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Hiroyuki Hamada - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation on Weld-line in Articles Molded by Injection Compression Molding
    Seikei-kakou, 2020
    Co-Authors: Kengo Nodo, Kazushi Yamada, Hiroyuki Hamada
    Abstract:

    Injection Compression Molding is an effective method to solve various Molding defects . In particular, it is said that it is effective both for the improvement of the transcript of molded articles and for the decrease of weld-line. However very few studies on Injection Compression Molding are reported, in particular, on qualitative weld-line examination. In this study, the effectiveness in the decrease of weld-line was compared between Injection Molding and Injection press Molding (one kind of technique of Injection Compression Molding) using PC/ABS. The ditch depth of weld-line was deeper in case of Injection Molding, whereas it was shallower in Injection press Molding.

  • Fabrication and mechanical properties of textile insert Injection Moldings
    2020
    Co-Authors: Tatsuro Fukui, Miyako Inoda, Asami Nakai, Hiroyuki Hamada
    Abstract:

    In this study, in order to extend one-unity composites to Injection Molding field, textile insert Injection Molding was developed. Knitted fabric was chosen as reinforcement configuration, which is one of the textile configurations. PE/PE one-unity composites were prepared inserting knitted polyethylene (PE) fiber as reinforcement and PE was injected as matrix by using Injection and Injection-Compression Molding process. Tensile properties of PE/PE one-unity knitted composites were investigated. From these results, it was found that the tensile properties were dependent on resin impregnation state into fiber bundles. Tensile properties of Injection-Compression specimens were higher than that of Injection specimens.

  • mechanical properties of textile inserted pp pp knitted composites using Injection Compression Molding
    Composites Part A-applied Science and Manufacturing, 2006
    Co-Authors: O A Khondker, X Yang, N Usui, Hiroyuki Hamada
    Abstract:

    Abstract This paper concentrates on the experimental investigation of the self-reinforced all-polypropylene composites. There exists an optimum processing condition to produce high quality specimens by Injection–Compression Molding. Tensile and 3-point bending properties of the virgin PP materials were nearly unaffected by the introduction of reinforcing knit layer(s) due to very low fibre content of the knitted fabrics used. 3-point bending properties were also unaffected by the surface of indentation-flexure. The applied impact energy was maintained at 5 J for the homo-PP and 27 J for the block-PP materials, respectively, to cause penetration during drop-weight impact tests. It is interestingly noteworthy that the self-reinforced homo-PP composites exhibited superior energy absorption capability when compared with the virgin matrix materials. The corresponding plate bending performances of the self-reinforced homo-PP composites also revealed consistent improvement as compared to their virgin counterparts. On the other hand, although virgin block-PP material exhibited better impact performances than its composite reinforced by the homo-PP knitted fabric, a notably small increase in the reinforcement fibre content revealed considerable improvement in the impact properties comparable to those of the virgin block-PP matrix materials. These self-reinforced homo-PP/block-PP materials have clearly indicated that they have the potential to out-perform the block-PP materials via modification and/or manipulation of the reinforcement knit structural/geometrical parameters and the content of reinforcement fibres. Both static and dynamic impact properties are likely to be affected by the local area properties of the tested face under indentation, and thereby contributing to the improved performances of the composite specimens with the knit face under the impact.

  • Mechanical properties of textile-inserted PP/PP knitted composites using Injection–Compression Molding
    Composites Part A-applied Science and Manufacturing, 2006
    Co-Authors: O A Khondker, X Yang, N Usui, Hiroyuki Hamada
    Abstract:

