SPE Library

The SPE Library contains thousands of papers, presentations, journal briefs and recorded webinars from the best minds in the Plastics Industry. Spanning almost two decades, this collection of published research and development work in polymer science and plastics technology is a wealth of knowledge and information for anyone involved in plastics.

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Recycling

Various topics related to sustainability in plastics, including bio-related, environmental issues, green, recycling, renewal, re-use and sustainability.

iMFLUX's Novel Low, Constant Pressure Molding Technology Overcomes Traditional Barriers to Achieving A Truly Sustainable, Circular Operation - Sponsored by SPE Recycling Division

Gene Altonen, June 2020

One of the biggest challenges facing the plastics industry today, is the need for technology solutions that enable a Circular Economy. This is especially true for injection molded parts, where operational tradeoffs are often encountered when running many sustainable materials. iMFLUX, a wholly owned subsidiary of Procter & Gamble, offers a novel injection molding technology they refer to as the “Green Curve” which uses low, constant plastic pressure to fill an injection mold. Gene Altonen, iMFLUX’s CTO, will share how this new technology addresses the key challenges molders face to deliver truly sustainable, circular solutions for their customers. Examples will be provided illustrating how this new approach to molding offers the ability to efficiently run post-consumer recycle and composites, substantially reduce energy use, and enable more sustainable part designs and materials. iMFLUX is collaborating with machine makers, material suppliers, educators, mold designers, data platforms, and sustainability industry associations to enable molders to benefit from the unique advantages this new technology provides.”

Advanced Simulation Methods for Prediction of Multi-Layer Non-Matching Fiber-Mat Applications In Resin Transfer Molding Process

Fred Yang, May 2020

The objective of this study is to use a simulation tool of resin transfer molding (RTM) process to get a comprehensive understanding of the permeabiliy measuring process. In order to varify the simulation tool’s capibility to simulate oil flow in non-matching fabric we build the mesh model of the measuring instrument cavity with the non-matching meshes in this study. This varifaciton case focuses on two properties of the RTM process, the arriving time and local pressure increasing trend in filling process. By using the simulation tools, we can observe the resin flow within the mold. The comparison between simulation and experiment result shows the reliability of simulation result. We expect that this study will help to clarify relevant issues and then reduce the trial-and-error time and materials.

Bottle-to-Bottle Recyclability for Barrier Packaging Enabled by Surface Modified HDPE

Zhenshuo Liu, May 2020

Ellen McArthur Foundation’s bold vision for The New Plastics Economy is one where plastic goods can be recycled and reused in a closed loop, a “Circular Economy”. A key hurdle to enabling closed loop recycling is the deterioration of polymer properties due to raw material contamination in the recycle stream. Mixed polymer systems, i.e. co-extrusion/multilayer packaging, use barrier materials such as EVOH or Nylon, creating significant issues during recycling. In contrast, having monolayer packaging enables the highest recyclability. Fluorinated HDPE enables monolayer barrier packaging solutions. To further understand its impact on recyclability, Inhance Technologies investigated the inclusion of fluorinated HDPE in the regular HDPE stream. Fluorinated HDPE and regular HDPE were blended at different ratios, re-extruded and pelletized. Following pelletization, bottles were molded from the regrind blends and their properties were evaluated. At all blend ratios, thermal-mechanical properties, chemical fingerprint, and sortability match those of virgin HDPE. The results demonstrate that fluorinated HDPE can be recycled as regular HDPE within the existing recycling infrastructure.

Circular Economy - New Styrenic Polymer Processing Concepts

Cassie Bradley, May 2020

Circular economy is a term describing a sustainable way to interact with all major stakeholders of the economic sphere. One basic idea is to minimize waste creation and to use post consumer waste as raw material for new products. This concept stands in contrast to the “linear economy”, based on products that end in landfill. Circular economy will play a particularly important role for all materials and goods having a short and mid-term lifetime and will have an implication on how these products are designed and recycled. Plastics food packaging are examples for goods, providing safety, protection and extended shelf-life and hence allow us to lead our modern life style. They typically have a short-term lifetime and are disposed after use. Within the challenge of “Circular Economy” however, producers of packaging, as well as upstream raw material producers are requested to provide new concepts for re-use in a true circular way, hence re-cycling rather than down-cycling or waste dumping in landfills. Plastics producers, and especially producers of Styrene-based plastics are taking up the challenge and started to “connect the dots” between municipalities, new recycling technology providers, raw material producers and customers. By promoting “chemical recycling” they are pursuing new ways to create high quality, even food grade plastics based on post consumer waste as new raw material.

