warmverpreßbares semi-finished product for the production of a formteils in sandwichbauweise

摘要

The invention relates to a moulding of sandwich construction which is constructed, from the point of view of simple production, from a resin system which is fibre-reinforced in the cover-layer region and foamed in the core region. To ensure a high-strength design of the cover layers and clean separation between the fibre-reinforced resin zones and the foamed resin zones, the resin matrix is reinforced in the region of the cover layers by fibre layers with aligned fibre orientation, whereas the foam core is constructed of foam particles incorporated into the resin system with uniform, homogeneous distribution. Said foam particles are formed from highly storage- stable thermoplastic beads which are added to the thickened resin system before curing, are prefoamed and completely expand at the curing temperature of the resin. Accordingly, the corresponding heat-pressable semi-finished product for producing the moulding consists of upper and lower textile fabrics or scrims and an intermediate layer which is inserted between these and is a homogeneous mixture of the unreinforced, thickened resin system and prefoamed, thermoplastic beads added to said resin system with uniform distribution.