GB1060151A - Improvements in or relating to method and apparatus for evacuation of plastics film packages - Google Patents

Abstract

1,060,151. Packaging. UNION CARBIDE CORPORATION. Aug. 13, 1963 [Aug. 13, 1962], No. 30954/62. Heading B8C. A method of packaging comprises placing an article in a pouch of flexible plastics film drawing a vacuum through the pouch opening to bring the film into tight engagement with the article, and closing and sealing the opening at a point adjacent to the article while maintaining the vacuum. Mounted on a frame 10 are an evacuating assembly 14 with a reciprocable evacuating plunger 30, a closing and cutting assembly 16 movable horizontally at right angles to the movement of the plunger, a support rail 64 and a support platform 82 movable about a hinge 84. An elastic plastics bag containing an article is fed on to the platform 82 and the neck of the bag is placed over a protruding barrel 26 of the evacuating assembly housing the plunger 30. The neck of the bag is held manually on the barrel 26 while the plunger 30 is advanced into the bag. If the article being packaged is hollow, e.g. a chicken, the plunger also advances into the cavity of the article. Air is withdrawn through radial openings 38 (Fig. 3, not shown). The plunger 30 is retracted, the withdrawing of air being continued until the openings 38 are closed by a flange 27 of the barrel 26. The platform 82 is then pivoted downwards and the package is left suspended over a support rail 64, the mouth still being held over the barrel 26. The weight of the article tensions the film between the article and the end of the barrel so that a metal clip or other closure can be applied. The closing and cutting assembly 16 now advances until aligned with the barrel 26, a strip 81 (Fig. 6) guiding the film over a knife sheath 74, the force from the tensioned film depressing a knife blade 72 below the surface of an anvil 73. A spring 80 returns the sheath and blade to the cutting position so that when the assembly 16 is retracted after application of a clip by known means (not detailed), the neck of the package is pulled between the blade 72 and the anvil 73, severing it just outside the clip. Since the mouth of the film bag remains firmly gripped against the barrel 26 during the sealing, a vacuum is maintained, thus preventing the re-entry of air into the package. The apparatus is pneumatically operated, means being provided to prevent advance of the closing and cutting devices prior to withdrawal of the plungers 30. The barrel 26 is rotatable by a hand lever 46 which also operates valves to carry out the various operations.