Abstract Rigid polyurethane foam (RPUF) has been fabricated and modified by hydrolyzed keratin to improve its flame retardancy and smoke suppression. Then, the limiting oxygen index (LOI), cone calorimeter (CONE), thermogravimetric analyzer and scanning electron microscope (SEM) were used to characterize the modified RPUFs. It was found that the LOI of the modified RPUFs increased with the presence of hydrolyzed keratin. In addition, the peak heat release rate (PHRR) and total heat release (THR) of the modified RPUF tended to decrease. The HRR of RPUF-HK5 reduced 28.8 kW/m2 compared with RPUF-0, and the THR of RPUF-HK5 was 0.74 MJ/m2 lower than that of RPUF-0. RPUF-HK5 had the most obvious smoke suppression effect. Compared with RPUF-0, the smoke density (Ds) and light transmittance (T) of RPUF-HK5 decreased by 8.88 and increased by 11.26%, respectively. The current research results showed that hydrolyzed keratin can improve the flame-retardant and smoke-suppression performances of RPUFs and that 5 wt% hydrolyzed keratin was the most suitable ratio for the modified RPUF.
{"title":"Fabrication of flame-retardant and smoke-suppressant rigid polyurethane foam modified by hydrolyzed keratin","authors":"Xu Zhang, Chen Xu, Zhi Wang, Hua Xie","doi":"10.1515/ipp-2022-4303","DOIUrl":"https://doi.org/10.1515/ipp-2022-4303","url":null,"abstract":"Abstract Rigid polyurethane foam (RPUF) has been fabricated and modified by hydrolyzed keratin to improve its flame retardancy and smoke suppression. Then, the limiting oxygen index (LOI), cone calorimeter (CONE), thermogravimetric analyzer and scanning electron microscope (SEM) were used to characterize the modified RPUFs. It was found that the LOI of the modified RPUFs increased with the presence of hydrolyzed keratin. In addition, the peak heat release rate (PHRR) and total heat release (THR) of the modified RPUF tended to decrease. The HRR of RPUF-HK5 reduced 28.8 kW/m2 compared with RPUF-0, and the THR of RPUF-HK5 was 0.74 MJ/m2 lower than that of RPUF-0. RPUF-HK5 had the most obvious smoke suppression effect. Compared with RPUF-0, the smoke density (Ds) and light transmittance (T) of RPUF-HK5 decreased by 8.88 and increased by 11.26%, respectively. The current research results showed that hydrolyzed keratin can improve the flame-retardant and smoke-suppression performances of RPUFs and that 5 wt% hydrolyzed keratin was the most suitable ratio for the modified RPUF.","PeriodicalId":14410,"journal":{"name":"International Polymer Processing","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49222874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shengtai Zhou, Renze Jiang, Xue Lei, H. Zou, A. Hrymak
Abstract In this work, a comparative study on the electrical conductivity (σ) and thermal properties of polypropylene (PP)/carbon microparts with different part thickness (namely, 0.85 and 0.50 mm) is reported. Two different types of carbon filler (i.e., CNT and CB) were adopted to study the efficacy of different carbon fillers in improving the σ of PP/carbon microparts. In general, the σ of 0.85 mm thickness microparts were higher than the 0.50 mm thickness microparts, regardless of the carbon filler type and testing directions. This suggested that higher shearing conditions that prevailed in the microinjection molding (μIM) process were unfavorable for the formation of intact conductive pathways in corresponding moldings, albeit the distribution of carbon fillers turned better with increasing shear rates, as confirmed by morphology observations. Differential scanning calorimetry results showed that prior thermomechanical histories (including melt blending and μIM) experienced by the polymer melts had an influence on the thermal behavior of subsequent moldings. Also, there existed a strong shear flow-induced crystallization of polymer chains during μIM because the crystallinity of microparts was higher than that of feed materials.
