The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform

A Kipping - One of the best experts on this subject based on the ideXlab platform.

  • understanding heat transfer mechanisms during the cooling phase of blow molding using infrared thermography
    Ndt & E International, 2005
    Co-Authors: Abdelhakim Bendada, Fouad Erchiqui, A Kipping
    Abstract:

    The cooling phase of the extrusion blow molding process has a large influence on the cycle time of the process as well as on the properties and quality of the molded products. A better understanding of the heat transfer mechanisms occurring during the cooling phase will help in the optimization of both mold cooling channels and operating conditions. A continuous extrusion blow molding machine and a rectangular bottle (motor oil type) mold were used to produce bottles. A high density polyethylene (HDPE) and a metallocene polyethylene (mPE) having different rheological properties were tested. Melt and mold temperatures, cooling time, inflating pressure and die gap were varied systematically. An infrared camera was used to measure the temperature distribution of the plastic Part just after mold opening as well as after Part Ejection. The wall thickness and dimensions of the bottles of the finished Parts were measured in order to determine the shrinkage and warpage. Finally, the infrared temperature fingerprints were used to explain what happens during the cooling phase and correlated with the final Part characteristics.

  • understanding heat transfer mechanisms during the cooling phase of blow molding using infrared thermography
    Ndt & E International, 2005
    Co-Authors: Abdelhakim Bendada, Fouad Erchiqui, A Kipping
    Abstract:

    The cooling phase of the extrusion blow molding process has a large influence on the cycle time of the process as well as on the properties and quality of the molded products. A better understanding of the heat transfer mechanisms occurring during the cooling phase will help in the optimization of both mold cooling channels and operating conditions. A continuous extrusion blow molding machine and a rectangular bottle (motor oil type) mold were used to produce bottles. A high density polyethylene (HDPE) and a metallocene polyethylene (mPE) having different rheological properties were tested. Melt and mold temperatures, cooling time, inflating pressure and die gap were varied systematically. An infrared camera was used to measure the temperature distribution of the plastic Part just after mold opening as well as after Part Ejection. The wall thickness and dimensions of the bottles of the finished Parts were measured in order to determine the shrinkage and warpage. Finally, the infrared temperature fingerprints were used to explain what happens during the cooling phase and correlated with the final Part characteristics.

Abdelhakim Bendada - One of the best experts on this subject based on the ideXlab platform.

  • understanding heat transfer mechanisms during the cooling phase of blow molding using infrared thermography
    Ndt & E International, 2005
    Co-Authors: Abdelhakim Bendada, Fouad Erchiqui, A Kipping
    Abstract:

    The cooling phase of the extrusion blow molding process has a large influence on the cycle time of the process as well as on the properties and quality of the molded products. A better understanding of the heat transfer mechanisms occurring during the cooling phase will help in the optimization of both mold cooling channels and operating conditions. A continuous extrusion blow molding machine and a rectangular bottle (motor oil type) mold were used to produce bottles. A high density polyethylene (HDPE) and a metallocene polyethylene (mPE) having different rheological properties were tested. Melt and mold temperatures, cooling time, inflating pressure and die gap were varied systematically. An infrared camera was used to measure the temperature distribution of the plastic Part just after mold opening as well as after Part Ejection. The wall thickness and dimensions of the bottles of the finished Parts were measured in order to determine the shrinkage and warpage. Finally, the infrared temperature fingerprints were used to explain what happens during the cooling phase and correlated with the final Part characteristics.

  • understanding heat transfer mechanisms during the cooling phase of blow molding using infrared thermography
    Ndt & E International, 2005
    Co-Authors: Abdelhakim Bendada, Fouad Erchiqui, A Kipping
    Abstract:

    The cooling phase of the extrusion blow molding process has a large influence on the cycle time of the process as well as on the properties and quality of the molded products. A better understanding of the heat transfer mechanisms occurring during the cooling phase will help in the optimization of both mold cooling channels and operating conditions. A continuous extrusion blow molding machine and a rectangular bottle (motor oil type) mold were used to produce bottles. A high density polyethylene (HDPE) and a metallocene polyethylene (mPE) having different rheological properties were tested. Melt and mold temperatures, cooling time, inflating pressure and die gap were varied systematically. An infrared camera was used to measure the temperature distribution of the plastic Part just after mold opening as well as after Part Ejection. The wall thickness and dimensions of the bottles of the finished Parts were measured in order to determine the shrinkage and warpage. Finally, the infrared temperature fingerprints were used to explain what happens during the cooling phase and correlated with the final Part characteristics.

