초록 ▼

A sound-absorbent material is made by compressing foamed synthetic plastics material so as to rupture the walls of at least some of the cells therein. Preferably a slab of polycarbodiimide foam is compressed to about 50% to 66% of its initial thickness while cold or at a temperature below 120°C., an

A sound-absorbent material is made by compressing foamed synthetic plastics material so as to rupture the walls of at least some of the cells therein. Preferably a slab of polycarbodiimide foam is compressed to about 50% to 66% of its initial thickness while cold or at a temperature below 120°C., and is moulded to shape while below 120°C., being bonded if desired to one or more sheets of covering or strengthening or decorative fabric or felt or other facing material.

대표청구항 ▼

A method for the manufacture of a sound-absorbent material, comprising compressing a slab of cellular polycarbodiimide foam of substantially closed cell construction, in a direction perpendicular to the slab, at a temperature below 120°C., and then releasing the pressure on the slab, said compressio

A method for the manufacture of a sound-absorbent material, comprising compressing a slab of cellular polycarbodiimide foam of substantially closed cell construction, in a direction perpendicular to the slab, at a temperature below 120°C., and then releasing the pressure on the slab, said compression being performed to such an extent that, upon release of the pressure, the slab recovers its original thickness to the extent that its final thickness is 50 to 66% of its original thickness. A sound-absorbent material produced by the method of claim 1.