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.

Injection Molded Polylactide (PLA) Composites for Automotive Applications

Angela Harris, September 2006

Polylactide (PLA) is a biodegradable compostable thermoplastic polymer produced from corn an annually renewable resource. In moving towards developing a sustainable vehicle use of materials such as PLA could greatly contribute to the goal of a more environmentally friendly vehicle. To date several non-automotive applications of PLA have been commercialized. These include PLA fiber/textile applications for clothing carpeting and linens; as well as blow molded articles for food packaging. Thus far for automotive use a single niche application of compression molded PLA has been developed. Here we seek to optimize the injection molding process conditions and composition of PLA composites for automotive interior applications. The effects of adding various reinforcements to the PLA resin for property improvements were assessed. Crystallinity modulus and strength properties were evaluated by differential scanning calorimetry (DSC) tensile and flexuarl testing.

Use of Agricultural Materials In Flexible Polyurethanes for Automotive Applications

Cynthia Flanigan, September 2006

The use of renewable materials in commercial products has gained attention over the past several years. Biomaterials can offer significant advantages over conventional materials such as: sustainability reduction of petroleum dependence lighter weight of components and potential lower cost. In our studies we demonstrate the use of soy-derived materials in two primary thermoset applications: sheet molding compounds (SMC) and polyurethane foam. SMC composites were produced using soy resin in place of a portion of the vinyl ester resin to evaluate mechanical performance process capabilities and component performance. In addition composite reinforcements of continuous hemp fiber non-woven hemp mats fiberglass and hybrids (fiberglass/continuous hemp twine mixtures) were examined. Results indicate that the soy resin composites demonstrate equivalent properties to those of the vinyl ester resin composites and are equally able to be molded in to complex geometries. While substitution of glass reinforcement with natural fibers was found to reduce the mechanical performance of the composites hybrid composites of glass and hemp fibers provided promising results. Hydroxylized soy oil has also been used as a polyol in flexible polyurethane foam formulations. Foam formulations have been optimized for mechanical and processing performance. One of the key technical challenges of soy foams are their inherent odor. Two odor reduction methods will be discussed including a novel low odor method to functionalize soybean oil.

Wood & Flax Fibre Polyolefin Composites

Johanne Denault, September 2006

In this work natural fiber and wood composites based on neat and recycled polypropylene (PP) were fabricated by melt processing. Different formulations including various reinforcement content different types of coupling agents different types of reactive additives and an impact modifier were developed. The reinforcements were in the form of natural fibers like banana flax rice husk and palm fibers and of wood sawdust. For the long fiber composite systems processing was done by compression molding of piles of long fiber mat and extruded polypropylene film. For the short fiber composite the samples were prepared by extrusion followed by injection molding. The tensile flexural and impact performance were characterized and all composites show superior mechanical properties when compared with the pristine matrix. Mechanical performance of the wood composites was also evaluated before and after conditioning in water for 1 and 7 days. Results indicate that the composites resist to humidity very well. The results also demonstrate the effect of formulations on the performance of the recycled composites.

A New Class of High-Performance Compostable Plastic Bags and Can Liners

Frank A. Ruiz, May 2006

Heritage Bag Company has developed compostable bags and liners, which are produced from composites utilizing polymer and mineral materials technology of Heritage Plastics, Inc. This product line is based on proprietary blends of different biodegradable polymers which have been modified using mineral reinforcement technology to produce a readily extrudable polymer composite. This modification yields polymer processing, end-use products such as film and bags with characteristics very similar those obtained with higher-alpha olefin LLDPE resins, yet meet the requirements of ASTM D 6400-99.

Application of Recycled Industrial Polyolefins in Pail Design Using FEM

S. Haider Rizvi, S.H. Masood, Igor Sbarski, May 2006

This paper presents the application of recycled industrial HDPE and PP and their blends with virgin resins in pail design using finite element analysis. Results predict that these blends can be used in pails for the packaging of non food grade materials such as paints, oil and grease.

Abbreviated Terms for Plastics - Implications and Challenges

Ranganath Shastri, Veronika Pesinova, May 2006

Abbreviated terms are routinely employed in the plastics industry in generic marking of molding products to assist in identification of the plastics for separation in recycling besides in trade and technical literatures. Existing ISO, ASTM and other standards provide clear guidelines for abbreviated terms for polymer families. In practice, however, a wide range of inconsistent abbreviated terms are quite common in the industry. This has significant implications for the general consumers as well as those involved with plastics recycling. The challenge is to arrive at uniform globally acceptable single set of abbreviated terms in order to addressing this issue.

