acetate copolymers, poly(ethylene-alpha) olefin elastomers, and olefin block copolymers to deliver the desired hardness, resiliency, mechanical performance, and haptics. This presentation will discuss the structure-property-foaming relationships of EVA, POE, and OBC that impact the balance of foaming and curing and end-use properties.
Polyolefin Foams - Fundamentals and Applications
Todd Hogan, The Dow Chemical Company
Polyolefin foams are utilized in a wide variety of applications ranging from protective packaging, sports and leisure, building and construction, automotive and others. Foams are utilized in these applications as they provide the key performance properties such as cushioning, energy absorption, sound insulation, thermal insulation and more. Polyolefin foams derive their performance in large part from the polyolefin based resins used in their composition, as well as the processing conditions used to fabricate the foam. Historically, the primary resin used in polyethylene foaming applications is low density polyethylene (LDPE) with a melt index of 1-4 g/10 min. LDPE is utilized as it has suitable melt strength and is easily processed. With LDPE as the base resin, the mechanical properties of the foam are mainly determined by the resin properties and foam density. Unfortunately, low foam densities typically result in lower mechanical properties, and therefore, a limit is reached with pure LDPE. Dow has developed a tailored LDPE/LLDPE blend solution to reduce packaging weight or volume while maintaining the required level of protection. Previously, a heavy item or an object that is shock-sensitive would require heavier or thicker foam, resulting in larger overall packaging weight. The new lightweight and sustainable enhanced polyethylene (EPE) solution achieves equivalent packaging integrity.
Using Rheological Measurement To Predict the Physical Foaming Windows for Polyolefin Copolymers
Hyunwoo Kim, The Dow Chemical Company
In this work, thermoplastic foams based on different ethylene copolymers were prepared by an auto-clave, batch foaming method. The physical foaming of polyolefin elastomers (POE), olefin block copolymer (OBC) and ethylene vinyl acetate (EVA) copolymers were compared in terms of cell size and foam density. These data were compared to their melt viscosity behavior with temperature. This allowed us to predict a foaming fabrication temperature window. These predictions correlated well with the best foaming conditions found in injection core-back foaming.
Packaging
New Balance of Polypropylene Stiffness, Heat Resistance, and Processibility for Packaging
Xuejia Yan | Daniel Johnson ExxonMobil Chemical Corporation
Unique polymer design gives Achieve™ Advanced Polypropylene exceptional properties in both flexible and rigid packaging. Higher stiffness and broader molecular weight distribution of the polymer help unlock opportunities for down gauging, high temperature resistance and process window improvement in applications including thermoformed rigid cups, containers and blown film.
Material Reduction and Biobased Materials Use For More Sustainable Polymer Packaging
Abdellah Ajji, Polytechnique Montreal
During the last decades, the food, pharmaceutical and many other industries have seen several changes in polymer packaging technology and applications because of new consumer demands, awareness and market trends. Among the drivers, sustainability through materials reduction, reuse, replacement and the use of renewable materials is more and more important. In this presentation, the results of recent studies directed towards addressing some of those concerns will be presented and discussed. Specifically, material reduction through the use of nanocomposites in barrier structures will be discussed as well as the use of renewable/biodegradable materials for barrier and seal layers. Nylon nanocomposites allow for example to reduce the barrier layer by half. Blending of PLA polymer with other polymers such as PCL or PBAT allows to obtain various seal layer performances for various applications, in addition to compostability
Biaxially Oriented Polyethylene (BOPE) Films Fabricated via Frame Process and Applications Thereof
Justice Alaboson, Dow Chemical
A novel polyethylene product was developed for making biaxially oriented polyethylene (BOPE) films via a commercial scale tenter frame line. As compared to the conventional polyethylene grade with a similar density and a similar melt index, the novel polyethylene could be stretched to 5x in the machine direction and 9x in the transverse direction in a wide temperature window. The BOPE film exhibited higher modulus, higher dart and puncture impact strength, easier tear, and better optical properties than the incumbent blown film used in lamination film applications. A laminated film with a BOPE layer was also evaluated and compared to the incumbent film that had a biaxially oriented polyamide layer. The BOPE laminated film showed equivalent performance at a lower film cost.
