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.
Bisphenol A is a key component of many epoxy resins, but is under pressure especially in food contact applications, necessitating the identification of high performance alternatives. In this work we report on the preparation, properties and performance of one such alternative, the bis(epoxide) of 2,2,4,4-tetramethyl-1,3-cyclobutanediol. This resin has been crosslinked with a typical amine hardener to produce a stiff, hard thermoset with a high Tg. Curing behavior and cured resin properties are improved vs. the bis(epoxide) of cyclohexanedimethanol, a structural isomer of CBDO. Compared to a BPAbased equivalent, resin viscosity and UV cutoff are lower and lap shear adhesion to mild steel is superior, the latter on par with a commercial heavy duty epoxy adhesive. These results indicate promise from this material as a high-performance BPA-free epoxy resin.
This paper investigates the effect of fiber type and fiber content on the foaming behaviors of cellulose fiber reinforced polylactic acid composites. Two types of cellulosic fibers with different sizes were used: micro- and nano-sized fibers. The composites were prepared by a film casting and hot pressing method and then foamed via a batch foaming process with CO2. The morphology and volume expansion ratio of the samples with different cellulose fiber contents were compared. The results suggested that micro-sized fibers had negative effects on the foam morphology and nano-sized fiber positively influenced the foam morphology. It is speculated that the crystals generated around the fibers affected the cell morphology significantly.
Polyphenylene Ether (PPE) is an engineering thermoplastic resin usually blended with polystyrene (PS) [crystal polystyrene (CCPS) and or High Impact Polystyrene (HIPS)] to improve properties including the processability. The overall performance of the resulting Noryl™ resin is highly dependent on the quality of the PS. This study presents some of the challenges involved in qualifying open loop PCR PS and key factors that could have affected their performance due to the recycle history and contaminations of the raw material compared to the virgin PS. PCR HIPS properties were simulated by recycling & spiking virgin HIPS with the contaminations.
In this study, the effect of polycarbonate oligomer (PC-O) addition on weld properties of injection molded polycarbonate (PC) and PBT alloy material was investigated. As a result of morphology observation around weld line, the size of PBT domains became smaller with an increase of PC-O and those were quite stretched when those are close to V notch. Charpy impact strength and V notch roughness were also improved when an addition of PC-O was increased. These results suggest that PC-O contributes to both flowability increase and compatibility of PC and PBT.
Multi-gate injection is often used to meet the demand of mass production of injection moldings, therefore weld line is inevitable. Weld line can not only affect the appearance quality but also reduce the mechanical property of injection molding productions and many researches focus on the improvement of weld line property. In this research, the effect of weld line and scratch on the mechanical property of PP and PC plates was investigated based on the drop impact test and SEM observation. For PP specimens, maximum load of weld specimens and scratch specimens decreased by 40% and 77% than that of non-weld specimens. The total energy of weld specimens and scratch specimens decreases by 68.9% and 75.0% than that of non-weld specimens. It indicated that there is significant effect of weld line and scratch on the drop impact property. For PC specimens, all the non- weld, weld and scratch specimen were not penetrated and the energy at maximum load is almost same. It reveals that there is no significant effect of weld line and scratch on the impact property of PC specimens.
The aim of this study was to optimize the long carbon fiber thermoplastics process. First of all, to increase interaction between carbon fiber and polypropylene matrix polymers, maleic anhydride grafted polypropylene was used according to different graft ratio. The composites were prepared by long fiber thermoplastic (LFT) system by Honam petrochemical Corp. Tensile, Flexural test and scanning electron microscopy (SEM) were performed to characterize the physical and morphological properties of the prepared composites. The tensile and flexural strength value of Polypropylene (PP)-long carbon fiber thermoplastic (LCFT) with PP-g-MA were higher compared to the values of carbon fiber reinforced PP composites. It was observed from SEM images that the addition of PP-g-MA in process improved the interfacial adhesion between the carbon fibers and PP matrix. Impregnation system was also optimized for improvement of wettability between carbon fiber and matrix polymer. Spreader pins which spread the fiber bundle were introduced in impregnation die and the optimum number of pin was investigated for prevent fiber damage.
