| 摘要 |
825,610. Making bags &c. LAMSON PARAGON Ltd. Jan. 17, 1958 [Jan. 17, 1957], No. 1830/57. Class 94(2). [Also in Group XV] A method of making a strip of connected bags (or envelopes) b from a web of heat sealable plastic material, or a web coated on at least one face with heat sealable material, comprises folding, the web lengthwise to form two superposed layers a<SP>1</SP>, a<SP>2</SP>, applying heat along transverse zones a<SP>3</SP> at longitudinally spaced intervals of the web to seal the layers together to provide a series of bags, and forming a transversely extending line of weakening a<SP>4</SP> between the adjacent bags of the series. As shown, the web has not been folded along its longitudinal centre line so that each bag is provided with a foldable flap. In the apparatus for making the bags, the web is fed from a reel over a guide roller to folding means ; it is then fed over heat sealing means, through perforating mechanism, and is rewound on a reel or into a zig-zag pack. The apparatus may include punching means which punches one or more holes through each bag to. provide ventilation of the contents of the bags in use. The web may be of polythene, or it may be of paper coated on one face with heat sealable material. |
