Glass fiber-filled thermoplastics. II. Cavity filling and fiber orientation in injection molding

1985 ◽  
Vol 25 (16) ◽  
pp. 1008-1016 ◽  
Author(s):  
Muneharu Sanou ◽  
Bin Chung ◽  
Claude Cohen
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Fiber Orientation ◽  
Cavity Filling

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.

Mechanical properties and fiber characteristics of glass fiber/carbon fiber reinforced polyethylene terephthalate hybrid composites fabricated by direct fiber feeding injection molding

2018 ◽  
Vol 38 (6) ◽  
pp. 513-523 ◽  
Author(s):  
Wiranphat Thodsaratpreeyakul ◽  
Putinun Uawongsuwan ◽  
Akio Kataoka ◽  
Takanori Negoro ◽  
Hiroyuki Hamada
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Injection Molding ◽  
Glass Fiber ◽  
Polyethylene Terephthalate ◽  
Fiber Orientation ◽  
Mechanical Performance ◽  
Hybrid Composites ◽  
Fiber Distribution ◽  
Volume Fractions

Abstract Improving the applicability of polyethylene terephthalate (PET) by carbon fiber/glass fiber reinforcement is of great interest. Glass fiber (GF)/carbon fiber (CF)/PET hybrid composites were fabricated by direct fiber feeding injection molding (DFFIM) process. The aim of DFFIM is to obtain longer fibers in composites in order to improve their mechanical properties. In this study, the mechanical properties of GF/PET composites fabricated by conventional injection molding and hybrid GF/CF/PET composites fabricated by DFFIM process were investigated. The influence of GF and CF volume fractions on fiber distribution, fiber orientation, and fiber length is discussed. Fiber distribution status was quantitatively measured by the fiber distribution index. Fiber agglomeration problem was observed by scanning electron microscopy. The results indicate that incorporating CF in GF/CF/PET hybrid composites by the DFFIM process greatly enhances mechanical performance even when only a small amount of CF is added. Too high GF content leads to less effective CF hybridization because it causes poor fiber distribution and poor fiber orientation and intensifies fiber attrition. The ideal volume fractions of GF and CF for fabricating GF/CF/PET hybrid composites by using DFFIM are provided.

Fracture Toughness of Discontinuous Long Glass Fiber Reinforced Polypropylene: An Approach Based on a Numerical Prediction of Fiber Orientation in Injection Molding

2005 ◽  
Vol 13 (2) ◽  
pp. 121-130 ◽  
Author(s):  
V. Rizov ◽  
T. Harmia ◽  
A. Reinhardt ◽  
K. Friedrich
Keyword(s):  
Fracture Toughness ◽  
Injection Molding ◽  
Glass Fiber ◽  
Fiber Orientation ◽  
Numerical Prediction ◽  
Fiber Reinforced ◽  
Local Fracture ◽  
Glass Fiber Reinforced ◽  
Long Glass Fiber ◽  
Injection Molded

The fracture toughness of discontinuous long glass fiber reinforced injection-molded polypropylene has been characterized by using the microstructural efficiency concept in combination with a numerical prediction of the fiber orientation during injection molding. The latter was performed by using the SIGMASOFT commercial software. In a three-dimensional numerical scheme, input data such as fiber volume fractions, shear viscosity and mean fiber aspect ratio have been used in order to perform the mold filling analysis. The resulted local fiber orientation parameters for injection molded square plates of long glass fiber reinforced polypropylene allowed to calculate the local fracture toughness with microstructural efficiency concept. The latter were compared with the experimental toughness values obtained by the use of compact tension test specimens. The good correlation between the calculated fracture toughness data and the measured ones shows that a fiber orientation prediction by the SIGMASOFT finite element computer code can be used in combination with the microstructural efficiency concept for the determination of local fracture toughness values in injection molded long glass fiber reinforced thermoplastics. The combined approach opens good opportunities for optimization of a thermoplastic workpiece in its design with respect to local fracture resistance. This will enable the material performance levels to be significantly extended, with consequent increases in engineering applicability.

scholarly journals Constant Temperature Approach for the Assessment of Injection Molding Parameter Influence on the Fatigue Behavior of Short Glass Fiber Reinforced Polyamide 6

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1569
Author(s):  
Selim Mrzljak ◽  
Alexander Delp ◽  
André Schlink ◽  
Jan-Christoph Zarges ◽  
Daniel Hülsbusch ◽  
...  
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Process Parameters ◽  
Fatigue Properties ◽  
Injection Molding Process ◽  
Molding Process ◽  
Short Glass Fiber ◽  
Glass Fiber Reinforced ◽  
Molding Parameter ◽  
Short Glass

Short glass fiber reinforced plastics (SGFRP) offer superior mechanical properties compared to polymers, while still also enabling almost unlimited geometric variations of components at large-scale production. PA6-GF30 represents one of the most used SGFRP for series components, but the impact of injection molding process parameters on the fatigue properties is still insufficiently investigated. In this study, various injection molding parameter configurations were investigated on PA6-GF30. To take the significant frequency dependency into account, tension–tension fatigue tests were performed using multiple amplitude tests, considering surface temperature-adjusted frequency to limit self-heating. The frequency adjustment leads to shorter testing durations as well as up to 20% higher lifetime under fatigue loading. A higher melt temperature and volume flow rate during injection molding lead to an increase of 16% regarding fatigue life. In situ Xray microtomography analysis revealed that this result was attributed to a stronger fiber alignment with larger fiber lengths in the flow direction. Using digital volume correlation, differences of up to 100% in local strain values at the same stress level for different injection molding process parameters were identified. The results prove that the injection molding parameters have a high influence on the fatigue properties and thus offer a large optimization potential, e.g., with regard to the component design.

scholarly journals Ultrasonic injection molding of glass fiber reinforced polypropylene parts using tungsten carbide-cobalt mold core

2021 ◽  
pp. 109771
Author(s):  
Xiong Liang ◽  
Yongjing Liu ◽  
Zehang Liu ◽  
Jiang Ma ◽  
Zhenxuan Zhang ◽  
...  
Keyword(s):  
Injection Molding ◽  
Tungsten Carbide ◽  
Glass Fiber ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced
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