Effects of Process Conditions on Mechanics Properties of Micro-Foaming PP/GF Composites

2011 ◽  
Vol 117-119 ◽  
pp. 256-261 ◽  
Author(s):  
Wei Gong ◽  
Ying He ◽  
Chun Zhang ◽  
Jian Hua Zhu ◽  
Li He

The microcellular foaming PP/GF composites was made under the condition of twice-open mold by using chemical foaming injection method, according to glass fiber reinforced mechanism, the effect rule of GF on mechanics properties was studied in microcellular foam PP composites. The results showed that tensile and impact strength of Micro-foam PP/GF composites by one-step method were higher than that of micro-foam PP/GF composites by two-step method, when the content of GF is 30%, the tensile and impact strength of micro-foam PP/GF composites by one-step method can reach 55.72MPa and 7.5kJ/m2respectively,one-step method can get higher strength and higher toughness micro-foam PP/GF composites.

1993 ◽  
Vol 58 (11) ◽  
pp. 2642-2650 ◽  
Author(s):  
Zdeněk Kruliš ◽  
Ivan Fortelný ◽  
Josef Kovář

The effect of dynamic curing of PP/EPDM blends with sulfur and thiuram disulfide systems on their mechanical properties was studied. The results were interpreted using the knowledge of the formation of phase structure in the blends during their melt mixing. It was shown, that a sufficiently slow curing reaction is necessary if a high impact strength is to be obtained. Only in such case, a fine and homogeneous dispersion of elastomer can be formed, which is the necessary condition for high impact strength of the blend. Using an inhibitor of curing in the system and a one-step method of dynamic curing leads to an increase in impact strength of blends. From the comparison of shear modulus and impact strength values, it follows that, at the stiffness, the dynamically cured blends have higher impact strength than the uncured ones.


Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 360 ◽  
Author(s):  
Hyun Kim ◽  
Joo Sohn ◽  
Youngjae Ryu ◽  
Shin Kim ◽  
Sung Cha

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.


2012 ◽  
Vol 501 ◽  
pp. 294-299 ◽  
Author(s):  
Zhi Bian ◽  
Peng Cheng Xie ◽  
Yu Mei Ding ◽  
Wei Min Yang

This study was aimed at understanding how the process conditions affected the dimensional stability of glass fiber reinforced PP by microcellular injection molding. A design of experiments (DOE) was performed and plane test specimens were produced for the shrinkage and warpage analysis. Injection molding trials were performed by systematically adjusting six process parameters (i.e., Injection speed, Injection pressure, Shot temperature, SCF level, Mold temperature, and Cooling time). By analyzing the statistically significant main and two-factor interaction effects, the results showed that the supercritical fluid (SCF) level and the injection speed affected the shrinkage and warpage of microcellular injection molded parts the most.


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

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.


2013 ◽  
Vol 750-752 ◽  
pp. 107-110
Author(s):  
Bang Sheng You ◽  
Kai Zhou Zhang ◽  
Jian Bing Guo ◽  
Li He

The influence of long glass fiber (LGF) content on properties of PVC/PP composites were investigated by means of scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), and mechanical properties. The experimental results demonstrate that long glass fiber could effectively improve the mechanical properties and storage modulus of PVC/PP. The DMA reveals good miscibility between PVC and PP. Based on SEM, good interfacial adhesion between matrix and long glass fiber in PVC/PP/LGF composites was observed. All results in this paper were consistent, and showed long glass fiber could effective influence the properties of PVC/PP, which were proved by the mechanical properties of the composites.


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