Demonstration of a Preliminary Simulation Framework for Foam Blow-Molding using Commercially Available Blow-Molding Software

Bhaskar Patham, May 2020

The use of foamed polymeric precursors for blow-molding and thermoforming applications is seeing increased use in the world of application development across a wide range of segments such as automotive, appliances, and packaging. Foam blow molding holds great potential for further enhancing lightweight solutions for complex hollow structures, while adding the potential of single-material solutions offering multi-functionality, e.g., thermo-acoustic isolation or damping. Unlike in the case of foam injection-molding, fundamental processing-structure-property interrelationships are not widely researched in the area of foam blow-molding. Modelling, simulations, and predictive engineering of foam blow molding processing are still in their infancy. Any simulation framework for this purpose needs to address the complex interplay between the matrix rheology, foam morphology and morphology evolution, and the resulting processability and thermo-rheological properties of the foamed product. Here, we report a preliminary simulation framework for foam blow molding, demonstrated in the context of foam extrusion blow molding. The framework addresses several important material and processing considerations. These include: (1) the initial foam morphology; (2) the nonlinear viscoelastic characteristics of the foamed melt; (3) the derivation of constitutive parameters for the foam – arriving at a homogenized representation of the foam rheological characteristics; (4) the implementation of blow-molding simulations using these parameters in a commercially available simulation software; and (5) finally correlating the local strains in the blow molded part to its morphology.

Mechanical Properties of Electrospun Fibers from Ozone-treated Lignin

Jiawei Chen, May 2020

Ligninis a viableprecursor alternative for electrospun carbon fiber. Purification of lignin typically involves chemicals. Ozone treatment is an environmentally-friendly approach to purify lignin. In this study, electrospinning of untreated and ozone-treated lignin was conducted with polyethylene oxide (PEO) as an aid-polymerto form submicron fibrous mats. Morphology and mechanical properties of the electrospun fibers were investigated. Electrospun ozone-treated lignin fibers showedspherical shapes attached to smooth fibers, characterized as beads-on-a-string (BOAS) morphology. It was found that longer duration of ozone treatment resulted in decreased average fiber diameter while increasing bead density, changing spindle-like beads into spherical beads. Ozone treatment did not have significant influence on the strain at failure of the electrospun lignin mats. Bead formation reduced the tensile strength and the elastic modulusof the electrospun fibers. Medium ozone consistency and short reaction duration were found to be the optimum conditions where highest tensile strength and elastic modulus were achieved.

Recycling PET into Plastic Lumber at Forward Operating Bases

Richard Heggs, May 2020

Recycling of plastic waste at Forward Operating Bases (FOBs) is becoming a topic of considerable interest to the Department of Defense. The ability to recycle plastic waste into plastic lumber that would be of use at the FOBs accomplishes two goals: (i) Reducing the environmental concerns caused by open pit burning of waste plastics (which is now prohibited at many sites) and, (ii) Providing the warfighter with useful materials for infrastructure improvements lessening the need for building supplies that in many cases must be delivered by convoy. This paper describes the investigation of using recycled PET (rPET) to make plastic lumber using flow intrusion molding and the resulting performance characteristics

Stabilization of Polymers for a More Circular Economy

Ian Query, May 2020

Polyethylene and polypropylene are two of the most easily recycled polymers. Recycling polyolefins can result in downcycling to simple functional polymers, true recycling for reuse in the intended application, or upcycling of the polymer into higher quality products. To take advantage of the available feedstock and improve its utilization, stabilizers are can be added to allow the polymer to retain its original physical properties. A variety of customer-based case studies on recycling and upcycling will be covered showing how additives allow for improvements in the recycle stream.

The Use of Novel Biomaterials For Affordable Packaging

Karnik Tarverdi, May 2020

The effects of the use of biomaterials for the development of novel packaging composites have been evaluated. An increase in the amount of treated fillers improved the dispersion of the particles and consequently led to an enhancement of the mechanical properties of the materials. The composites were melt-blended using co-rotating intermeshing twin screw extrusion technology and although there can be degradation of the organic additives during extrusion processing, it did not affect the dispersion of the novel biocomposites and the biofillers.A range of techniques used to characterise these materials will be discussed, including morphology, differential scanning calorimetry, (DSC), Scanning electron microscopy (SEM), including experimental techniques likemechanical property evaluations.

SPE Recycling Division 2020 1st Quarter Newsletter

SPE Recycling Division, February 2020

Read the 2020 1st Quarter newsletter for SPE Recycling Division.

Commercializing Recyclable Plastic Packaging – A Journey of Discovery

Lawrence Effler, February 2020

Major brands and retailers have made various pledges to have recyclable plastic packaging by various targets dates. However, most recyclable solutions are not drop in replacements for existing packaging. Also, it’s not enough for the package to be reprocessable to be commercially recyclable other elements must also be in place. So, what does it take to have a commercially recyclable package and how do we get there?

