GB1378742A - Manufacture of cartons - Google Patents

Abstract

1378742 Gusseted cartons BOXFOLDIA Ltd 7 Jan 1972 [8 Oct 1970] 47813/70 Heading B8P To prevent content loss and incursion of atmospheric environment, a carton is erected from a blank of laminated material partially cut through at the corner junction 17 of each closure wing 15 and flap 16 over at least a major portion of the length of the junction so that upon folding the flaps 16 over the wings 15 an inner lamina may delaminate at each corner from the remainder of the material to form an integral gusset 25. The area of delamination may be limited in part by a cut or score line (20, Fig. 2, 24, Fig. 5) in the inner lamina. The laminated material may be completely cut through over a minor portion of the length of the junction (22, Fig. 5). The flaps 16 may project beyond the wings (Figs. 3, 4). The inner lamina may extend part-way over the outer lamina of a flap 16 (Fig. 4) from the fold line 14 or beyond the flap, the excess outer or inner lamina being removed during carton manufacture. To facilitate delamination, adhesive employed for lamination may be less densely applied, may be partially or wholly removed, may be weaker or may be weakened by heat activation between the wing and flap laminae. Two different adhesives may be used to laminate the flap and wing laminae, one being softened prior to carton closure and one being cured at a higher temperature to cause rebonding. Inner and/or outer wing and flap laminae may be printed or impregnated with a release agent, e.g. oil or grease. Discrete or the whole area of the wings and flaps may be treated to facilitate delamination. The laminated material may comprise an outer lamina of wood pulp card adhered by wax or a thermoplastic resin to an inner lamina of glassine paper: part of the outer lamina may be removed to provide a window. The junction 17 may be offset from the corner fold 12.