Apparatus for Preparing Thermoplastic Composites

The properties of high performance composites with semi-crystalline thermoplastic matrices are dependent upon the processing conditions during manufacturing. To study the relationship between processing and material properties, a low cost molding apparatus was developed and evaluated. This apparatus is capable of processing both thermoplastic composite and pure thermoplastic polymer test specimens at controlled combinations of cooling rate, molding temperature and consolidation pressure. It consists of a water cooled aluminum mold, a high flow rate water pump and a hydraulic molding press with heated platens. A description of the molding apparatus is presented along with a detailed descrip tion of the molding procedures used to fabricate and anneal both composite and pure polymer specimens. Using this apparatus specimens of carbon fiber/PEEK and PEEK polymer composites were molded at cooling rates ranging from 0.01 °F/min up to as high as 21,000°F/min. Differential Scanning Calorimetry (DSC) testing showed specimen crystallinities ranging from 0 to 45 percent crystallinity are readily obtainable.