PBT玻璃纤维增强复合材料水辅注塑成型的实验研究外文翻译.doc

An experimental study of the water-assisted injection molding of glass ?ber ?lled poly-butylene-terephthalate (PBT) composites Abstract The purpose of this report was to experimentally study the water-assisted injection molding process of poly-butylene-terephthalate (PBT) composites. Experiments were carried out on an 80-ton injection-molding machine equipped with a lab scale water injection system, which included a water pump, a pressure accumulator, a water injection pin, a water tank equipped with a temperature regulator, and a control circuit. The materials included virgin PBT and a 15% glass ?ber ?lled PBT composite, and a plate cavity with a rib across center was used. Various processing variables were examined in terms of their in?uence on the length of water penetration in molded parts, and mechanical property tests were performed on these parts. X-ray di?raction (XRD) was also used to identify the material and structural parameters. Finally, a comparison was made between water-assisted and gas-assisted injection molded parts. It was found that the melt ?ll pressure, melt temperature, and short shot size were the dominant parameters a?ecting water penetration behavior. Material at the mold-side exhibited a higher degree of crystallinity than that at the water-side. Parts molded by gas also showed a higher degree of crystallinity than those molded by water. Furthermore, the glass ?bers near the surface of molded parts were found to be oriented mostly in the ?ow direction, but oriented substantially more perpendicular to the ?ow direction with increasing distance from the skin surface. 2006 Elsevier Ltd. All rights reserved. Keywords: Water assisted injection molding; Glass ?ber reinforced poly-butylene-terephthalate (PBT) composites; Processing parameters; B. Mechanical properties; Crystallinity; A. Polymer matrix composites; Processing 1. Introduction Water-assisted injection molding technology [1] has proved itself a breakthrough in the manufactu