{"title":"Influence of mold cavity thickness on electrical, morphological and thermal properties of polypropylene/carbon micromoldings","authors":"Shengtai Zhou, Renze Jiang, Xue Lei, H. Zou, A. Hrymak","doi":"10.1515/ipp-2022-4288","DOIUrl":"https://doi.org/10.1515/ipp-2022-4288","url":null,"abstract":"Abstract In this work, a comparative study on the electrical conductivity (σ) and thermal properties of polypropylene (PP)/carbon microparts with different part thickness (namely, 0.85 and 0.50 mm) is reported. Two different types of carbon filler (i.e., CNT and CB) were adopted to study the efficacy of different carbon fillers in improving the σ of PP/carbon microparts. In general, the σ of 0.85 mm thickness microparts were higher than the 0.50 mm thickness microparts, regardless of the carbon filler type and testing directions. This suggested that higher shearing conditions that prevailed in the microinjection molding (μIM) process were unfavorable for the formation of intact conductive pathways in corresponding moldings, albeit the distribution of carbon fillers turned better with increasing shear rates, as confirmed by morphology observations. Differential scanning calorimetry results showed that prior thermomechanical histories (including melt blending and μIM) experienced by the polymer melts had an influence on the thermal behavior of subsequent moldings. Also, there existed a strong shear flow-induced crystallization of polymer chains during μIM because the crystallinity of microparts was higher than that of feed materials.","PeriodicalId":14410,"journal":{"name":"International Polymer Processing","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48056184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Erkliğ, Bashar Younus, N. Doğan, M. Alsaadi, M. Bulut, B. Sulaiman
Abstract The present study investigates the effect of carbon fiber hybridization and graphene nanoplatelets inclusion on the vibration damping properties of glass fiber reinforced polymer composites. The hand layup method was utilized with hot press molding in hybrid/non-hybrid composite plate production. A total of sixteen laminates, eight containing pure glass/epoxy and pure carbon/epoxy, and the remainder containing glass/carbon, were stacked in four different arrays and impregnated with an epoxy matrix to provide a hybrid/non-hybrid configuration. In the first hybrid configuration, the glass fiber fabric is on the outer surface and the carbon fiber fabric is on the inside of the composite plate; in the second configuration, the opposite of this sequence was used. Graphene Nanoplatelets (GNPs) were added into the epoxy resin in different weight fractions (0, 0.1, 0.25, and 0.5 wt%). Experimental modal analysis was performed to evaluate the natural frequency and damping ratios of the GNPs modified/unmodified test samples. According to the results obtained, carbon fiber hybridization not only increased the natural frequency but also caused a decrease in the damping ratio of the glass fiber reinforced composite material. On the other hand, incorporating 0.5% by weight of GNPs into the epoxy matrix improved damping ratios by approximately 42.1, 51.6, 16.7 and 17.2% for the G05, GC05, CG05 and C05 samples, respectively, compared to the pure samples. Also, a decrease in natural frequency and loss storage values were observed at high GNPs content.
{"title":"Vibration damping properties of graphene nanoplatelets filled glass/carbon fiber hybrid composites","authors":"A. Erkliğ, Bashar Younus, N. Doğan, M. Alsaadi, M. Bulut, B. Sulaiman","doi":"10.1515/ipp-2022-4241","DOIUrl":"https://doi.org/10.1515/ipp-2022-4241","url":null,"abstract":"Abstract The present study investigates the effect of carbon fiber hybridization and graphene nanoplatelets inclusion on the vibration damping properties of glass fiber reinforced polymer composites. The hand layup method was utilized with hot press molding in hybrid/non-hybrid composite plate production. A total of sixteen laminates, eight containing pure glass/epoxy and pure carbon/epoxy, and the remainder containing glass/carbon, were stacked in four different arrays and impregnated with an epoxy matrix to provide a hybrid/non-hybrid configuration. In the first hybrid configuration, the glass fiber fabric is on the outer surface and the carbon fiber fabric is on the inside of the composite plate; in the second configuration, the opposite of this sequence was used. Graphene Nanoplatelets (GNPs) were added into the epoxy resin in different weight fractions (0, 0.1, 0.25, and 0.5 wt%). Experimental modal analysis was performed to evaluate the natural frequency and damping ratios of the GNPs modified/unmodified test samples. According to the results obtained, carbon fiber hybridization not only increased the natural frequency but also caused a decrease in the damping ratio of the glass fiber reinforced composite material. On the other hand, incorporating 0.5% by weight of GNPs into the epoxy matrix improved damping ratios by approximately 42.1, 51.6, 16.7 and 17.2% for the G05, GC05, CG05 and C05 samples, respectively, compared to the pure samples. Also, a decrease in natural frequency and loss storage values were observed at high GNPs content.","PeriodicalId":14410,"journal":{"name":"International Polymer Processing","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45462356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The mechanical, thermal and dielectric properties of lanthanum manganite (LaMnO3) epoxy nanocomposites reinforced with silane coated E-glass fiber are reported. Structural and morphological characteristics of the LaMnO3, synthesized by the solution combustion method, were studied via X-ray diffraction, EDAX and scanning electron microscopy. LaMnO3/epoxy composites containing various percentages of LaMnO3 (LME) were prepared via hand lay-up method and tested for tensile, flexural and impact strength. Improved properties were obtained with the addition of LME compared to plain epoxy composites. The thermal stability of the composites remains almost unaltered by the filler loading. Variation in the dielectric characteristics with filler loading is attributed to the percolation of charge carriers due to the interfacial zonal overlapping in the nanocomposite resulting in a change of the dielectric characteristics.
