GB965032A - Package and packaging apparatus - Google Patents

Abstract

965,032. Packaging articles in film; endless conveyers. OSCAR MAYER & CO. Inc. Aug. 15, 1962, No. 31265/62. Headings B8A and B8C. Rows of articles are sealed in a folded film of supercooled polyvinylidene chloride film, or between two such films, using the property of such supercooled films of fusing together on contact and without heating. The films are drawn together by vacuum and are subsequently crystallized. An admixture of vinyl chloride may be included in the film. In the form shown batches of wieners are enclosed between upper and lower webs. The Specification includes a list of other articles which may be similarly packaged. Applying and sealing webs. Endless conveyers.-The wieners 47 (Fig. 1A) are delivered from a device 48 on to the lower web 37 where they rest on bottom dies 44 carried by endless chains. Side dies 95 (Figs. 5 and 22) are then placed in position on either side of the wieners by endless chains 87, 91, and upper dies 53, carried by endless chains 113 are lowered on to the upper band 38 guided above the side guides 95. All the dies are formed with passages (see Fig. 18) connected through conduits 57 to a rotary valve 56 (Fig. 1A) controlling connections to vacuum, atmosphere, and an inert gas such as nitrogen. By these means the upper and lower films are first held by vacuum against the corresponding dies while the space between them is flushed by nitrogen connected at one end and vacuum connected at the other. Vacuum is then connected to the interior between the films at the same time as the vacuum holding them to the dies is released. This causes the films to form around the wieners, sealing together where they come into contact, as shown in Fig. 18. Slits 146 (Fig. 18) in the side dies prevent the webs from closing the passages leading to the space between the webs. The chains 125, 113 carrying the lower and upper dies are guided by members 126, 115. The side dies 95 are guided by rollers 98, 99 (Figs. 5 and 22) engaging cam tracks 100, 105, and are lowered into engagement with the lower web by rollers 106 engaging a further cam track. When sealing is complete the upper and lower dies are retracted so that the packages are supported by the side dies as indicated in the middle of Fig. 1B. Heating to crystallize film.-A radiant heater 58 (Fig. 1B) completes crystallization of the supercooled film. Cutting packages from web.-The packages are cut from the webs by dies 59, 62 (Fig. 1B) carried by endless chains 186, 190 and guided by suitable cam surfaces. Each upper die includes a member 173 (Fig. 28) carrying blades 176 which take into slots 181 in the lower die. The members 173 are depressed, against the bias of springs 171, when rods 172 are engaged one after the other, by a fixed cam 195 during the movement of the die. The lower die supports the packages by means of rods 183. The packages fall on to a conveyer 66 (Fig. 1B) and the waste portion of the webs 67 is delivered to a storage roller 68. Endless conveyers; delivering articles to be packaged.-The wieners, previously connected by a paper band, are pushed over rollers 82 (Fig. 5), set in a table 74, on to the upper film 37, by pushers 80. The pushers 80 are carried by metal slats 78, forming with wider metal slats 75 a chain guided round vertical sprockets. Towards the end of the conveyer thus formed the pushers 80 are feathered as indicated in Fig. 5. Opening packages.-If the films are partly crystallized before being brought into contact the seal, while hermetic, can be peeled apart. To facilitate this a tab may be enclosed between the films. Producing and cooling film.-The film may be extruded and cooled as described in Specification 965,033. Laminated or simple film may be employed. Specifications 965,031 and 965,034 also are referred to.