The poly (lactic acid) (PLA) based biocomposite reinforced with different natural reinforcement consisting of bamboo fiber, vetiver grass fiber, coconut fiber, silk fiber and bamboo charcoal powder were prepared and the mechanical properties were tested. To enhance the adhesion between reinforcement and PLA matrix, the flexible epoxy resin was selected and used as a novel surface treatment for natural reinforcement. It was found that the stiffness of untreated biocomposites increased significantly. However, the mechanical strengths such as tensile, flexural and Izod impact strength of composites decreased with increasing of reinforcement content. The flexible epoxy surface treatment reduced the stiffness of all composites while it increased considerably the tensile, flexural and impact strength when comparing with the untreated composites. However, it can be seen that the effects of flexible epoxy treated on the mechanical strengths improvement are dependent on the type of reinforcement. There are two interfaces consisting of interface between reinforcement and flexible epoxy resin and interface between flexible epoxy resin and PLA matrix, which resulted in the different fracture mechanism.
In this paper, the tensile strength of hybrid polypropylene composites reinforced with glass fiber and jute fiber has been studied. The specimens have been fabricated by injection molding with different jute fiber hybrid content. The tensile strength of hybrid composite was predicted by using a modified rule of hybrid mixture (MRoHM) strength equation based on the orientation direction of reinforcing fiber. The fiber orientation was determined from the fracture surface observation method. Experimentally, the tensile strength of hybrid composite was lower than the monotonic glass fiber/PP composite. Moreover, the further increase of jute fiber content has no influence on the tensile strength of hybrid composites. However, the predicted strength of hybrid composites decreases with increasing of jute fiber content. The reduction of predicted strength is contributed to the effect of reduction of glass fiber length and increment of 90 degree orientation of jute fiber. It was interest to note that the tensile strength of hybrid composites was higher than that predicted by the modified rule of hybrid mixture, showing a positive hybrid effect between glass fiber and jute fiber.
Coating thickness variation along the transverse direction is a crucial defect in micro gravure roll to roll coating process to manufacture hard coated plastic film. This variation takes place mainly due to the applied tension to substrate and the solvent evaporation during the drying process. In this study, the effect of drying conditions on the coating thickness variation was investigated. It was found that slow drying rate resulted in the lowering of thickness variation. Drying temperature and roll speed (web speed) are main processing parameters to control the drying rate. In addition, the characteristics of coating solution such as solvent, solid content and molecular weight also affected the drying rate in micro gravure roll to roll coating process.
The Noryl™ resin compositions discussed in this paper are prepared using polyphenylene ether and post-consumer recycled (PCR) polystyrene (PS). The use of PCR in these environmentally progressive Noryl™ resin products may reduce plastic waste diverted to landfill, thereby lowering carbon footprint and energy conservation when compared to virgin Noryl™ resins. A comparison of properties of Noryl™ resins comprising PCR PS versus virgin Noryl™ resins will be presented in this paper. Life cycle assessment work is in progress and will also be presented during conference.
Sulfur extended Polyvinyl Acetate co-polymers (SEPC) were prepared in a melt blender at 100 rpm for different times and temperatures, and mixed with asphalt in pug-mil to improve its quality for road maintenance applications. The amounts of SEPC in asphalt vary according to the properties of asphalt used. SEPC was mixed with asphalt at 4-6% by weight. The SEPC blended asphalt was mixed with asphalt concrete in Marshall mix at 140°C using different ratios to produce polymer modified asphalt concrete mix (PMACM). The resulted PMACM was studied by means of stability, stability loss, performance grade )PG(, rutting resistance, fatigue resistant and the results showed improvements in the properties. The results are within the acceptable limits and comparable to the results obtained for other commercial polymers such as polybilt. The presence of chemically bonded sulfur will reduce the amount of polymers to be used in asphalt modification and add value to elemental sulfur. The use of SEPC in asphalt is expected to increase the service life of highways and reduction in maintenance cost.
Two solid waste streams that originated either directly from biomass or from the processing of biomass material have been evaluated for their potential as fillers in thermoplastic compounds. In this initial investigation the two materials were taken directly form the source and compounded with the thermoplastic without any conditioning. Injection molded samples were characterized, mechanically tested and compared to compounds made from a commercial masterbatch. The results indicated that both of the waste materials could be used to make compounds with consistent, and, for some applications, improved properties compared to current commercial compounds.
