scholarly journals Improvement of the Appearance of Injection Molded Products made of Polypropylene Containing Bright Flakes by Injection Mold Capable of Melt Flow Control and Induction Heating and Cooling

2019 ◽  
Vol 85 (1) ◽  
pp. 79-83
Author(s):  
Yasuhiko MURATA ◽  
Tsukasa HATAYAMA ◽  
Takuya HIYAMA ◽  
Yasumi NAGASAKA ◽  
Syogo KASHIWAGI
Keyword(s):  
Flow Control ◽  
Induction Heating ◽  
Injection Mold ◽  
Melt Flow ◽  
Heating And Cooling ◽  
Injection Molded

scholarly journals Development of an Injection Mold Capable of Melt Flow Control and Induction Heating and Cooling

2017 ◽  
Vol 11 (6) ◽  
pp. 985-992 ◽  
Author(s):  
Yasuhiko Murata ◽  
Hidekazu Suzuki ◽  
Shogo Kashiwagi ◽  
◽  
Keyword(s):  
Flow Control ◽  
Mechanical Strength ◽  
Glass Fiber ◽  
Induction Heating ◽  
Glass Fibers ◽  
Injection Mold ◽  
Fiber Reinforced ◽  
Melt Flow ◽  
Heating And Cooling ◽  
Glass Fiber Reinforced

Weldlines are a type of defect in polymer injection molding and are known to impair the appearance and mechanical strength of the molded product. A previous study involved designing and fabricating an induction heating and cooling mold that incorporates an induction coil, allowing it to rapidly heat up. The study verified that the use of this mold prevents weldlines and improves the surface properties of the molded product. Although it is possible to prevent impairment of the external appearance caused by weldlines or the exposure of glass fibers on the surface when the mold is applied to glass fiber reinforced thermoplastic, the results of the previous study indicated that it did not significantly improve the mechanical strength. Hence, the present study involved designing and fabricating an injection mold capable of melt flow control in addition to induction heating and cooling by incorporating a melt flow control mechanism that employs a movable core pin to control the flow direction in the mold used in the previous study. The mold is used to form samples of short- and long-glass fiber reinforced polypropylene while simultaneously performing heating and cooling and melt flow control to obtain samples with smooth flat surfaces in which the exposure of glass fibers is prevented while exhibiting increased bending strength.

scholarly journals Effects of Heating and Cooling of Injection Mold Cavity Surface and Melt Flow Control on Properties of Carbon Fiber Reinforced Semi-Aromatic Polyamide Molded Products

2021 ◽  
Author(s):  
Yasuhiko Murata ◽  
Ryota Kanno
Keyword(s):  
Carbon Fiber ◽  
Flow Control ◽  
Fiber Orientation ◽  
Aromatic Polyamide ◽  
Injection Mold ◽  
Fiber Reinforced ◽  
Melt Flow ◽  
Heating And Cooling ◽  
Product Surface ◽  
Carbon Fiber Reinforced

Fiber reinforced thermoplastics (FRTP), which is reinforced with glass or carbon fibers, are used to improve the mechanical strength of injection-molded products. However, FRTP has problems such as the formation of weld lines, the deterioration of the appearance due to the exposure of fibers on the molded product surface, and the deterioration of the strength of molded products due to the fiber orientation in the molded products. We have designed and fabricated an injection mold capable of melt flow control and induction heating and cooling that has the functions of both heating and cooling the injection mold as well as the function of controlling the melt flow direction using a movable core pin. In this study, the above-mentioned mold was used for the molding of carbon fiber reinforced semi-aromatic polyamide. As a result, we found that increasing the heating temperature of the mold and increasing melt flow control volume contribute to the prevention of the generation of a weld line and the exposure of fibers on the molded product surface, as well as to the formation of a flat surface and increased bending strength. The relationships of these results with the carbon fiber orientation in the molded products and the crystallization of semi-aromatic polyamide were also examined in this study.

scholarly journals Effects of Heating and Cooling of Injection Mold Cavity Surface and Melt Flow Control on Properties of Carbon Fiber Reinforced Semi-Aromatic Polyamide Molded Products

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 587 ◽  
Author(s):  
Yasuhiko Murata ◽  
Ryota Kanno
Keyword(s):  
Carbon Fiber ◽  
Flow Control ◽  
Fiber Orientation ◽  
Aromatic Polyamide ◽  
Injection Mold ◽  
Fiber Reinforced ◽  
Melt Flow ◽  
Heating And Cooling ◽  
Product Surface ◽  
Carbon Fiber Reinforced

Fiber reinforced thermoplastics (FRTP), reinforced with glass or carbon fibers, are used to improve the mechanical strength of injection-molded products. However, FRTP has problems such as the formation of weld lines, the deterioration of appearance due to the exposure of fibers on the molded product surface, and the deterioration of the strength of molded products due to the fiber orientation in the molded products. We have designed and fabricated an injection mold capable of melt flow control and induction heating and cooling. This mold can both heat and cool the injection mold. It can also control the melt flow direction using a movable core pin. In this study, the above-mentioned mold was used for the molding of carbon fiber reinforced semi-aromatic polyamide. As a result, we found that increasing the heating temperature of the mold and increasing melt flow control volume contribute to the prevention of the generation of a weld line and the exposure of fibers on the molded product surface, as well as to the formation of a flat surface and increased bending strength. The relationships of these results with the carbon fiber orientation in the molded products and the crystallization of semi-aromatic polyamide were also examined in this study.

