Laser assisted tape winding is a manufacturing technique to produce thermoplastic composite parts of high quality. It is an additive semi-freeform fabrication process that utilizes thermoplastic composite prepreg tape as the base material. The tape is fused by the heat delivered from a laser beam, while it is wound onto a cylindrical mandrel. To ensure proper consolidation to the substrate, a roller applies the necessary compaction pressure. The fabrication of high quality rings with circular (Beyeler, 1988 and Irwin, 1994) and non-circular (Pistor et al. 1995) shape using quarter inch wide prepreg tape (PPS/Carbon, PEEK/Carbon) has been successfully demonstrated. The shape of the beam utilized in these investigations was determined by a series of lenses that formed the circular beam of the CO2 laser into a vertical narrow ellipse approximately 6.4 mm high and 2 mm wide (Pistor et al., 1995). The area illuminated by the infrared laser was therefore preset and not adjustable, limiting the set-up to the processing of quarter inch wide tape. One of the advantages of using a laser beam for the consolidation of thermoplastic resins is the that extremely high heat trnsfer rates to the resin are possible. This can be exploited not only for laser power adjustments in response to variations in tape laying velocity (Pistor et al., 1995), but also for scanning of a circular beam spot over the desired consolidation area. For the described set-up, a vertical slit of adjustable height was realized by scanning the laser beam vertically with a frequency of 100–500 Hz. Scanning height and frequency as well as motion and laser power are computer controllable.
激光辅助卷绕是一种生产高质量热塑性复合材料零件的制造技术。它是一种以热塑性复合预浸料带为基材的增材半自由成形制造工艺。当胶带缠绕在圆柱形芯轴上时，由激光束发出的热量将其熔化。为了确保基材的适当固结，辊子施加必要的压实压力。使用四分之一英寸宽的预浸料带(PPS/Carbon, PEEK/Carbon)制造高质量的圆形(Beyeler, 1988年和Irwin, 1994年)和非圆形(Pistor等人，1995年)形状的环已被成功证明。这些研究中使用的光束形状是由一系列透镜决定的，这些透镜将CO2激光器的圆形光束形成一个垂直的窄椭圆，高约6.4 mm，宽约2mm (Pistor et al.， 1995)。因此，红外激光照射的区域是预设的，不可调节的，限制了设置，以处理四分之一英寸宽的磁带。使用激光束固化热塑性树脂的优点之一是，极高的热传递率树脂是可能的。这不仅可以用于激光功率调整以响应胶带铺设速度的变化(Pistor等人，1995年)，还可以用于扫描所需固化区域上的圆形光束点。对于所描述的设置，通过以100-500 Hz的频率垂直扫描激光束来实现高度可调的垂直狭缝。扫描高度、频率、运动和激光功率均由计算机控制。
{"title":"Evaluation of Process Control During On-Line Consolidation of Thermoplastic Composites","authors":"C. Pistor, M. Yardimci, Raoul Castro, S. Güçeri","doi":"10.1115/imece1997-0627","DOIUrl":"https://doi.org/10.1115/imece1997-0627","url":null,"abstract":"\u0000 Laser assisted tape winding is a manufacturing technique to produce thermoplastic composite parts of high quality. It is an additive semi-freeform fabrication process that utilizes thermoplastic composite prepreg tape as the base material. The tape is fused by the heat delivered from a laser beam, while it is wound onto a cylindrical mandrel. To ensure proper consolidation to the substrate, a roller applies the necessary compaction pressure.\u0000 The fabrication of high quality rings with circular (Beyeler, 1988 and Irwin, 1994) and non-circular (Pistor et al. 1995) shape using quarter inch wide prepreg tape (PPS/Carbon, PEEK/Carbon) has been successfully demonstrated. The shape of the beam utilized in these investigations was determined by a series of lenses that formed the circular beam of the CO2 laser into a vertical narrow ellipse approximately 6.4 mm high and 2 mm wide (Pistor et al., 1995). The area illuminated by the infrared laser was therefore preset and not adjustable, limiting the set-up to the processing of quarter inch wide tape.\u0000 One of the advantages of using a laser beam for the consolidation of thermoplastic resins is the that extremely high heat trnsfer rates to the resin are possible. This can be exploited not only for laser power adjustments in response to variations in tape laying velocity (Pistor et al., 1995), but also for scanning of a circular beam spot over the desired consolidation area. For the described set-up, a vertical slit of adjustable height was realized by scanning the laser beam vertically with a frequency of 100–500 Hz. Scanning height and frequency as well as motion and laser power are computer controllable.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125437618","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}
This paper presents plastic foam processing for the manufacture of LLDPE foams in rotomolding. In order to better understand the mechanisms of foaming, a fundamental study on the foaming process in rotomolding has been conducted. First, the decomposition behavior of the chemical blowing agents was studied by a thermogravimetric analyzer (TGA). The rheological properties of zero-shear viscosity and melt elasticity for LLDPEs were measured using a rotational stress rheometer. Also, an optical microscope with a hot stage was effectively used to study the cell nucleation, growth, coalescence and coarsening in LLDPE melts which provide an improved understanding of the foaming dynamics with a chemical blowing agent in rotational molding. Finally, the actual foaming behavior in rotomolding has also been studied. The experimental results indicate that the amount of blowing agent, the heating time, and the processing temperature play an important role in determining the cell morphology in rotational foam molding.
