The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform

Yanjin Guan - One of the best experts on this subject based on the ideXlab platform.

  • Characteristic of rapid Heating Cycle moulding and warpage analysis of products
    Plastics Rubber and Composites, 2020
    Co-Authors: X.-p. Li, Guoqun Zhao, Yanjin Guan
    Abstract:

    Rapid Heating Cycle moulding (RHCM) injection method can be used to solve many defects on the surface of the products produced by conventional injection method, such as weld mark, flow mark and so on. In this paper, the process of RHCM technology was presented. By comparing the new technology with the conventional injection method and the products produced by them, the advantages of RHCM technology were demonstrated. However, large warpage of the products was considered as the main defects of this technology. The reasons that caused the warpage of the products were analysed. Through finite element simulation and engineering experiment, the layout of the cold runners in the RHCM mould was optimised in order to decrease the warpage of the part. The results of the experiments and the finite element simulation were very close, proving that the simulation carried out in the paper was right.

  • Effect of rapid Heating Cycle injection mold temperature on crystal structures, morphology of polypropylene and surface quality of plastic parts
    Journal of Polymer Research, 2015
    Co-Authors: Weihua Wang, Xianghong Wu, Yanjin Guan, Guoqun Zhao, Yang Hui
    Abstract:

    The present study mainly investigated the effect of mold cavity surface temperature in the filling process on the crystallization status of polypropylene (PP) in different thickness layers of injected plastic parts, and revealed the inner relationship between the surface quality of plastic parts, crystallinity and residual stress under rapid Heating Cycle molding (RHCM) process conditions. The morphology of PP was studied by using a transmission-polarized optical microscope (POM) and a scanning electron microscope (SEM). The crystal structures of PP on different thickness layers of plastic parts were examined by using a wide-angle X-ray diffraction (WAXD). The surface quality of plastic parts was characterized by using a glossiness tester. With the increase of mold cavity surface temperature, the thickness of frozen layer of plastic parts is drastically reduced, and the crystallinity of PP in the external surface first increases, then decreases, and finally tends to a constant, but the crystallization in the sub-surface layer first increases, then decreases, and finally increases again. When the temperature of mold cavity surface is close to the glass transition temperature of PP, the crystallinity in the external surface reaches the maximum and the crystallization status in the sub-surface and core layers is close to each other. Meanwhile, the surface glossiness of plastic parts also achieves its best. In addition, the high crystallinity and low residual stress in the external surface are both favorable conditions for obtaining a high surface glossiness of plastic parts.

  • multi objective optimization of the Heating rods layout for rapid electrical Heating Cycle injection mold
    Journal of Mechanical Design, 2010
    Co-Authors: Guoqun Zhao, Xiping Li, Yanjin Guan
    Abstract:

    Rapid electrical Heating Cycle injection molding (ERHCM) technology is a promising green manufacturing technology for plastic parts. By using this technology, the defects that usually appear on the surface of conventionally injected parts, such as weld and flow marks, can be avoided effectively. This paper studies rapid electrical Heating Cycle injection molding technology and its mold structure design techniques. Temperature distribution uniformity and Heating efficiency on the mold cavity surface are considered as the major influencing factors on product quality and production efficiency. A multi-objective optimization model for the Heating rods layout in the mold cavity plate is formulated to optimize temperature distribution uniformity and Heating efficiency with respect to the Heating rods layout. An application to a liquid crystal display TV panel is implemented successfully using a genetic algorithm.

  • 3D Finite Element Simulation of Transient Temperature Field for Rapid Electrical Heating Cycle Injection Mold
    Advanced Materials Research, 2009
    Co-Authors: Xiping Li, Guoqun Zhao, Yanjin Guan
    Abstract:

    Rapid electrical Heating Cycle injection molding technology can be used to produce polymer parts with no weld mark, flow mark and other surface defects on the parts surface. Recently, it has been gradually found wide use in plastic injection industry. In this paper, a structure of the rapid electrical Heating Cycle injection mold and its working processes were presented. As the production efficiency and the part’s quality are seriously affected by the temperature of the mold cavity surface and its distribution uniformity, the heat transfer process of the mold was analyzed by using 3D finite element simulation. The transient temperature values on different places of the cavity surface were obtained. The results provided theoretical guidelines for the engineers to evaluate the layout of the Heating rods in the mold.

