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.

Effect of Catalyst on Compatibilization of Poly(lactic acid) / Polyamide Blends

JeongIn Gug, Margaret J. Sobkowicz, May 2015

The effects of catalysts p-toluenesulfonic acid (TsOH) on trans-reactions in poly (lactic acid) (PLA)/polyamide (PA11) blends were investigated in this study. The extent of reaction was tracked using solubility, modulated differential scanning calorimetry (MDSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR). The organic acid catalyst appeared to induce trans-reaction but also reduced overall molecular weight in PLA/PA11 blends. The interchange reactions appeared to compatibilize the blends as evidenced by calorimetry and microscopy.

Undergraduate Modules for Biobased Plastics

Carol Barry, Bridgette Budhlall, Ramaswamy Nagarajan, May 2015

Educational modules focused on bio-based polymers were successfully developed and implemented for undergraduate curricula. These modules included experiments for (1) synthesis of a biodegradable polymer, (2) characterizing the properties of this polymer and comparing these properties with those of a commonly-used petroleum-based polymer, and (3) melt processing a bio-based, biodegradable polymer. All modules were well-received by and produced significant learning by the undergraduate students.

Effect of Pigments Compounding on Product Performance

Rakshit Amba, May 2015

As global leader in custom colored engineering thermoplastics SABIC is committed to investigating sustainable methods in process and analytical techniques. SABIC has long history partnering with customers to differentiate their products by developing desired looks and aesthetics for unique branding. SABIC and its COLOREXPRESSTM is therefore, capable in handling complex color matching, formulation to meet product performance and utilizing expertise in delivering long term product performance regardless of lot size.

Processors commonly use color concentrate or master batch for product coloring during molding or extrusion. This process involves modification of screw design or feeder for optimal product quality. Custom compounders such as SABIC use pigments with various polymers and additives, with optimized formulation, screw design, and feeding methods. Therefore providing customers with convenience and superior product performance than color concentrate or master batch.

General concerns include pigments dispersion, its effects on engineering thermoplastics properties and surface appearance. Theory behind agglomerate break-up and its effects on experimental molded samples are discussed in the paper.

For this study samples were produced using different pigment feeding methods including standard pigment compounding method and use of color concentrates. Also, SABIC?s proprietary method was compared. It is critical that pigments be evenly dispersed and distributed in the polymer matrix while maintaining consistent viscosity and optimal mechanical properties.

Commonly used pigments in polymers include titanium dioxide and carbon black. Typically color compounds incorporate more than one pigment which adds to the complexity. Experimental findings from the various compounding methods on mechanical properties, surface, heat/hydro aging and color appearance are presented. This paper also compares and reveals some superior pro

Effect of Polypropylene Contamination on Weld Strength of Recycled Polyamide 6

Hesam Ghasemi, Phil Bates, Amin Mirzadeh, Ying Zhang, Musa Kamal, May 2015

Two different recycled polyamide 6 resins were used in this study: post-industrial waste polyamide 6 (PIW) obtained from a fiber manufacturer; and post-consumer waste polyamide 6 (PCW) recycled from used carpets. Differential scanning calorimetry (DSC) and Dynamic mechanical analysis (DMA) proved the presence of polypropylene (PP) in PCW. Moreover, thermal gravimetric analysis (TGA) showed that PCW contained approximately 10 times more ash content than that of PIW. The PP and inorganic contamination of PCW come from PP carpet backing and calcium carbonate (CaCO3) filled latex binder, respectively [1]. Due to higher inorganic filler content, PCW exhibited higher melt viscosity and also higher storage modulus than that of PIW. Tensile tests were performed on dog-bone specimens cut from injection molded plaques. PIW displayed approximately 20% higher tensile strength than that of PCW. However, a 70% drop in PCW vibration weld strength was observed. This is attributed to its PP contamination.

Vegetable-based Copolymers Based on Blend of Acrylated Epoxidized Soybean Oil and Tung Oil

Samy Madbouly, Kunwei Liu, David Grewell, May 2015

A biorenewable thermosetting polymer was synthesized by copolymerizing acrylated epoxidized soybean oil and tung oil using a free radical polymerization method. It is found that tung oil acts as a plasticizer in acrylated epoxidized soybean oil. This article presents a simple, versatile, and environmentally friendly technique to produce thermosets with a wide range of thermo-mechanical properties.

Engineering Resin Based on Post-consumer Recycled Polyamide 66 from Carpets

Avelino F. Lima, May 2015

This study provides foundation for the development of a post-consumer recycle resin with low purity Post Consumer Recycle Polyamide 66 (PCR-PA66) and no delamination. These resin were developed using a novel concept of maximizing usage of low purity PCR-PA66 while maintaining part functionality. Main impurities in the PCR-PA66, which are calcium carbonate, latex, polypropylene, colorants and additives need to be taken into consideration to come up with a robust product. From these contaminants polypropylene (PP) present in the carpet backing and carried over in the PCR-PA66 stream causes serious potential for delamination and will be discussed in depth. A fixed amount of glass reinforcement provides part functionality, and total aim reinforcement was targeted to 36%. Delamination test was developed and this study aimed to uncover how to predict, measure and avoid potential of delamination while maximizing usage of low purity PCR-PA66. This paper describes the properties of optimized resins and boundary regions.

