SPE Library

This paper examines the recycling of sorted plastic offcuts produced during the manufacture of continuous carbon-fiber-reinforced polyamide 66 sheets. The idea is to process the offcuts so that they can be conveyed to a value adding application. For this study, the offcut is shredded into recyclate and processed by injection molding to produce specimens. The processing properties of the recyclate and the mechanical properties of the specimens are at the focus of the investigations. Good processability of the recyclate is achieved in the tests by using a stuffing device in the hopper of the injection molding machine. With optimum injection molding parameters, an outstanding tensile strength of 293 MPa is obtained in the tests.

Synergistic green composites of polypropylene (PP) with cardboard and waste paper are produced via solid-state shear pulverization (SSSP) without any compatibilizers or surface modification. The property enhancements are comparable to those from more expensive forms of cellulose. Additionally, optimization of SSSP processing, commercial viability and melt processability of the composites are evaluated.

PHBV (Poly (3-hydroxybutyrate-co-3-hydroxyvalerate)) is a bio-derived semi-crystalline polymer of interest to the packaging industry looking for alternatives to the petroleum based materials currently used. The brittle nature of PHBV material requires blending with other polymers such as Poly (?-caprolactone) (PCL), Poly (L-lactic acid) (PLA), and natural rubber. Natural rubbers (NR), cis-1,4-polyisoprene, are classified as elastomers due to their high elasticity and yield strength. Therefore, the objective of this study was to characterize the thermal and mechanical properties of PHBV blended with natural rubber in two different concentrations.

Today everyone is concerned about Sustainability - protecting today's environment for future generation. Sustainability has become major initiative by all companies. Consumers want sustainable/ Green packaging but most of them do not want to pay more for Green Packaging. Consumers & Customers want 'Cost-effective Sustainable' Packaging”. It's responsibility of everyone in supply chain to work together to meet demands of their consumers and customers.

Interest in alternatives to electroplated chrome is expanding dramatically. Color and appearance affects are limited with traditional chrome electroplating and successful “paint-on-chrome” applications are expensive and highly proprietary. Collectively the automotive, home appliance and cosmetic market are actively searching for alternatives with the appearance and durability of electroplating, but without the environmental side effects, appearance and functional design limitations, and costs associated with this decades old process. “Chrome look” processes and coatings for decorative and automotive lighting PVD applications have been used in the UV curable coating industry for over twenty years. As development of UV curable coatings for PVD has progressed, so has the understanding of the process and its unique capabilities and applications. This paper will address the advantages of PVD as a chrome alternative to include functional / design capabilities that are either cost prohibitive, or impossible to achieve with electroplated applications, as well as describe some of the tradeoffs associated when using coatings systems as an alternative for chrome electroplating.

New wear resistance (WR) thermoplastic co-polyester elastomers (COPE) deliver improved performance over a wide range of speed and load conditions in sliding or moving applications. These elastomers have excellent cold temperature impact strength and work well at a broad range of temperature and humidity conditions, primarily in injection molded articles. Various grades with wide range of hardness are suitable for applications requiring excellent tribological properties. These elastomers provide outstanding ductility combined with the excellent chemical and environmental resistance properties of polyesters. The unreinforced and higher flexibility COPE grades fill the property gap between standard thermoplastic polyester urethanes and vulcanized rubbers by providing excellent fatigue strength and hence an increased operational lifetime. These elastomers are easy to process, recyclable and retain their impact strength down to -30 °C.

The use of polyolefins in pipe applications has global acceptance. As such, polyolefin based pipes are expected to maintain their properties over an extremely long service life where the polymer must withstand climatic, extractive and mechanical forces. The success of polyolefin pipes has been enabled by the development of suitable resins with a defined molecular architecture plus stabilization systems which have enabled the protection of the polymer during both melt processing and the end use application. Through the proper development of the stabilizer systems for this challenging application it is possible to protect the polymer and also extend the service life of the pipe under various environmental factors.

Poly(lactic acid) (PLA) was reactively modified by using a multifunctional co-agent (triallyl trimesate) in the presence of dicumyl peroxide. The viscosity, elasticity and melt strength of PLA increased substantially following reactive compounding. Furthermore, the rate of crystallization of co-agent in modified PLA was significantly higher than that of the pristine PLA and a distinct crystallization peak appeared. Reactively modified blends of PLA with an elastomeric polyhydroxyoctanoate exhibited similar features, and significant improvements in blend morphology.

