摘要 |
1,011,798. Lined cartons. PETROLITE CORPORATION. Aug. 22, 1962 [Aug. 23, 1961], No. 32269/62. Heading B8P. [Also in Division B5] In making cartons of layers of materials, such as paper 42, Fig. 6, and paperboard 40, secured together by thermoplastic adhesive 41 by a process including scoring the carton blanks and subsequent folding, damage or rupture of the adhesive at the fold (50, Fig. 6), with consequential impairment of the carton's liquid- and vapour-tightness, is remedied by applying heat with or without pressure in the neighbourhood of the score lines to soften or fuse the adhesive and reconstitute it as a coherent layer, as shown in Fig. 7. Heat is preferably applied by a heated iron which may have two seating faces about <SP>3</SP>/ 16 inch wide at 90 degrees, and may be applied to the folds of a flat folded blank (at 180 degrees) or of a blank, as shown, which has been opened after edge sealing, or after filling and sealing. Apart from paper and paperboard, the materials of the layers may comprise non- thermoplastic films such as regenerated cellulose or metal foils. The adhesive may be wax or microcrystalline wax, with or without a polymeric additive, or added rubber, resin or gum, or may be asphalt, polythene, polyterpene or a cellulose derivative. Specifications 1,011,796 and 1,011,800 are referred to. |