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.
In the present study, HDPE-fumed silica (FS) composites were prepared by melt-mixing with different filler loading and in presence of PE-g-MA compatibilizer. Dynamic rheological properties and morphological analyses of the composites supported the plausible interfacial interaction between reactive groups of PE-g-MA and surface silanol groups of FS. Oxygen and water vapor permeability of the films made from composites were increased due to presence of FS as well as due to compatibilization.
There are two processes to polymerize polycarbonate in the petrochemical industry: One is interfacial polymerization(interfacial PC) and the other is melt polymerization(melt PC). Recently, the latter is mostly used in that it is eco-friendly process. The most difference of product produced by two systems is the content of specific end-group. It is detected to a little bit value in interfacial polymerization, while it generally has more content in melt polymerization. It is supposed that the more content of the end-group is, the bigger change of the property induce as surrounding environment. In order to analyze an effect of the end-group, polycarbonate substituted to other end-group was made from melt PC using a suitable end-capping agent. And then, several properties were examined like melt index, viscosity and color. As the result, the end-capped PC showed less change of the properties than general melt PC, and it is similar to interfacial PC. It was verified that the properties of melt PC is adversely affected by the specific end-group.
In the last three years the production capacities of biopolymers increased threefold. The current trend in the development of biopolymers is towards bio-based and durable materials, it veers away from biodegradable and compostable materials. As a result of this change and the significant growing market there is a bottleneck regarding the availability of information and technical data of biopolymers. The biopolymer database offers a knowledge platform about biopolymers with producer data and newly measured comparable properties. The presented comprehensive database reflects the market situation and serves as connection between manufacturers, converters and end users.
In contrast to conventional injection molding, where the tool is cooled continuously, in Rapid Temperature Cycle Molding RTC™ the cavity surface is rapidly heated to around the glass transition or melting temperature of the plastic before melt injection. Benefits are summarized and quantitative results cited. These include: achieving fine surface finish and gloss, including for foamed and filled materials (Ra for foamed ABS reduces from 1500 to 30 nm and for LGF PP from 1600 to 150nm); elimination of visible weld line defects; improved transcription of surface micro- features; improved optical properties in clear moldings; reduction of injection pressure, allowing longer flow paths, lower machine tonnage, part thickness reduction with reduced cooling time, and reduced molded-in stress. Implementation of the two leading technologies for implementation of RTC™ are described: heating with steam; or use of external induction heating to rapidly raise the cavity surface temperature, both followed by water cooling. A case study for RTC™ is described, leading to series production of a metalized part for a German automotive OEM. Performance requirements dictated a thin metalized layer (0.2 -0.3?m), formed by physical vapor deposition. This being insufficient to hide weld line defects, and use of a thick primer layer (15 ?m) being unacceptable, raising the cavity surface by RTC™ induction heating was trialed and shown to be entirely successful in removing defects.
Styrenic copolymers such as HIPS and ABS are taking a very important place in the electronic industry. As they burn easily, brominated flame retardants are used to improve their flame retardancy. This paper presents developments with tris(tribromophenyl) triazine showing its contribution to environment protection by lowering carbon foot print and by its non-blooming behavior. Tris(tribromophenyl) triazine flame retardant systems enable reduction or even elimination of antimony trioxide while maintaining a good level of properties.
The extrusion-die is one of the main components in an extrusion line and influences the product quality as well as the whole process efficiency. The requirements on extrusion-dies are versatile and the design of extrusion-dies is a very complex process with the necessity for huge know-how. Therefore the whole design process of a spiral-mandrel-die (SMD) based on a parametric 3D-CAD-mastermodel has been coupled with a 3D-CFD-simulation and implemented into a fully automized process. The flexibility of the extrusion dies to reach a high product quality for different materials is one of six criteria for the automatic interpretation of the extrusion die quality.
During the injection molding of fiber reinforced materials, the molded component's mechanical properties strongly depend on the resulting distribution of the fiber lengths in the component. Owing to various influencing factors in the injection molding process, the fiber lengths are shortened in comparison to the pellet's initial fiber lengths. Within the scope of the experimental investigations, the different influencing factors, especially the influence of the mixing nozzle, were identified and analyzed.
