장섬유강화 복합재료의 사출성형에 있어서 섬유배향에 관한 연구

Abstract

This dissertation aims to systematically study the various phenomena which arise from injecton molding of plastic composites reinforced with long fiber. Seperation and orientation result from the difference in flow of matrix and fiver during the molding process of fiber-reinforced plastic composites. There has been many research on these matters in consideration of compression molding of composites which are composed of fiber mats. However, there has been no research on the molding conditions which affect the fiber content in injection-molded fiber-reinforced composites. This thesis experimentally studies the influences of such molding parameters such as fiber length and content affecting on distribution of fiber content in products. Long fiber-reinforced composites are injection-molded in order to measure the orientation in injection-molded products, and the products are photographed with soft x-rays. The intensity of the photograph is applied by an image scanner, and the fiber orientation distribution of products is measured by using an image-processing technique. Finally the relationship of the weight rate in fiber content of the product and fiber orientation function J and that of the injection molding condition and fiber orientation function J are investigated.