PROCEEDINGS OF PPS-33 : The 33rd International Conference of the Polymer Processing Society – Conference Papers最新文献

{"title":"Mixing characteristics of different kneading elements: An experimental study","authors":"Y. Nakayama, S. Esaki, K. Nakao, T. Kajiwara, Takahide Takeuchi, K. Kimura, H. Tomiyama","doi":"10.1063/1.5121652","DOIUrl":"https://doi.org/10.1063/1.5121652","url":null,"abstract":"We discuss the melt-mixing characteristics of different geometries of pitched-tip kneading disks (ptKD). Extrusion experiment was performed under the fully-filled state in the kneading zone by controlling the fill lengths for different KDs. We study the variation of the particle size distribution and the rheological response of ABS (acrylonitrilebutadiene-styrene copolymer) caused by melt-mixing. We found that the increase or decrease of the fine and coarse particles depends on the type of KD. Furthermore, the change of the particle size distribution affects the storage modulus at low frequencies. From these results, different mixing characteristics of different KDs are evaluated.We discuss the melt-mixing characteristics of different geometries of pitched-tip kneading disks (ptKD). Extrusion experiment was performed under the fully-filled state in the kneading zone by controlling the fill lengths for different KDs. We study the variation of the particle size distribution and the rheological response of ABS (acrylonitrilebutadiene-styrene copolymer) caused by melt-mixing. We found that the increase or decrease of the fine and coarse particles depends on the type of KD. Furthermore, the change of the particle size distribution affects the storage modulus at low frequencies. From these results, different mixing characteristics of different KDs are evaluated.","PeriodicalId":268370,"journal":{"name":"PROCEEDINGS OF PPS-33 : The 33rd International Conference of the Polymer Processing Society – Conference Papers","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132004127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automatic cooling channel design for injection moulds","authors":"C. Hopmann, M. Theunissen, T. Schneppe, M. Schmitz","doi":"10.1063/1.5121657","DOIUrl":"https://doi.org/10.1063/1.5121657","url":null,"abstract":"During the injection moulding process, local differences in pressure and temperature lead to different shrinkage over the part. This inhomogeneous shrinkage can lead to internal stresses, which are compensated by an undesirable warpage of the part. A sophisticated design of the cooling channels can avoid most of these problems. In previous research, it was shown that a locally adjusted temperature distribution on the cavity surface leads to less warpage of the part. In order to achieve this temperature distribution, an adapted cooling channel design is necessary. This design process is not possible with an analytical calculation but is the result of an iterative and numerical optimisation process. In this paper, a simulative approach for an automatic cooling channel layout via an inverse heat conduction problem is presented. Based on previous results, the methodology is adapted to three-dimensional problems. This approach brings the local heat and cooling demand of the part in equilibrium based on the postulate of a locally homogeneous material density. By this methodology, a proper cooling channel design close to the mould surface is determined. Simulations show a significant reduction of warpage by at least 22 % which will be validated by experimental results.During the injection moulding process, local differences in pressure and temperature lead to different shrinkage over the part. This inhomogeneous shrinkage can lead to internal stresses, which are compensated by an undesirable warpage of the part. A sophisticated design of the cooling channels can avoid most of these problems. In previous research, it was shown that a locally adjusted temperature distribution on the cavity surface leads to less warpage of the part. In order to achieve this temperature distribution, an adapted cooling channel design is necessary. This design process is not possible with an analytical calculation but is the result of an iterative and numerical optimisation process. In this paper, a simulative approach for an automatic cooling channel layout via an inverse heat conduction problem is presented. Based on previous results, the methodology is adapted to three-dimensional problems. This approach brings the local heat and cooling demand of the part in equilibrium based on the pos...","PeriodicalId":268370,"journal":{"name":"PROCEEDINGS OF PPS-33 : The 33rd International Conference of the Polymer Processing Society – Conference Papers","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124267967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modified talcum as crosslinking agent for polyolefins","authors":"A. Uray, G. Riess, T. Lucyshyn, C. Holzer, W. Kern","doi":"10.1063/1.5121690","DOIUrl":"https://doi.org/10.1063/1.5121690","url":null,"abstract":"","PeriodicalId":268370,"journal":{"name":"PROCEEDINGS OF PPS-33 : The 33rd International Conference of the Polymer Processing Society – Conference Papers","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115114521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermodynamic properties and