GB1410932A - Cross bottom bag and manufacture thereof - Google Patents

Abstract

1410932 Lined cross-bottom bags WINDMOLLER & HOLSCHER 12 Oct 1972 [6 Nov 1971] 47166/72 Heading B8K [Also in Division B5] In a cross-bottom bag having a plastics lining closed at at least one end by a folded crossbottom which is incorporated in a folded crossbottom of a single or multiply outer, the last folded side flap of the lining at the or each end is foreshortened during the formation of the bottom to expose a portion of the associated side flap of the outer so that this exposed portion can be adhered directly to an underlying portion of the other outer side flap of the bottom. The bag is formed from a bag section comprising an inner tube section S 2 which projects from an outer tube section A 2 at the or each end at which a cross-bottom is to be folded. The inner and outer tube sections include cuts E and F at the or each end, whereat the inner tube section S 2 is also adhered at both faces to the outer tube section A 2 along spaced lines of adhesive 1, 2, 3 and 4. The or each end of a bag section is opened up, as shown in Fig. 5, and the last folded side flap of the inner section is foreshortened by folding along the respective adhesive line 1 or 4 to expose a portion of the outer tube section side flap 8<SP>1</SP>. Strips of adhesive 10, 10<SP>1</SP>, 11 and 11<SP>1</SP> are applied and the crossbottom is completed by first folding the outer tube section side closure flap 8 and its associated overlying inner tube section side closure flap about a line 12 and then folding the side closure flap 8<SP>1</SP> and its associated inner tube section side closure flap so that the exposed area of the side closure flap 8<SP>1</SP> overlaps and is adhered to the side closure flap 8 and the bottom of the lining is sealed. The bag sections are assembled by laying overlapped inner tube sections on a paper web provided with lines 1-4 or (3<SP>1</SP>, 4<SP>1</SP>), Figs. 1a-4a (not shown), of adhesive and transverse perforations at bag section intervals and tubing the paper web about the inner tube sections before separating the bag sections by tearing along the perforations. A valve tube V can be incorporated in the cross-bottom by placing the tube V on the opened-up bottom as shown in Fig. 5 so that upon completion of the cross-bottom it is adhered to the inner and outer tube sections about its periphery by lines 10 and 11 of adhesive.