Optical fiber based sensors have potential in the composites processing industry as well as many other industries, but cost and robustness often mitigate the advantages of optical fiber sensors. The least expensive type of optical fiber sensor is a length of fiber either embedded in the part or in distal contact with the part surface. In the case of embedded evanescent mode sensors, important issues hinge on interpreting the evanescent signal obtained during processing or in service inspection. An optical model based on mode coupling theory is presented below to provide a description of the sensing volume around the fiber from which signal is collected during evanescent measurements. The model is developed for a fluorescence sensor but the optical theory could be equally applied for infrared or other types of optical fiber sensors.
{"title":"Mode Coupling Theory for Evanescent Wave Optical Fiber Sensors","authors":"R. Parnas, D. L. Woerdeman","doi":"10.1115/imece1997-0628","DOIUrl":"https://doi.org/10.1115/imece1997-0628","url":null,"abstract":"\u0000 Optical fiber based sensors have potential in the composites processing industry as well as many other industries, but cost and robustness often mitigate the advantages of optical fiber sensors. The least expensive type of optical fiber sensor is a length of fiber either embedded in the part or in distal contact with the part surface. In the case of embedded evanescent mode sensors, important issues hinge on interpreting the evanescent signal obtained during processing or in service inspection. An optical model based on mode coupling theory is presented below to provide a description of the sensing volume around the fiber from which signal is collected during evanescent measurements. The model is developed for a fluorescence sensor but the optical theory could be equally applied for infrared or other types of optical fiber sensors.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"1 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":"130991018","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 resin transfer molding process experiences an unavoidable phenomenon known as race-tracking in which the resin flows along the edges of the mold ahead of the central flow. This phenomena may be severe whereby the resin reaches the top of the mold and exits the mold before it is completely filled. It is of interest to predict this behavior prior to the resin injection. A pre-injection method has been developed to predict whether the flow will be even or skewed and the severity of race tracking. This paper discusses how the method was developed. This method has been successfully used to predict the degree of severity of race tracking in vacuum-assisted resin transfer molding to a high degree of accuracy.
{"title":"Prediction of Race Tracking in Resin Transfer Molding","authors":"S. Owusu-Ofori, D. Pai, R. Sadler","doi":"10.1115/imece1997-0640","DOIUrl":"https://doi.org/10.1115/imece1997-0640","url":null,"abstract":"\u0000 The resin transfer molding process experiences an unavoidable phenomenon known as race-tracking in which the resin flows along the edges of the mold ahead of the central flow. This phenomena may be severe whereby the resin reaches the top of the mold and exits the mold before it is completely filled. It is of interest to predict this behavior prior to the resin injection. A pre-injection method has been developed to predict whether the flow will be even or skewed and the severity of race tracking. This paper discusses how the method was developed. This method has been successfully used to predict the degree of severity of race tracking in vacuum-assisted resin transfer molding to a high degree of accuracy.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"32 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":"131012907","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}
Injection/compression molding (ICM) is often referred to as coining, stamping, compressive-fill, or hybrid molding. It can produce parts with more homogeneous properties and less molded-in stresses, and this may not be possible with conventional injection molding. It can also produce extremely thin or large parts which may require larger machine if conventional injection molding were used. A CAE software has been developed to simulate the ICM process. Two areas will be emphasized to show the advantage of the ICM process over the conventional injection molding process. One is the opening of the mold halves during the molding process allows resin flow to proceed to the extremities of the cavity more easily and consequently reduces the injection pressure and clamping force. Process window design will be discussed. The other is the packing due to the compression motion requires less pressure gradient, i.e., more effective packing. It results in more uniform and smaller pressure throughout the entire cavity. This is essential to produce parts with low residual stress such as compact disk and lens.
{"title":"Numerical Simulation of Injection/Compression Molding","authors":"T. J. Wang","doi":"10.1115/imece1997-0621","DOIUrl":"https://doi.org/10.1115/imece1997-0621","url":null,"abstract":"\u0000 Injection/compression molding (ICM) is often referred to as coining, stamping, compressive-fill, or hybrid molding. It can produce parts with more homogeneous properties and less molded-in stresses, and this may not be possible with conventional injection molding. It can also produce extremely thin or large parts which may require larger machine if conventional injection molding were used.\u0000 A CAE software has been developed to simulate the ICM process. Two areas will be emphasized to show the advantage of the ICM process over the conventional injection molding process. One is the opening of the mold halves during the molding process allows resin flow to proceed to the extremities of the cavity more easily and consequently reduces the injection pressure and clamping force. Process window design will be discussed. The other is the packing due to the compression motion requires less pressure gradient, i.e., more effective packing. It results in more uniform and smaller pressure throughout the entire cavity. This is essential to produce parts with low residual stress such as compact disk and lens.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"43 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":"122117443","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}
In this paper, a mathematical definition of part warpage is presented by strain tensors and part quality is quantified via numerical simulation. An objective function of part quality is proposed that must be optimized. The resulting optimum is obtained by iterative search in the constrained space based on an numerical optimization algorithm — Simulated Annealing method, which is a global and robust method. The efficiency of the simulated Annealing method is in between calculus-based methods, such as DFP, BFGS, MFD and common search schemes, such as, simplex and exhaust search method, etc. (Goffe, 1994). The results are shown by a number of numerical examples where the part warpage is significantly reduced after optimization.