{"title":"Thermal, mechanical and dielectric properties of glass fiber reinforced epoxy-lanthanum manganite nanocomposites","authors":"Preseetha Paul Chiriyankandath, S. Varghese","doi":"10.1515/ipp-2022-0009","DOIUrl":"https://doi.org/10.1515/ipp-2022-0009","url":null,"abstract":"Abstract The mechanical, thermal and dielectric properties of lanthanum manganite (LaMnO3) epoxy nanocomposites reinforced with silane coated E-glass fiber are reported. Structural and morphological characteristics of the LaMnO3, synthesized by the solution combustion method, were studied via X-ray diffraction, EDAX and scanning electron microscopy. LaMnO3/epoxy composites containing various percentages of LaMnO3 (LME) were prepared via hand lay-up method and tested for tensile, flexural and impact strength. Improved properties were obtained with the addition of LME compared to plain epoxy composites. The thermal stability of the composites remains almost unaltered by the filler loading. Variation in the dielectric characteristics with filler loading is attributed to the percolation of charge carriers due to the interfacial zonal overlapping in the nanocomposite resulting in a change of the dielectric characteristics.","PeriodicalId":14410,"journal":{"name":"International Polymer Processing","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41847224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract It is difficult to directly measure the steady extensional viscosity of thermoplastic composite materials, especially at high extension rates. The famous Cogswell method was derived analytically from the pressure drop of entrance flow in commercial capillary rheometers for estimating the extensional viscosity. However, using Cogswell´s extensional viscosity has always resulted in over-predictions of pressure drop. Recently, the GNF-X (eXtended Generalized Newtonian Fluid) model with a weighted shear/extensional viscosity was proposed to show the typical extension-induced vortex growth in entrance flow simulations. Under given various values of Trouton’s ratio for extensional viscosity, the GNF-X model is introduced to perform three-dimensional flow simulations of capillary rheometry over a range of apparent shear rates. The difference between the predicted pressure drops and the relevant experimental data is minimized such that the estimation of extensional viscosity is optimized herein.
{"title":"Three-dimensional simulation of capillary rheometry for an estimation of extensional viscosity","authors":"H. Tseng","doi":"10.1515/ipp-2022-4280","DOIUrl":"https://doi.org/10.1515/ipp-2022-4280","url":null,"abstract":"Abstract It is difficult to directly measure the steady extensional viscosity of thermoplastic composite materials, especially at high extension rates. The famous Cogswell method was derived analytically from the pressure drop of entrance flow in commercial capillary rheometers for estimating the extensional viscosity. However, using Cogswell´s extensional viscosity has always resulted in over-predictions of pressure drop. Recently, the GNF-X (eXtended Generalized Newtonian Fluid) model with a weighted shear/extensional viscosity was proposed to show the typical extension-induced vortex growth in entrance flow simulations. Under given various values of Trouton’s ratio for extensional viscosity, the GNF-X model is introduced to perform three-dimensional flow simulations of capillary rheometry over a range of apparent shear rates. The difference between the predicted pressure drops and the relevant experimental data is minimized such that the estimation of extensional viscosity is optimized herein.","PeriodicalId":14410,"journal":{"name":"International Polymer Processing","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49659078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Extensional flows generally take place in a channel with varied cross-sectional areas. During polymer processing with a variety of complex geometric features, it is difficult to separate extensional rates from shear rates in state-of-the-art predictive engineering tools of computational fluid dynamics. The recently proposed method of Tseng [Tseng, H.-C., “A Revisitation of Generalized Newtonian Fluids,” J Rheol 64 493–504 (2020)] decomposed the generalized strain rate as the characteristic shear and extensional rates via the rate-of-deformation tensor rotated along streamline coordinates. As validation for an isothermal center-gated disk flow, the predicted flow field profiles fairly matched the analytical solution for Newtonian fluid. Under injection molding simulations, an objective indicator is defined to visualize the colorful contours of extensional flows encountered in the gate-vicinity and the mid-plane of the cavity’s thickness direction, as well as contraction-expansion channels.
