| 摘要 |
<p>1,230,795. Laminated packaging foil; moulding plastic materials. J. R. DURAND. 24 April, 1968 [25 April, 1967; 26 Sept., 1967], No. 19413/68. Headings B5A and B5N. [Also in Division B8] A flexible packaging foil comprises a flexible substrate 2, Fig. 1, to which is adhered a layer 3 of a plastics material so arranged that the plastics material layer is flexible, the plastics material being alterable by the application of heat at a temperature which will not affect the substrate, to provide a rigid sheet or package. The layer 3 may be a thermosetting resin, but preferably consists, as shown, of a plurality of expansible pellets of P.V.C. or polystyrene adhesively secured to one or between two foils of aluminium. The, or each, foilmay be reinforced with kraft paper, which may be apertured to allow an electrical connection to be made to the foil. When only one metal foil is present, the other face of the layer 3 may be covered by a layer of kraft paper, or may be coated over those parts of its area which, after folding of the foil to form a package, do not contact the metal foil, with an electrically conducting ink. When two metal foils are present one of them may be coated in the contacting areas 4 with an electrically insulating material. The foil may be produced by coating selected areas of a metal foil with adhesive and depositing expansible pellets thereof. In moulding a flexible packaging foil 27, Fig. 7, comprising a metal foil having expansible pellets secured to one face thereof, the foil 27 is wrapped around an article 26 and placed within a metal mould 21, 22. Conductors 24, 23 are connected to the metal foil and the mould respectively and high frequency current is passed through them to heat the pellets and expand them, thus filling the mould and producing a rigid package. In another method the mould is not used, but the laminate includes an outer metal foil to which one of the conductors is connected.</p> |
