GB974827A - Heat sealing and severing apparatus - Google Patents

Abstract

974,827. Seaming non-metallic sheet material; making bags. PAUL MOORE CO. Ltd. Oct. 29, 1962 [Sept. 28, 1962], No. 40860/62. Headings B5D and B5K. [Also in Division B8] Apparatus for heat sealing at least a pair of laminated plies of material partly coated with a thermoplastic material, including a planar first member having at least one elongate portion terminating, at one end thereof, in at least one extension which is at least in part disposed substantially angularly to the elongate portion; a heating element mounted on said first member; a pair of side plates mounted on said first member and extending substantially throughout the length of said heating element normally to the plane of said first member; a strip of flexible heat-resistant material draped intermediate the side plates, spaced from and covering the heating element; severing means mounted on the first member; and a second member co-operating with the first member and on which the material is placed; a selected one of said members being movable with respect to the other, whereby the heating element seals adjacent coated portions together throughout an area corresponding to the length of the heating element. In the embodiment shown in Fig. 1, the planar first or upper member 2 has a pair of spaced parallel elongate portions 4, 6 interconnected at one end by a curved extension 8 and at the other end by a member 10 provided with hand grip 12. Extending substantially throughout its length is a heating element 14 comprising a metal bar with a resistance wire therein, an outer side plate 17 and inner side plate 18. The plate 17 is formed with a sharpened edge 22 so as to act as a cutting member. Draped between the side plates 17, 18 is a strip 24 of heat resistant material such as tetrafluoroethylene. There is also a layer of tetrafluoroethylene together with a layer of heat insulating material between the element 14 and the member 2. A second member 30 constitutes a pressure pad co-operating with the first member 2 and consisting of a resilient portion covered by a layer of tetrafluoroethylene and a hardened portion, e.g. of steel on the outside thereof and having a V- shaped slot for co-operating with the cutting edge 22. In use (Fig. 4) the first member is hingedly mounted at 42 on a table bed 44, the second member 30 being secured to the bed 44 and located beneath the first member. Laminated material 48 from a reel 46 passes over and under a folding bar 54 to form upper and lower plies 56, 58 and is positioned between the first and second members. Alternatively, the material 46 may have been previously folded in half or it may be in tube form. Matter or article 60 to be packaged is placed between the two plies of material and when the heating element 14 has attained the required temperature the grip 12 is pulled downwardly, thus fusing the two plies 56, 58 beneath the heating element and severing the package from the remainder of the material. Instead of the sealing and cutting taking place simultaneously, separate sealing and cutting elements may be provided on the first member, the material being moved from beneath the sealing element after the sealing operation to beneath the cutting element. In other embodiments, different shaped members are shown for producing other shaped packages and in some the sealing and/or cutting is done in two stages by moving the material. In further embodiments arrangements are provided for forming a gusset at the bottom of the bag or package and another embodiment enables several bags to be formed in one operation. Specification 974,826 is referred to.