Biomimetic Nanocoatings with Exceptional Mechanical and Barrier Properties for Polyolefin Films
Luyi Sun, University of Connecticut
Large-scale biomimetic organic/inorganic hybrid nanocoatings with a nacre-like microstructure were prepared via a facile co-assembly process. Different from conventional polymer nanocomposites, such nanocoatings contain a high concentration of nanosheets, which can be well aligned along a substrate surface. Moreover, the nanosheets and the polymer matrix can be chemically co-crosslinked. As a result, the nanocoatings exhibit exceptional mechanical and barrier properties, but meanwhile they are highly transparent. The nanocoatings are particularly ideal for polyolefin films, which usually have a poor oxygen barrier. After coating treatment, the coated films exhibit outstanding oxygen barrier properties, and thus ideal for many applications such packaging.
Extreme Performance Polyethylene Resins
Mosha Zhao, ExxonMobil Chemical Company
In the world of Polyolefins, polyethylene (PE) is a commonly used resin. PE finds use in a wide array of applications, and with ever demanding customer application requirements, new grades of PE are being constantly explored. ExxonMobil recently unveiled to the world its latest innovation in the field of performance PE resins. These new grades have been commercialized as Exceed® XP resins and are designed to provide exceptional properties under the most challenging conditions - when eXtreme Performance matters.
Unlock new opportunities in packaging
Xuejia Yan, ExxonMobil Chemical Company
A unique polymer design gives Achieve™ Advanced Polypropylene exceptional properties in packaging. The higher stiffness and broader molecular weight distributionof the polymer help unlock opportunities for downgauging, high temperature resistance and process window improvement in applications including thermoformed rigid cups and containers.
Process Technologies
Advances in Polyolefin Foaming Technology
Colin Li Pi Shan | Brian Yu | Kyle Kummer, The Dow Chemical Company, Dow Packaging and Specialty Plastics
Xian Jiang, E.I. du Pont de Nemours and Company, Inc
The Borealis Technologies Suite - Toolbox for Innovative Solutions beyond Common Polyolefin Applications
Franz Langhauser, Borealis Polyolefine GmbH
Based on the set of technologies Borealis can provide complete polyolefin solutions to markets and applications, which are not seen as classical for Polyolefins. Combining the ability to manufacture a broad series of PO types from high stiffness to lowest density and elastomers/plastomers with post treatment technologies for i. e. increased melt strength, advanced packaging, lightweight construction and recyclability allows unlocking new application fields beyond typical Polyolefin applications. Borealis is strongly focussing on developments with value chain partners enabling a customer centred development approach. The presentation will provide an overview of the Borealis technology suite and provide examples for efficient solutions combining our technologies with material science and customer insight.
- Easy processing, halogen free flame retardant PP with 125°C classification for automotive wiring.
- Borealis Quentys solutions for solar panels to combine advanced material properties with advantages during the manufacturing process.
- Single PO solutions enabling improved recyclability as part of Borealis' strategy to continuously develop sustainable solutions - underpinned by our "STOP" initiative to reduce marine littering.
