METHOD OF PRODUCING A THERMOFORMABLE, FIBER-REINFORCED SEMI-FINISHED PRODUCT ON THE BASIS OF POLYETHER IMIDES

摘要

Polyetherimide (PEI) fibers and non-bound reinforcing fibers are continuously laid down by an air lay-up or carding method and needled. The fleece produced is heated in a contact or circulating oven or by infra-red radiation to above the softening temperature of PEI. Consolidation of the fleece into a glass mat reinforced thermoplastic sheet (GMT) is effected in either a calender, a polishing stack or a coating machine. Functional layers are simultaneously or subsequently pressed onto the semi-finished product. Independent claims are included for: (a) a GMT sheet 0.2-4mm thick comprising 10-80wt% of PEI and 90-20wt% of reinforcing fibers with a mean length of 40-200mm homogeneously mixed together; and (b) use of the GMT sheet for molding three-dimensional products.