{"title":"Rotational Molding of Low-Density LLDPE Foams","authors":"Guobin Liu, Chul B. Park, J. Lefas","doi":"10.1115/imece1997-0618","DOIUrl":"https://doi.org/10.1115/imece1997-0618","url":null,"abstract":"\u0000 This paper presents plastic foam processing for the manufacture of LLDPE foams in rotomolding. In order to better understand the mechanisms of foaming, a fundamental study on the foaming process in rotomolding has been conducted. First, the decomposition behavior of the chemical blowing agents was studied by a thermogravimetric analyzer (TGA). The rheological properties of zero-shear viscosity and melt elasticity for LLDPEs were measured using a rotational stress rheometer. Also, an optical microscope with a hot stage was effectively used to study the cell nucleation, growth, coalescence and coarsening in LLDPE melts which provide an improved understanding of the foaming dynamics with a chemical blowing agent in rotational molding. Finally, the actual foaming behavior in rotomolding has also been studied. The experimental results indicate that the amount of blowing agent, the heating time, and the processing temperature play an important role in determining the cell morphology in rotational foam molding.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115865014","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}
The electrical conductivity of alternating current (AC) and permittivity of carbon-black (CB)-filled low density polyethylene (LDPE) has been measured as function of time at a temperature higher than the melting temperature of matrix polymer. The conductivities measured at lower frequencies (If) can be used for the characterization of the properties of the interlayer between the CB-particles. The conductivities measured at higher frequencies (hf) reflects the properties of the internal structure of the individual CB-aggregate. At a characteristic time t°, the lf AC conductivity suddenly increased up to the hf conductivity and the permittivity suddenly decreased. The CB aggregates are probably linked together by paracrystalline layers after a certain time of annealing. The time t° increases with the weight percent of CB. It was also found that t° increases as the temperature of annealing decreases. The time t° is interpreted as a relaxation of potential energy of electrostatic repulsion forces between the reversible disintegrated CB particles. The poor reproducibility and stability of CB-filled plastics can be explained by the observed changes of conductivity.
{"title":"Intelligent Processing of Carbon-Black Loaded Plastics","authors":"V. Bouda","doi":"10.1115/imece1997-0635","DOIUrl":"https://doi.org/10.1115/imece1997-0635","url":null,"abstract":"\u0000 The electrical conductivity of alternating current (AC) and permittivity of carbon-black (CB)-filled low density polyethylene (LDPE) has been measured as function of time at a temperature higher than the melting temperature of matrix polymer. The conductivities measured at lower frequencies (If) can be used for the characterization of the properties of the interlayer between the CB-particles. The conductivities measured at higher frequencies (hf) reflects the properties of the internal structure of the individual CB-aggregate. At a characteristic time t°, the lf AC conductivity suddenly increased up to the hf conductivity and the permittivity suddenly decreased. The CB aggregates are probably linked together by paracrystalline layers after a certain time of annealing. The time t° increases with the weight percent of CB. It was also found that t° increases as the temperature of annealing decreases. The time t° is interpreted as a relaxation of potential energy of electrostatic repulsion forces between the reversible disintegrated CB particles. The poor reproducibility and stability of CB-filled plastics can be explained by the observed changes of conductivity.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117274674","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}
Orientation formation in a steady, Newtonian, Hele-Shaw flow containing rigid, neutrally buoyant, slender fibers is numerically analyzed. The Hele-Shaw model is used to simulate flows through mold cavities consisting of thin planar sections. In this study, orientation results are calculated for a mold cavity containing a three to one sudden contraction. The suspension is injected from a single inlet gate at constant volume flow rate. Initially, the planar stream function is numerically solved by an Eulerian finite difference method to obtain the flow field. Subsequently, a Lagrangian particle tracking method is used to calculate the orientation field from the flow kinematics. The three-dimensional orientation formation throughout the mold cavity is obtained by a new method which calculates the second-order orientation tensors directly from flow kinematics and particle aspect ratio. With this new method, time-consuming integrals and inaccurate closure approximations commonly used in orientation calculations are avoided. The rotational dynamics of each particle are described by Jeffery’s theory. The numerical results are valid for multi-particle, dilute suspensions in which the orientation field can be fully described by the second-order moment of the orientation probability density function (OPDF). The orientation results are presented at different layers through the thickness of the mold cavity, ranging from the midplane to the top wall. In addition, the second-order orientation tensor is averaged through the mold thickness at a number of points in the vicinity of sudden contraction. These averaged orientation tensors are compared with the experimental data obtained from the same flow configuration by Olivero et al. (1997).