    Abstract This paper concentrates on the experimental investigation of the self-reinforced all-polypropylene composites. There exists an optimum processing condition to produce high quality specimens by Injection–Compression Molding. Tensile and 3-point bending properties of the virgin PP materials were nearly unaffected by the introduction of reinforcing knit layer(s) due to very low fibre content of the knitted fabrics used. 3-point bending properties were also unaffected by the surface of indentation-flexure. The applied impact energy was maintained at 5 J for the homo-PP and 27 J for the block-PP materials, respectively, to cause penetration during drop-weight impact tests. It is interestingly noteworthy that the self-reinforced homo-PP composites exhibited superior energy absorption capability when compared with the virgin matrix materials. The corresponding plate bending performances of the self-reinforced homo-PP composites also revealed consistent improvement as compared to their virgin counterparts. On the other hand, although virgin block-PP material exhibited better impact performances than its composite reinforced by the homo-PP knitted fabric, a notably small increase in the reinforcement fibre content revealed considerable improvement in the impact properties comparable to those of the virgin block-PP matrix materials. These self-reinforced homo-PP/block-PP materials have clearly indicated that they have the potential to out-perform the block-PP materials via modification and/or manipulation of the reinforcement knit structural/geometrical parameters and the content of reinforcement fibres. Both static and dynamic impact properties are likely to be affected by the local area properties of the tested face under indentation, and thereby contributing to the improved performances of the composite specimens with the knit face under the impact.

Hanxiong Huang - One of the best experts on this subject based on the ideXlab platform.

  • microcellular Injection Compression Molding micm a novel technology for effectively improving cellular structure of polystyrene foams
    Polymer Engineering and Science, 2014
    Co-Authors: Hanxiong Huang, Jiadong Tian, Weisheng Guan
    Abstract:

    A novel technology, being called as microcellular Injection-Compression Molding (MICM), was proposed for the first time to search an effective way for improving the cellular structure of foamed parts. Both MICM and standard microcellular Injection Molding (MIM) were used to mold rectangular foamed polystyrene plates with the thicknesses of 5, 4, and 3 mm. Compared to the MIM samples, the MICM samples exhibited thinner outer zone, in which irregular striation-shaped cells were dominated, at three positions along the sample axis; the MICM samples exhibited a little more uniform cellular shape and size distribution in the outer zone, and more uniform cellular structure with smaller sizes in the inner zone, being dominated by ellipsoidal cells, at three positions. Improved cellular structure in the MICM sample leads to its higher storage modulus in the glassy state. Based on the cellular structure in the samples with the three thicknesses, a cellular development mechanism in the Compression stage during MICM was proposed and analyzed thoroughly. Moreover, using the MICM can lower the maximum cavity pressure by about 18.6, 29.3, and 55.6% for 3, 4, and 5-mm-thick samples, respectively. POLYM. ENG. SCI., 54:327–335, 2014. © 2013 Society of Plastics Engineers

  • A Proposed Technique to Acquire Cavity Pressure Using a Surface Strain Sensor During Injection-Compression Molding
    Journal of Manufacturing Science and Engineering-transactions of The Asme, 2013
    Co-Authors: Weisheng Guan, Hanxiong Huang
    Abstract:

    A new technique was proposed and experimentally verified for the cavity pressure acquisition in the Injection-Compression Molding (ICM). The surface strain of the fixed mold half and the cavity pressure were monitored simultaneously during ICM. In the Compression stage, a directly proportional relationship between the cavity pressure and mold surface strain was found and determined via the regression analysis. By taking the advantage of this relationship, the cavity pressure profile with high accuracy was indirectly obtained from the nondestructive measurement of the mold surface strain. Moreover, the mold surface strain profile could indicate the part weight or thickness and the critical time when the part surface lost contact with the cavity surface in a large area. The monitoring of the mold surface strain could serve as an interesting alternative to the direct monitoring of the cavity pressure with respect to process and part quality control for ICM.

  • manipulation and online monitoring of micro replication quality during Injection Compression Molding
    Journal of Micromechanics and Microengineering, 2012
    Co-Authors: Weisheng Guan, Hanxiong Huang, Ze Wu
    Abstract:

