| 摘要 |
1501009 Plastics bags; packages R J R ARCHER Inc 19 Dec 1975 [20 Jan 1975] 52116/75 Headings B8K and B8C A bag 10 is formed of plastics film the inside surface of which has a matte finish to produce a translucent appearance, the arrangement being such that when contacting sides of the bag are heat-sealed the plastics film becomes fused together to produce a transparent appearance to provide a visual indication of seal integrity. As described the bag is produced by coating a web of nylon 16, Fig. 2, with an adhesive promoter 18, applying a layer 20 of low density polyethylene to the coated web, extruding a layer 22 of "Surlyn" (Registered Trade Mark), an ethylene/acrylic acid copolymer, onto the layer 20, and applying a drill roll to the layer 22 to give it a matte surface 24. The web is then slit and sealed to form bags 10 which are transparent along heat seals 26, 28, 30. In use of the bag an article, e.g. a cut of meat, is placed in the bag, a vacuum is drawn on the bag causing portions of the bag walls to contact one another, the open end of the bag is heatsealed, and the sealed package is passed through a hot air or hot water heat tunnel so that all contacting portions of the bag walls are fused together thereby causing the film to become transparent to provide a visual indication of seal integrity. |