{"title":"Numerical visualization of extensional flows in injection molding of polymer melts","authors":"H. Tseng","doi":"10.1515/ipp-2022-4316","DOIUrl":"https://doi.org/10.1515/ipp-2022-4316","url":null,"abstract":"Abstract Extensional flows generally take place in a channel with varied cross-sectional areas. During polymer processing with a variety of complex geometric features, it is difficult to separate extensional rates from shear rates in state-of-the-art predictive engineering tools of computational fluid dynamics. The recently proposed method of Tseng [Tseng, H.-C., “A Revisitation of Generalized Newtonian Fluids,” J Rheol 64 493–504 (2020)] decomposed the generalized strain rate as the characteristic shear and extensional rates via the rate-of-deformation tensor rotated along streamline coordinates. As validation for an isothermal center-gated disk flow, the predicted flow field profiles fairly matched the analytical solution for Newtonian fluid. Under injection molding simulations, an objective indicator is defined to visualize the colorful contours of extensional flows encountered in the gate-vicinity and the mid-plane of the cavity’s thickness direction, as well as contraction-expansion channels.","PeriodicalId":14410,"journal":{"name":"International Polymer Processing","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46510298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The practical applications of poly (vinyl chloride) have been constrained due to its poor thermal stability, low dielectric constant and inability to shield against ultraviolet (UV) radiation. In this study, we tried to improve the optical properties, thermal stability, temperature-dependent electrical conductivity and dielectric constant using copper alumina (Cu–Al2O3) nanoparticles reinforced poly (vinyl chloride) (PVC). Optical absorption measured with an ultraviolet-visible (UV-visible) spectrometer emphasises the blueshift in absorption edges and decreasing bandgap energies of PVC/Cu–Al2O3 nanocomposites compared to PVC. The presence of Cu–Al2O3 in PVC and its interaction with the polymer were confirmed by FTIR spectroscopy. Thermogravimetric analysis (TGA) demonstrates that nanocomposites have higher thermal stability than PVC, and that thermal stability increases with filler loading. Scanning electron microscopy (SEM) indicates the homogeneous dispersion of nanosized Cu–Al2O3 in the polymer matrix. The activation energy determined by the Arrhenius equation revealed that AC conductivity increases with the addition of nanoparticles up to a specific loading. The dielectric constant increases as a function of temperature and decreases with frequency. The magnitude of AC conductivity and dielectric constant were highest for 7 wt% loaded nanocomposites. The dielectric constant predicted by the Bruggeman and Maxwell-Garnet models were in good agreement with the experimental permittivity. The semiconducting nature of nanocomposites was investigated by impedance analysis. The semi-circular nature of Cole-Cole plots manifests the combination of parallel capacitance with low bulk resistance. The enhanced optical, thermal, electrical and dielectric properties of PVC/Cu–Al2O3 nanocomposites can be utilized in fabricating optoelectronic devices with excellent charge-storing ability.