    The accurate and rapid replication of micro-/nano-features with a high aspect ratio (AR) is one of the main challenges in micro-Molding. In this work, the micro-Injection–Compression Molding (µ-ICM) process and a new monitoring technique were combined to replicate micro-features with controllable and detectable ARs. Using a surface strain sensor mounted on the external surface of the mold, indirect acquisition of accurate cavity pressure during post-filling was realized, based on the specific pressure distribution on the mold predicted by the Hele–Shaw flow simulation. The feasibility of the proposed measuring technique was verified both numerically via finite-element analysis for the mold strain and experimentally by comparing cavity pressure profiles acquired directly and indirectly. Furthermore, primarily dominated by the maximum cavity pressure appearing during post-filling, the AR of molded polystyrene micro-feature in the downstream of cavity could be monitored via this technique with certain accuracy, and controlled by manipulating the Compression force. Also the qualitative AR results of the other upstream micro-features were detectable in µ-ICM. Within a cycle time of 26 s, a maximum AR of about 12.1 was achieved on micro-features, indicating the potential for the mass production of complex micro parts applying µ-ICM.

  • back melt flow in Injection Compression Molding effect on part thickness distribution
    International Communications in Heat and Mass Transfer, 2012
    Co-Authors: Weisheng Guan, Hanxiong Huang
    Abstract:

    Abstract The flexibility of Injection–Compression Molding (ICM) was demonstrated to be adequate for replication of precise polymeric parts in this work. Under the optimal processing conditions, the rectangular polystyrene (PS) plates with the standard deviation of 0.15% for the part thickness were molded by ICM. Experimental analyses suggested that the part thickness uniformity was significantly affected by the melt temperature and Compression-related processing factors (including the Compression force, Compression stroke, and Compression speed), but was much less affected by the Injection rate. Furthermore, with the generalized Hele–Shaw flow simulation, the mechanism dominating the part thickness distribution was investigated. The simulated results gave an insight into the back melt flow within the cavity during the compensation stage. It was revealed that the melts flowed back from the cavity to the gate when the Compression was completed. Such back flow, which was mainly controlled by the melt temperature and Compression-related factors, could obviously redistribute the melts within the cavity, and more importantly distribute the final part thickness. As an increased amount of melts within the cavity was transferred via the back flow, the area near the gate received more compensation for the part shrinkage, whereas the area near the end of the cavity exhibited greater part shrinkage correspondingly.

  • Back melt flow in Injection–Compression Molding: Effect on part thickness distribution
    International Communications in Heat and Mass Transfer, 2012
    Co-Authors: Weisheng Guan, Hanxiong Huang
    Abstract:

    Abstract The flexibility of Injection–Compression Molding (ICM) was demonstrated to be adequate for replication of precise polymeric parts in this work. Under the optimal processing conditions, the rectangular polystyrene (PS) plates with the standard deviation of 0.15% for the part thickness were molded by ICM. Experimental analyses suggested that the part thickness uniformity was significantly affected by the melt temperature and Compression-related processing factors (including the Compression force, Compression stroke, and Compression speed), but was much less affected by the Injection rate. Furthermore, with the generalized Hele–Shaw flow simulation, the mechanism dominating the part thickness distribution was investigated. The simulated results gave an insight into the back melt flow within the cavity during the compensation stage. It was revealed that the melts flowed back from the cavity to the gate when the Compression was completed. Such back flow, which was mainly controlled by the melt temperature and Compression-related factors, could obviously redistribute the melts within the cavity, and more importantly distribute the final part thickness. As an increased amount of melts within the cavity was transferred via the back flow, the area near the gate received more compensation for the part shrinkage, whereas the area near the end of the cavity exhibited greater part shrinkage correspondingly.

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

  • mechanical properties of textile inserted pp pp knitted composites using Injection Compression Molding
    Composites Part A-applied Science and Manufacturing, 2006
    Co-Authors: O A Khondker, X Yang, N Usui, Hiroyuki Hamada
    Abstract:

