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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Various topics related to sustainability in plastics, including bio-related, environmental issues, green, recycling, renewal, re-use and sustainability.
The Effect of Reprocessing on Mechanical Properties of Polypropylene
Polypropylene (PP) was injection molded up to 20 runs to study the effect of recycling procedures. The influence of the recycling was studied by observing changes in melt viscosity, tensile and impact resistance properties. The main effect of recycling was decrease in melt viscosity, which is attributed to molecular weight reduction. The observed degradation processes only slightly affected the small strain properties of the materials studied. However, break properties were affected apparently. All the tensile properties related to breaking as well as impact resistance of recycled polypropylene decreased with recycling.
The Effects of Matrix Type and P Roperties upon the Tensile Properties and Notch Sensitivity of Recycled Jute Mat Reinforced Polymerica Matrix Composites
The main objective of this research is to study the effects of matrix type and properties on the tensile properties and notch sensitivity of recycled jute mat reinforced polymeric matrix composites. A single recycled jute fiber mat was used as a natural fiber reinforcement system for three kinds of composites made from three types of resins. The three thermoset resins which were used as matrix for these composites are vinyl ester and two types of unsaturated polyester, low and high tensile strength resins. Three types of jute composites having the same fiber weight content were fabricated by the modified hand lay-up method with pre-impregnation stage in vacuum; we developed this method to solve the problem of the poor impregnation in the thick fiber mats using the normal hand lay-up method. This modification showed in this research as well as our previous research a better impregnation of resin throughout the jute mats and lower voids contents in the composites. Tensile tests have been performed on smooth specimens to evaluate the effect of matrix type and properties on the mechanical properties for the all considered composites. Also, tensile tests have been carried out on notched specimens with different center-hole diameters and having similarly geometrical diameter/width ratio to evaluate the notch sensitivity for each composite. All considered jute mat composites exhibited a higher tensile modulus than that of their neat resins. Although the higher tensile strength of the neat unsaturated polyester resin than that of the neat vinyl ester resin, the jute composites with vinyl ester matrix showed a higher tensile strength by 74% and 55% than that of both composites with unsaturated polyester matrix. In comparison with jute composites with high strength unsaturated polyester matrix, the jute composites with vinyl ester matrix showed a higher tensile modulus and strength by 13% and 55%, respectively. The two jute composites with unsaturated polyester matrix showed
The Feasibility of Using Lignin as Additive and Colorant in Polypropylene
The history of using agricultural base additive and colorant in polymer goes back to the time prior to the introduction of synthetic polymer and plastics materials. The extraction of lignin and the use of lignin in production of natural adhesives can be traced back to the ancient time of Roman, Persian and Egyptian Empire. The human exposures to these materials have proven to have minimal health consequences and minimal precautions. The lignin, as a byproduct of agriculture and paper industry, has a potential of offering a viable natural and sustainable resources as additive and colorant in plastics industry. The application of lignin as a color has a potential of minimizing the use of heavy base colorant to prevent environmental contaminations as well as offering a sustainable, worldwide available and accessible bio-mass. The intention of this investigation has been to study the process-ability, the ease of production as well as the quality of products as a function of the lignin grade and processing technique, and parameters for polypropylene mixed with different amount of lignin.
The Study on the Cell Size and Cell Density Distribution in Microcellular Injection Process with Dynamic Mold Temperature Control Assistance Technology
MuCell® (Microcellular injection molding) is a well-known green molding technology, but the surface defects are the common limitation for its application. Nowadays, the cosmetic drawback of MuCell® process could be resolved via high mold surface temperature and gas counter pressure control. The purpose of this study is to realize the correlation of cell size and density between microcellular injection molding in different mold temperature and composite mold inserts (M333, QC-10 and M333 combination, and QC-10). The numerical approach was also discussed with Moldex3D. In the experimental results of rapid cooling between three kinds of mold-insert design, the QC-10 insert has the best cooling efficiency to achieve 10 °C/sec. When the initial mold temperature was set at 120 °C, the average cell size can also be reduced from 192.92?m, 123.95?m, and 84.97?m, with the cooling rate 1.1°C/sec, 5.1°C/sec, and 10.9°C/sec individually. The DMTC (dynamic mold temperature control) was proved that it not only improves surface quality of product but controls the cell quality in microcellular injection molding effectively.
Thermoforming of Biodegradable Sheets Obtained from a Thermoplastic Starch and Polylactic Acid Blend
This paper describes the blending and the thermoforming performance of a thermoplastic starch (TPS) and polylactic acid (PLA) compound. A twin screw extruder (TSE) was used for corn starch plasticizing and blending with the plasticized PLA. A single screw extruder was used to melt, functionalize and feed the plasticized PLA into the TSE. Extruded pellets were used to make sheets through extrusion calendering, which were ultimately thermoformed in a parallelepiped shape. Thermoformability of the sheets was evaluated by the area ratio, the maximum uniaxial deformation, and the thickness measurement in the machine direction (MD) and transversal direction (TD). The operating window was defined using DMA techniques. The compound showed good thermoformability characteristics.
