Effect of Pre-Molding Process and Additive of Injection Molded Wood/PP Composites

2014 ◽  
Vol 29 (4) ◽  
pp. 440-446
Author(s):  
Y. Yu ◽  
Q. Y. Yang ◽  
M. Nomura ◽  
H. Hamada
2010 ◽  
Vol 654-656 ◽  
pp. 2636-2639
Author(s):  
Lei Xie ◽  
Timo Grueneberg ◽  
Leif Steuernagel ◽  
Gerhard Ziegmann ◽  
Holger Militz

Due to the water absorption of wood fillers and poor adhesion between wood fillers and polymer matrix, the loosen material structure always appears in wood/polymer composites after injection molding process, which results in reduced composites mechanical properties. In this study, two kinds of wood particles with different sizes and properties were compounded with Polypropylene (PP) in highly filled level (by 50% and 60% weight concentration). The experimental tensile test samples were prepared by one double-gate injection mould integrated an ultrasonic generator unit. The experiments were carried out for studying how the ultrasonic output power and the oscillation inducing time affect the injection molded wood/PP composites mechanical properties. 3 output power levels (400W, 600W and 800W) and 2 inducing mode were set (Mode1. the oscillation is induced from injecting moment to ejection moment; Mode2. the oscillation is induced from injecting moment to packing procedure finishing). The results show that the E module, tensile strength and density of the test parts are obviously changed with various ultrasonic output power and inducing time. Comparing the mechanical properties of parts with and without ultrasonic assistant indicates that the ultrasonic oscillation is a practical method to improve mechanical properties of injection molded wood/PP composites parts.


2006 ◽  
Vol 326-328 ◽  
pp. 187-190
Author(s):  
Jong Sun Kim ◽  
Chul Jin Hwang ◽  
Kyung Hwan Yoon

Recently, injection molded plastic optical products are widely used in many fields, because injection molding process has advantages of low cost and high productivity. However, there remains residual birefringence and residual stresses originated from flow history and differential cooling. The present study focused on developing a technique to measure the birefringence in transparent injection-molded optical plastic parts using two methods as follows: (i) the two colored laser method, (ii) the R-G-B separation method of white light. The main idea of both methods came from the fact that more information can be obtained from the distribution of retardation caused by different wavelengths. The comparison between two methods is demonstrated for the same sample of which retardation is up to 850 nm.


2012 ◽  
Vol 629 ◽  
pp. 55-59
Author(s):  
Ai Yun Jiang ◽  
Jing Chao Zou ◽  
Bao Feng Zhang ◽  
Hai Hong Wu

For conductive-carbon-fiber-filled polymer composites, the residual stresses developed during injection molding process may affect not only the molding’s conductive property, but its dimensional stability as well. In order to improve the conductivity of the molding fabricated with this kind of composites, we investigated, using layer removal method, the distribution of the residual stresses of injection-molded conductive-carbon-fiber-filled polypropylene in this paper. The residual stresses were obtained under the actions of different processing conditions. Our results indicate that processing pressures have more significant effects on the residual stresses at the skin areas than the core areas of the sample because of fiber orientation. The tensile stresses of the molding at the core areas drop under the action of packing pressure, but the compressive stresses at the skin areas increase. The results reveal that the action of packing pressure may decrease the anisotropy of the residual stresses in the molding.


Author(s):  
D. Sordelet ◽  
J. Neil ◽  
M. Mahoney ◽  
A. Hecker

GTE Laboratories has been supporting Allison Gas Turbine Division of General Motors under the current ATTAP program since early 1988. Injection-molding process development and component fabrication has been the emphasis of this effort, but material property enhancement studies have also been an important complement. Attempts to increase the resistance to foreign object damage have been made through parallel investigations of microstructural control and SiC whisker reinforcement. The research activities aimed at improving fracture toughness of GTE PY6 Si3N4 are discussed.


2017 ◽  
Vol 728 ◽  
pp. 258-263
Author(s):  
Badin Pinpathomrat ◽  
Suchalinee Mathurosemontri ◽  
Supaphorn Thumsorn ◽  
Hiroyuki Hamada

Aim of this study focused on insert injection molding process, which is molded the melted polymer around an inserted part placed in the molded cavity of injection molding process. The interfacial adhesive strength between the inserted and an injected polymer parts were investigated by Intron universal test machine in order to investigate the effect of material in inserted and injected part. During tensile testing the acoustic emissions (AE) measurement was applied to evaluate the fracture behavior of insert injection molding. It was found that interfacial adhesive strength of insert injection molded of all specimens increased according with increasing the bonding area of adhesive interface. The fracture mode of the insert injection molded specimens was depended on the length of bonding area of the inserted part. The fracture of mode of the insert-injection molded specimens was confirmed by acoustic emission.


2013 ◽  
Vol 22 (6) ◽  
pp. 425-435 ◽  
Author(s):  
Ying Yu ◽  
Yuqiu Yang ◽  
Masuo Murakami ◽  
Manabu Nomura ◽  
Hiroyuki Hamada

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