{"title":"Orientation Formation in Planar Mold Filling: Theory and Numerical Predictions","authors":"Jufang He, K. Olivero, M. Altan","doi":"10.1115/imece1997-0637","DOIUrl":"https://doi.org/10.1115/imece1997-0637","url":null,"abstract":"\u0000 Orientation formation in a steady, Newtonian, Hele-Shaw flow containing rigid, neutrally buoyant, slender fibers is numerically analyzed. The Hele-Shaw model is used to simulate flows through mold cavities consisting of thin planar sections. In this study, orientation results are calculated for a mold cavity containing a three to one sudden contraction. The suspension is injected from a single inlet gate at constant volume flow rate. Initially, the planar stream function is numerically solved by an Eulerian finite difference method to obtain the flow field. Subsequently, a Lagrangian particle tracking method is used to calculate the orientation field from the flow kinematics. The three-dimensional orientation formation throughout the mold cavity is obtained by a new method which calculates the second-order orientation tensors directly from flow kinematics and particle aspect ratio. With this new method, time-consuming integrals and inaccurate closure approximations commonly used in orientation calculations are avoided. The rotational dynamics of each particle are described by Jeffery’s theory. The numerical results are valid for multi-particle, dilute suspensions in which the orientation field can be fully described by the second-order moment of the orientation probability density function (OPDF). The orientation results are presented at different layers through the thickness of the mold cavity, ranging from the midplane to the top wall. In addition, the second-order orientation tensor is averaged through the mold thickness at a number of points in the vicinity of sudden contraction. These averaged orientation tensors are compared with the experimental data obtained from the same flow configuration by Olivero et al. (1997).","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127066307","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}
During the filling stage of injection molding, important thermal phenomena take place in the mold feeding system. We present a non-isothermal model for the flow through the runners and the gates that permits us to accurately simulate the filling of thermoplastics parts. Comparison with experiments demonstrates the validity of our approach.
{"title":"Calculation and Optimisation of the Feeding System in Thermoplastics Injection","authors":"N. Van Rutten, F. Dupret","doi":"10.1115/imece1997-0644","DOIUrl":"https://doi.org/10.1115/imece1997-0644","url":null,"abstract":"\u0000 During the filling stage of injection molding, important thermal phenomena take place in the mold feeding system. We present a non-isothermal model for the flow through the runners and the gates that permits us to accurately simulate the filling of thermoplastics parts. Comparison with experiments demonstrates the validity of our approach.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125680577","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}
A novel process control system for injection molding based on the integration of Computer Aided Engineering systems (CAE) and process control models has been studied and verified. The objective is to develop a scientific approach for on-line process control by making use of the results from the CAE systems. Initially, the design of injection molded products should be finished with the help of the CAE systems after the dimensions of the products have been determined. From a set of process conditions given by the CAE results, an automatic design of experimentation procedure was conducted for locating the processing window. The processing window was then employed as the CAE inputs for establishing a process model by employing adaptive fuzzy-neural networks. In addition, a set of quasi-optimal process condition was achieved if an optimization objective had been determined based on production requirement. Finally, appropriate cycle-to-cycle control actions on tuning process conditions were taken while the pertinent feedback signals from the process were stored. This process control methodology has been demonstrated with test cases showing promising results.
