Verfahren zur Verarbeitung von Prepreg-Verschnittresten
The recycling and processing uncured prepreg offcuts of carbon fibre-reinforced thermosetting resin involves: a) removing the protective film from the pre-preg and cutting the offcuts into smaller pieces; b) passing the offcuts through a cutting mill at 20 deg. C below the glass transition temperature of the uncured resin; c) placing the milled recycled material on a carrier and processing in a pressing or autoclaving process to cure the resin. A claimed plate moulded in the recycled material after removal of the carrier film has a density of 0.7-0.8g/ cm3, tensile strength of 80 MPa and a bending stiffness of 140MPa in a three point bending test. A similar plate moulded in the same material together with the carrier film has a density of 1.2g/cm3, tensile strength of 100MPa and bending stiffness of 190MPa. USE - The process is for recycling carbon fibre-reinforced prepreg offcuts occuring especially in the aerospace industry. ADVANTAGE - The prepreg structure is largely retained so th at products moulded in the recycled materials still have high physical properties.
DE 1996-19640786 A1: 19961002