Punching cuts into a soft plastics foam slab - includes selectively compressing the slab in a zone parallel to and spaced from the cut (NL 24.6.77)

摘要

In a process of punching cuts into slabs of soft plastics foam, the slab is compressed in a zone parallel to, and spaced from, the place where the cut is to be made. It is thus compressed in that zone more strongly than very near the cut. The depth of the cut can then be accurately controlled where the cut is not to pass right through the entire thickness of the slab. The compression exerted increases within a zone parallel to the place of cutting, reaching a max. in the middle between 2 adjacent cuts. The slab may be pre-compressed, in that parallel zone, before a punching tool is applied. The compression may be continuously increased, in the parallel zone, during the punching operation. In order to make equidistant cuts in a slab, esp. of polyurethane soft foam, several parallel zones are simultaneously pre-compressed; the punching tools are applied and pressed down; and the slab is synchronously further compressed.