| 摘要 |
<p>PURPOSE:To remove bulges at both end edges generated on a belt-shaped body by forming a cylindrical body made of a plastic molding material by extrusion molding into the belt-shaped body with a folding roll and pressing both end edges of the belt-shaped body with a pressing roll. CONSTITUTION:A plastic material is injected through the hopper 11 of an extrusion molding machine 1 and extruded through a dice 12 as a cylindrical body 3. This cylindrical body 3 is folded by a folding roll to form a belt-shaped body 3A, and further bulges at both end edges of the belt-shaped body 3A are crushed by pressing both end edges with a pressing roll 10. At this time, the center section of the belt-shaped body 2A is somewhet separated. Then, predetermined positions are fused and sealed and cut to produce a plastic bag. Since this bag has no bulges at both end edges, no dislocation occurs even if many bags are stacked.</p> |
