| 摘要 |
1445215 Making bags; seaming and reinforcing edges of sheet material ROBERT BOSCH GmbH 8 July 1974 [9 July 1973] 30190/74 Headings B5D and B5K [Also in Division B8] A bag of a laminate of cellulose acetate or polyester film 17 and a polyethylene lining 16 having a W-shaped fold at its base has holes 24 adjacent the ends of the folds whereby the inner layer 16 flows around the periphery of the holes upon application of heat and pressure to fuse together the plies of the fold. The sheet material 31 is fed from a roll 30 and folded into a strip with the W-fold 13 and is then perforated by a punch 33. L- shaped welding jaws 34 form the side and bottom seams of each bag and shears 36 separate each bag. |