{"title":"An Optimization Scheme for Part Quality in Injection Molding","authors":"Hua Ye, Yinghui Wu, K. K. Wang","doi":"10.1115/imece1997-0625","DOIUrl":"https://doi.org/10.1115/imece1997-0625","url":null,"abstract":"In this paper, a mathematical definition of part warpage is presented by strain tensors and part quality is quantified via numerical simulation. An objective function of part quality is proposed that must be optimized. The resulting optimum is obtained by iterative search in the constrained space based on an numerical optimization algorithm — Simulated Annealing method, which is a global and robust method. The efficiency of the simulated Annealing method is in between calculus-based methods, such as DFP, BFGS, MFD and common search schemes, such as, simplex and exhaust search method, etc. (Goffe, 1994). The results are shown by a number of numerical examples where the part warpage is significantly reduced after optimization.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"2015 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":"127318850","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}
Process modeling has been successfully used in the plastics injection molding industry over the past decade. However, mathematical descriptions in certain areas of plastics processing are either not very well understood or are too complicated to be formulated. An alternative method, such as the semi-empirical approach which integrates models with data bases, has been found to be very effective in helping the tooling engineer with the following problems: understanding the interactions between product design, process conditions, and materials; identifying the process windows; and shortening the tooling design cycle time. Two semi-empirical process models, for the polyurethane foaming and profile extrusion processes, are discussed here to illustrate this useful methodology.
{"title":"Semi-Empirical Process Modeling: Model and Database Integration","authors":"H. P. Wang, E. M. Perry, Martin K. Lee","doi":"10.1115/imece1997-0619","DOIUrl":"https://doi.org/10.1115/imece1997-0619","url":null,"abstract":"\u0000 Process modeling has been successfully used in the plastics injection molding industry over the past decade. However, mathematical descriptions in certain areas of plastics processing are either not very well understood or are too complicated to be formulated. An alternative method, such as the semi-empirical approach which integrates models with data bases, has been found to be very effective in helping the tooling engineer with the following problems: understanding the interactions between product design, process conditions, and materials; identifying the process windows; and shortening the tooling design cycle time. Two semi-empirical process models, for the polyurethane foaming and profile extrusion processes, are discussed here to illustrate this useful methodology.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"311 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":"133200170","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 covers the technology of melt vibration during the molding of plastic material (more specifically at low frequency) to reduce the viscosity and ease processability and to produce orientation benefits. The effect of vibration frequency and amplitude on melt viscosity is explained in terms of shear-thinning criteria. The effect of pressure, temperature and cooling rate on shear-thinning is also reviewed to predict how these variables interfere with melt vibration. Applications to injection molding, extrusion and blow molding of uneasily processable plastic melts (such as metallocenes polyolefins) are suggested.
{"title":"Smart Processing of Plastics Through Vibration Controlled Shear-Thinning and Orientation","authors":"J. Ibar","doi":"10.1115/imece1997-0632","DOIUrl":"https://doi.org/10.1115/imece1997-0632","url":null,"abstract":"\u0000 This paper covers the technology of melt vibration during the molding of plastic material (more specifically at low frequency) to reduce the viscosity and ease processability and to produce orientation benefits. The effect of vibration frequency and amplitude on melt viscosity is explained in terms of shear-thinning criteria. The effect of pressure, temperature and cooling rate on shear-thinning is also reviewed to predict how these variables interfere with melt vibration. Applications to injection molding, extrusion and blow molding of uneasily processable plastic melts (such as metallocenes polyolefins) are suggested.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"50 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":"124843538","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}
Numerical and experimental studies are conducted on the demolding stage of injection molding process. Based on an integrated computer-aided-engineering software package, a numerical approach has been proposed to predict the ejection force and to analyze the layout of ejector pins. The predictions are validated in this work by injection molding of polycarbonate boxes. The boxes are molded at given processing condition while ejected with different layouts of ejector pins. The ejection force is measured by load transducers installed behind the ejector pins. The shrinkage of the boxes is also measured by displacement transducers. It is found that the measured total ejection force and its distribution over the pin layouts compare reasonably well with numerical predictions. The validation is also supported by the agreement between the predicted and measured warpage of the boxes. Additional results are provided for a complex molding geometry for which the mold opening and ejection operations need to be considered in studying the demolding.