    Abstract This paper concentrates on the experimental investigation of the self-reinforced all-polypropylene composites. There exists an optimum processing condition to produce high quality specimens by Injection–Compression Molding. Tensile and 3-point bending properties of the virgin PP materials were nearly unaffected by the introduction of reinforcing knit layer(s) due to very low fibre content of the knitted fabrics used. 3-point bending properties were also unaffected by the surface of indentation-flexure. The applied impact energy was maintained at 5 J for the homo-PP and 27 J for the block-PP materials, respectively, to cause penetration during drop-weight impact tests. It is interestingly noteworthy that the self-reinforced homo-PP composites exhibited superior energy absorption capability when compared with the virgin matrix materials. The corresponding plate bending performances of the self-reinforced homo-PP composites also revealed consistent improvement as compared to their virgin counterparts. On the other hand, although virgin block-PP material exhibited better impact performances than its composite reinforced by the homo-PP knitted fabric, a notably small increase in the reinforcement fibre content revealed considerable improvement in the impact properties comparable to those of the virgin block-PP matrix materials. These self-reinforced homo-PP/block-PP materials have clearly indicated that they have the potential to out-perform the block-PP materials via modification and/or manipulation of the reinforcement knit structural/geometrical parameters and the content of reinforcement fibres. Both static and dynamic impact properties are likely to be affected by the local area properties of the tested face under indentation, and thereby contributing to the improved performances of the composite specimens with the knit face under the impact.

  • Mechanical properties of textile-inserted PP/PP knitted composites using Injection–Compression Molding
    Composites Part A-applied Science and Manufacturing, 2006
    Co-Authors: O A Khondker, X Yang, N Usui, Hiroyuki Hamada
    Abstract:

    Abstract This paper concentrates on the experimental investigation of the self-reinforced all-polypropylene composites. There exists an optimum processing condition to produce high quality specimens by Injection–Compression Molding. Tensile and 3-point bending properties of the virgin PP materials were nearly unaffected by the introduction of reinforcing knit layer(s) due to very low fibre content of the knitted fabrics used. 3-point bending properties were also unaffected by the surface of indentation-flexure. The applied impact energy was maintained at 5 J for the homo-PP and 27 J for the block-PP materials, respectively, to cause penetration during drop-weight impact tests. It is interestingly noteworthy that the self-reinforced homo-PP composites exhibited superior energy absorption capability when compared with the virgin matrix materials. The corresponding plate bending performances of the self-reinforced homo-PP composites also revealed consistent improvement as compared to their virgin counterparts. On the other hand, although virgin block-PP material exhibited better impact performances than its composite reinforced by the homo-PP knitted fabric, a notably small increase in the reinforcement fibre content revealed considerable improvement in the impact properties comparable to those of the virgin block-PP matrix materials. These self-reinforced homo-PP/block-PP materials have clearly indicated that they have the potential to out-perform the block-PP materials via modification and/or manipulation of the reinforcement knit structural/geometrical parameters and the content of reinforcement fibres. Both static and dynamic impact properties are likely to be affected by the local area properties of the tested face under indentation, and thereby contributing to the improved performances of the composite specimens with the knit face under the impact.

Akbar Shojaei - One of the best experts on this subject based on the ideXlab platform.

  • A Theoretical Analysis on Resin Injection/Compression Molding
    Key Engineering Materials, 2007
    Co-Authors: Akbar Shojaei, A. Spah
    Abstract:

    In the present investigation, mold filling process of resin Injection/Compression Molding (RI/CM) is compared with resin transfer Molding (RTM) for simple mold geometry. To do this, analytical solutions are obtained for RI/CM in unidirectional flow. Based on the analytical solutions, flow front progression and pressure distribution are compared with RTM at different fiber content. The results indicate that the RI/CM reduces the mold filling time significantly, particularly for composite parts with higher fiber content.

  • a numerical study of filling process through multilayer preforms in resin Injection Compression Molding
    Composites Science and Technology, 2006
    Co-Authors: Akbar Shojaei
    Abstract:

    Abstract In resin Injection/Compression Molding (RI/CM), a preform often comprises layers of different fiber reinforcements. Each fiber reinforcement has unique through thickness and in-plane permeabilities as well as compressibility, creating a heterogeneous porous medium in the mold cavity. In the present article, numerical simulation is utilized to investigate the filling process of RI/CM in such a heterogeneous porous medium. The filling stage is simulated in a full three-dimensional space by using control volume/finite element method and based upon an appropriate filling algorithm. The flow in the open gap which may be present in the mold cavity is modeled by Darcy’s law using an equivalent permeability. Numerical simulations of filling process for preforms containing two and three layers of different reinforcements in various stacking sequences are conducted with the aid of computer code developed in this study. Results show that the Injection time as well as flow front progression depends on fiber types in the whole preform, fiber stacking sequence and open gap provided in the mold cavity. Simulated results also suggest that the presence of open gap at top of reinforcement can lead to both low Injection time and uniform flow pattern.