For the production of micro parts with very small shot weights, the micro-injection molding has become an established technology with a variety of concepts. Currently, a trend can be seen that the special procedures will be introduced in the micro-injection molding. The micro injection molding machine , formicaPlast, is prepared for these usual procedures. It does not matter if the micro parts have to be produced as an one component or a two component part, the technology os available to serve the indsutry needs for a high automised micro injection molding process.Furthermore, the powder injection molding and the silicone injection molding is already possible to turn a standard formicaPlast machine. The liquid silicone injection molding requires certain changes to the machine, but these are very limited. The following article presents the possibilities of liquid silicone injection molding production for various tasks and batch sizes of the formicaPlast.
The aim of this work was to improve the dosability of sisal fibers by coating sisal yarns with a film former prior to cutting, to yield dosable fiber bundles, which can be processed with standard plastics processing equipment and to evaluate the effectiveness of such fibers in a thermoplastic matrix. We found, that it is possible to produce such fiber bundles, which are properly dosable and yielded good properties in polypropylene matrix composites, although there is room for improvement via the selection of a film former, which is more compatible with the matrix.
Traditional composite based micro-mechanics can be used to predict linear elastic properties for thermoset matrix system accounting for the effects of filler type, concentration and size. The focus of this paper is to understand the effect of rigid fillers on the constitutive properties of a fully cured epoxy thermoset polymer covering non- linear regime including failure. A methodology, using a combination of DIGIMAT and ABAQUS based FE-modeling was developed to fully capture the stress-strain behavior using a Leonov -based material model.
This paper focuses on the synthesis and morphological characterization of carbon nanostructures obtained from the decomposition of residual solids waste tire (RSWT) in quartz tubes under reduced pressure (1.33 Pa) at 900 °C for 15 minutes. The synthesis exhibits, principally the formation of two phases: the first a fragmented solid black powder constituted by multi-walled carbon nanotubes (MWCNTs), onion-type fullerenes and spheres, the second a very bright metallic dark film. Analysis by microscopy (SEM and TEM) showed that the MWCNTs had an average diameter of approximately 25 nm and a length greater than 100 nm while the diameter of onion-type fullerenes was found to be 8 nm. The nanospheres showed different diameters, from 500 nm to 1.5 ?m and some have a metallic core surrounded by layers of carbon. The infrared spectra of the nanotubes exhibited absorption bands at 1631 and 1458 cm-1, corresponding to the double C=C and C-C bonds, and signals at 3438 and 1080 cm-1 that are related to the OH and C-O groups from oxidized graphite as it was identified in the dark film.
Differential scanning calorimetry (DSC), x-ray diffraction, dynamic mechanical analysis (DMA) and electrical conductivity measurements were performed on multiwalled carbon nanotube/polyamide 6,6 composites with three different types of well-characterized tubes manufactured using fixed-bed catalytic processes. The tubes differed in diameter, number of walls and surface chemistry. There were not large differences in behavior with respect to modulus, maximum electrical conductivity and percolation threshold.
The goal of this paper and presentation is to give an overview of the research effort to date being conducted at the National Institute of Standards and Technology on polymeric fibers used in soft body armor (SBA) and a discussion of future directions. The overview covers chemical and mechanical fiber testing, microscopy, and x-ray scattering as means to understand potential mechanisms of degradation in these materials. Tensile testing results at quasi-static and at high strain rates that are comparable to strain rates experienced during ballistic events are also presented.
