Cushioned seat parts prodn., having different hardness - by adding foaming resin to covering in mould, curing, replacing top mould tool by one with undercut, and adding resin binder plus top covering

摘要

A cushion for a seat with areas of different hardness is produced by laying a covering in a mould, closing the mould or its opening with a top tool, and adding a resin to the cavity beneath the top tool; this resin used is a reactive mixture which expands into a soft foam and fills the cavity to form part of the cushion. The top tool is next removed and replaced by another, the foam core remaining in place, leaving a second cavity between itself and the second top tool; this second cavity is however thinner than the first and corresponds to the hard part of the final cushion; a second resin is then added to this second cavity. The mould is designed to provide an undercut near its inlet; when it is closed by the first top tool the undercut is closed off from the first cavity by that tool; when the second top tool is applied the second cavity on top of the foamed core then includes the undercut for filling with the second resin. ADVANTAGE - In the procedure the edges of the covering used are removed cleanly from the product.