The aim of this work was to investigate the influence of the film former type applied on a sisal yarn prior to cutting on the processability of said cut fibers. Furthermore, the effects of the film former on the mechanical properties of the prepared composites are also investigated. We found, that it is possible to use different film formers for producing dosable fiber bundles. Furthermore, the type of film former shows an influence on the processability as well as on the mechanical properties of the composites. Although a reduction can be found in few properties, the use of a film former enables the dosing of fiber lengths on standard equipment, which are not processable if unsized
In this paper, the mixing efficiency of two slightly different fluted mixing elements is studied. RGB spectral analysis is used for the quantification of the mixing. The overall mixing appears to be equal after sufficient mixing time. The mixer without the wiping flight, however, creates a stagnation layer of material which rotates between the mixer and the barrel. This layer is characterized by a long residence time. The residence time of the layer is twice as long as for a mixer with the wiping flight. The long residence time is again measured by RGB spectral analysis and also visualized in the video. The results of a 3D FEM simulation shows that the mass flow rate of the stagnation layer represents almost 50% of the total mass flow rate.
It is common to assume stationary conditions to describe extrusion processes theoretically, nevertheless it is shown that transient multiphase modeling leads to more accurate explanations of the occurring phenomena and can even lead to important information to develop new die designs. A practical example is presented for color and material changes in two different spiral mandrel die geometries due to the highly dynamical process behavior. The interaction between two different melt phases can be represented and geometrical regions with negative influence on the change processes are identified.
Cross-linked polyethylene (PEX) pipes used in hot water supply are required for high mechanical strength and high creep resistance at high temperature. Especially PEX-a pipes which are made by peroxide cross-linking have better performance, such as creep resistance and thermal shock resistance than the pipes made by the other cross-linking method. Because the PEX-a pipes indicate the higher degree of cross-linking as compared with the other PEX pipes. In this study, the PEX-a pipes which were mixed with several stabilizers were tested to evaluate the effects on degree of cross-linking and the oxygen induction time. And also they are tested to evaluate the performance of the long-term hydrostatic pressure test and the long-term hydro dynamic pressure test with chlorine test. As a result, it was found that the combination of antioxidants for PEX-a pipes plays an important role to prolong the oxygen induction time without inhibiting the cross-linking. From the results of the 1H pulsed NMR measurement over the melting point of polyethylene, it was found that each peroxide PEX pipe with different antioxidant combinations indicated the different proportion and cross-linking density of cross-linking region, in addition, that these pipes had the effective structure of cross-linking for the hydrostatic and hydrodynamic pressure test with chlorine solution. Therefore, it was considered to be useful results for studies of the stricture of cross-linking of polyethylene.
This paper presents an approach for 3D-CFD-simulations of plastification of polymeric materials in highspeed extrusion processes. A new material model enables to differ between solid phase and fluid phase in dependence of temperature in just one set of property descriptions. Hence it becomes possible to simulate melting in a single fluid domain without presupposing any melting mechanism. The main focus is set on the numerical robustness of the model so that it is applicable for simulations of extrusion processes under high-speed conditions. Until now trials for a 35 mm-extruder with screw speeds up to 2000 rpm have been tested successfully.
Radiopaque compounds used to produce catheters that are inserted into the body for diagnostic or interventional procedures often use a polyether block amid based polymer. A number of radiopaque fillers are compounded into the polyether block amide polymers to render the catheter visible under fluoroscopy or x-ray imaging. Data on the effects of the various radiopaque fillers on the properties of the polyether block amide polymers is not readily available. This paper will demonstrate the effects of type and loading of radiopaque fillers on polyether block amide polymers.
Improper mold venting can cause defects we usually overlooked. We studied different venting block designs using movable inserts in the mold, e.g. along the flow direct ion cross the flow direct ion. The resulting tensile specimen were injected at different inject ion speeds including 100, 300, and 500 mm/s, and were later subjected to the tensile test for their strength. The venting design effects on melt temperature and pressure were verified by numerical method with same processing conditions. The results showed that the temperature and the pressure increased with the inject ion speed. The product tensile strength also enhanced with increasing injection speeds and when proper venting was conducted.
The rotomolding process is distinguished by a strong dependence on polyethylene (PE) as the main material used. In order to provide a range of different properties, PE grades are often blended together. This study examines the use of the well-known “rule of mixtures” for predicting the performance of PE blends from the properties of the individual blend components. Blends of high and low density linear PE’s were tested for composite melt index, density, tensile / flexural properties and impact strength. In addition, differential scanning calorimetry was used to evaluate the crystalline content of each blend and whether the blend components had co-crystallized or had formed separate domains.
Any article that is cited in another manuscript or other work is required to use the correct reference style. Below is an example of the reference style for SPE articles:
Brown, H. L. and Jones, D. H. 2016, May.
"Insert title of paper here in quotes,"
ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
Society of Plastics Engineers
Note: if there are more than three authors you may use the first author's name and et al. EG Brown, H. L. et al.
If you need help with citations, visit www.citationmachine.net