Improved Understanding of the Impact of Alkanes when Using Condensed Mode Cooling for PE Production
Timothy F. L. McKenna, University de Lyon
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Heterogeneously-catalyzed gas-phase polymerization of ethylene in fluidized bed reactors (FBRs) is the single type of reactor used for polyethylene (PE) production. Due to an ever-increasing demand for PE, it is possible to substantially improve the heat removal efficiency, and consequently increase the production capacity of an FBR by exploiting the so-called condensed mode cooling method. In this method, compounds referred to as induced condensing agents (ICAs), typically C3-C6 alkanes, are added to the reactor recycle stream, (partially) liquefied in an external heat exchanger and then injected into the reactor in the form of small droplets along with the gaseous components. The fast evaporation of the liquid phase inside the reactor absorbs additional polymerization heat and thus enhances the production capacity of the unit. ICAs are chemically inert in the sense that they do not have any influence on the behavior of the active sites. Nonetheless, recent papers from our group have clearly demonstrated that the rate of ethylene polymerization (Rp) increases in the presence of ICAs due to the cosolubility effect. Furthermore, changing the temperature of the reactor can have unexpected implications because of this. In certain circumstances, the observed rate of polymerisation can actually decrease as the temperature increases since the cosolubility effect becomes less and less important. A new process model is being developed. At the reactor scale it is shown that gains in productivity come at the cost of reduced catalyst mileage. At the level of the growing single particle, thermodynamic simulations, performed by employing the Sanchez-Lacombe EoS, show that it is possible to appropriately describe the observed influence of n-hexane on the local rate of polymerization (Rp) by taking into account the both cosolubility and codiffusion effects; during the early stages of the reaction, a specific magnitude of the enhancement in the ethylene diffusivity due to the codiffusion effect of n-hexane causes a more significant impact on the ethylene concentration gradient and therefore the efficiency (η) and overall rate of polymerization. Furthermore, preliminary studies of the impact of ICA on polymer crystallization suggest that in certain circumstances, nascent polymer particles can actually be significantly more amorphous for long periods of time than one might infer from analyses of dry reactor powders.
Hyperzone PE Process Technology A new polyethylene technology for the plastics industr
Gerben Meier, LyondellBasell
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LyondellBasell introduces a new polyolefin process, HyperzonePE Technology, which produces high density polyethylene (HDPE) resin with exceptional characteristics. This technology utilizes three distinct reaction zones in two reactors, which enables the production of tailored polymer structures to meet customers’ demanding processing and product requirements. LyondellBasell is currently constructing a world-scale HyperzonePE plant at our La Porte, TX facility with an annual capacity of 1.1 billion pounds (500,000 metric tons). Start-up is planned for 2019.
Sustainbility
Impact of Sustainability Upsurge on Polyolefin Demand
Roberto Ribeiro, Townsend Solutions
"Sustainability is no longer an idealistic trend - it is now essential for business survival and a mainstream issue driving attention and investment growth on a global scale and particularly in plastics. Regulatory changes and growing consumer awareness along with mega-trends are already rewriting the plastics demand map for several key applications (consumer packaging, automotive, etc.) as attention shifts to energy efficiency, recyclability and durability (value-add). Many end-use markets are already seeing demand pattern changes begin to emerge and strengthen, often driven by downstream stakeholders and supported by regulatory changes. During this presentation Townsend will provide deep-dive insights into the potential impacts of global sustainability aspects (reduce, reuse, recycle, recover) on overall growth rates for Polyethylene (PE), Polypropylene (PP) and related feedstocks. We will also review specific application level trends in the growing use of recyclates, discuss applications at greatest risk for sustainability driven demand shifts, and outline key levers impacting innovation and investment (megatrends, regulatory, societal influences, circular models, downstream stakeholders e.g. brand owners & retailers)."
Sustainable Plastics: How Plastic Additives can Enable a Circular Economy
Katrina Knauer, BASF
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Plastic packaging is essential for the preservation of food, prevention of food waste, and the lightweight transportation of food products. Besides these beneficial properties, food packaging causes rising concern for the environment due to its high production volume, often short usage time, and problems related to waste management and littering. Reduction, reuse, and recycling (mechanical and chemical) support the aims of the circular economy. These tools also have the potential to decrease the environmental impact of food packaging. Yet recycling remains a challenge. The polyolefins used in food packaging will discolor and degrade after multiple heat processing cycles when they are not properly stabilized. Additionally, multi-layered materials and other mixed plastic streams contribute to the contamination of post-consumer recycled material (PCR) and yield unstable resins. This work provides an overview of how plastic additives can be used to enable the recycling of food packaging materials and increase the quality/value of PCR.
