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 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 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.

scholarly journals Warpage Reduction of Glass Fiber Reinforced Plastic Using Microcellular Foaming Process Applied Injection Molding

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 360 ◽  
Author(s):  
Hyun Kim ◽  
Joo Sohn ◽  
Youngjae Ryu ◽  
Shin Kim ◽  
Sung Cha
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Fiber Orientation ◽  
Mechanical And Thermal Properties ◽  
Micro Ct ◽  
Fiber Reinforced ◽  
Foaming Process ◽  
Microcellular Foaming ◽  
Glass Fiber Reinforced ◽  
The Impact

This study analyzes the fundamental principles and characteristics of the microcellular foaming process (MCP) to minimize warpage in glass fiber reinforced polymer (GFRP), which is typically worse than that of a solid polymer. In order to confirm the tendency for warpage and the improvement of this phenomenon according to the glass fiber content (GFC), two factors associated with the reduction of the shrinkage difference and the non-directionalized fiber orientation were set as variables. The shrinkage was measured in the flow direction and transverse direction, and it was confirmed that the shrinkage difference between these two directions is the cause of warpage of GFRP specimens. In addition, by applying the MCP to injection molding, it was confirmed that warpage was improved by reducing the shrinkage difference. To further confirm these results, the effects of cell formation on shrinkage and fiber orientation were investigated using scanning electron microscopy, micro-CT observation, and cell morphology analysis. The micro-CT observations revealed that the fiber orientation was non-directional for the MCP. Moreover, it was determined that the mechanical and thermal properties were improved, based on measurements of the impact strength, tensile strength, flexural strength, and deflection temperature for the MCP.

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.

Study on the Mechanical Properties of Carbon Fiber Composite Material of Wood

2015 ◽  
Vol 1120-1121 ◽  
pp. 659-663
Author(s):  
De Jun Shen ◽  
Zi Sheng Lin ◽  
Yan Fei Zhang
Keyword(s):  
Carbon Fiber ◽  
Glass Fiber ◽  
Aramid Fiber ◽  
Polymerization Process ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Fiber Reinforced Plastic ◽  
Reinforced Composite ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic

through the use of domestic carbon fiber cloth and combining domestic fast-growing wood of Larch and poplar wood, the CFRP- wood composite key interface from the composite process, stripping bearing performance, Hygrothermal effect, fracture characteristics and shear creep properties to conducted the system research . Fiber reinforced composite (Fiber Reinforced Plastic/Polymer, abbreviation FRP) material by continuous fibers and resin matrix composite and its types, including carbon fiber reinforced composite (Carbon Fiber Reinforce Plastic/Polymer, abbreviation CFRP), glass fiber reinforced composite (Glass Fiber Reinforced Plastic/Polymer, abbreviation GFRP) and aramid fiber reinforced composite (Aramid Fiber Reinforced Plastic/Polymer, abbreviation AFRP). PAN based carbon fiber sheet by former PAN wires, PAN raw silk production high technical requirements, its technical difficulty is mainly manifested in the acrylonitrile spinning technique, PAN precursor, acrylonitrile polymerization process with solvent and initiator ratio. Based on this consideration, the subject chosen by domestic PAN precursor as the basic unit of the CFRP as the object of study.

Sign in / Sign up

Export Citation Format

Share Document