IE33932L - Plastics bag manufacture - Google Patents

Abstract

1292038 Bags INDUSTRIELE ONDERNEMING WAVIN N V 2 Oct 1969 [10 Oct 1968 2 April 1969] 48473/69 Heading B8K A plastics bag is made from a flattened tubular blank 1 by forming a first corner flap 11 between a longitudinal edge 3 of the blank and an incision 8 made from one end of the blank, bottom flaps 14a, 14b being formed from the incision 8 towards the other longitudinal edge 2, the bottom edges 6, 7 of the bottom flaps being inclined relative to the longitudinal edges 2, 3 and a second corner flap 21 being formed by folding triangular portions of the bottom flaps adjacent the other longitudinal edge, inwardly towards that edge. As shown, the blank is folded about lines 10, 13 and the bottom flaps 14a, 14b and the triangular face 12 formed thereby are folded about lines 13a, 13b. The flaps 14a, 14b are then folded back and a triangle 12a defined by lines 15, 17, 20 is folded under the remainder of the face 19 to bring a triangle 12b beneath triangle 12a. The same procedure is followed with triangles 12c and 12d, whereafter the flaps 14a, 14b are folded over one another and sealed as shown, either discontinuously or continuously, and with or without the interposition of plastics foam 24. In another arrangement, Fig. 4 (not shown), the triangles 12a, 12c are folded back on to the remainder of flap 21. In another arrangement, Figs. 5-8 (not shown), an additional incision is made adjacent the side edge 2. In a further arrangement, Figs. 9-11 (not shown), comprising two incisions in the blank, the inclined end edges extend only between the incisions, and the inner portion of the flap 11 is provided with superficial incisions to improve flexibility of the flap and to facilitate the valve action of the flap. The superficial incisions are formed by a toothed clamping member (39)- (41), Fig. 13 (not shown), and sealed joints are obtained by means of a sealing member (44), Fig. 14 (not shown). [GB1292038A]