Biodegradable poly(lactic acid) (PLA) blend with other materials is widely demanded as an effective approach for preparation of porous materials. In the present wok, two phases blends of PLA and polystyrene (PS) were prepared by twin-screw extruder and Torque Rheometer. For the latter blending method, the effects of various conditions such as blends mass and the temperature of mixing chamber on phase morphology were explored. A bimodal distribution of porous structure was presented after extracting the PS phase from the samples prepared by two different blending methods. Different with Torque Rheometer, the blends of twinscrew extruder rarely appears reunion phenomenon; therefore, a better phase morphology can be expected. It further found that the phase morphology of blends was apparently optimized under proper post annealing conditions.

For over one hundred years, components made of elastomers have been commonly used in practice. However, the knowledge concerning the aging behavior of the material lags behind the existing demands of modern day industries. The property spectrum of elastomeric components extends across a broad range. Areas of application for such materials include aerospace, automotive, and mechanical engineering, plant construction, shipbuilding and civil engineering sectors. When considering the moldability, workability, flexibility and adhesion of elastomers, it is unsurprising that these materials are employed in so many industries. Yet, despite their application in numerous fields, only limited amounts of research has been carried out concerning these materials, and hardly exceeds basic examinations. Hence, intensive studies are necessary in this area. Previous research has already verified that the mechanical properties of elastomers change over time. These scientific findings make intensified research regarding the long-term behavior of elastomers indispensable. Chemical aging studies are highly significant, because the molecular structure and the networking of the material change during the aging process. Due to these changes, various material properties may also alter. In order to be able to make more accurate predictions concerning the life span and durability of elastomeric components, all environmental influences must be intensively researched experimentally. Basic research in the field of chemical aging is essential. In this paper, the aging behavior of natural rubber was tested using the media air, distilled water, and 3%- and 6% de-icing salt solutions.

The rotomolding industry commonly uses two connected tests to assess the quality of plastic powders: Dry Flow and Bulk Density. Industry-specific test methods are available for both parameters. Repeated measurements were carried out on five different rotomolding powders, in order to assess the influence of the various equipment and environmental parameters that are thought to affect the test. This enabled estimates to be made of the limits for the accuracy and repeatability that are achievable practically. The results obtained from the Dry Flow test suffer from significantly higher variance than those obtained from the Bulk Density test.

This research was carried out to improve mechanical properties of PBS by melt blending with recycled PET flakes from drinking bottles. Content of PET adding was 1, 2 and 5% by weight. Properties of polymer blends were evaluated by tensile test, impact test, SEM, DSC, and TGA. It is found that blending PET into PBS yielded stronger mechanical properties compared to neat PBS. However, melt blending between them required high temperature enough to melt PET flakes, so it caused thermal scission in PBS molecules as evidenced in TGA analysis. PBS/PET blends had higher tensile modulus but reduced flexibility with higher PET content. For DSC analysis, it is found that blending PBS with PET increased crystallinity of PBS matrix due to nucleating effect of PET dispersed spheres.

In this paper, the foaming behavior and thermal property of biodegradable poly(butylene succinate) (PBS)/nanosized calcium carbonate(nanoCaCO3) composites were investigated. This article focused on the study of the effect of nanoCaCO3 on foam morphology of PBS using supercritical CO2 as the foaming agent. The presence of nanoCaCO3 acted as nucleation site to facilitate the crystallization of PBS that results in the increase of PBS crystallization up to 63.63%. The effect of incorporation of the nanoCaCO3 particles on the thermal stability was quantified by the temperature at 5% and 10% weight loss. Along with the addition of nanoCaCO3, the temperatures at 5% and 10% weight loss of PBS/nanoCaCO3 composites are higher than pure PBS. The SEM results shows that with the addition of nanoCaCO3, the foam samples cell size decreased and cell density increased greatly.

Due to environmental and sustainability issues, the request for renewable resources increases. Natural fiber-reinforced injection molded materials are therefore an interesting prospect for the automotive industry. To achieve a broader market launch of this new material in the automotive industry, numerical simulation of this new material is essential. Besides rheological and mechanical properties, the fiber morphology and the fiber orientation are the most important properties for the simulation. To evaluate the simulation results experiments are necessary. The morphology of natural fibers (sisal, hemp and regenerated cellulose fibers) was determined by image analysis of the original fibers and the fibers after the procedures of compounding and injection molding. Therefore the fibers were extracted from the granules and the injection molded components. The size of the fibers was significantly reduced during the compounding process, whereas no further reduction could be observed during the injection molding process. Quantitatively, the same results could be found in simulation based on a mechanistic model. Fiber orientation measurements were done via TeraHertz Spectroscopy to evaluate the simulation of the injection molding process and to be able to predict the mechanical properties of the components.