  • A numerical study of filling process through multilayer preforms in resin Injection/Compression Molding
    Composites Science and Technology, 2006
    Co-Authors: Akbar Shojaei
    Abstract:

    Abstract In resin Injection/Compression Molding (RI/CM), a preform often comprises layers of different fiber reinforcements. Each fiber reinforcement has unique through thickness and in-plane permeabilities as well as compressibility, creating a heterogeneous porous medium in the mold cavity. In the present article, numerical simulation is utilized to investigate the filling process of RI/CM in such a heterogeneous porous medium. The filling stage is simulated in a full three-dimensional space by using control volume/finite element method and based upon an appropriate filling algorithm. The flow in the open gap which may be present in the mold cavity is modeled by Darcy’s law using an equivalent permeability. Numerical simulations of filling process for preforms containing two and three layers of different reinforcements in various stacking sequences are conducted with the aid of computer code developed in this study. Results show that the Injection time as well as flow front progression depends on fiber types in the whole preform, fiber stacking sequence and open gap provided in the mold cavity. Simulated results also suggest that the presence of open gap at top of reinforcement can lead to both low Injection time and uniform flow pattern.

Ming-chang Jeng - One of the best experts on this subject based on the ideXlab platform.

  • The Influence of Injection Molding and Injection Compression Molding on Ultra-high Molecular Weight Polyethylene Polymer Microfabrication
    International Polymer Processing, 2011
    Co-Authors: Ming-chang Jeng
    Abstract:

    Abstract The replication accuracy of ultra-high molecular weight polyethylene (UHMWPE) was investigated by using Injection Molding (IM) and Injection Compression Molding (ICM). The mold insert was fabricated by using a stainless-steel etching method. Both the Injection molded part and the Injection Compression molded part were observed under a microscope to compare the quality and accuracy of the replication. A high performance surface profiler was used to measure the microstructure profile. For the mold insert, the Injection molded parts and Injection Compression molded parts were measured. The experimental results show that the UHMWPE can fill in microcavities by using IM and ICM technology. The height and shape of microstructure were influenced by the IM process parameters. For an Injection molded part, the Injection velocity was the most significant factor. This study also revealed that the ICM method was a more stable microstructure processing method than that of the IM. However, for better replicati...

  • Mechanical Properties and Microfabrication Study of Injection Molding on Ultra-High Molecular Weight Polyethylene Polymer
    Volume 3: Design and Manufacturing Parts A and B, 2010
    Co-Authors: Ming-chang Jeng
    Abstract:

    In this study, the experiments were divided into three categories: tensile strength experiments, wear test experiments and microstructure Molding experiments. Firstly, as the tensile strength of UHMWPE being concerned, the experimental results indicate that the effect of process parameters is relatively smaller than weld line on the tensile strength of specimens. The frictional heating could enhance the molecular bonding and self-diffusion in the frozen layer of both sides on the weld line region during the experimental observations. Secondly, as the wear behavior being concerned, the experimental results show that the friction coefficient increase linearly with the increase of sliding frequency. The results also indicate that the wear resistance in the sliding direction perpendicular to the melt flow direction is stronger than that in the sliding direction parallel with the melt flow direction. The main wear mechanisms in dry sliding conditions were plastic deformations and wrinkled formations observed by optical microscopy. Thirdly, as the micro-fabrication being concerned, replication accuracy was examined for Injection Molding and Injection Compression Molding. Both the Injection Molding parts and the Injection Compression Molding parts were observed under microscope to compare their replication accuracy. The experimental results show that the micro-structures can be filled with UHMWPE by Injection Molding and Injection Compression Molding technology. The height and shape of microstructure were affected by process parameters. Thus for better replication accuracy, both Injection Molding and Injection Compression Molding processes will be in need of a parametric optimization.Copyright © 2010 by ASME