{"title":"Optical and temperature dependent electrical properties of poly (vinyl chloride)/copper alumina nanocomposites for optoelectronic devices","authors":"S. Suvarna, A. Sebastian, Furhan, M. T. Ramesan","doi":"10.1515/ipp-2022-4270","DOIUrl":"https://doi.org/10.1515/ipp-2022-4270","url":null,"abstract":"Abstract The practical applications of poly (vinyl chloride) have been constrained due to its poor thermal stability, low dielectric constant and inability to shield against ultraviolet (UV) radiation. In this study, we tried to improve the optical properties, thermal stability, temperature-dependent electrical conductivity and dielectric constant using copper alumina (Cu–Al2O3) nanoparticles reinforced poly (vinyl chloride) (PVC). Optical absorption measured with an ultraviolet-visible (UV-visible) spectrometer emphasises the blueshift in absorption edges and decreasing bandgap energies of PVC/Cu–Al2O3 nanocomposites compared to PVC. The presence of Cu–Al2O3 in PVC and its interaction with the polymer were confirmed by FTIR spectroscopy. Thermogravimetric analysis (TGA) demonstrates that nanocomposites have higher thermal stability than PVC, and that thermal stability increases with filler loading. Scanning electron microscopy (SEM) indicates the homogeneous dispersion of nanosized Cu–Al2O3 in the polymer matrix. The activation energy determined by the Arrhenius equation revealed that AC conductivity increases with the addition of nanoparticles up to a specific loading. The dielectric constant increases as a function of temperature and decreases with frequency. The magnitude of AC conductivity and dielectric constant were highest for 7 wt% loaded nanocomposites. The dielectric constant predicted by the Bruggeman and Maxwell-Garnet models were in good agreement with the experimental permittivity. The semiconducting nature of nanocomposites was investigated by impedance analysis. The semi-circular nature of Cole-Cole plots manifests the combination of parallel capacitance with low bulk resistance. The enhanced optical, thermal, electrical and dielectric properties of PVC/Cu–Al2O3 nanocomposites can be utilized in fabricating optoelectronic devices with excellent charge-storing ability.","PeriodicalId":14410,"journal":{"name":"International Polymer Processing","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42303046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract As the final stage of the mixing process, the final mixing has a profound impact on the properties of rubber compounds. The influence of the process parameters of a continuous final mixer on the properties of carbon black/rubber composites is studied. It is found that there are two factors affecting the performance of the composite: the rotating speed of the dual rotors and the temperature of the continuous final mixer. When the temperature is unchanged, the extruding temperature of the final-mixing rubber compound increases with increasing rotating speed, and the Mooney viscosity, T10, T90 and rolling resistance gradually decrease. The Payne effect decreases first and then increases, and the overall trend gradually decreases. When the rotating speed is constant, as the temperature of the continuous final mixer rises, the extruding temperature also rises, and the temperature difference between feeding and extruding increases. Mooney viscosity and tensile strength increase. The Payne effect is more significant. T10, T90 and rolling resistance gradually decrease. The M300 of a vulcanized sample shows the following laws: When the control temperature is low, the influence of rotational speed is small, the fluctuation range is small, and has a steady rising trend; however, when the temperature is higher, M300 fluctuates greatly under the influence of rotational speed. The optimal process parameters of the rubber continuous final mixer are determined: the double rotor speed is 30RPM, and the temperature control temperature is 60–70 °C.
{"title":"Influence of process parameters of a continuous final mixer on the properties of carbon black/rubber composites","authors":"Kongshuo Wang, Deshang Han, Xinxin Xiao, Luyin Wang, Guangzhi Niu, Shoufeng Zhang, Chuansheng Wang, H. Bian","doi":"10.1515/ipp-2022-4265","DOIUrl":"https://doi.org/10.1515/ipp-2022-4265","url":null,"abstract":"Abstract As the final stage of the mixing process, the final mixing has a profound impact on the properties of rubber compounds. The influence of the process parameters of a continuous final mixer on the properties of carbon black/rubber composites is studied. It is found that there are two factors affecting the performance of the composite: the rotating speed of the dual rotors and the temperature of the continuous final mixer. When the temperature is unchanged, the extruding temperature of the final-mixing rubber compound increases with increasing rotating speed, and the Mooney viscosity, T10, T90 and rolling resistance gradually decrease. The Payne effect decreases first and then increases, and the overall trend gradually decreases. When the rotating speed is constant, as the temperature of the continuous final mixer rises, the extruding temperature also rises, and the temperature difference between feeding and extruding increases. Mooney viscosity and tensile strength increase. The Payne effect is more significant. T10, T90 and rolling resistance gradually decrease. The M300 of a vulcanized sample shows the following laws: When the control temperature is low, the influence of rotational speed is small, the fluctuation range is small, and has a steady rising trend; however, when the temperature is higher, M300 fluctuates greatly under the influence of rotational speed. The optimal process parameters of the rubber continuous final mixer are determined: the double rotor speed is 30RPM, and the temperature control temperature is 60–70 °C.","PeriodicalId":14410,"journal":{"name":"International Polymer Processing","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66814074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The corner vortex phenomenon occurring in entry flow is relevant to both polymer rheology and polymer processing. The famous viscoelastic constitutive equations in numerical computations of fluid mechanics have always had limited relevance at low apparent shear rates. However, three-dimensional (3D) simulations of viscoelastic fluids have been rarely found in advanced rheology. Recently, the GNF-X (eXtended Generalized Newtonian Fluid) constitutive equation of the weighted shear/extensional viscosity developed in advanced rheology of complex fluids has been incorporated into state-of-the-art predictive engineering tools. Thereby, 3D numerical simulations of entry flow were performed for a LDPE (low-density polyethylene) melt. As a validation, the predicted vortex streamlines are in good agreement with related experimental observations. More importantly, the simulation results show the vortex growth with respect to apparent shear rates, contraction ratios, and inlet angles. In particular for extensional viscosity, the stronger extension hardening characteristic yields a large vortex size.