crystallization kinetics of isotactic polypropylene under pressure","authors":"F. Santis, R. Pantani","doi":"10.1063/1.5121688","DOIUrl":"https://doi.org/10.1063/1.5121688","url":null,"abstract":"The effect of pressure on the processing and, in particular, on the crystallization kinetics of a polymeric material, is often ignored because of the difficulties involved in the experimental measu...","PeriodicalId":268370,"journal":{"name":"PROCEEDINGS OF PPS-33 : The 33rd International Conference of the Polymer Processing Society – Conference Papers","volume":"33 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114114196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermally conductive polymer-graphene nanoplatelet composite foams","authors":"Mahdi Hamidinejad, R. Chu, T. Filleter, Chul B. Park","doi":"10.1063/1.5121675","DOIUrl":"https://doi.org/10.1063/1.5121675","url":null,"abstract":"A new class of thermally conductive microcellular polymer nanocomposites of graphene nanoplatelets (GnP) is reported. Foamed and solid high-density-polyethylene (HDPE)-GnP composites containing different GnP contents (0-18 vol.%) were injection-molded. Foamed composites were fabricated using a facile technique of melt mixing followed by supercritical fluid-treatment and physical foaming in an injection molding process. The effects of foaming on the dispersion, exfoliation, orientation and inter-connectivity of platelets, and heat dissipation functionality were investigated. The introduction of microcellular foaming, significantly changed the orientation of platelets, enhanced their inter-connectivity and further exfoliated GnPs in the polymer. Hence, foaming reduced the density of the injection-molded samples and enhanced the thermal conductivity of product up to 800% (3.75 W/m.k). The results revealed that lightweight, highly thermally conductive products with lower filler loading, can be fabricated using foam injection molding for various applications in miniaturized electronic devices, and electric motor systems.A new class of thermally conductive microcellular polymer nanocomposites of graphene nanoplatelets (GnP) is reported. Foamed and solid high-density-polyethylene (HDPE)-GnP composites containing different GnP contents (0-18 vol.%) were injection-molded. Foamed composites were fabricated using a facile technique of melt mixing followed by supercritical fluid-treatment and physical foaming in an injection molding process. The effects of foaming on the dispersion, exfoliation, orientation and inter-connectivity of platelets, and heat dissipation functionality were investigated. The introduction of microcellular foaming, significantly changed the orientation of platelets, enhanced their inter-connectivity and further exfoliated GnPs in the polymer. Hence, foaming reduced the density of the injection-molded samples and enhanced the thermal conductivity of product up to 800% (3.75 W/m.k). The results revealed that lightweight, highly thermally conductive products with lower filler loading, can be fabricated usin...","PeriodicalId":268370,"journal":{"name":"PROCEEDINGS OF PPS-33 : The 33rd International Conference of the Polymer Processing Society – Conference Papers","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125249939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Static yield stress of a magnetorheological fluid containing pickering emulsion polymerized Fe3O4/polystyrene composite particles","authors":"Sangsok Han, J. Choi, H. Kim, SeHyun Kim, Y. Seo","doi":"10.1063/1.5121687","DOIUrl":"https://doi.org/10.1063/1.5121687","url":null,"abstract":"Magnetorheological (MR) fluids are a type of smart material with rheological properties that may be controlled through mesostructural transformations. MR fluids form solid-like fibril structures along the magnetic field direction upon application of a magnetic field due to magneto-polarization of particles suspended in the inert medium. A reverse structural transition occurs upon removal of the applied field. The structural changes occur very quickly, on the order of milliseconds. Recent applications have increased the demand for better performing MR materials with good long-term stability. A variety of industrial MR materials have been developed and tested in experimental and theoretical studies. This article briefly describes our recent progress in the search for advanced MR fluid materials and novel approaches to analyzing the MR flow behavior. To distinguish between the static yield stress and the dynamic yield stress and to describe the flow behavior under a broad range of shear rates, we applied Seo-Seo model. Several routes to improving the stability and efficiency of the MR fluids are summarized.Magnetorheological (MR) fluids are a type of smart material with rheological properties that may be controlled through mesostructural transformations. MR fluids form solid-like fibril structures along the magnetic field direction upon application of a magnetic field due to magneto-polarization of particles suspended in the inert medium. A reverse structural transition occurs upon removal of the applied field. The structural changes occur very quickly, on the order of milliseconds. Recent applications have increased the demand for better performing MR materials with good long-term stability. A variety of industrial