| 摘要 |
1529621 Seaming HAYSSEN MFG CO 2 Jan 1976 [2 Jan 1975] 00035/76 Heading B5K Units U (e.g. of cheese) are packaged in flexible sheet material by a method comprising forming a continuous web W of the flexible sheet material heat sealable on at least the upper face F thereof into a tube by causing the margins M of the web to converge and meet in inside face to inside face engagement, heating the inside faces of the margins by delivering hot gas from heating means 3 to between the margins M, and pressing the heated margins together to seal them, and providing transverse seals across the tube with a unit U to be packaged positioned within the tube between successive transverse seals. The units U are supplied by a conveyer 11, the web W being pulled through the packaging machine by oscillatory movement of the transverse sealing jaws (141, 143) to which means for severing the separately packaged units from each other may be attached. The margins of the web are brought together by passing them between adjacent horizontal plates (41L, 43, 41R) and between converging sets of guiding rollers (53, 55, 57) Fig. 3 (not shown). The heating gas used may form a protective gas for the units to be packaged, and further protective gas, e.g. carbon dioxide or nitrogen, may be blown into the formed tube by a plurality of horizontally spaced gas jets (125) extending downstream of the rollers (93, 95) which provide the pressure needed to form the longitudinal seal to form the tube (Fig. 6, not shown). Means may be provided for blowing air transversely across the end of the nozzle supplying the hot gas whereby excessive heating of the margins can be prevented should the web be left stationary in the plant. |
