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 Synthesis and Investigation of Cryogenic Mechanical Properties of Chopped-Glass-Fiber-Reinforced Polyisocyanurate Foam

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 446
Author(s):  
Jeong-Dae Kim ◽  
Jeong-Hyeon Kim ◽  
Dong-Ha Lee ◽  
Dong-Ju Yeom ◽  
Jae-Myung Lee
Keyword(s):  
Thermal Conductivity ◽  
Mechanical Strength ◽  
Glass Fiber ◽  
Cryogenic Temperature ◽  
Raw Materials ◽  
Glass Fibers ◽  
Polymerization Process ◽  
Mechanical And Thermal Properties ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced

Polyisocyanurate foam (PIF) has been adopted as a liquefied natural gas (LNG) insulating material owing to its various mechanical merits such as high structural stability and mechanical strength, and excellent insulating ability. In an attempt to increase the mechanical strength of PIF, chopped-glass-fiber-reinforced polyisocyanurate foam (CGR-PIF) was synthesized by adding chopped glass fibers to polyol and isocyanate, which are the raw materials used in the polymerization process for producing PIF. The main objective is to closely observe the compression material characteristics of PIF and CGR-PIF in terms of the cryogenic temperature. Therefore, compressive tests were conducted at cryogenic temperature including low temperatures, and microscopic images were obtained to analyze the cell size and distribution that affects the mechanical and thermal properties of the foam. Furthermore, recovery ratio and weight loss which are important factors of brittle fracture were evaluated, and the applicability of the foams to a cryogenic environment was evaluated. Finally, thermal conductivity, an important parameter of insulation, was evaluated. The obtained results confirm that the compressive strength of CGR-PIF significantly increases at cryogenic temperatures; moreover, a relatively higher thermal conductivity was observed in the case of CGR-PIF as compared to that of PIF owing to the chopped glass fibers.

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.

scholarly journals A Fatigue Damage Model for Life Prediction of Injection-Molded Short Glass Fiber-Reinforced Thermoplastic Composites

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2250
Author(s):  
Mohammad Amjadi ◽  
Ali Fatemi
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Fatigue Damage ◽  
Life Prediction ◽  
Glass Fibers ◽  
Damage Model ◽  
Fiber Reinforced ◽  
Short Glass Fiber ◽  
Glass Fiber Reinforced ◽  
Short Glass

Short glass fiber-reinforced (SGFR) thermoplastics are used in many industries manufactured by injection molding which is the most common technique for polymeric parts production. Glass fibers are commonly used as the reinforced material with thermoplastics and injection molding. In this paper, a critical plane-based fatigue damage model is proposed for tension–tension or tension–compression fatigue life prediction of SGFR thermoplastics considering fiber orientation and mean stress effects. Temperature and frequency effects were also included by applying the proposed damage model into a general fatigue model. Model predictions are presented and discussed by comparing with the experimental data from the literature.

Properties of Fresh and Hardened Glass Fiber Reinforced Fly Ash Based Geopolymer Concrete

2013 ◽  
Vol 594-595 ◽  
pp. 629-633 ◽  
Author(s):  
Behzad Nematollahi ◽  
Jay Sanjayan ◽  
Jessie Xia Hui Chai ◽  
Tsui Ming Lu
Keyword(s):  
Fly Ash ◽  
Glass Fiber ◽  
Glass Fibers ◽  
Experimental Results ◽  
Geopolymer Concrete ◽  
Hardened Glass ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced ◽  
Naoh Solution ◽  
Compressive And Flexural Strengths

This paper evaluates the effects of glass fiber addition on the properties of fresh and hardened fly ash based geopolymer concrete (GPC) activated by 8 M NaOH solution (28.6%) + Na2SiO3 (71.4%) with a SiO2/Na2O ratio of 2.0. Glass fibers at the dosages of 0.50%, 0.75%, 1.00% and 1.25% by volume of concrete were added to the GPC mix. The properties of fresh and hardened glass fiber reinforced fly ash based GPC in terms of workability, density, compressive and flexural strengths were compared with those of the fly ash based GPC without using glass fiber. The experimental results indicated that inclusion of the glass fibers resulted in decrease of the workability but increase of the density, compressive and flexural strengths of the fly ash based GPC with increased fiber content.

The Influence Capitalize of Properties Improvement for Reinforced Plastics by Resin Flow Control Molding Method

2012 ◽  
Vol 6 (4) ◽  
pp. 522-528 ◽  
Author(s):  
Naoki Mori ◽  
◽  
Kiyohito Gondou ◽  
Kohei Shimada ◽  
Takahiro Kitamura ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Flow Control ◽  
Physical Properties ◽  
Glass Fiber ◽  
Poly Lactic Acid ◽  
Resin Flow ◽  
Fiber Reinforced ◽  
Molding Method ◽  
Reinforced Plastics ◽  
Glass Fiber Reinforced

We are now engaged in the study on a resin flow control molding method in which molecules and fillers are positively oriented by displacing resin flows in the mold. We intend to confirm that the resin flow control molding method can properly control the orientation of fibers in glass fiber reinforced polypropylene moldings. We have also attempted to improve physical properties of poly-lactic acid molded by the resin flow control molding method. We have directly observed the process of filling resins into a glass-inserted mold to prove effectiveness of the resin flow control molding method.

Mechanical properties of norbornene-based silane treated glass fiber reinforced polydicyclopentadiene composites manufactured by the S-RIM process

e-Polymers ◽  
2017 ◽  
Vol 17 (2) ◽  
pp. 159-166 ◽  
Author(s):  
Hyeong Min Yoo ◽  
Dong-Jun Kwon ◽  
Joung-Man Park ◽  
Sang Hyuk Yum ◽  
Woo Il Lee
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Glass Fibers ◽  
Process Conditions ◽  
Fiber Reinforced ◽  
Scanning Calorimetry ◽  
Reaction Injection Molding ◽  
Structural Reaction Injection Molding ◽  
Pull Out ◽  
Glass Fiber Reinforced

AbstractA lab scale structural reaction injection molding (S-RIM) piece of equipment was designed and used to fabricate glass fiber reinforced polydicyclopentadiene (p-DCPD) composites for three different fiber contents. In order to obtain information regarding the optimal process temperature (>80°C) and the curing time (<30 s), differential scanning calorimetry (DSC) was used to investigate the curing behavior of DCPD resin under isothermal conditions. Further, a norbornene-based silane treatment was used to improve the interfacial adhesion between the glass fibers and DCPD as confirmed by the micro-droplet pull-out test and scanning electron microscopy (SEM). Fabrication of glass fiber/p-DCPD composites with improved mechanical properties was carried out based on the optimized process conditions and surface treatment of glass fiber.

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