MR materials have been developed and tested in experimental and theoretical studies. This article briefly describes our recent progress in the search for advanced MR fluid materials and novel approaches to analyzing the MR flow behavior. To distinguish between the static yield stress and the dynamic yield stress and to describe the flow behavior under a broad range of shear rates, we applied Seo...","PeriodicalId":268370,"journal":{"name":"PROCEEDINGS OF PPS-33 : The 33rd International Conference of the Polymer Processing Society – Conference Papers","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132929628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generation of high performance polyphenylene sulfide-thermotropic liquid crystalline polymer composite filaments for use in fused filament fabrication","authors":"Mubashir Q. Ansari, D. Baird","doi":"10.1063/1.5121693","DOIUrl":"https://doi.org/10.1063/1.5121693","url":null,"abstract":"In this work, a novel dual extrusion process was used to fabricate high performance continuously-reinforced composite filaments for use in Fused Filament Fabrication (FFF). The processing conditions required to reinforce polyphenylene sulfide (PPS) using a commercially available thermotropic liquid crystalline polymer (TLCP), composed of terephthalic acid (TA), 4-hydroxybenzoic acid (HBA), hydroquinone (HQ) and hydroquinone derivatives (HQ-derivatives) were established. The TLCPs possess high mechanical properties arising from the stearic hindrance of their rodlike monomers. The TLCP of interest melts at 320 ℃ but can stay molten up to around 35 ℃ below its melting temperature when cooled from 360 ℃, exhibiting a phenomenon known as supercooling behavior. However, the melt stability was found to vary drastically with the temperature. At 290 and 295 °C, the sample begins to solidify in 43 and 317 seconds, respectively. However, at 300 °C and above, the melt is stable for more than 3600 seconds. Isothermal time sweeps performed on PPS indicate an unstable melt complex viscosity above 320 ℃. Shear step strain tests performed on the TLCP indicate that the TLCP should be heated to at least 360 °C to melt all the residual crystallites. Due to the difference in processing temperatures, the filaments are generated using a unique process in which the higher melting point TLCP is spun within the matrix to form an in situ reinforced filament. The resins are plasticated in two different extruders at different temperatures and then the stream of the TLCP is injected into the stream of PPS. The composite stream is passed through a series of static mixers which subdivide the streams into finer streams, and then the composite stream is drawn to impart molecular orientation to the TLCP phase. The filaments so produced are processed in FFF by melting the PPS without melting the TLCP. The properties of the plaques generated from these strands will be reported.In this work, a novel dual extrusion process was used to fabricate high performance continuously-reinforced composite filaments for use in Fused Filament Fabrication (FFF). The processing conditions required to reinforce polyphenylene sulfide (PPS) using a commercially available thermotropic liquid crystalline polymer (TLCP), composed of terephthalic acid (TA), 4-hydroxybenzoic acid (HBA), hydroquinone (HQ) and hydroquinone derivatives (HQ-derivatives) were established. The TLCPs possess high mechanical properties arising from the stearic hindrance of their rodlike monomers. The TLCP of interest melts at 320 ℃ but can stay molten up to around 35 ℃ below its melting temperature when cooled from 360 ℃, exhibiting a phenomenon known as supercooling behavior. However, the melt stability was found to vary drastically with the temperature. At 290 and 295 °C, the sample begins to solidify in 43 and 317 seconds, respectively. However, at 300 °C and above, the melt is stable for more than 3600 seconds. Isothermal ...","PeriodicalId":268370,"journal":{"name":"PROCEEDINGS OF PPS-33 : The 33rd International Conference of the Polymer Processing Society – Conference Papers","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127171434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of process engineering on the morphology and crystallization of biobased poly(trimethylene terephthalate) – PTT and nylon 6 blends","authors":"Amandine Codou, A. Mohanty, M. Misra","doi":"10.1063/1.5121670","DOIUrl":"https://doi.org/10.1063/1.5121670","url":null,"abstract":"Poly(trimethylene terephthalate) (PTT), a partially biobased polymer, was blended with nylon 6 in order to develop a new bio-material. PTT and nylon 6 blends were prepared in a twin-screw extruder ...","PeriodicalId":268370,"journal":{"name":"PROCEEDINGS OF PPS-33 : The 33rd International Conference of the Polymer Processing Society – Conference Papers","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131657458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compounding and direct compounding of crimped fiber reinforced thermoplastic elastomers","authors":"J. Gattinger, R. Köppl, M. Zeppenfeld","doi":"10.1063/1.5121676","DOIUrl":"https://doi.org/10.1063/1.5121676","url":null,"abstract":"The use of wavy fibers as reinforcement elements accounts for higher strengths and preserves the flexibility of elastomers. For this purpose, the