This study examined the crystallization behaviour of polyamide 6 from post-industrial carpet waste (PIW6-GF) and virgin polyamide 6 (PA6-GF) - both reinforced with 30 wt% glass fibers. Neutron activation analysis was used to detect the presence of contaminants – principally TiO2, a common pigment in carpet fibers. Once the Ti content in the glass fibers was accounted for, the TiO2 contents in the resin fraction of PIW6-GF and PA6-GF were estimated to be 0.14% and 0% respectively. Differential scanning calorimetery (DSC) was performed to assess the overall level of crystallinity and rate of crystallization. Experiments showed that, regardless of the cooling rate, PIW6-GF started to crystallize sooner and at higher crystallization temperatures than PA6-GF. This was attributed to the presence of TiO2 acting as a nucleating agent. Towards the end of the crystallization process, the rate of crystallization for PIW6-GF was observed to slow down relative to PA6-GF. At the highest cooling rates attainable in the DSC (200 °C/min), PA6-GF completed crystallization before that of the PIW6-GF compound. This reduction in crystallization rate is again attributed to the nano-scale TiO2 that could be interfering with the later stages of the crystallization process. The total crystallinity of moulded parts was observed to be greater for PA6-GF than PIW6- GF. Dynamic mechanical thermal analysis (DMTA) was performed on both materials one minute after ejection from a 30°C injection mould. This allowed the capture of rigidity data during the cooling of the specimen at a constant temperature of 25°C. PIW6-GF parts exhibited significantly lower complex moduli during the 30 minutes after moulding. Interestingly, modulus values at 25°C of both materials measured one week after the moulding were equal. The slightly lower crystallinity and the slower rate of crystallization are the suspected causes of this stiffness difference.
In this article, numerical modeling is used to simulate the distribution of liquid diffusion in bioplastic material and to determine the hygroscopic stress. The material used is homogeneous PLA based plastic exposed to aggressive automotive liquid. An analytical one-dimensional liquid diffusion solution is also presented to consider liquid concentration distribution, which shows a remarkable agreement with numerical simulation results. The results display non-mechanical stress distribution inside the homogenous material due to non-uniform liquid concentration profile.
Electrospinning is a simple and versatile technique to produce fibers. This is accomplished by using an electrostatically driven polymer jet, which thins as it whips towards a grounded target. The micronsized fibers produced from electrospinning are typically collected in the form of a random mat. The size and disordered structure greatly limit their application for areas that require well aligned, highly ordered arrangements such as tissue growth, protective clothing, highly effective thermal insulation and filters for fine particles and reinforcing fillers. Process parameters were studied as a function of percent aligned fibers while microscopy was used to characterize fiber orientation.
Nowadays, with the increasing variety, complexity, and dimensional accuracy required for plastic products, CAE tools have been widely used in solving product design and manufacturing issues. However, lacking the consideration of process-induced effects on material properties in analysis, there is a significant deviation between the structural analysis results and the real product deformation. Besides, during the injection molding process performed for the production, it is essential to understand how the high pressure and high temperature plastic melt affects the mold surface for further investigation of the life cycle of metal mold. In this paper, we have proposed the simulation technology using Moldex3D-FEA interface to connect injection molding simulation (Moldex3D) and structural analysis (ANSYS). Using this technology, we can predict the injection molding product life cycle to cover injection molding process-induced variation on the part. At the same time, we also can evaluate how the process-induced effects will influence the mold metal life cycle. The results are very important for people to make the comprehensive consideration for full system lifecycle management.
Most commercial intumescent materials consist of hydrated ceramic compounds in a polymer matrix that expand due to water vaporization when heated above 100°C. There are many applications that could benefit from intumescent, fire suppressant/protection materials where the system operating temperatures exceed 100 °C (e.g., aircraft applications, power generation facilities, chemical and materials processing facilities, etc.). To meet this need, a high-temperature intumescent material was developed that will only intumesce when local temperatures exceed 200°C. Once the initiation temperature is reached, the high-temperature intumescent material rapidly expands to approximately 10 times its original thickness, creating a physical barrier that is robust enough to block the spread of fire.
Heat sealed plastic bags are widely used in food packages, vacuum-seal, and so on. It is very important to understand about heat sealing properties of these packages to confirm the reliability for using with their products. This research studied the heat sealed properties and peelability of heat sealed poly(ethylene terephthalate) (PET) and oriented polypropylene (OPP) films with low- temperature seal layer (adhesion layer). The peel strength and fracture surface of heat sealed PET-based films and OPP-based films were investigated by using peel testing and SEM. The sensitivity for peelable of heat sealed package was investigated by brain wave measurement.
Supercritical carbon dioxide was used with melt blending to form nanocomposites of polypropylene-organoclay. The collapse of the clays is investigated to further understand the processing limitations at high clay content. TEM and WAXD are provided to investigate these effects. It was found that shear forces result in collapse of the exfoliated structure in the composite. However, if the melt is not subject to enough processing, dispersion suffers. An intermediate solution must be determined.
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ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
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