Integrating Post-Consumer HDPE Resin in Film Applications
Sandra Lewis, Envision Plastics
In a world where sustainability is imperative, packaging with post-consumer resin (pcr) is not only attractive, but in some cases, required. Learn how to successfully integrate pcr into a variety of film applications including direct food contact applications. This presentation will share data and findings on how to reduce gels and increase clarity while at the same time, increasing the percentage of pcr content.
Using Agricultural Waste to Create More Environmentallly Friendly and Affordable Products
Walter Bradley, Baylor University & Texas A&M
Coconuts are an abundant renewable resource, with 50 billion being harvested annually. However, only the coconut oil and coconut water currently have significant commercial value. The hard coconut shell and the fibrous coconut husk are often discarded as agricultural waste. The goal of this research has been to create polymeric composite materials that are less expensive, more environmentally friendly and with superior mechanical properties. For example, the modulus of polypropylene can be nearly doubled by using coconut shell powder as functional filler. Non-woven fabric composites that are compression molded into automotive parts can be stiffened by replacing synthetic fibers with fibers from the coconut husk (called coir). This presentation will provide detailed mechanical properties and cost reductions for several examples of polymeric composites made from constituent parts of coconuts. One of the composites to be discussed received an SPE National Innovation Award for work done in partnership with Ford Motors for a part in their electric car.
Design for Recycling: PE Film
Sandi Childs | Curt Cozart, Association of Plastics Recyclers
The Association of Plastic Recyclers will offer training on PE bag and film recycling beginning with the imperatives and societal drivers to increase recycling, including commitments brand owners are making to the Ellen MacArthur Foundation and other NGOs. Design for Recyclability will be emphasized, presented by the authors of the APR Guide. APR is a brand owner's conduit to the circular economy through the APR Design™ Guide for Plastics Recyclability. The training session will address PE film collection, reclamation, end uses, and challenges. Industry collaboration opportunities to improve supply and increase demand for products made with film post-consumer recycled resin will be mentioned. The session will conclude with suggested action items for the audience to begin to make a difference right away. Don't miss this opportunity to learn the basics and imagine new responses.
End of Life Vehicle (ELV) Recycling
Kevin Cronin, Ultra-Poly Corporation
Approximately 11-12 million vehicles are scrapped in the US every year
- Scrap yards remove items that can be sold into the Aftermarket
- Most durable functional/mechanical components, some body panels
- The remainder of the vehicle is generally sent to the shredder
- Metals are extracted and recovered
- Plastic components wind up in ASR (Automotive Shredder Residue) which is most frequently landfilled
Life Cycle Assessment for Corrugated HDPE Drainage Pipe
Daniel Currence, Plastic Pipe Institute
Plastic Waste Changes & Data University of Georgia Study
- China has stopped importing nearly half of the worlds’ plastic waste as of January 2018 (mainly from wealthiest nations)
- Approximately 72% of the world’s plastic waste went to China & Hong Kong since 1992 w/HK passing on 63% to China.
- Waste management facilities are struggling to process the excess waste. Some states are now allowing recyclable materials into landfills
- 2016: California exported 500K tons of low grade plastic to China
- An estimated 111 million metric tons could pile up by 2030
MISC.
Resin Blending and Variability of HDPE Recycled Pipe Materials
Daniel Figola, Advanced Drainage Systems
Presentation of the results of a study analyzing base post-consumer raw materials and the impact physical and melt blending has on the various resin properties used in the production of corrugated HDPE pipe.
Ti AND Zr Catalysts in the Macromolecular Melt Regenerate Unfilled and Filled Virgin, Regrind and Recycled Plastics
Salvatore J. Monte, Kenrich Petrochemicals, Inc.