Environmental Qualification of Cables to IEEE Standards and End-User Specifictions

Elliot B. Lee, Roy Haller, Abbas Zaidi, Koksal Tonyali, Srini Siripurapu, May 2015

General Cable Corporation recently committed to a multi-year effort on development and qualification of 60-year life Class 1E cables. The major milestones achieved in the development include (a) Introduction of 60-year life nuclear cables in the industry (b) Approval of 60-year cables for service in the new nuclear power stations (Vogtle site and V.C. Summer site) and (c) Use in a new generation nuclear reactor power plant AP1000 designed and sold by Westinghouse Electric Company. Cable constructions tested were 600V cables, 2 kV cables and 15kV MV power cables. This paper presents the scope of overall qualification program and test results conducted per IEEE standards and end-user specifications. The cable testing will be discussed in relation to thermal aging and radiation exposure followed by DBE (Design Basis Event) accident conditions.

Evaluation of Mechanical Properties of Cellulose Composite

Hiroyuki Nishimura, Yoshiki Hashimoto, Kazushi Yamada, Yoshikazu Kondo, Hiroki Sakamoto, May 2015

Cellulose nanofiber (CeNF) is generally provided by micronizing a plant fiber to a nanometer-size in diameter. A CeNF reinforced thermoplastic composite is recently expected to indicate integrated high performance concerning light weight, thermal resistance and mechanical strength. It is important to disperse and defibrate CeNF uniformly in a resin in the extrusion process. In this study, various compounds of microcrystalline cellulose (MCC), CeNF, PLA, and PP were made using additives by the extrusion process. The mechanical properties were also evaluated.

Failure Analysis of a Fractured Polyamide 6 Shock Absorber Housing

Brian Ralston, May 2015

A polyamide 6 shock absorber housing on a jogging stroller fractured completely during service. A range of techniques were utilized in the failure analysis, including DSC, TGA, FTIR, ICP-OES, SEM-EDS, and mechanical testing. Lithium grease, calcium, and chlorine were detected on and near the fracture surface. Fracture morphology observed by SEM suggests chemical interaction played a role in initiating the fracture. The combination of mechanical stress and the presence of known environmental stress cracking (ESC) agents in CaCl2 and LiCl is suspected to have led to time-dependent crazing, cracking, and eventual fracture of the housing.

Failure Analysis of Copolyester Clamps

Tommy L. Washington, May 2015

Cracking and subsequent failure of a clamp feature on a broken copolymer component occurred through brittle fracture as a result of environmental stress cracking. Environmental stress cracking (ESC) is a phenomenon whereby a particular plastic resin is affected by a specific chemical agent while under stress. ESC occurs commonly in polymeric components but the fractographic features of copolyester are similar in both ESC and creep. The analytical techniques employed in this article provide a guideline by which to properly determine the root cause of failure for copolyester components and describes characteristics typically observed in copolyester ESC failures.

Functionalization of Soy Fatty Acid Alkyl Esters as Bioplasticizers

Dharma R. Kodali, Lucas Stolp, Subbarao Kandula, Benjamin Woldt, Michael Grass, May 2015

The combination of various functional groups such as epoxy, acetoxy, methoxy, thiirane, aziridine on the acyl chain of soy fatty acid alkyl esters have been synthesized and evaluated as plasticizers in poly vinyl chloride (PVC) applications. Numerous synthetic procedures such as epoxidation, methoxylation, acetylation, thiiration, and aziridination were used for synthesizing multifunctional soy fatty acid alkyl esters. Epoxidized soybean oil fatty acid alkyl ester served as the key intermediate to incorporate most of the functional groups on the fatty acid backbone. The physical and analytical properties of bioplasticizers such as acid and saponification values are acceptable for plasticizer applications. The high viscosity and darker color of aziridine and thiirane derivatives limit their usefulness, whereas the physical properties of the other derivatives were acceptable. The plasticizer evaluation of methoxy, acetoxy soy fatty acid esters (methyl and n-butyl) demonstrated good compatibility with PVC, high efficiency (Shore Hardness) and gelling properties and were comparable to commercial plasticizer, diisononylphthalate (DINP).

