METHOD AND APPARATUS FOR ROLLING AND DRAWING AND PLASTIC BELT STRING

摘要

PROBLEM TO BE SOLVED: To increase tensile strength and separation resistance force by providing a heating means on the upstream side of the nip between opposed rollers and excluding the dent parts in the vicinity of both side edge parts of a sheet like workpiece and the protruding transfer points between the dent parts and the main central part of the workpiece to increase the average degree thereof. SOLUTION: Before a workpiece 122 is passed through the nip 146 between the upper and lower rollers 142, 144 of a zero gap assembly 120, the roller 142 is surrounded by a pair of the heaters 188 preheating the edge part of the workpiece 122. The heaters 188 are arranged in an axial direction along the axial line of the roller 142 so as to be also optimally arranged to both end parts of the workpiece 122. Further, a pair of second heaters 190 are connected on the upstream side of the heaters 188. As a result, the dent parts within the regions just adjacent to the edge parts of the sheet and the transfer protruding regions of the connection part between the main central part of the sheet and the depressed side edges thereof are effectively removed to uniformize the thickness shape of the sheet 122.