A thermally stable neoalkoxy titanate coupling agent [neopentyl (diallyl) oxy, tri(dioctyl)phosphato titanate] and its zirconate analog are shown to act as a REPOLYMERIZATION catalyst in the unfilled or filled macromolecular melt to increase mechanical properties. When two or more polymers are present, COPOLYMERIZATION occurs to create a compatibilzation effect of multi-dissimilar addition & condensation polymers. For example, where delamination occurs in the injection molding of HDPE parts containing more than 5% PP, blends of PE/PP-50/50 are made compatible with titanate catalyst. Since Ti and Zr are used as catalysts in the formation of addition (polyolefins) and condensation (polyesters) polymers, the catalytic compatibilization effect will be shown to occur in a mixture of macromolecules such as HDPE/PP/PET. Multi-polymer compatibility obviates the need for matching polarities such as needed with copolymer compatibilizers and depolymerization concerns when maleated copolymers come in contact with condensation polymers such as PET and Nylon. When powder or pellet masterbatches of subject organometallics are made using Aluminum based inorganics as the carrier, a combination metallocene-ZN catalysis effect is obtained to optimize compatibilization. In addition, the Neoalkoxy structure of the organometallic catalyst allows for proton coordination coupling with the interface of non-silane reactive inorganics and organics such as CaCO3, Portland cement, BaSO4, Carbon Black, and other organics such as pigments, dyes, and cellulosics. The titanate coupling mechanism does not require hydrolysis as with silanes wherein water of condensation remains at the interface to create subsequent delamination when subjected to water boil aging tests. The combination of the SIX FUNCTION effects of subject organometallics will be shown to achieve many of the issues related to the sustainability goals of plastic.
Dr. Michael Pluimer
Michael Pluimer, University of Minnesota - Duluth
Corrugated HDPE pipes manufactured with recycled materials have been used in the agricultural and land drainage industries for decades. However, until recently, most specifying agencies in the United States did not allow recycled materials to be used in HDPE pipes for highway applications due to the lack of research regarding the long-term service life of these pipes. Because of the economic and environmental benefits of incorporating recycled materials into corrugated HDPE pipes, specifying agencies have expressed an interest in these pipes for their drainage infrastructure and funded two National Cooperative Highway Research Program (NCHRP) projects to assess the long-term service life of pipes manufactured with recycled content. One of the primary factors governing the service life of corrugated HDPE pipes is Stage II stress cracking. To address this concern, corrugated pipe specifications contain a Notched Constant Ligament Stress (NCLS) test performance requirement. An additional concern for pipes manufactured with recycled materials is the presence of contaminants that may act as stress risers that could accelerate Stage II stress cracking. To evaluate this concern, an Unnotched Constant Ligament Stress (UCLS) test was developed. Since there is no notch in the test specimen, cracking originates from the presence of contaminants that may exist in recycled materials. If the test is conducted at multiple temperatures and stresses in water, bi-directional shift factors may be applied to the failure times of specimens to predict the service life in typical field service conditions. The service life prediction model has been evaluated on several full-scale corrugated HDPE test pipes manufactured with varying levels of recycled materials in a test installation in the field and in constant deflection test in the laboratory. Based on the full-scale pipe test results, the service life prediction model via the UCLS test was validated. An ASTM standard (ASTM F3181) for the UCLS test was published within ASTM F17, and new requirements for pipes containing recycled materials were incorporated into AASHTO and ASTM pipe standards. Additionally, the service life prediction model was published as an AASHTO standard practice.
