Method and apparatus for reducing the size of hollow bodies

摘要

The hollow product (20) is compressed until the opposing walls (21) lie flat against each other to form a twin layer surface. Cuts are made through both walls and areas (24) to the sides of each cut are reshaped in such a way that both walls are diverted away from the plane formed by the compressed twin layer and project above the latter. Cuts are completely surrounded by unsevered areas. The two walls in areas (24) near a cut are diverted away from the twin layer plane in opposite directions. Successive cuts lie along the same line while adjacent lines of cuts are offset from each other in the cut direction. Product compression is effected by twin rolls (12a,12b) with axes one above the other. The gap between both rolls is at least twice wall thickness. The same rolls also perform the cutting action, the cuts being produced by claw-like surface projections (17a,17b) and adjacent cut-outs (15). The cutting profiles on opposing rolls correspond so that the claws on one roll engage in claws or cut-outs of the other roll to produce cuts by a shearing action. Cuts produced have frayed-out edges (25) which grip each other to prevent the compressed walls returning back into the original twin layer plane. An Independent claim is included for the process equipment including two compression and cutting rolls with engaging claw-like projections and adjacent cut-outs, the claws extending through the compressed twin layers and forming cuts of limited length.