{"title":"Three-dimensional simulation of vortex growth within entry flow of a polymer melt","authors":"H. Tseng","doi":"10.1515/ipp-2022-4277","DOIUrl":"https://doi.org/10.1515/ipp-2022-4277","url":null,"abstract":"Abstract The corner vortex phenomenon occurring in entry flow is relevant to both polymer rheology and polymer processing. The famous viscoelastic constitutive equations in numerical computations of fluid mechanics have always had limited relevance at low apparent shear rates. However, three-dimensional (3D) simulations of viscoelastic fluids have been rarely found in advanced rheology. Recently, the GNF-X (eXtended Generalized Newtonian Fluid) constitutive equation of the weighted shear/extensional viscosity developed in advanced rheology of complex fluids has been incorporated into state-of-the-art predictive engineering tools. Thereby, 3D numerical simulations of entry flow were performed for a LDPE (low-density polyethylene) melt. As a validation, the predicted vortex streamlines are in good agreement with related experimental observations. More importantly, the simulation results show the vortex growth with respect to apparent shear rates, contraction ratios, and inlet angles. In particular for extensional viscosity, the stronger extension hardening characteristic yields a large vortex size.","PeriodicalId":14410,"journal":{"name":"International Polymer Processing","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48008645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract With a rotating mold core during the injection molding of fibre-reinforced plastics, the rotational shear caused by the rotation is superimposed on the injection-induced shear. This allows the fibre orientation in this area to be intentionally manipulated so that, for example, in the case of internal pressure loading, the fibres can be oriented in the tangential main loading direction. This paper deals with the impact of a rotating mold core on the fibre orientation and burst strength of short-and long-fibre-reinforced polypropylene. It is shown that the fibre orientation and strength can be significantly influenced for both short and long fibres, whereby increases in bursting strength of mostly over 80%, in some cases over 200%, could be achieved. The ultimate strength depends, among other things, on the wall thickness used and the fibre content. Major differences between the short-and long-fibre-reinforced polypropylene are less evident in the strength and more in the fibre orientation.
{"title":"Comparison of fibre reorientation of short-and long-fibre reinforced polypropylene by injection molding with a rotating mold core","authors":"Philipp Land, T. Krumpholz, H. Heim","doi":"10.1515/ipp-2022-4252","DOIUrl":"https://doi.org/10.1515/ipp-2022-4252","url":null,"abstract":"Abstract With a rotating mold core during the injection molding of fibre-reinforced plastics, the rotational shear caused by the rotation is superimposed on the injection-induced shear. This allows the fibre orientation in this area to be intentionally manipulated so that, for example, in the case of internal pressure loading, the fibres can be oriented in the tangential main loading direction. This paper deals with the impact of a rotating mold core on the fibre orientation and burst strength of short-and long-fibre-reinforced polypropylene. It is shown that the fibre orientation and strength can be significantly influenced for both short and long fibres, whereby increases in bursting strength of mostly over 80%, in some cases over 200%, could be achieved. The ultimate strength depends, among other things, on the wall thickness used and the fibre content. Major differences between the short-and long-fibre-reinforced polypropylene are less evident in the strength and more in the fibre orientation.","PeriodicalId":14410,"journal":{"name":"International Polymer Processing","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49342385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：