Compatibilization of Polypropylene/Polysulfone Membranes

S. Lawal, V. Flaris, May 2006

Polypropylene (PP) and polysulfone (PSU) have not been previously blended due to viscosity and processing temperature variations. These blends made using an environmentally-friendly process showed structureproperty improvements with the addition of functional polyolefins.

Development and Use of Eco-Plastics in Mexico and Latin America

Veronika Pesinova, Ranganath Shastri, May 2006

In Mexico and other countries of Latin America, the per capita consumption of plastics has more than doubled during the last decade. This results in the increased generation of plastic residues which leads to the growing plastics waste disposal problem. This paper presents a concept of Eco-plastics" which is an integrated approach to solving plastic waste generation challenges in Latin America. A feasibility study is recommended as a first step towards the implementation of this concept."

Applications of Thermoformability Analyzer

Amit Dharia, May 2006

Thermoforming consistent parts depend on knowing and controlling several material and process variables, the most important being the quality of the sheet feed stock. The extruded sheet of the same material could vary in terms of polymeric contamination, thickness, thermal stresses, and amount of regrind, volatiles, color, gloss and grain. Mold material and mold temperature could also vary. Many times, effects of such variations manifest during actual thermoforming in form of tearing, wall thinning, shape distortion, fading, pinholes, and grain distortion. We illustrate use of novel equipment for rapid detection of such variables and their effects on thermoformability, sparring need for expensive plant time and material waste.

Dispersed Nanoclay in GFRP as a Barrier Against Environmental Attack

Naveenkamal Ravindran, Rakesh K. Gupta, May 2006

E-glass fiber-reinforced vinyl ester plastics with up to 5 wt% montmorillonite dispersed in the matrix were immersed in distilled water for nine weeks. At one week intervals, samples were removed and sectioned, both perpendicular and parallel to the fiber direction. Scanning electron microscopy revealed progressive degradation of the matrix and the glass reinforcement. However, the rate of moisture attack decreased with increasing amount of dispersed clay; this was confirmed by strength, stiffness and ductility measurements.

Effect of Environmental Stress Cracking Agents on, Fatigue and Creep of a MDPE Pipe

R. Ayyer, A. Hiltner, E. Baer, R. Matheson, May 2006

The effect of environmental liquids on slow crack propagation in MDPE pipe is investigated. At 50°C, the differences in kinetics and mechanism of crack propagation in fatigue and creep are described relative to that in air. The relationship between fatigue and creep was strongly affected by the presence of environmental liquids.

Effect of Molecular Weight on the Interfacial Properties of GF/PP Injection Molded Composites

H. Okumura, T. Yoshida, U.S. Ishiaku, A?Nakai, H. Hamada, May 2006

For the fabrication of GF/PP injection molded composite, 3 types of PP with different molecular weights were used in order to simulate the recycling process of PP. Effects of weight-average molecular weight on interfacial adhesion between GF and PP were investigated. Moreover, effects of fiber length was also examined through high-back and low-back pressure at the injection molding condition.

Bio-Based Polyurethane Nanocomposites

Rama Krishna R. Etekallapalli, Christopher C. Ibeh, May 2006

Polyols derived from soybean oil are new polyurethane raw materials derived from the renewable resources, and with isocyanates they produce polyurethanes that can compete in many aspects with ones derived from the petrochemical polyols. Combined with polyisocyanurates, they produce materials of good thermal, oxidative and weather stability.The main objective of this research is to synthesize mechanically reinforced polyurethanes, and study the influence of the concentration of nanoparticles on the properties of the new material. Two different soybean oil based polyols, SOY169 and SOY201 were selected to synthesize the polyurethane nanocomposites using a diisocyanate (pure MDI) as a curing agent. The clay used at different concentrations (0%, 1%, 3%, and 5%) in the synthesis of the nanocomposite polyurethanes was organo modified Montmorillonite clay, Cloisite®10A. Methanol was chosen as solvent media in preparing the samples.Several methods were used to analyze the samples like, mechanical tests – Tensile strength, Flexural modulus, and Notched Izod Impact strength; Thermal analysis – Differential Scanning Calorimetry (DSC), Thermomechanical Analysis (TMA), and Thermogravimetric Analysis (TGA); Structural analysis – Atomic force microscopy (AFM), Fourier Transform Infrared spectra (FTIR).

