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.

The SPE Library is just one of the great benefits of being an SPE member! Are you taking advantage of all of your SPE Benefits?

Not an SPE member? Join today!

Use % to separate multiple keywords.

Search SPE Library

Conference Proceedings

MECHANICAL PROPERTIES OF MODIFIED STARCH FILLED POLY(L-LACTIC ACID)

Jiwen Wang , Wenge Zheng, May 2010

Starch with surface modification by grafting with polyethylene glycol (PEG) of different molecular weight (Starch-g-PEG) was developed and blended with poly(L-lactic acid) (PLA). Tolylene diisocyanate (TDI) was used as a coupling agent. The properties of PLA/Starch-g-PEG were investigated by tensile and impact testing, Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM). Significant increase in the elongation at break and impact strength of PLA/Starch-g- PEG blends without sacrificing the tensile modulus and strength at optimum PEG molecular weight range was obtained compared to those of PLA.

STERILE BARRIERS FOR MEDICAL DEVICES: FAILURE MODES AND MITIGATION

Adriana Knapkova, Libor Friedel, Bruce Dehning2, Jiri G. Drobny, May 2010

From sterilization to use, medical device packaging must provide a microbial barrier for the devices they protect. Reliability of this packaging is of the utmost importance since packaging materials must endure folding, rubbing, and a host of other mechanical and environmental stresses that can challenge the barriersƒ?? integrity. Pouches consist of flashspun high-density polyethylene (FS-HDPE) sheeting and laminates films composed of polyolefins and nylons. Case studies regarding sterile pouch failures that occurred at various stages of qualification testing and solutions for mitigating failures are presented. Common failure modes and mechanisms are discussed in detail.

AMT INVESTMENTS: MEASURING AND STRENGTHENING OF THEIR INFLUENCE ON COMPANYƒ??S PERFORMANCE

Adriana Knapkova , Libor Friedel , Bruce Dehning , Jiri G. Drobny, May 2010

Paper discusses research in progress which is focused on performance management and measurement with regard on Advanced Manufacturing Technologies (AMT) investments. The aim of the paper is to show new combinations perspectives and potentials how to see the impact of AMT in the chain of performance effects.Based on critical literature review and experience from different performance management cases we determined several ƒ??toolsƒ? - EVA BSC ABC/M and EFQM Excellence Model as a suitable and powerful concepts which can be used mutually for measurement and management of the companyƒ??s performance. The synergic effects of the above mentioned concepts are discussed and the influence of AMT investments on companyƒ??s performance is analyzed.

COLOR MATCHING OF WEATHERABLE CO-EXTRUDED FILMS

Antonio. J. Carrillo, A. I. Isayev, May 2010

Color matching of two-layer co-extruded films was performed by color compensation in either the top layer or bottom layer. With the former approach, excellent initial color match (??E<1.0) and weathering performance ??E~2.3 at 6,000kJ/m2 exposure) were achieved; however, a large color shift due to thickness variation (??E>3.0 at 50% thickness reduction) was observed. On the contrary, with the latter approach, poor initial color match (??E>4.0) and weathering performance (??E>3.0 at 6,000kJ/m2 exposure) were experienced; nonetheless, a very small color shift due to thickness variation (??E<1.0 at 50% thickness reduction) was produced.

BIREFRINGENCE IN GAS-ASSISTED INJECTION MOLDINGS: CONTRIBUTION OF THERMAL BIREFRINGENCE

Antonio. J. Carrillo , A. I. Isayev, May 2010

Various components of birefringence in polystyrene (PS) tubular moldings obtained by gas-assisted injection molding (GAIM) were simulated considering both flowand thermally-induced stresses using linear and nonlinear viscoelastic theories respectively. Flow birefringence components were calculated using the stress optical rule while thermal birefringence components were simulated using a photoviscoelastic model. Free quenching experiments in tubular and rod samples were performed and various components of birefringence were measured. The measured values were found to be in fair agreement with predicted results. Considering thermal and flow birefringence in simulations provides a better description of experimental results indicating that in GAIM moldings the birefringence near the mold wall and inner wall were caused mainly by flow and thermal stresses respectively.