Produce Rescue Center: A Working Model for Plastics Circular Economy

Carmelo Declet-Perez, February 2020

In 2017, the Montgomery County Food Bank (MCFB) and Dow partnered to create the Produce Rescue Center. The MCFB supports 65+ partner agencies in Montgomery County, TX. The Produce Rescue Center seeks to increase the amount of fresh produce that reaches people in need serviced through the partner agencies. In this presentation we will highlight the impact and accomplishments from the Produce Rescue Center and the role plastic packaging plays in this success. We will also discuss next steps for the project to complete a circular economy model for plastics packaging.

Improving Physical Properties in Sustainable Thermoplastic Elastomers through Incorporation of a TRA

Megan Robertson, February 2020

Thermoplastic elastomers (TPEs) are widely used in electronics, clothing, adhesives and automotive components due to their high processability and flexibility. ABA triblock copolymers, in which A represents glassy endblocks and B the rubbery midblock, are commercially available TPEs. The most commonly used triblock copolymer TPEs contain glassy polystyrene endblocks and rubbery polydiene midblocks. However, commercial TPEs are derived from petroleum. The manufacturing and disposal of petroleum-derived products have undesired environmental impacts, which promotes development of TPEs from sustainable sources. Vegetable oils and their fatty acid derivatives are attractive alternatives to petroleum due to their abundancy and low cost. Our group has previously reported replacing polydienes in commercial TPEs with sustainable polyacrylates derived from fatty acids. However, polymers with bulky constituents, such as the long alkyl side-chains of fatty acid-derived polymers, typically exhibit poor mechanical performance due to lack of entanglements in the rubbery matrix. To improve the mechanical properties, a transient network was incorporated into the fatty-acid derived midblock through hydrogen bonding. Specifically, triblock copolymers containing polystyrene endblocks and a midblock composed of a random copolymer of poly(lauryl acrylate) (derived from lauric acid) and acrylamide (which undergoes hydrogen bonding) were synthesized. Quantitative FTIR analysis confirmed the formation of a transient network. The polymers exhibits disordered spherical morphologies, desirable for application as TPEs. Rheological measurement revealed the order-disorder transition temperature reduced with increasing acrylamide content, beneficial for high temperature melting process. Importantly, triblock copolymers with hydrogen bonding in the matrix exhibited significantly higher modulus, strain at break, and tensile strength as compared to comparable polymers in the absence of hydrogen bonding.

The Role of Mechanical Recycling in the Circular Economy for Polyolefins (Paper)

John Dorgan, February 2020

The global production and use of plastics (especially polyolefins) continues to grow and is expected to double to nearly 800 million metric tons per year by 2040. The use of plastics has resulted in convenience and reduced overall energy consumption, though we are also beginning to recognize challenges due to the mismanagement of plastic waste. Public concern over issues such as ocean plastics, along with the emergence of the concept of the circular economy, has resulted in commitments by some consumer packaged goods (CPG) companies to use recyclable packaging and to use more recycled plastic in their packaging. Mechanical recycling is an established approach that provides an opportunity to better manage waste plastics by creating value from otherwise worthless waste. The increasing demand for recycled content should increase the recycled plastic price further, resulting in an increase in the global plastics recycling rate from the current level of approximately 12%. We will provide an overview of mechanical recycling technologies while also highlighting some of the technical limitations that prevent immediate widespread incorporation of recycled polyolefins into new packaging and other high value products. We will also discuss potential approaches to overcoming these technical challenges and the role of the REMADE Institute in these developments. In addition, we will discuss how mechanical recycling will be a critical first step in many of the chemical recycling approaches that are beginning to emerge.

The Role of Mechanical Recycling in the Circular Economy for Polyolefins (Presentation)

John Dorgan, February 2020

Biomass-based Renewable Polymers – A Pathway to a Sustainable Future

Joshua Yuan, February 2020

Major environmental challenges associated with petrochemical plastics need to be addressed via a) reduction of environmental contamination through enhanced recyclability at the end of service life and b) the supply of low cost renewable feedstock for plastics production. In particular, there is a large need for innovative plastics that are readily recyclable to lower environmental hazards and the renewable feedstocks for these plastics must be made widely and cheaply available. We have developed two aspects of advances to enable widespread production of such innovative plastics. On one front, we will develop various pretreatment, fractionation and metabolic engineering technologies to enable the efficient conversion of lignocellulosic biomass or lignin waste to PHA for bioplastics. On the other front, we have tailored lignin chemistry and designed lignin-based composite material both with enhanced performance and with controlled degradability at the end of service time. These innovative technologies produce desirable lignin-based plastics in the context of biorefinery design, in a manner that adds value for a lignocellulosic biorefinery. The overall impact could significantly enhance environmental sustainability by replacing the non-degradable plastics and enabling lignocellulosic bioproduction.

