| 摘要 |
960,359. Seaming non-metallic sheet material. FR. HESSER, MASCHINENFABRIK A.G. March 15, 1963 [June 6, 1962], No. 10292/63. Heading B5K. [Also in Division B8] Heat sealable sheets 1, 2 are heat sealed by forming, before sealing, perforations 6 or depressions in at least one of the sheets so that during subsequent formation of the heat seal a part of the sealing material of the other sheet penetrates into and anchors in the perforations 6 or depressions. In one embodiment, Fig. 2, a container body 1 of cardboard 4 having a thermoplastic coating 3 is provided with a thermoplastic cover 2 having a stand-up rim 7 sealed to the body 1 by a seam 5. Before sealing, perforations 6 are formed in the body 1 so that on application of heated sealing jaws 8, 9 part of the material of the rim 7 forms pips penetrating into the perforations 6. In an alternative embodiment, Fig. 3, a closure seam 10 for a bag of material 13 having a thermoplastic coating 14 is formed after the provision of perforations 15 in both sheets 11, 12 to be seamed. The width of the perforations 6 or 15 or the depressions is preferably less than the width of the seam 5 or 10. |