  • optimal design of Heating channels for rapid Heating Cycle injection mold based on response surface and genetic algorithm
    Materials & Design, 2009
    Co-Authors: Xiping Li, Yanjin Guan, Guoqun Zhao
    Abstract:

    Rapid Heating Cycle molding (RHCM) technology is a novel polymer injection molding method developed in recent years. In this paper, the principle of RHCM was introduced and a RHCM mold for producing a large-size LCD TV panel was presented. Aiming at achieving a uniform temperature distribution on the cavity surface of the stationary mold insert, the distances between the neighbor Heating channels were considered as the main design variables. An objective function for optimizing the temperature distribution uniformity was proposed. The experiment samples for calculating the objective function were selected by using the Latin Hypercube Design experiment method. A quadric response surface equation for calculating temperature distribution uniformity was established. The design variables were optimized by using genetic algorithm and the optimal solutions were obtained. The temperature distribution uniformity on the stationary mold insert cavity surface was greatly improved. The effectiveness of the optimization method presented in this paper was also demonstrated by industrial injection production of a LCD TV panel.

D.j. Cagliostro - One of the best experts on this subject based on the ideXlab platform.

  • Temperature profile estimation for a thermal regenerator
    Proceedings of the 38th IEEE Conference on Decision and Control (Cat. No.99CH36304), 1999
    Co-Authors: K.r. Muske, J.w. Howse, G.a. Hansen, D.j. Cagliostro
    Abstract:

    The thermal regenerator system studied is the blast furnace stoves for the No. 7 blast furnace at the Ispat Inland facility in East Chicago, Indiana. The paper outlines the process model and model-based state estimation techniques implemented on these stoves. The process model is a detailed heat transfer model of the stoves used as part of a predictive control scheme to determine the minimum amount of fuel necessary to heat the blast air. Batch nonlinear least squares estimation is used to update the predicted temperature profile at the end of each cooling Cycle. This estimated profile is then used by the model-based controller to determine the minimum fuel requirement for the subsequent Heating Cycle.

Makoto Kasu - One of the best experts on this subject based on the ideXlab platform.

Guoqun Zhao - One of the best experts on this subject based on the ideXlab platform.

  • Characteristic of rapid Heating Cycle moulding and warpage analysis of products
    Plastics Rubber and Composites, 2020
    Co-Authors: X.-p. Li, Guoqun Zhao, Yanjin Guan
    Abstract:

    Rapid Heating Cycle moulding (RHCM) injection method can be used to solve many defects on the surface of the products produced by conventional injection method, such as weld mark, flow mark and so on. In this paper, the process of RHCM technology was presented. By comparing the new technology with the conventional injection method and the products produced by them, the advantages of RHCM technology were demonstrated. However, large warpage of the products was considered as the main defects of this technology. The reasons that caused the warpage of the products were analysed. Through finite element simulation and engineering experiment, the layout of the cold runners in the RHCM mould was optimised in order to decrease the warpage of the part. The results of the experiments and the finite element simulation were very close, proving that the simulation carried out in the paper was right.

  • Effect of rapid Heating Cycle injection mold temperature on crystal structures, morphology of polypropylene and surface quality of plastic parts
    Journal of Polymer Research, 2015
    Co-Authors: Weihua Wang, Xianghong Wu, Yanjin Guan, Guoqun Zhao, Yang Hui
    Abstract:

    The present study mainly investigated the effect of mold cavity surface temperature in the filling process on the crystallization status of polypropylene (PP) in different thickness layers of injected plastic parts, and revealed the inner relationship between the surface quality of plastic parts, crystallinity and residual stress under rapid Heating Cycle molding (RHCM) process conditions. The morphology of PP was studied by using a transmission-polarized optical microscope (POM) and a scanning electron microscope (SEM). The crystal structures of PP on different thickness layers of plastic parts were examined by using a wide-angle X-ray diffraction (WAXD). The surface quality of plastic parts was characterized by using a glossiness tester. With the increase of mold cavity surface temperature, the thickness of frozen layer of plastic parts is drastically reduced, and the crystallinity of PP in the external surface first increases, then decreases, and finally tends to a constant, but the crystallization in the sub-surface layer first increases, then decreases, and finally increases again. When the temperature of mold cavity surface is close to the glass transition temperature of PP, the crystallinity in the external surface reaches the maximum and the crystallization status in the sub-surface and core layers is close to each other. Meanwhile, the surface glossiness of plastic parts also achieves its best. In addition, the high crystallinity and low residual stress in the external surface are both favorable conditions for obtaining a high surface glossiness of plastic parts.