{"title":"Numerical and Experimental Studies on the Demolding of Injection Molding Parts","authors":"Hao Wang, K. Kabanemi, G. Salloum","doi":"10.1115/imece1997-0623","DOIUrl":"https://doi.org/10.1115/imece1997-0623","url":null,"abstract":"\u0000 Numerical and experimental studies are conducted on the demolding stage of injection molding process. Based on an integrated computer-aided-engineering software package, a numerical approach has been proposed to predict the ejection force and to analyze the layout of ejector pins. The predictions are validated in this work by injection molding of polycarbonate boxes. The boxes are molded at given processing condition while ejected with different layouts of ejector pins. The ejection force is measured by load transducers installed behind the ejector pins. The shrinkage of the boxes is also measured by displacement transducers. It is found that the measured total ejection force and its distribution over the pin layouts compare reasonably well with numerical predictions. The validation is also supported by the agreement between the predicted and measured warpage of the boxes. Additional results are provided for a complex molding geometry for which the mold opening and ejection operations need to be considered in studying the demolding.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"4 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":"117083506","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}
Mingwen Jiang, C. L. Thomas, R. Peterson, A. J. Bur
An ultrasonic transducer installed facing a pressure transducer in the cavity of a rectangular plaque injection mold shows new sensitivities to the solidification of the polymer in the mold. Features of the amplitude variation of a pulse transmitted twice through the polymer are sensitive to the flow rate and solidification state of the polymer at the transducer face. The signal from a normal incidence shear transducer gives a direct indication of solidification. A model was developed to describe the changing amplitude of a pulse transmitted through the polymer. The model illustrates how temperature, pressure, flow rate, and signal frequency affect the measured echo amplitude.
{"title":"New Ultrasonic Solidification Sensing Techniques for Injection Molding","authors":"Mingwen Jiang, C. L. Thomas, R. Peterson, A. J. Bur","doi":"10.1115/imece1997-0631","DOIUrl":"https://doi.org/10.1115/imece1997-0631","url":null,"abstract":"\u0000 An ultrasonic transducer installed facing a pressure transducer in the cavity of a rectangular plaque injection mold shows new sensitivities to the solidification of the polymer in the mold. Features of the amplitude variation of a pulse transmitted twice through the polymer are sensitive to the flow rate and solidification state of the polymer at the transducer face. The signal from a normal incidence shear transducer gives a direct indication of solidification. A model was developed to describe the changing amplitude of a pulse transmitted through the polymer. The model illustrates how temperature, pressure, flow rate, and signal frequency affect the measured echo amplitude.","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":"130509059","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 increasing requirements on auto makers to reduce both the cost and weight of passenger vehicles as well as meet ever more restrictive government regulations make the use of fiber reinforced plastics very attractive. In particular, the use of thermoset composites, such as SMC and BMC, have been used for years by the major auto makers to produce high quality, strong, stiff, and lightweight body panels. Increasingly, it is being used for more structural components throughout the vehicle. However, the use of fiber filled thermoset composites is not limited to the automotive industry. It is also extensively used in electronic components, sports equipment, and general consumer goods. Accordingly, the need to be able to design these molded parts and to predict the complex behavior during manufacture and in service is paramount to reducing the time from concept to production. This paper introduces a finite element based simulation program that allows the entire molding process, including mold filling, fiber orientation, heat transfer, cure, residual stress and warpage, to be simulated on the computer rather than by experimental prototyping. The software allows designers and engineers to determine product performance during the design stage before the tooling needs to be manufactured. Then, by modifying the design and process with the computer, part optimization can be accomplished prior to building the mold. The paper discusses the models and methods implemented by the simulation program along with the accompanying assumptions. The results of the simulation are compared with experimental results for a variety of parts. This paper then highlights a case study of an injection/compression molded component showing how the simulation can be used as a design optimization tool.
{"title":"Optimization of the Compression (Injection/Compression) Molding Process Using Numerical Simulation","authors":"B. Davis, R. P. Theriault, T. Osswald","doi":"10.1115/imece1997-0624","DOIUrl":"https://doi.org/10.1115/imece1997-0624","url":null,"abstract":"\u0000 The increasing requirements on auto makers to reduce both the cost and weight of passenger vehicles as well as meet ever more restrictive government regulations make the use of fiber reinforced plastics very attractive. In particular, the use of thermoset composites, such as SMC and BMC, have been used for years by the major auto makers to produce high quality, strong, stiff, and lightweight body panels. Increasingly, it is being used for more structural components throughout the vehicle. However, the use of fiber filled thermoset composites is not limited to the automotive industry. It is also extensively used in electronic components, sports equipment, and general consumer goods. Accordingly, the need to be able to design these molded parts and to predict the complex behavior during manufacture and in service is paramount to reducing the time from concept to production.\u0000 This paper introduces a finite element based simulation program that allows the entire molding process, including mold filling, fiber orientation, heat transfer, cure, residual stress and warpage, to be simulated on the computer rather than by experimental prototyping. The software allows designers and engineers to determine product performance during the design stage before the tooling needs to be manufactured. Then, by modifying the design and process with the computer, part optimization can be accomplished prior to building the mold.\u0000 The paper discusses the models and methods implemented by the simulation program along with the accompanying assumptions. The results of the simulation are compared with experimental results for a variety of parts. This paper then highlights a case study of an injection/compression molded component showing how the simulation can be used as a design optimization tool.","PeriodicalId":220828,"journal":{"name":"CAE and Intelligent Processing of Polymeric Materials","volume":"67 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132478571","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}
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：