GB1437726A - Automatic packaging - Google Patents

Abstract

1437726 Packaging M E WALLIS 29 Aug 1973 [31 Aug 1972] 40697/73 Heading B8C [Also in Division B2] Articles are conveyed by a conveyer 12 to intercept a molten sheet or film 13 of plastics material extruded from a head 14 and as the article intercepts the molten sheet 13, a partial vacuum is developed around the article to cause the sheet to wrap and seal about the article. To create the partial vacuum, suction is applied through an elongate orifice 17 having a length at least as great as the width of the extruded sheet 13. As the wrapped article is moved away from the region of the head 14 by a conveyer 16, the suction separates the trailing portion of the extruded sheet from that wrapping the article and also breaks away excess film from the wrapped article. The plastics scrap is drawn into and collected in a perforated basket 28 located in a chamber 24 between the suction orifice 17 and a blower. The scrap may alternatively be gathered and carried away by a conveyer or a vacuum transfer system. Air from the blower is directed through ducting 54 and blown on to the wrapped articles as they are conveyed on a perforated belt conveyer 62. To produce a seal between the molten sheet and the trailing side of an article, the article may be conveyed into the molten sheet in an inclined position so that the trailing side has a somewhat upwardly facing surface. Alternatively the article may be modified and, as disclosed, a tray to be wrapped has a flange 47 extending from its trailing side 44 and to the upper surface of which the molten sheet material seals. The flange 47 includes a line of perforations 48.