The effects of silica chemistry and high-speed compounding on the morphology and rheology of poly(butylene succinate) (PBS)/fumed silica nanocomposites were investigated in this work. The filler content of the nanocomposites was determined by thermogravimetric analysis and matched estimated values well. Depending on the distribution and surface chemistry of fillers, distinct surface texture could be identified in the PBS/silica nanocomposites. Using high-speed mixing and compatibilizing surface functionalizations can result in enhanced polymer-particle interactions and influence the composite rheology dramatically. The relaxation hierarchy can be identified from the linear viscoelastic response of PBS compounded with mixture of modified and pure fumed silica particles.

This paper investigates the foaming behaviors of polylactic acid (PLA)/cellulose nanofiber composites and the mechanical properties of the composites and their foams. The composites were fabricated by mixing PLA and nanofibers in a solvent with different fiber contents, followed by drying and hot pressing into test specimens. The composites were then foamed via a batch foaming process with CO2 as a blowing agent at different foaming conditions. The effect of nanofiber content on the cell morphology of PLA was studied. The impact strength and thermo-mechanical properties of PLA composites and their foams were also investigated.

Poly(lactic acid) (PLA) is one of the most promising biodegradable aliphatic polyesters derived from renewable resources and has received significant attention over the last decade. The blending of PLA with poly(butylene adipate-co-terephthalate) (PBAT) and poly(butylene succinate) (PBS) is employed to overcome its inherent drawbacks. All prepared fully biodegradable blends show a thermodynamically stable complete wetting behavior which was in good agreement with the thermodynamic analysis. The results for the ternary blends demonstrate a viable route towards the achievement of biodegradable polymers systems with a highly balanced property set.

Injection molding simulation of natural fiber thermoplastic composites NFTC requires material full characterization of the following parameter: density, thermal expansion, viscosity, (Pressure- Volume- Temperature) PVT-behavior, thermal conductivity, thermal degradation, polymer structure, specific heat and dynamic mechanical properties. The effect of fiber type (regenerated cellulose, sisal, hemp, wood fiber, wheat straw and kenaf), fiber content (10 and 30 wt.-%) and fiber length (0.5 and 1.5 mm for cellulose) on the mentioned material parameter as well as on their processing behavior during injection in a spiral mold was characterized. Compound viscosity and fiber type/ size were correlated. Other auxiliary results are found in this study concerning the constancy of fiber content along the injected products and the pore formation due to the inevitable gas evolution from the natural fibers.

Historically phthalates have been used as plasticizers in PVC to provide flexibility over a wide temperature range. In applications where higher flame retardancy is needed along with flexibility, brominated phthalates have been used to meet the requirements. DynaSil™ is a novel flame retardant synergist that has properties of flexibilizing PVC while allowing for the replacement for antimony trioxide (ATO), brominated phthalate plasticizer, and/or ammonium octamolybdate (AOM) in PVC formulations. The results show that by using the DynaSil™, brominated phthalates, ATO and AOM can be replaced without loss of flame retardant properties, sacrificing flexibility, and negatively affecting smoke properties. In addition, DynaSil™ can preserve or improve performance properties such as tensile and elongation while providing a very eco-friendly solution at reduced costs.

The American market for recycled plastic offers both enormous economic potential and strategic challenges. Especially in light of the domestic shale oil boom, recyclers must find ways to maintain competitive advantage in the market. Tackling increasingly contaminated, wet and hard-to-process materials offers a path to this end. Co-rotating twin screw extruders are well suited for accepting plastic regrind of different shapes, bulk densities and contamination levels. Energy extensive drying steps after the washing process can be eliminated, when steam and moisture is removed in special venting barrels. In this paper, process experiences with a novel continuous melt filter are presented, which offers superior processing and flexibility for recyclers to capture untapped value. The functionality and processing potential of this filter in combination with the twin screw extruder is explained by using examples from the post- industrial recycling market, the automotive recycling effort and as well as the post-consumer recycling sources.