| 摘要 |
<p>1,243,441. Making flat-bottomed packages. MIRA-PAK Inc. 25 Feb., 1969 [12 Aug., 1968], No. 9889/69. Heading B8C. In a method for forming a flat-bottomed package a continuous web is folded into a tube around a hollow reciprocable mandrel 20 by a former 12 and sealed longitudinally by a device 13, and transversely by reciprocating jaws 15a, 15b, which have optionally heated flat platen surfaces 40, and which may descend about paths 17a, 17b to advance the tube whereupon after cutting the tube with a co-operating knife and slot 16a, 16b the jaws 15a, 15b separate slightly to allow a formed package A to drop and also to allow slight upward movement of the bottom seal when the mandrel 20 descends to flatten the bottom against the platen surfaces 40, the seal then lying flat against the bottom which may be enhanced by previously applying glue to the outer surface of the bottom seal. Product is introduced via a nozzle 21 prior to the flattening operation The jaws 15a, 15b and the mandrel 20 then return to their original position whereupon the jaws 15a, 15b reclose to form the package top seal. The jaws 15a, 15b may return to a position slightly higher than the sealing position so that they might upon descent scrape any product from the sealing area. In a modification, the sealing jaws 15a, 15b are vertically stationary the tube feeding being performed by the mandrel 20 moving below the sealing jaws and wherein, optionally the former 12 may move upwardly to form additional lengths of tubing. The mandrel 20 may be rectangular and have longitudinal V-shaped side recesses which co-operate with V-shaped gusset bars 33 to form gusseted packages. The sealing jaws 15a, 15b and/or the sealing device 13 may be moved through 90 degrees.</p> |