Online Transition Between Incompatible Catalysts
Nayef AL-Enazi, SABIC
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During the production of olefin polymers in a polymerization reactor it will often be necessary to transition from one type of catalyst system producing polymers having certain properties and characteristics to another catalyst system producing polymers having different specifications. The developed process relates to transition between two incompatible catalysts in continuous polymerization reaction, utilizing advanced Ziegler-Natta catalyst system and chromium-based catalyst. The transition process is performed with no discontinuity to the reactor operation, where, it starts with the first catalyst in continuous polymerization reaction of ethylene and alpha olefin co-monomer for producing a linear low density polyethylene (LLDPE) in a gas phase reactor to the second catalyst and different co-monomer for producing a high density polyethylene (HDPE). The transition process comprising initially a feed reducing of the first co-monomer into the reactor until the ratio of co-monomer to ethylene in the reactor is less than zero. Then, discontinuing the first catalyst of Ziegler-Natta while the introduction of a co-catalyst of the Ziegler-Natta catalyst is continued and subsequently discontinuing the introduction of the co-catalyst. The polymerization conditions in the reactor are kept with no change in this stage and permitting polymerization of LLDPE to continue for a time. Then, discontinuing the introduction of all feeds into the reactor, depressurizing, flow-purging the reactor and introducing more ethylene and other feeds to prepare the reactor for the new conditions for the second polymerization reaction, wherein the partial pressure of ethylene is increased to the pressure for the second polymerization reaction at such a speed that the reactor temperature is maintained at a temperature lower than the temperature of the first polymerization conditions. After that, reactor temperature to be increased to a temperature of the chromium-based catalyst polymerization conditions and start feeding the catalyst into the reactor. Then, the second co-monomer is introduced into the reactor to obtain a reactor composition for HDPE polymerization reaction.
A New Approache for Evaluating the Processing Stability of Polyolefins Using Microcompounding
Niall Marshall, Everspring Middle East WLL
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The processing stability of polymers is traditionally done by extruding the polymer multiple times, each time retaining a sample to measure the melt flow, yellowness index and in some instances mechanical properties. While useful and providing valuable information, multiple extrusion studies have two disadvantages: firstly they require relatively large samples of each formulations being studied (depending on the size of the extruder used, but typically of the order of several kilograms) and, secondly, each study is time consuming. These disadvantages limit the number of formulations which can realistically be studied in an experimental program and are often carried out without considering reproducibility. A new approach, which makes use of a DSM X-plore MicroCompounder, has been developed and evaluated against traditional multiple extrusion and been found to not only provide comparable results with statistical repeatability but is also well suited for multifactor experimental designed projects.
Development of a Polyolefin Stabilizer Blend with Predefined Properties and Food Contact Status
Robert L. Sherman Jr., Baerlocher USA
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Development of a new additive or additive blend is a complex, time intensive process. Baerlocher has introduced Baeropol Resin Stabilization Technology (RST) as a synergistic stabilizer blend for polyolefins. A discussion of the work necessary to develop a new blend including regulatory, performance, and properties will be discussed.
Ultrasonic Technology Applied to Polyethylene Pipe Butt-Fusion Joints Uses, Limits, Acceptance Criteria
Harvey Svetlik, Harvey Svetlik Consulting.LLC.
Understanding the polyethylene butt fusion joint structure is important when using Non-Destructive Examination (NDE) technologies to examine for flaws, discontinuities, tolerable defects, and critical defects. PAUT and TOFD and MICROWAVE are accepted non-destructive examination methods used on HDPE pipe and fusion joints, each with its own benefits. Each can detect voids and inclusions, under controlled environmental conditions. Field implementation requires adjustment versus controlled conditions, in order to obtain clear calibrated readings. While certain implemented technologies are portrayed in as proprietary, some general guidelines exist for acceptance criteria, which parallel the guidance from ASME BPVC Section XI.
Ultrasonic Technology Applied to Polyethylene Pipe Butt-Fusion Joints Uses, Limits, Acceptance Criteria
Xian Jiang, E.I. du Pont de Nemours and Company, Inc.
Colin Li Pi Shan | Brian Yu | Kyle Kummer, Dow Packaging and Specialty Plastics
- Influence of polymer structure on crystallinity and rheology
- Chemical foaming – polymer-property relationships
- Ionomer addition for ultra low density foams