Fouad Erchiqui - One of the best experts on this subject based on the ideXlab platform.

  • understanding heat transfer mechanisms during the cooling phase of blow molding using infrared thermography
    Ndt & E International, 2005
    Co-Authors: Abdelhakim Bendada, Fouad Erchiqui, A Kipping
    Abstract:

    The cooling phase of the extrusion blow molding process has a large influence on the cycle time of the process as well as on the properties and quality of the molded products. A better understanding of the heat transfer mechanisms occurring during the cooling phase will help in the optimization of both mold cooling channels and operating conditions. A continuous extrusion blow molding machine and a rectangular bottle (motor oil type) mold were used to produce bottles. A high density polyethylene (HDPE) and a metallocene polyethylene (mPE) having different rheological properties were tested. Melt and mold temperatures, cooling time, inflating pressure and die gap were varied systematically. An infrared camera was used to measure the temperature distribution of the plastic Part just after mold opening as well as after Part Ejection. The wall thickness and dimensions of the bottles of the finished Parts were measured in order to determine the shrinkage and warpage. Finally, the infrared temperature fingerprints were used to explain what happens during the cooling phase and correlated with the final Part characteristics.

  • understanding heat transfer mechanisms during the cooling phase of blow molding using infrared thermography
    Ndt & E International, 2005
    Co-Authors: Abdelhakim Bendada, Fouad Erchiqui, A Kipping
    Abstract:

    The cooling phase of the extrusion blow molding process has a large influence on the cycle time of the process as well as on the properties and quality of the molded products. A better understanding of the heat transfer mechanisms occurring during the cooling phase will help in the optimization of both mold cooling channels and operating conditions. A continuous extrusion blow molding machine and a rectangular bottle (motor oil type) mold were used to produce bottles. A high density polyethylene (HDPE) and a metallocene polyethylene (mPE) having different rheological properties were tested. Melt and mold temperatures, cooling time, inflating pressure and die gap were varied systematically. An infrared camera was used to measure the temperature distribution of the plastic Part just after mold opening as well as after Part Ejection. The wall thickness and dimensions of the bottles of the finished Parts were measured in order to determine the shrinkage and warpage. Finally, the infrared temperature fingerprints were used to explain what happens during the cooling phase and correlated with the final Part characteristics.

Phill Dickens - One of the best experts on this subject based on the ideXlab platform.

  • Predicting stereolithography injection mould tool behaviour using models to predict Ejection force and tool strength.
    International Journal of Production Research, 2010
    Co-Authors: Neil Hopkinson, Phill Dickens
    Abstract:

    The work reported involved Finite Element Analysis (FEA) modelling of heat transfer in a stereolithography (SL) tool and then performing a series of experiments to measure true heat transfer in the tool. The results from the practical measurement of heat transfer were used to validate and modify the FEA model. The results from the modified FEA model were then used to predict the tensile strength of the tool at various stages after injection of the thermoplastic melt. Previously developed equations to predict Ejection forces were used to estimate the Ejection forces required to push the moulding from the SL core. During the practical experiments the true Ejection forces were measured. The combination of predicted tool strength and Ejection forces were intended to be used a basis for to determine whether certain SL tool designs will fail under tension during Part Ejection. This would help designers and manufacturers to decide whether SL tooling is suitable for a specific application. The initial FEA heat tr...