Improving the Properties of Injection Molded Products with Induction Heating and Cooling Molds

2015 ◽  
Vol 9 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Yasuhiko Murata ◽  
◽  
Masayoshi Koike ◽  
Song Pan
Keyword(s):  
Tensile Test ◽  
Surface Temperature ◽  
Induction Heating ◽  
High Impact ◽  
Mold Cavity ◽  
Cavity Surface ◽  
Filling Process ◽  
High Impact Polystyrene ◽  
Heating And Cooling ◽  
Injection Molded

An induction heating and cooling mold that can keep the surface temperature of the entire mold cavity uniform and has a new heating and cooling insert with a gas vent mechanism is designed and produced. The effects of the temperature of the mold cavity surface, of the cavity air during the melt filling process, and of the organic gas generated fromthe melt on the appearance andmechanical properties of an injectionmolded product made of high impact polystyrene are studied. It is found that the heating and coolingmold with a gas vent can suppress molding defects, such as a weld lines and gas burns, and can greatly increase the displacement ratio of molded products obtained in the tensile test. This means that the effects of the gas vent and the surface temperature of the cavity have been quantitatively clarified using this type of mold.

An Interchangeable Turning Sprue Bushing in a Multi Cavity Family Injection Mold

2012 ◽  
Vol 548 ◽  
pp. 600-604
Author(s):  
Rozana Mohd Dahan ◽  
Saiful Bahri Mohd Yasin ◽  
Zakaria Razak ◽  
Mohd Helmi Omar
Keyword(s):  
Temperature Distribution ◽  
Test Piece ◽  
Volume Shrinkage ◽  
Injection Mold ◽  
Melt Flow ◽  
Flexural Test ◽  
Test Pieces ◽  
The Family ◽  
Separate Injection

Interchangeable Turning Sprue Bushing (ITSB) is a small insert at the centre of core side used to change runner directions for injecting 2 different products in a separate injection mold by shifting the melt filling to the cavities. The development of ITSB is significant in cutting down cost and time consumed during fabrication of a multi cavity family mold. In this study, the tensile and flexural test pieces were designed using CAD Solidwork. The test pieces analysis was performed using CAE Cadmould simulation in order to observe the melt flow of four multi cavities family mold incorporated without and with ITSB insert. The Cadmould simulation was used specifically to analyse the melt filling, temperature distribution and volume shrinkage of the test pieces. The simulation result demonstrated that ITSB is a useful insert that can be used to overcome problems encountered in the family mold system by balancing the melt filling, minimize temperature distribution and reduced the differential of volume shrinkage of the test piece manufactured. ITSB also reduced the frequent defects formed during production such as short molding, flashing and warpage.

scholarly journals Post-Processing Time Dependence of Shrinkage and Mechanical Properties of Injection-Molded Polypropylene

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 22
Author(s):  
Artur Kościuszko ◽  
Dawid Marciniak ◽  
Dariusz Sykutera
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Injection Molding ◽  
Accelerated Aging ◽  
Mold Temperature ◽  
Degree Of Crystallinity ◽  
Injection Mold ◽  
Secondary Crystallization ◽  
Scanning Calorimetry ◽  
Injection Molded

Dimensions of the injection-molded semi-crystalline materials (polymeric products) decrease with the time that elapses from their formation. The post-molding shrinkage is an effect of secondary crystallization; the increase in the degree of polymer crystallinity leads to an increase in stiffness and decrease in impact strength of the polymer material. The aim of this study was to assess the changes in the values of post-molding shrinkage of polypropylene produced by injection molding at two different temperatures of the mold (20 °C and 80 °C), and conditioned for 504 h at 23 °C. Subsequently, the samples were annealed for 24 h at 140 °C in order to conduct their accelerated aging. The results of shrinkage tests were related to the changes of mechanical properties that accompany the secondary crystallization. The degree of crystallinity of the conditioned samples was determined by means of density measurements and differential scanning calorimetry. It was found that the changes in the length of the moldings that took place after removal from the injection mold were accompanied by an increase of 20% in the modulus of elasticity, regardless of the conditions under which the samples were made. The differences in the shrinkage and mechanical properties of the samples resulting from mold temperature, as determined by tensile test, were removed by annealing. However, the samples made at two different injection mold temperature values still significantly differed in impact strength, the values of which were clearly higher for the annealed samples compared to the results determined for the samples immediately after the injection molding.

Melt flow control in a multistrand tundish using a turbulence inhibitor

2000 ◽  
Vol 31 (6) ◽  
pp. 1505-1515 ◽  
Author(s):  
R. D. Morales ◽  
J. Palafox-Ramos ◽  
J. de J. Barreto ◽  
S. Lopez-Ramirez ◽  
D. Zacharias
Keyword(s):  
Flow Control ◽  
Melt Flow ◽  
Turbulence Inhibitor

The Heat Performance Analysis of HSK Shrink Toolholder

2012 ◽  
Vol 723 ◽  
pp. 275-279
Author(s):  
Jian Chen ◽  
Gui Cheng Wang ◽  
Wei Song ◽  
Gang Liu
Keyword(s):  
Thermal Stress ◽  
Fatigue Life ◽  
Performance Analysis ◽  
Induction Heating ◽  
Thermal Structure ◽  
Optimal Temperature ◽  
Ansys Software ◽  
Heating Performance ◽  
Heating And Cooling ◽  
Fea Model

The principle of the HSK shrink toolholder is expanding with heat and contracting with cold. The heat performance of HSK is analyzed. Firstly, the induction heating performance is studied by using electromagnetism-thermal-structure FEA in ANSYS software and experiment, the optimal temperature of HSK shrink toolholder is got. Secondly, thermal fatigue and calculation of the fatigue life is analyzed by using thermal-stress in ANSYS software and Coffin-Manson formula. The loads applied on the FEA model are temperature during the cycle of heating and cooling.

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