Overview of the Current Plastic Recycling Landscape

Manuel Prieto, February 2020

Trends in plastic waste management, recycling and reuse are evolving rapidly – the demand for single use plastics continues to grow and more complex plastic applications are further challenging existing infrastructure. Finding a solution requires action across all steps of the value chain (from product design to consumer education to collection to separation to recycled polymer reuse), as well as across stakeholders (from chemical companies to converters to brand owners to recycling companies to governments to investors and public figures). Chemical recycling, conversion, and decomposition technologies offer further flexibility to recover and reuse a broader set of materials and potentially provide the missing piece in the recycling equation. However, the economics of these technologies is not yet proven.

Chemical Recycling: Upcycling of End-of-Life Plastics

Carlos Monreal, February 2020

There is no time to lose in figuring out how to solve the plastic challenge and increase both the recycling rates and the recycled content in product. In parallel of this regulatory drive, many large brand owners have committed to reach 100% of recyclable packaging by 2030. Plastic Energy has developed a solution to address low-value mixed plastics that cannot be mechanically recycled. The Thermal Anaerobic Conversion (TAC) produces recycled oils (TACOIL) from end-of-life plastics. The TACOIL is then used as a new feedstock for the (petro)chemical industry to generate recycled plastics by replacing virgin oil with TACOIL. Our TAC process is a low-pressure thermal depolymerization process patented in Europe and the US. To be more specific, the shredded, densified and then molten feedstock is pumped into the oxygen free reactors at a controlled rate and temperature. The multicomponent hydrocarbon vapour produced in the reactor passes through our patented contactor vessel which finally controls the hydrocarbon chain length and quality before entering the condensation system. The TACOIL is then be subjected to various additional purification / polishing steps before being sent to the steam-crackers of the chemical industry. In addition of having two industrial plants running 24/7 more than 330 days per year for the past 3 years, Plastic Energy through its experience has managed to stabilise the output the specifications required by the chemical industry. This has led to the value-chain validation of the circularity of the Plastic2Plastic process by the ISCC+ to produce the Certified Circular Polymers. This chemical recycling process effectively upcycles the plastic through conversion to the original monomers in each process of recycling, making it safe and reusable as a food-grade product. After explaining the technical and industry experience of reach an optimal product and efficient operations, the presentation will stress some real-life Plastic2Plastic applications developed with the value-chain, and will continue on the upscaling and expansion of the capacities of Plastic Energy and the potential of the chemical recycling industry in improving recycling and creating a circular economy.

China’s Plastic Waste Import Ban: Global & Regional Implications

Jim Rounick, February 2020

China used to import large volumes of polymer waste from around the world. The sudden 2017 decision by the Chinese government to ban imports of recyclables created a supply chain gap for plastic waste processors in China. He-Ro will outline how this supply chain gap issue has been addressed by the PR China plastic waste processors & how the value chain has adapted. With additional plastic waste bans now in place in other Asian countries, will this ’new system’ created by the plastic waste processors be rolled out across Asia and the rest of the world? Will their learnings form a base for other countries to build their own supply chain infrastructure?

Developments in End-of-Life Technologies for Multilayer and Barrier Flexible Packaging

Terence Cooper, February 2020

Flexible packaging is more economical than other formats because of its lower material and energy consumption and manufacturing and transport costs. It also provides reduced waste of packaged products, particularly food, generates much less packaging waste than rigid formats and has favorable LCAs. Consequently, its use, particularly in multilayer barrier films and pouches, has been steadily growing and replacing rigid packaging. Despite this, it is still opposed by environmental groups due to difficulties in end-of-life collection, sorting and processing and concerns about “single-use” packaging and sustainability. Because of its film and multilayer construction, and often food-waste contamination, post-consumer flexible packaging is not readily mechanically recyclable and is presently generally landfilled, so that environmental groups have pressured food and other companies to stop using it. To combat this, and to eradicate landfilling, the food, packaging and recycling industries are supporting a wide range of initiatives including: a). improved mechanical recycling systems to handle film packaging and the development and introduction of supporting collection, identification and sorting technologies and infrastructure; b). new package designs and materials facilitating mechanical recyclability by reducing polymer types and number of layers, mono-material and all-polyethylene pouches, compatibilizer incorporation, and using barrier adhesives and coatings and recyclable and biodegradable barrier materials; c). economic film layer separation and recovery methods; d). chemical recycling processes to produce monomers or valuable feedstocks; e). waste-to-energy recovery systems such as anaerobic gasification and plasma pyrolysis; and f). pyrolytic waste-to-fuel and waste-to-chemicals recovery operations. These developments are surveyed to demonstrate the wide range and intensity of current activities.