Health Product Declarations-The Good, The Bad and The Ugly

Marty Sweeney, May 2015

Today, your products may be excluded from a project simply because you do not have an HPD (Health Product Declaration). This presentation will not advocate for, or against, Health Product Declarations (HPDs) and/or other instruments for demonstrating ingredient transparency. Rather, the goal of this presentation is to examine the evolution of Health Product Declarations, determine the true impact these mechanisms are having on buying decisions today, and discuss the likely impact in the future. Most importantly, we will discuss the ?as is? of ingredient transparency initiatives and the relative merits of defending and/ or embracing these initiatives, for building material manufacturers and raw material suppliers

Topics will include:
What is a Health Product Declaration?
Growing influence of green building rating systems (such as LEED) and how this is changing product development
Who?s on board? Who are the stakeholders driving change?
Ingredient Disclosure: Hazardous Chemical lists vs. Risk & Exposure Assessment
How do I decide if an HPD is right for my company?
Now that you?ve decided?what?s next?

High Performance Cellulosics for Demanding Medical Device Applications

Lea C. Paslay, May 2015

The increased use of disinfectants to combat hospital-acquired infections (HAIs) has created materials engineering challenges for medical device manufactures and designers. As disinfecting frequency increases, chemical resistance, e.g., environmental stress cracking, becomes increasingly important for materials historically used to manufacture medical devices. Although the chemical resistance requirements for materials are becoming more stringent, device designs continue to be complicated and intricate, limiting manufacturers? abilities to transition to a highly chemical resistant material if the material does not also exhibit ease of processing. This work investigates and outlines the processing and chemical resistance advantages of Eastman Tenite? propionate 360, a material manufactured from the bio-renewable resource, cellulose.

Implementation of Post Consumer Recycled Plastic in Electronic Products

James P. Drummond, May 2015

The path towards the use of post consumer recycled plastic in electronic products has a long and cyclical history. The use of these materials is ultimately desired not only for the environmental benefit to our world, but also for the potential financial benefit of reclaiming a high value waste stream. To most outside the plastics or recycling industries, recycling plastic seems like a simple and obvious thing to do. The reality of it however is much more complicated. Ever-changing variables such as supply and demand, shifting waste streams, environmental regulations, and the price of oil, keep the sand shifting under the feet of those trying to succeed in this field. Together with recycling industry leaders our team has worked through many of the obstacles to achieve industry leading post consumer recycle content in our electronic products. Here we will present the history and challenges of a project set forth to increase post consumer recycle content, and demonstrate the benefits of the project in the form of successful implementation of its results.

Influences of Wood Particle Shape and Surface Modification of Wood on Wood/PP Composites

HU Y. Xu, Hiroyuki Hamada, Mnabu Nomura, May 2015

Nature fibers are increasingly being used as reinforcement in commercial thermoplastics due to their low cost, high specific properties and renewable nature. All of nature fiber, wood is the most popular one that researched by many scientists. To understand how wood flour influence the mechanical properties of polypropylene composites, we first investigated the effect of different sizes of wood flour particles on the mechanical properties of wood-flour-filled polypropylene composites by tensile test. And we modified the surface of wood with H-1000P and bondfast (BF-E), researched effect of them to mechanical properties of wood/PP composites based on tensile test. The result shows that the wood/PP composites which reinforced by high aspect ratio wood, the elastic modulus will be improved, which reinforced by low average particle length, the elongation will be better. On the other hand, according to modifying the surface of wood by H-1000P and BF-E, the mechanical properties of wood/PP composites is improved.

Integrated Waste Heat Utilization for Extruder Barrels by Interconnection of Fluid Streams

Christoph Ketteler, Johannes Wortberg, May 2015

During the extrusion of polymers, it is generally necessary to provide heating and cooling capabilities at the extruder barrel for start-up and temperature control during operation. The most common solutions used, are electric resistance heaters in combination with air-cooling by radial blower fans. These heaters are usually grouped in zones to allow the setting of temperature profiles along the barrel. Although this well-established solution benefits from several of its properties, there is one major disadvantage. At certain operating points, it is unavoidable that cooling is applied to keep the processing temperature within the given limits. By the use of air-cooling, the extracted heat is wasted and the energy efficiency of the extrusion process decreases.

The main goal of the presented approach is to preserve this extracted energy inside the system and make it utilizable at another location in the process. This is achieved by a fluid heating system using thermal oil as heat transfer medium. The system provides two global temperature levels of thermal oil and uses bypasses for each zone along the barrel of the extruder. These bypasses allow the setting of a specific desired feed temperature for every single zone without the requirement to provide an independent fluid heating system respectively. The return flow is distributed back to the global fluid streams based on the fluid temperature after the zone. Depending on the specific operating conditions, this distribution leads to a decreasing power demand of the complete temperature control system by utilizing extracted process heat to minimize the additional global heat requirement.