  • Three-dimensional numerical simulation of the filling process in rapid Heating Cycle molding
    2010 International Conference on Mechanic Automation and Control Engineering, 2010
    Co-Authors: Guoqun Zhao, Guilong Wang
    Abstract:

    Rapid Heating Cycle molding (RHCM) is a novel injection molding technology. The mold cavity is heated up to a high temperature before the filling stage, usually higher than the glass transition temperature of the polymer. This new technology can be used to inject plastic parts with a shiny surface, no weld lines and no flow marks. A Rapid Heating Cycle Molding Simulation System (RHCM-S) was developed on the basis of an open software library OpenFOAM. The coupled velocity and pressure fields were solved using the PISO (Pressure Implicit with Splitting of Operations) algorithm. The VOF (volume of fluid) method was used to track the melt flow front. The filling process of polymer melt was simulated under various mold temperature. Mold temperature has significant influence on the flow field, temperature field, shear rate and injection pressure of the polymer melt. The results showed that the RHCM process with a relatively high mold temperature could improve the surface quality and performance of the plastic parts.

  • multi objective optimization of the Heating rods layout for rapid electrical Heating Cycle injection mold
    Journal of Mechanical Design, 2010
    Co-Authors: Guoqun Zhao, Xiping Li, Yanjin Guan
    Abstract:

    Rapid electrical Heating Cycle injection molding (ERHCM) technology is a promising green manufacturing technology for plastic parts. By using this technology, the defects that usually appear on the surface of conventionally injected parts, such as weld and flow marks, can be avoided effectively. This paper studies rapid electrical Heating Cycle injection molding technology and its mold structure design techniques. Temperature distribution uniformity and Heating efficiency on the mold cavity surface are considered as the major influencing factors on product quality and production efficiency. A multi-objective optimization model for the Heating rods layout in the mold cavity plate is formulated to optimize temperature distribution uniformity and Heating efficiency with respect to the Heating rods layout. An application to a liquid crystal display TV panel is implemented successfully using a genetic algorithm.

  • 3D Finite Element Simulation of Transient Temperature Field for Rapid Electrical Heating Cycle Injection Mold
    Advanced Materials Research, 2009
    Co-Authors: Xiping Li, Guoqun Zhao, Yanjin Guan
    Abstract:

    Rapid electrical Heating Cycle injection molding technology can be used to produce polymer parts with no weld mark, flow mark and other surface defects on the parts surface. Recently, it has been gradually found wide use in plastic injection industry. In this paper, a structure of the rapid electrical Heating Cycle injection mold and its working processes were presented. As the production efficiency and the part’s quality are seriously affected by the temperature of the mold cavity surface and its distribution uniformity, the heat transfer process of the mold was analyzed by using 3D finite element simulation. The transient temperature values on different places of the cavity surface were obtained. The results provided theoretical guidelines for the engineers to evaluate the layout of the Heating rods in the mold.

Hiromichi Arai - One of the best experts on this subject based on the ideXlab platform.

  • Application of the stabilized zirconia thin film prepared by spray pyrolysis method to SOFC
    Solid State Ionics, 1990
    Co-Authors: Toshiaki Setoguchi, Masanori Sawano, Koichi Eguchi, Hiromichi Arai
    Abstract:

    Thin films of calcia-stabilized zirconia were fabricated from Zr and Ca acetylacetonato complexes on a La0.6Sr0.4MnO3porous electrode substrate by spray pyrolysis method. Although the cracks formed in the film during drying, thermal decomposition, and heat treatment, they could be eliminated by optimizing the substrate temperature and repeating the film deposition and Heating Cycle. The fuel cell consisting of 33 μm thick electrolyte, La0.6Sr0.4MnO3porous cathode substrate, and Ni-YSZ cermet anode attained the open circuit voltage of 0.96 V and maximum power density of 0.5 W·cm-2. © 1990.