BIREFRINGENCE IN GAS-ASSISTED INJECTION MOLDINGS: CONTRIBUTION OF THERMAL BIREFRINGENCE

Antonio. J. Carrillo , A. I. Isayev, May 2010

Various components of birefringence in polystyrene(PS) tubular moldings, obtained by gas-assisted injectionmolding (GAIM), were simulated considering both flowandthermally-induced stresses using linear and nonlinearviscoelastic theories, respectively. Flow birefringencecomponents were calculated using the stress optical rule,while thermal birefringence components were simulatedusing a photoviscoelastic model. Free quenchingexperiments in tubular and rod samples were performedand various components of birefringence were measured.The measured values were found to be in fair agreementwith predicted results. Considering thermal and flowbirefringence in simulations provides a better descriptionof experimental results indicating that, in GAIM moldings,the birefringence near the mold wall and inner wall werecaused mainly by flow and thermal stresses, respectively.

OPTIMIZATION OF MATERIAL FORMULATION AND PROCESSING PARAMETERS FOR WOOD PLASTIC COMPOSITE EXTRUSION

Yasuhiro Kawaguchi, Yoshiyuki Kosaka, Takeshi Nakachi, Hiroshi Kake, Jae Kyung Kim, Haruo Shikuma, Masahiro Ohshima, May 2010

The development of wood plastic composite (WPC) has facilitated the economical extrusion of profiles for various applications. The extrusion processing can be optimized by regulating the process temperatures, use of compatibilizer, lubricants and melt flow index of polymers. In this study, a rectangular WPC profile was produced from high density polyethylene (HDPE) and wood fiber (WF) with different extrusion conditions and material formulations using lab scale twin-screw extruder profile line. The influence of HDPE melt index, lubricant contents and processing parameters on extrudate quality and mechanical properties are discussed.

THERMALLY-EXPANDABLE MICROCAPSULES FOR POLYMER FOAMING – ITS EXPANDABILITY AND VISCOELASTICITY

Yasuhiro Kawaguchi , Daichi Ito , Yoshiyuki Kosaka , Takeshi Nakachi , Hiroshi Kake , Jae Kyung Kim , Haruo Shikuma , Masahiro Ohshima, May 2010

The thermally expandable microcapsule is a new type of blowing agent for polymer foaming. It has a core and shell structure. A low boiling point hydrocarbon liquid is encapsulated by the shell of acrylonitrile co-polymer. Mixing the microcapsules with the thermoplastic polymer and letting them thermally expand in the polymer can foam the polymer. In this study we developed a new microcapsule so that it can be used at high operating temperatures over 200 oC for foaming polypropylene (PP) by injection molding and extrusion. We investigated the effect of viscoelasticity of the shell polymer on the expandability of the microcapsule as well as on the surface appearance. The visual observation of batch foaming the rheological measurement and the experiments of foam injection molding and extrusion elucidated the existence of the optimal degree of cross-linking of the shell polymer that could realize the superior expandability and appearance at PP foam injection molding and extrusion.

THERMALLY-EXPANDABLE MICROCAPSULES FOR POLYMER FOAMING – ITS EXPANDABILITY AND VISCOELASTICITY

Yasuhiro Kawaguchi , Daichi Ito , Yoshiyuki Kosaka , Takeshi Nakachi , Hiroshi Kake , Jae Kyung Kim , Haruo Shikuma , Masahiro Ohshima, May 2010

The thermally expandable microcapsule is a new type of blowing agent for polymer foaming. It has a core and shell structure. A low boiling point hydrocarbon liquid is encapsulated by the shell of acrylonitrile co-polymer. Mixing the microcapsules with the thermoplastic polymer and letting them thermally expand in the polymer can foam the polymer. In this study, we developed a new microcapsule so that it can be used at high operating temperatures over 200 oC for foaming polypropylene (PP) by injection molding and extrusion. We investigated the effect of viscoelasticity of the shell polymer on the expandability of the microcapsule as well as on the surface appearance. The visual observation of batch foaming, the rheological measurement and the experiments of foam injection molding and extrusion elucidated the existence of the optimal degree of cross-linking of the shell polymer that could realize the superior expandability and appearance at PP foam injection molding and extrusion.