Failures of Plastic Products Due to Not Adequately Replacing of Metals by Plastics

J.L. Spoormaker, Ihor Skrypnyk, Anton Heidweiller, May 2006

Replacing metals by plastics often results in unreliable products. The main failure causes will be presented. As a practical example mechanical and thermal failures of a waste water tank designed for metal and replaced by HDPE will be discussed in detail. The solution to a problem to design snap-fit assemblies on buckling ribs is outlined.

Fracture Behaviour of Injection Moulding Post-Consumer Wood/Plastic Composite Foams

R. Gosselin, B. Riedl, D. Rodrigue, May 2006

This study investigates fibre reinforced microcellular foams produced via injection moulding using recycled polymers. The objective is to determine the effect of wood, blowing agent and coupling agent contents on impact and tensile properties. Birch wood fibres were blended with a post-consumer HDPE/PP matrix to produce the composites. Azodicarbonamide was used as a blowing agent while maleic anhydride polypropylene copolymer was used as a compatibilizer. Optimal results were obtained with 20 wt.% wood contents.

Bio-Fiber Composites from Recycled Polyropylene

Minh-Tan Ton-That, Florence Perrin-Sarazin, Johanne Denault, Kenneth C Cole, May 2006

In this work, natural fiber and wood composites based on neat and recycled polypropylene (PP) were fabricated by melt processing. Different formulations, including various reinforcement contents, different types of coupling agents, different types of reactive additives, and an impact modifier were developed. The reinforcements were in the form of natural fibers like banana, flax, rice husk and palm fibers and of wood sawdust. For the long fiber composite systems, processing was done by compression molding of piles of long fiber mat and extruded polypropylene film. For the short fiber composite, the samples were prepared by extrusion followed by injection molding. The tensile, flexural and impact performance were characterized and all composites show superior mechanical properties when compared with the pristine matrix. Mechanical performance of the wood composites was also evaluated before and after conditioning in water for 1 and 7 days. Results indicate that the composites resist humidity very well. The results also demonstrate the effect of formulations on the performance of the recycled composites.

Interfacial Adhesion in Bamboo Fiber/Biodegradable Polymer Composites

M. Nakamura, K. Kitagawa, H. Okumura, U.S. Ishiaku, M. Kotaki, H. Hamada, May 2006

Surface treatment with natural resin on bamboo fibers is hypothesized to improve the interfacial adhesion between bamboo fibers and biodegradable polymers. Effect of the surface treatment on the interfacial adhesion was investigated by evaluation of mechanical properties and fracture behavior of the composites.

Measurement of Fuel Barrier Properties of Rotational Molded Materials

B.A. Graham, D. Cook, May 2006

Future California Air Resources Board (CARB) and US Environmental Protection Agency (EPA) fuel emission standards will change the rotational molding industry. This study outlines an apparatus and test method useful to screen various materials relative to these new standards. Quantification of permeation rate and the identification of individual permeating components were conducted on actual coupons from rotational molded parts. A correlation to rotomolded tanks is presented with the preferred material candidates being explained.

Mechanical Recycling of Injection-Molded Wood-Thermoplastic Composites

Maja Rujni?-Sokele, Mladen Šercer, Gordana Bari?, May 2006

Wood-thermoplastic composites are usually processed by extrusion, and therefore an attempt has been made to study their suitability for injection molding. The experiments were made to study the behavior of the wood flour-polypropylene composite during injection molding, and to what extent the mechanical properties deteriorate after several processing cycles, i.e. mechanical recycling.

Phenomenon of Gas Fading in Thermoplastic Elastomer in Automotive Interior Applications

J. McCoy, K. MacInnis, A. Montalvo, M.R. Sadeghi, May 2006

Thermoplastic Elastomers (TPE) are suitable materials for automotive interior applications. TPE can be adequately stabilized for protection against extended exposure to UV and heat during compounding, subsequent fabrication, and end use. Under certain environmental conditions, material discoloration can occur. We will explore the nature of this discoloration, and review the current technology to eliminate it.