GB1042513A - Skin-pack - Google Patents

Abstract

1,042,513. Packaging-machines. G. MISSBACH. April 8, 1963 [April 7, 1962], No. 13945/63. Heading B8C. In an apparatus for forming skin packs the operations on the packs are performed during continuous forward movement of the articles. In the illustrated embodiment, the articles 3 (Fig. 1, not shown) advance on a supporting layer 2 which is permeable to air, over a table 1 and thence around a drum 8 which rotates continuously. A covering plastics film 6 is fed over the articles, heated at 16 to plasticize it and then pressed on to the supporting layer 2 at intervals by a reciprocating pressure plate 17. Suction orifices 10 (Fig. 3, not shown) in the drum 8 are now uncovered by an internal elastic covered drum causing the covering layer 6 to be drawn skin tight over the articles. Thermoplastic adhesive applied to the layer 2 at 4 is activated by the heated covering film 6 causing the two to unite. The orifices 10 are again covered and the packages pass through a cooling zone. The thermoplastic adhesive on the layer 2, or ordinary adhesive moistened at 4, help to locate the articles accurately. If the articles are of a magnetic material, they may be retained by a magnetic force. The drum 8 may be of increased diameter at its ends to form an annular chamber 11 with guide surfaces 14 for the covering layer 6. The layer 6 may be held in contact with the surfaces 14 by two endless guide belts 15 or by vacuum applied through a plurality of inserts of porous material within the walls 13. Alternatively, the drum 8 may have a constant diameter throughout and the covering layer 6 be guided over the articles in a bell formation prior to the deformation. To aid this arrangement the layer 6 may be heated in advance, below plasticization point, prior to reaching the drum 8. The continuous web forming the supporting layer 2 may be replaced by individual sheets and the chamber 11 of the first embodiment is subdivided into lengths slightly longer than the lengths of the sheets by transverse walls which may be pivotably mounted on the base 12 by spring-controlled hinges to enable the table 1 to be brought close to the drum 8. The supporting layer 2 may be made of a cardboard inherently permeable to air or may be rendered permeable by perforations. To ensure uniform heating of the cover layer 6 and prevent damage of the articles 3, an insulating layer 22 is placed therebetween beneath the heater 16.