GB967576A - Leakproof carton and blank for forming same - Google Patents

Abstract

967,576. Cartons and blanks for same. AMERICAN CAN CO. March 21, 1963, No. 11224/63. Heading B8P. A cut, separating adjacent closure flaps of a tubular carton, stops short of the flap hinge line at a transverse cut extending into the flaps whereby a web is formed by planar tearing of the closure flaps when they are outfolded. As shown, cuts 40 which may extend only partly through the material terminate the separating slits 30, 31 between flaps 15 to 17. A blank (Fig. 1) is formed into a tube by folding flap 10 about score line 1 so as to overlie the flap 14 and securing; flap 15 being simultaneously secured to flap 26. After setting up, each end of the tube is then closed by firstly outfolding flaps 15, 16 and 17, causing planar cleavage of the material beginning at the junction of cut line 40 with the separation cut 42 and extending through the blank progressing outwardly along the cut 40. The webs 50 thus formed lie in a plane substantially perpendicular to the side walls. Flaps 18 and 19 are then folded over the open end of the tube, flap 19 being secured to flap 16 and the end closure is completed by infolding flaps 15, 27 and 17, 33 and finally flap 16, 19. Preferably the whole interior of the blank is coated with polyethylene. Each of the sealing points at the stage shown in Fig. 8 will then have a polyethylene to polyethylene contact except where flap 18 meets the webs 50. In a modification (Fig. 11) the cut line 40 does not extend wholly through the blank and is provided with downwardly extending end portions 40b to facilitate better directional control in forming the web 50.