Flexible expanded PVC sheet with decorative relief surface - prepd. using expansible plastisol coated on support resting on perforated metal sheet

摘要

Process comprises (a) applying an expansible PVC paste contg. a chemical blowing agent on a support (b) pregelling the paste at 100-170 degrees C; (c) opt. applying a non-expansible PVC paste as a cover layer on the expansible layer (d) opt. pregelling at 100-170 degrees C; followed by (e) completely gelling and expanding at a higher temp. Improvement is that a metal sheet with orifices is placed underneath the support prior to the complete gelification and expansion stop and the assembly is then heated from above in a tunnel. The process is simpler than chemical or mechanical embossing processes. Expansion of the PVC paste occurs only in the parts of the layer which are above the orifices of the metal sheet. Used for the prodn. of floor and wall cladding webs.