AN INJECTION/COMPRESSION OVER-MOLDING PROCESS FOR CONTINUOUS FIBER REINFORCED THERMOPLASTIC COMPOSITES

摘要

This paper describes a novel injection/compression approach to the composites over-molding process. In this breakthrough process, ribs, bosses and relevant features are injection-molded off line as one or multiple pieces. This injection molded insert can be made from either unfilled or chopped fiber reinforced thermoplastic resin. The insert is then precisely placed via automation in a compression molding tool along with a preform that is composed of thermoplastic towpreg in a unidirectional, fabric, or hybrid form that is designed to meet the strength and stiffness requirements of the application. The resin used in the injection molded component is compatible with the molding temperatures of the resin matrix used in the composite preform. The composite preform and the insert are co-molded using compression molding, where excess resin in the injection molded insert flows sufficiently to create a homogenous bond between the two. The result is a continuous fiber reinforced component with integral ribs, inserts, bosses and design features as could be provided with an injection over-molded part, except far more economically without the associated investment requisite for the over-molding process. This approach also adds significant capital cost reduction and improved feature tailor-ability. Technical and market requirements, emerging needs and supplier future considerations are included in the presentation.