{"title":"A Novel Process Control for Injection Molding Based Upon On-Line CAE Systems","authors":"Pei-Jen Wang, Jin-Yow Lin","doi":"10.1115/imece1997-0634","DOIUrl":"https://doi.org/10.1115/imece1997-0634","url":null,"abstract":"\u0000 A novel process control system for injection molding based on the integration of Computer Aided Engineering systems (CAE) and process control models has been studied and verified. The objective is to develop a scientific approach for on-line process control by making use of the results from the CAE systems. Initially, the design of injection molded products should be finished with the help of the CAE systems after the dimensions of the products have been determined. From a set of process conditions given by the CAE results, an automatic design of experimentation procedure was conducted for locating the processing window. The processing window was then employed as the CAE inputs for establishing a process model by employing adaptive fuzzy-neural networks. In addition, a set of quasi-optimal process condition was achieved if an optimization objective had been determined based on production requirement. Finally, appropriate cycle-to-cycle control actions on tuning process conditions were taken while the pertinent feedback signals from the process were stored. This process control methodology has been demonstrated with test cases showing promising results.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127857010","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}
A numerical procedure to simulate the formation of a sink mark near the base of a rib in an injection molded plastic part has been presented. Two commercially available software packages, C-Mold and Abaqus, have been used to predict sink marks. Dependence of sink mark depth on various geometric and molding parameters has been analyzed. The predicted sink mark depth is found to be in good agreement with experimental results from the literature.
{"title":"Finite Element Prediction of Sink Marks in Injection Molded Plastic Parts","authors":"D. J. Battey, M. Gupta","doi":"10.1115/imece1997-0639","DOIUrl":"https://doi.org/10.1115/imece1997-0639","url":null,"abstract":"\u0000 A numerical procedure to simulate the formation of a sink mark near the base of a rib in an injection molded plastic part has been presented. Two commercially available software packages, C-Mold and Abaqus, have been used to predict sink marks. Dependence of sink mark depth on various geometric and molding parameters has been analyzed. The predicted sink mark depth is found to be in good agreement with experimental results from the literature.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126909482","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}
A. J. Bur, K. Migler, Mark G. Vangel, D. Johnsonbaugh
We have developed a measurement methodology for measuring resin temperature and temperature profiles during processing using fluorescence spectroscopy. The technique consists of mixing a temperature sensitive fluorescent dye with a polymer resin at very low concentration, on the order of 10−6 molar concentration, and monitoring the temperature dependence of the fluorescence spectra. Two classes of fluorescent dyes are used: (a) excimer producing dyes such as bis-(pyrene) propane, and (b) band broadening dyes such as perylene and benzoxazolyl stilbene. Because the fluorescence measurement reflects the temperature in the neighborhood of the dye molecule, true resin temperature is observed and effects due the large thermal mass of the processing machine are minimized. Real-time monitoring was achieved using optical fiber sensors which were inserted into the process line at existing instrumentation ports. We monitored both injection molding and extrusion observing effects due to shear heating, crystallization and thermal diffusion. Temperature profiles in a flowing resin were measured using a sensor with confocal focusing optics. With this sensor, excitation light is focused to a point in the resin and the temperature at that point is deduced from the resultant fluorescence. In most cases, the fluorescence data must be corrected for effects due to pressure in order to yield an accurate temperature measurement.
{"title":"Real-Time Resin Temperature Measurements for Polymer Processing Using Fluorescence Spectroscopy","authors":"A. J. Bur, K. Migler, Mark G. Vangel, D. Johnsonbaugh","doi":"10.1115/imece1997-0630","DOIUrl":"https://doi.org/10.1115/imece1997-0630","url":null,"abstract":"\u0000 We have developed a measurement methodology for measuring resin temperature and temperature profiles during processing using fluorescence spectroscopy. The technique consists of mixing a temperature sensitive fluorescent dye with a polymer resin at very low concentration, on the order of 10−6 molar concentration, and monitoring the temperature dependence of the fluorescence spectra. Two classes of fluorescent dyes are used: (a) excimer producing dyes such as bis-(pyrene) propane, and (b) band broadening dyes such as perylene and benzoxazolyl stilbene. Because the fluorescence measurement reflects the temperature in the neighborhood of the dye molecule, true resin temperature is observed and effects due the large thermal mass of the processing machine are minimized. Real-time monitoring was achieved using optical fiber sensors which were inserted into the process line at existing instrumentation ports. We monitored both injection molding and extrusion observing effects due to shear heating, crystallization and thermal diffusion. Temperature profiles in a flowing resin were measured using a sensor with confocal focusing optics. With this sensor, excitation light is focused to a point in the resin and the temperature at that point is deduced from the resultant fluorescence. In most cases, the fluorescence data must be corrected for effects due to pressure in order to yield an accurate temperature measurement.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122268182","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}
The speed and accuracy with which Fused Deposition (FD) ABS plastic components can be made gives this rapid-prototyping technology unique potential as a new method for manufacturing complex structural components. Quantitative relationships between the FD process variables and the resulting mechanical properties are needed for intelligent manufacture of polymer components with tailored strength properties. This work examined the influence of the process variables on the resulting microstructure (void and interface bond length densities) of two configurations with uniaxial fiber orientation. The results showed the void and interface densities to be strongly dependent on the fiber-to-fiber gap and extrusion flow rate settings; the influence of extrusion and envelope temperatures is much smaller. The skewed fiber configuration exhibited the lowest void density but also the lowest interface density values. However, the difference observed in the values for the interface density were not as big as for the case of the void density. An investigation of the influence of the process variables on the interface bond strengths and the tensile behavior of pre- and post-extruded fibers as a function of loading rate and test temperature is in progress.