Intelligent Labels as a Basis for Auto-Sorting of Plastic Packaging

Edward Kosior, Jon Mitchell, Kelvin Davies, Martin Kay, Rafi Ahmad, Edwin Billiet, Jack Silver, May 2015

Polypropylene (PP) from packaging is a significant polymer in the mixed plastics waste stream and closed loop recycling of it back into packaging would enable considerable carbon savings to be realised and generate significant revenues. Recent estimates suggest that 143,000 tonnes of the total PP packaging is used for food-grade application. One of the remaining barriers to closing the loop on the recycling of PP food packaging waste back to food grade applications is the absence of an automated method for sorting PP packaging waste to separate a stream consisting of at least 99% PP packaging that has been previously used for food from other non-food PP packaging.
Machine readable inks (including fluorescent pigments) have shown great potential for the identification and separation of plastic packaging. Unlike existing NIR sorting practices, these technologies are not polymer specific and could be applied to targeted streams like food grade PP packaging and others, using commercial labelling and decoration methods and sorted using MRF infrastructure with only minor modification.
This report describes the work of an identification technique which is based on fluorescent pigments that can be applied to labels and packaging as a machine readable ink (MRI) to enable the automatic separation of target materials such as the sorting of food grade PP packaging for closed loop recycling.
Based on the audit of commercial of PP waste indicating that 55% detectability of existing packages together with potential yields of 98% from the sorting trials, it can be estimated that of the 143,000 tonne of PP food packaging, 77,077 tonnes could be recovered each year in the UK. This would increase dramatically if label design and application was modified to better accommodate identification and sorting requirements.

Investigation of Applying Gas Counter Pressure (GCP) Technology in Improving Metal Injection Molding Flow Characteristics and Molded Part?s Quality

Shia-Chung Chen, Edward Suhartono, Cheng-Chang Hsieh, Sung-Wei Huang, Wen-Bing Liu, May 2015

Metal Injection Molding (MIM) is a combination between injection molding and powder metallurgy process. The process bolsters a mass-production manufacturing of small, complex, precise parts as a molded part undergoes de-binding and sintering stages right after the molding one. Most of the MIM studies focus on how to treat the feedstock while to control the distribution of powder concentration and density through the process settings, for example, melt temperature, mold temperature, and injection speed is still less discovered. Therefore, this study investigates the effects of those settings on flow characteristics and molded part?s quality which focuses on the green part. Moreover, Gas Counter Pressure (GCP) technology is carried out to improve the process. Numerical approach along with SEM analysis is also conducted for verification, and the results exhibit that an anisotropic behavior occurs in experiment with different temperature and speed settings. In addition, both experiment and simulation have demonstrated that GCP implementation can improve both process and part?s quality; the shear stress is reduced up to 98.49%, and the density can be increased up to 1.43% in experiment and 0.01% in simulation.

Isothermal Crystallization Behavior of Poly(Lactic Acid)/Cellulose Nanofiber Composites with Presence of CO2

WeiDan Ding, Raymond K. Chu, Chul. B. Park, Mohini Sain, May 2015

The isothermal melt crystallization behavior of poly(lactic acid) (PLA)/cellulose nanofiber (CNF) at atmospheric pressure and two CO2 pressures was investigated using regular and high-pressure differential scanning calorimeters (DSC). The DSC analysis and polarized optical microscope (POM) result indicated that CNFs acted as crystal nucleating agents and accelerated the crystallization kinetics by providing more nuclei and decreasing the crystallization half-time. It was found that the crystallization kinetics of PLA materials was changed depending on the crystallization temperature, CNF content, and CO2 pressure. During isothermal process, the crystallization kinetic constant, k, increased with temperature up to a critical isothermal temperature before decreased; increasing CO2 pressure accelerated the crystallization kinetics of PLA at temperatures below 110 øC, but depressed at higher temperatures. The highest crystallinity was achieved at 15 bar.

Lignin Powder as a Filler for Thermoplastic Automotive Lightweight Components

Hendrik Mainka, May 2015

Lightweight design is an essential part of the overall Volkswagen strategy reducing the CO2 emissions. The use of lignin as a filler for thermoplastic materials offers an enormous lightweight potential. Here, a Lignin-PP compound filled with up to 30% Lignin powder offers a 20% weight reduction compared to traditional filled PP compounds assuring the same mechanical performance. Furthermore, in comparison to unfilled thermoplastics a potential cost reduction potential of up to 30% by using lignin as filler seems possible. Today, the use of lignin as filler for thermoplastic materials in automotive components in mass series applications is unknown.
Key aspects for the investigation of novel lignin based fillers are: the examination and quantification of lignin, the optimization of the manufacturing processes, the characterization and quantification of the mechanical properties of the novel lignin filled thermoplastics within an established material pre-validation process and a final economic efficiency and sustainability analysis.
Furthermore, the process ability of the products and demonstrators as well as the suitability for high volume production of the developed processes are investigated as main issues for successful implementation in future lightweight vehicle concepts.