THE EFFECTS OF RESIDUAL STRESS AND CRYSTALLINITY ON RCP RESISTANCE IN PE-100 POLYETHYLENES

Christos P. Argyrakis , Patrick S. Leevers, May 2010

PE-100 pipe materials owe their excellent impact and brittle rapid crack propagation (RCP) resistance to ductile regions adjoining the inside and outside pipe surfaces. Slow cooling after extrusion seems to further toughen these regions by increasing crystallinity, but slow cooling also changes the distribution and magnitude of residual strain in the pipe wall and this may reduce the RCP driving force. This paper describes an experimental technique, which decouples these two effects and shows that crystallinity has less effect than expected. The effect of residual strain, meanwhile, is analysed using a semianalytical model of RCP, which indicates that its role may have been underestimated.

STUDY OF THE THERMAL ENDURANCE AND THE THERMAL DEGRADATION KINETICS OF A POLYPROPYLENE WOOD COMPOSITE

Makoto Seino, Manabu Nomura, Masaya Kotaki, May 2010

The thermal endurance and the thermal degradation kinetics of a Polypropylene wood composite are studied. The study is done by using several kinetics analysis methodologies including the following: conventional TGA, modulated TGA, Flynn-Wall-Ozawa isoconversional analysis (ASTM E1641-07), thermal endurance (ASTM E1877-05) and Friedmad isoconvertional method. The thermal degradation of the Polypropylene wood composite is compared with the thermal degradation of pure Polypropylene and wood powder. Despite of a discoloration process, the temperature peaks of wood decomposition for the composite and for the wood power are coincident. On the other hand, the temperature peak of Polypropylene decomposition for the composite is shifted to higher temperatures.

NOVEL AROMATIC POLYKETONE BLENDS WITH A NEW SILOXANE POLYETHERIMIDE COPOLYMER

Alejandro Londoño-Hurtad, Lena Marks, Gerhard Ziegmann, Tim Osswald, May 2010

New siloxane polyetherimide copolymers (SILTEM* resin) and aromatic polyketones form compatible blends across the composition range and exhibit superior mechanical, thermal and flame resistance properties. The exceptional properties of these blends make them suitable candidates for a wide range of applications including injection molded articles and electrical wire insulation. In particular, wire coatings made from these blends show excellent tensile elongation to break, high softening temperature, flexibility and good processibility and show promise for use in high temperature, halogen-free wire coatings and tubings.

FIBER JAMMING AND FIBER-MATRIX SEPARATION DURING KNITLINE FORMATION OF FIBER REINFORCED COMPOSITES

Alejandro Londoño-Hurtado , Lena Marks , Gerhard Ziegmann , Tim Osswald, May 2010

Knitline formation in the compression molding of sheet molding compound (SMC), a defect highly influenced by Fiber-Matrix separation, was studied through experiments and computer simulations.Square plates with meeting flow fronts where compression molded varying the initial mold coverage. In order to evaluate the influence of mold coverage on knitline development, tensile and three point bending tests of specimens taken from the meeting point of the flow fronts where performed.Mechanistic computer simulations of fiber suspensions where used to validate the experiments.

INTERFACIAL STRENGTH AND SCRATCH RESISTANCE OF METALLOCENE PE FILM INSERTED PP INJECTION MOLDED PARTS

Katsuhisa Kitano , Takeo Kitayama , Masaya Kotaki , Hiroyuki Hamada, May 2010

Interfacial strength of Metallocene PE film-inserted PP injection molded parts (mPE/PP FIMs) was evaluated by micro-cutting method. Scratch properties of the FIMs were also characterized by progressive load scratch tests in comparison with Ziglear-Natta PE film-inserted PP injection molded parts (zPE /PP FIMs). It was found that interfacial strength of mPE2/PP FIMs increased with the increase of film thickness as well as the critical normal load for onset of film fracture obtained by scratch tests. TEM observation showed the penetration of PP lamella crystal into mPE film.

ENHANCED WATER STABILITY OF SOY PROTEIN PLASTICS USING ACID ANHYDRIDES.

Tohru Morii, Tohru Fujita, Hiroyuki Hamada,, May 2010

Protein based plastics were processed using anhydride chemistries in conjunction with glycerol to obtain modified soy protein polymers that were water stable. Formulations processed with chemistries such as maleic anhydride (MA) and phthalic anhydride (PTA) produced relatively water stable soy protein based plastics. Various formulations were produced by varying the anhydride content (3-10% w/w) in the final plastic mass. The respective mixtures were extruded and injection molded to form the samples for characterization. Formulations with 10% PTA were observed to have water absorption of only 19% after 24 hrs of water submersion as compared to 250% for the control formulation.

