| 摘要 |
1439354 Plastics bags WAVIN BV 18 May 1973 [30 May 1972] 23740/73 Heading B8K A square bottom plastics bag is formed by making two slits (2, 3, Fig. 1, not shown) in the bottom edge of an open ended tube, folding the bottom to the form shown in Fig. 2 thereby producing corner flaps 6, 7 and bottom flaps 8 , 8<SP>1</SP>. Further folds are made about lines 10, 10<SP>1</SP> to produce the folded bag bottom shown in Fig. 3 and finally making at least one continuous heat seal 24 connecting the two overlapping bottom flaps with the underlying foil layers of the corner flap. Further seals can be made at 19, 23, 32 to improve the moisture tightness, and sealed joints 25 connect the overlapped bottom flaps 8, 8<SP>1</SP>. |