  • Selection of mould design variables in direct stereolithography injection mould tooling
    Proceedings of the Institution of Mechanical Engineers Part B: Journal of Engineering Manufacture, 2002
    Co-Authors: Russell A. Harris, H A Newlyn, Phill Dickens
    Abstract:

    AbstractStereolithography (SL) can be used rapidly to produce injection moulding tools. The disadvantage of the technique is that it is capable of producing only a small number of Parts before failure. Stereolithography tools may break under the force exerted by Part Ejection when the friction between a moulding and a feature of the tool is greater than the tensile strength of the tool, resulting in tensile failure.Very few justified recommendations exist concerning the choice of mould design variables that can lower the Part Ejection force experienced and reduce the risk of SL tool failure. This research investigates the Ejection forces resulting from the injection moulding of polypropylene (PP), acrylonitrile-butadiene-styrene (ABS) and polyamide 66 (PA66) Parts from SL tools that are identical in all respects except for their build layer thickness (a process variable when generating the SL tooling cavities) and incorporated draft angles (a tooling design variable). This work attempts to identify approp...

  • layer thickness and draft angle selection for stereolithography injection mould tooling
    International Journal of Production Research, 2002
    Co-Authors: Russell A. Harris, H A Newlyn, Neil Hopkinson, Richard J.m. Hague, Phill Dickens
    Abstract:

    The introduction of rapid prototyping has allowed engineers and designers to generate physical models of required Parts very early on in the design and development phase. Further to this, the use of stereolithography (SL) cavities as a rapid tooling method has allowed plastic prototype Parts to be produced in their most common production manner -- by injection moulding. The process is best suited to small production runs where the high costs of conventionally machined tooling is prohibitive. One of the major drawbacks of the SL injectionmoulding process is the susceptibility of the tools to premature failure. SL tools may break under the force exerted by Part Ejection when the friction between a moulding and a core is greater than the tensile strength of the core, resulting in tensile failure. Very few justified recommendations exist about the choice of mould design variables that can lower the Part Ejection force experienced and reduce the risk of SL tool failure. This research investigates the Ejection ...

Chengkui Jen - One of the best experts on this subject based on the ideXlab platform.

  • real time diagnosing polymer processing in injection molding using ultrasound
    Journal of Applied Polymer Science, 2012
    Co-Authors: Lijuan Zhao, Yu Lai, Chen Pei, Chengkui Jen
    Abstract:

    Ultrasonic diagnosing technique with a new high-temperature ultrasonic transducer is developed to real-time diagnose polymer processing and its morphology changes in injection molding processing. Compared with the previous researches, the new technique can provide more and accurate information. In this study, ultrasound diagnosis shows that longitudinal wave can real-time characterize the data of the injection process and polymer morphology changes, including melt flow arrival time, the Part Ejection time, filling and packing stages, polymer solidification process, and the morphology changes during polymer crystallization. Shear waves can real-time diagnose Young's and shear storage modulus, anisotropy property of polymer in injection molding. During our research, real-time ultrasonic diagnosis shows that the storage modulus along the vertical direction is larger than that of the parallel to the melt flow direction under our setup injection conditions. Scanning electron microscopy and dynamic mechanical analysis measurements present that it is because the crystalline lamellas of HDPE are parallel arrangement and grow in a vertical to melt flow direction owing to injection shear force under a certain injection conditions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

  • Real‐time diagnosing polymer processing in injection molding using ultrasound
    Journal of Applied Polymer Science, 2012
    Co-Authors: Lijuan Zhao, Yu Lai, Chen Pei, Chengkui Jen
    Abstract:

    Ultrasonic diagnosing technique with a new high-temperature ultrasonic transducer is developed to real-time diagnose polymer processing and its morphology changes in injection molding processing. Compared with the previous researches, the new technique can provide more and accurate information. In this study, ultrasound diagnosis shows that longitudinal wave can real-time characterize the data of the injection process and polymer morphology changes, including melt flow arrival time, the Part Ejection time, filling and packing stages, polymer solidification process, and the morphology changes during polymer crystallization. Shear waves can real-time diagnose Young's and shear storage modulus, anisotropy property of polymer in injection molding. During our research, real-time ultrasonic diagnosis shows that the storage modulus along the vertical direction is larger than that of the parallel to the melt flow direction under our setup injection conditions. Scanning electron microscopy and dynamic mechanical analysis measurements present that it is because the crystalline lamellas of HDPE are parallel arrangement and grow in a vertical to melt flow direction owing to injection shear force under a certain injection conditions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012