manufacturing of wavy short fiber reinforced thermoplastic elastomers by injection molding was investigated. Thermoplastic elastomer and crimped staple fibers were separately compounded and molded (SCM) or directly compounded in the injection molding machine (DCM). Comparative tension bars were manufactured with compounds derived from straight fiber (tow, same fiber type). Selected specimens were dissolved in cyclohexane and the fibers were characterized regarding fiber length and degree of crimp (quotient of the extended fiber length and the crimped fiber length). Tensile tests were performed to evaluate the mechanical properties. The examination of the resulting fiber length and shape in the injection molded parts showed that every processing step (compounding or injection molding) and every raw fiber, whether straight or crimped, produced wavy fibers in the resulting granules or parts.The use of wavy fibers as reinforcement elements accounts for higher strengths and preserves the flexibility of elastomers. For this purpose, the manufacturing of wavy short fiber reinforced thermoplastic elastomers by injection molding was investigated. Thermoplastic elastomer and crimped staple fibers were separately compounded and molded (SCM) or directly compounded in the injection molding machine (DCM). Comparative tension bars were manufactured with compounds derived from straight fiber (tow, same fiber type). Selected specimens were dissolved in cyclohexane and the fibers were characterized regarding fiber length and degree of crimp (quotient of the extended fiber length and the crimped fiber length). Tensile tests were performed to evaluate the mechanical properties. The examination of the resulting fiber length and shape in the injection molded parts showed that every processing step (compounding or injection molding) and every raw fiber, whether straight or crimped, produced wavy fibers in the r...","PeriodicalId":268370,"journal":{"name":"PROCEEDINGS OF PPS-33 : The 33rd International Conference of the Polymer Processing Society – Conference Papers","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114636690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement of electrical resistivity of highly filled graphite/PP composite based bipolar plates for fuel cells by addition of carbon black","authors":"B. Krause, P. Pötschke, T. Hickmann","doi":"10.1063/1.5121681","DOIUrl":"https://doi.org/10.1063/1.5121681","url":null,"abstract":"Novel material solutions for polymer based bipolar plates in fuel cells require adapted ways to develop suitable material compositions. The common pathway to develop materials with at the same time high electrical as well as thermal conductivity is the use of conductive graphite as filler with contents up to 80-85 wt.%. However, there is a need to develop recipes with maximized conductive behavior at lowest possible content of conductive filler to enhance the mechanical properties and allow good processability. In this study, composites based on polypropylene (PP) and different filler systems were melt-mixed using a lab scale co-rotating twin-screw extruder and compression molded to bipolar type plates. As fillers synthetic (G) or expanded (EG) graphites were incorporated. At the overall filler content of 60 wt.% or 80 wt% part of the graphite was replaced by highly conductive carbon black (CB, 2.5 wt.%, 5.0 wt.%). It was found that the addition of CB significantly reduced the electrical volume as well as the surface resistivity up to values of 0.12 Ω·cm or 4 mΩ/square, respectively. For the values of thermal conductivity the kind and particle size of the selected graphite was important. If expanded graphite was partially replaced by CB, the thermal conductivity of PP/EG+CB composites decreased significantly. Otherwise, the combination of synthetic graphite and CB changed the thermal conductivity of PP composites only marginal at the same overall filler content. For both graphite types the filler with larger particle size resulted in higher thermal conductivity.Novel material solutions for polymer based bipolar plates in fuel cells require adapted ways to develop suitable material compositions. The common pathway to develop materials with at the same time high electrical as well as thermal conductivity is the use of conductive graphite as filler with contents up to 80-85 wt.%. However, there is a need to develop recipes with maximized conductive behavior at lowest possible content of conductive filler to enhance the mechanical properties and allow good processability. In this study, composites based on polypropylene (PP) and different filler systems were melt-mixed using a lab scale co-rotating twin-screw extruder and compression molded to bipolar type plates. As fillers synthetic (G) or expanded (EG) graphites were incorporated. At the overall filler content of 60 wt.% or 80 wt% part of the graphite was replaced by highly conductive carbon black (CB, 2.5 wt.%, 5.0 wt.%). It was found that the addition of CB significantly reduced the electrical volume as well as...","PeriodicalId":268370,"journal":{"name":"PROCEEDINGS OF PPS-33 : The 33rd International Conference of the Polymer Processing Society – Conference Papers","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122156844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}