{"title":"Characterizing the Microstructure of Fused Deposition Polymer Components","authors":"J. Rodríguez, James P. Thomas, J. Renaud","doi":"10.1115/imece1997-0636","DOIUrl":"https://doi.org/10.1115/imece1997-0636","url":null,"abstract":"\u0000 The speed and accuracy with which Fused Deposition (FD) ABS plastic components can be made gives this rapid-prototyping technology unique potential as a new method for manufacturing complex structural components. Quantitative relationships between the FD process variables and the resulting mechanical properties are needed for intelligent manufacture of polymer components with tailored strength properties. This work examined the influence of the process variables on the resulting microstructure (void and interface bond length densities) of two configurations with uniaxial fiber orientation. The results showed the void and interface densities to be strongly dependent on the fiber-to-fiber gap and extrusion flow rate settings; the influence of extrusion and envelope temperatures is much smaller. The skewed fiber configuration exhibited the lowest void density but also the lowest interface density values. However, the difference observed in the values for the interface density were not as big as for the case of the void density. An investigation of the influence of the process variables on the interface bond strengths and the tensile behavior of pre- and post-extruded fibers as a function of loading rate and test temperature is in progress.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116142223","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}
Global manufacturers of thermoplastic molded parts increasingly require 100% quality inspection levels that are difficult to achieve. While process complexity makes it difficult to attain the desired part properties during start-up. the stochastic nature of the process causes difficulty in maintaining part quality during production. This paper formally compares several alternative quality control methods that are currently utilized for processing of polymeric materials. To identify the technical issues associated with this goal, the injection molding process is described utilizing a control systems approach. Afterwards, four different methods of quality regulation are synthesized for injection molding: open loop quality control, statistical process control, trained parameter control, and on-line quality regression. For each strategy, the level of quality observability and controllability are determined against the dynamics of the manufacturing system. The results indicate that none of the quality regulation strategies have the underlying design architecture to deliver 100% quality assurance across a diverse set of application characteristics (quality requirements, material properties, mold geometries, and machine dynamics). As such, subsequent discussion focuses on defining the system requirements for achieving ‘intelligent’ processing of polymeric materials that are needed by industry.
{"title":"Synthesis and Analysis of Quality Control Methods for Intelligent Processing of Polymeric Materials","authors":"D. Kazmer, T. Petrova","doi":"10.1115/imece1997-0633","DOIUrl":"https://doi.org/10.1115/imece1997-0633","url":null,"abstract":"\u0000 Global manufacturers of thermoplastic molded parts increasingly require 100% quality inspection levels that are difficult to achieve. While process complexity makes it difficult to attain the desired part properties during start-up. the stochastic nature of the process causes difficulty in maintaining part quality during production. This paper formally compares several alternative quality control methods that are currently utilized for processing of polymeric materials. To identify the technical issues associated with this goal, the injection molding process is described utilizing a control systems approach. Afterwards, four different methods of quality regulation are synthesized for injection molding: open loop quality control, statistical process control, trained parameter control, and on-line quality regression. For each strategy, the level of quality observability and controllability are determined against the dynamics of the manufacturing system.\u0000 The results indicate that none of the quality regulation strategies have the underlying design architecture to deliver 100% quality assurance across a diverse set of application characteristics (quality requirements, material properties, mold geometries, and machine dynamics). As such, subsequent discussion focuses on defining the system requirements for achieving ‘intelligent’ processing of polymeric materials that are needed by industry.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125015463","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}
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