| 摘要 |
1,011,799. Cartons. DETROLITE CORPORATION. Aug. 22, 1962 [Aug. 23, 1961], No. 32270/62. Heading B8P. A carton blank has at least one series of end closure flaps, including inner flaps 33, 34 an intermediate flap 32 and an outer flap 31 which when the carton is erected form a multi-layered closure, the intermediate flap being recessed along an edge 64 so as to provide an area of overhang of the intermediate flap 32 by the outer flap 31 when the flaps are folded over each other upon closing the carton, the inner flap providing a surface for opposed facing relation with the outer flap in the area of overhang, at least one of the flaps being provided with adhesive which is disposed and activated in said area, the carton being closed and sealed by applying adhesive-activating conditions such as infra-red rays, dielectric heating or microwaves to said flaps. The recess on the intermediate flap can either be curved at the inner edge 64 or continue to the fold line 56. The carton blank can be made of laminated sheet material with layers of waxed paper sheet and thick paperboard sandwiching a layer of thermoplastic laminating adhesive, the blank being of the form shown in Fig. 2, divided into four side panels 21-24 with a glue flap 25. The top flap 31 carries a layer of thermoplastic adhesive 12a for sealing of this edge to the upper surface of flap 32. The blank can also be made of single ply paperboard, the outer flap being provided with a complete layer of thermoplastic adhesive. The blank can further be made of a two-ply paperboard, the outer flap then being provided with a coating of thermoplastic adhesive in the areas immediately adjacent its lateral and longitudinal edges. The blank can also be made of foil mounted paper, parchment paper, greaseproof paper, glassine papers, non- woven fabrics or polyethylene coated paper. Fig. 6 is a partial cross-sectional view of the top of the carton after erection and sealing where the thermoplastic laminant adhesive has extruded outwardly from the recessed edge 63 of the intermediate flap 32, forming a band of thermoplastic adhesive laminant between the inner and outer flaps. When single ply or double ply material is used the carton is sealed by the thermoplastic coating on the outer flap 31. Several kinds of adhesive are referred to such as hot melt adhesives preferably based on petroleum wax, especially microcrystalline waxes, and heat-sealing adhesives of various thermoplastic hydrogen waxes. Specifications 1,011,796 and 1,011,800 are referred to. |