Thermoplastic Starch: The Prepation Method
This work presents a systematic study about thermoplastic starches. Corn starch was mixed with 2 and 4 wt.% of carboxylic acid and 20 to 30 wt.% of water. The samples were prepared in an internal mixer coupled to a torque rheometer, and the torque values were monitored during mixing. The specimens for mechanical tests were calendered and cut with a knife. The mixtures were characterized by mechanical testing (tensile strength), scanning electron microscopy, and thermal analysis. The torque curves indicated that the samples with and without adipic acid addition suffer retrogradation. When the water content is increased, the glass transition temperature values decrease because water acts as a plasticizer for starch. The mechanical test results showed that samples with 2 wt.% acid content present the highest values of elastic modulus and tensile strength, and the lowest values of elongation at rupture.
Thickness Measurement Methods Aiding Lightweighting of PET Bottles
The aim of lightweighting PET bottles is to reduce waste in material use by optimizing the design and manufacture process. Efficient lightweighting development requires adapting robust techniques for thickness measurements. Knowledge of the final thickness distribution at different locations of the bottle is essential for identifying critical locations that could be modified in the preform or mold. X-ray tomography, IR-based thickness measurements, and Hall Effect techniques have been demonstrated as nondestructive tools for thickness measurement. Some methods are slow or expensive. Here, a low cost method for thickness measurement of PET bottles based on cross section measurement also was demonstrated using an optical scanner.
Trends in Failure of Synthetic Polymers and Human Biopolymers
Some trends in failure are due to errors of design or bad judgment (plastics) or unwise life conditions (human biopolymers). An encouraging trend for human biopolymers is synthetic polymers designed as replacements for damaged biopolymers (electrical polymers for nerves, and targeted drug delivery). Environmental, recycling and health effects on failure are a strong recent trend in polymer failure. Examples are bisphenol A (BPA) and phthalate plasticizers, both limited by bans for health reasons. PVC is also attacked for health reasons. Even if a plastic is very worthy, inexpensive and was accepted for years, it may be considered for banning (PE thin bags).
Using Zemac® Copolymers to Upgrade Virgin Nylon Performance
Nylon is widely used in many applications. At the 2013 ANTEC, our paper covered the results obtained with compounding primarily recycled nylon with the addition of small quantities of alternating copolymers of ethylene and maleic anhydride and specific property improvements for applications in injection molded compounds. The resulting compounds have performance that can match or exceed prime virgin nylon at 30-50% cost savings. This current paper will cover the unique chemistry of alternating copolymers of ethylene and maleic anhydride to provide several advantages for upgrading prime or virgin nylon. For example, this paper will cover results of increasing relative viscosity and the advantages that brings to various applications. Another set of results will cover the unique improvements obtained in impact-modified nylon-6 and nylon-6,6 by reducing the negative impact of traditional impact modifiers by offering synergistic set of properties.
Why You Should Consider a Contour Printed Package
Contour Print aka distortion printing or preprint is nothing new to the thermoforming industry. We believe every innovative thermoformer has tried registering print at one time or another. What’s different about Contour Print is how it came about and why we think it will become a preferred package for brands, consumers and recyclers. Contour print was developed after attending PackEx, Sustainability/LCA, Product Design & other packaging conferences. Contour print takes into consideration the needs of all parties involved in consumer packaging: brand owners, retailers, consumers, recyclers and converters. By taking prominent recycled material like RPET, standard roll fed thermoforming equipment and adding the distorted printing you get a consumer friendly pack that’s easy to recycle. With public concerns for recycling and consumer confusion, using one material for the entire package greatly reduces this problem. Contour Print also reduces weight by replacing flat printed components with printing that is applied directly to the formed plastic package.
High-performance compostable polymer biocomposites
Blending modified polylactic acid with hemp or jute fibers using hot melt extrusion improves its mechanical properties and compostability.
SPE Bioplastic and Renewable Technologies Division Summer 2014 Newsletter
Read the latest issue of the SPE Bioplastic and Renewable Technologies Division newsletter.
Antibiotic wound dressings
Incorporating ampicillin into electrospun polyurethane makes bandages that control common infections.
Enhanced cold crystallization of glassy poly(L-lactic acid)
Glassy PLA samples prepared by rapid compression possess lower onset crystallization temperature, higher crystallization rate, and larger final crystallinity than samples prepared by other methods.
Bioplasticized poly(vinyl chloride)
Treatment with epoxidized soybean oil and bis(2-ethylhexyl) succinate for wire and cable applications softens the polymer but preserves tensile elongation properties after heat aging.
Enhancing properties and value of recycled plastics
Adding graphene nanoflakes to recycled high-density polyethylene drastically improves its performance.
Post-industrial waste nylon for automotive applications
Although slightly lower in tensile and fatigue strength, glass-fiber-reinforced waste nylon can be a viable substitute for reinforced prime nylon in cyclically loaded under-hood automotive applications.
Biopolyesters filled with date seed powder
Using date seed powder to reinforce the biodegradable polyesters poly-L-lactide and poly(butylene adipate-co-terephthalate) improves their properties.
Green technology for modification of poly(vinyl chloride)
Biodegradable poly(hydroxybutyrate) copolymers plasticize, toughen, improve processing, and reduce UV discoloration.
New biodegradable composites for food packaging
Beer spent grain fibers are a biodegradable waste resource that forms breathable thin films by conventional extrusion film blowing under processing conditions scalable to industrial production.
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