Hard polyurethane foam building component with varying foam density - is foamed in a mould with heat absorbing metal inserts which are removed after moulding

摘要

Building component of plastics, e.g. polyurethane, hard foam has its outer portions i.e. those nearer the surface, of more compact foam than its core section. The core may also have zones of comparatively more compact structure depending on the intended uses and static loas to which the prod. is to be subjected. Mfr. comprises moulding the foamed prod. in a closed mould in which there are inserts, e.g. of metal, with relatively high heat-absorptive capacity. The inserts, e.g. steel rods, are subsequently removed and the remaining spaces filled with hardenable mechanically strong material.