DUAL AE TRANSDUCER METHODOLOGY FOR FRACTURE PROCESS MONITORING IN SHORT FIBER REINFORCED COMPOSITES

Tohru Morii , Tohru Fujita, May 2010

This study dealt with application of acoustic emission (AE) to characterize fracture process of short glass fiber reinforced thermoplastic composites. Generally, only one type of AE transducer with resonant frequency of 100- 200kHz is adopted to evaluate fracture process of composites by AE. However, the authors clarified AE transducer with resonant frequency of 1MHz was sensitive to detect fiber dominant fracture. From this background we propose dual AE transducer system with different resonant frequency (140kHz and 1MHz) to characterize fracture process of composites by AE monitoring. This methodology is applied to evaluate fracture process during tensile loading for various composites.

HALOGEN-FREE FLAME RETARDANT THERMOPLASTIC POLYESTERS WITH ENHANCED PROCESSABILITY

Tohru Morii, Takahiro Horie, Hiroyuki Hamada, May 2010

Many phosphorus containing additives and nitrogen synergists are available for use as flame retardant systems in engineering plastics, to develop halogen-free products for the electrical & electronics industry. However, many issues such as blooming, mold deposits, short-shots, and tool corrosion are associated with the use of such additives in polyesters. We illustrate typical issues encountered with the use of halogen-free systems in PBT and demonstrate how the Celanex?? XFR?? series from Ticona overcomes those issues and can be used as a viable alternate to halogenated compounds. We also highlight the unique advantages of our halogen-free PBT products over conventional halogenated PBT products.

FRACTURE BEHAVIOR OF GLASS FIBER/UNSATURATED POLYESTER RESIN LAMINATE BY DUAL AE TRANSDUCER MONITORING SYSTEM

Tohru Morii , Takahiro Horie , Hiroyuki Hamada, May 2010

AE was applied to evaluate fracture mechanism of glass fabric reinforced unsaturated polyester laminates with different fiber surface treatment. For AE monitoring dual transducer monitoring system was adopted to discuss dominant fracture under tensile loading. AE transducers with resonant frequency of 140kHz and 1MHz were applied to monitor matrix and fiber dominant fracture, respectively. By this system, effect of fiber surface treatment on fracture was discussed. Cumulative AE counts from fiber dominant fracture were constant independent of fiber surface treatment and loading pattern.This result suggested laminate strength was determined by accumulation of fiber related fracture.

ACOUSTIC EMISSION CHARACTERISTICS OF SHORT AND LONG FIBER REINFORCED PP INJECTION MOLDINGS

Tohru Morii , Nobuyuki Jumonji , Hiroyuki Hamada, May 2010

This study dealt with effect of fiber length on AE characteristics of glass fiber reinforced PP injection moldings. Short and long fiber reinforced PP was molded by injection molding, and static tensile tests were conducted with AE monitoring. In AE monitoring, dual transducer system with resonant frequency of 140kHz and 1MHz was adopted. Effect of fiber length on fracture was discussed by AE initiation stress and maximum amplitude.From these parameters fracture process was divided into two phases; interfacial fracture dominated by fibers oriented perpendicular to loading and fiber breakage and following matrix cracking by fibers oriented parallel to loading.

RELATIONSHIP BETWEEN PROPERTIES, CITRATE CONTENT AND POSTPRODUCTION TIME FOR A PLASTICIZED POLYLACTIC ACID

Jungjoo Lee, Lih-Sheng Turng, May 2010

Due to the recent interest on citrates as a biodegradable plasticizer for Polylactic acid PLA, several PLA blends that were plasticized with tributyl citrate TBC were prepared in a co-rotating twin screw extruder. A range of 12.4 to 22.5% by weight was considered for the plasticizer content. The thermal, rheological and mechanical properties were correlated with the plasticizer content and compared with pure Polylactic acid. Additionally, the change of these properties as a function of postproduction time was studied and correlated with the plasticizer permanence.