GB522460A - Improvements in or relating to the packaging of materials, particularly perishable foodstuffs - Google Patents

Abstract

522,460. Packing. DEWEY & ALMY, Ltd., (Dewey & Almy Chemical Co.). Dec. 21, 1938, No. 37215. [Class 94 (i)] Relates to a method of packaging materials, particularly perishable foodstuffs which are intended to be preserved subsequently by cold storage or chilling. According to the invention, an envelope or bag of flexible and elastic material impervious to air and moisture is distended to a predetermined size, an article is inserted therein, and the envelope is then caused or permitted to contnact on to the article. The envelope may be of unvulcanized or partly vulcanized rubber, and it may be of cylindrical shape but is formed preferably with an enlarged upper portion 29, Fig. 6. The envelope 3, Fig. 1, is inserted in a cylindrical container 1 and its upper edge is turned over the rim 5 of the container to form an air-tight seal between them. Air is then withdrawn from the chamber through a pipe 6 to cause the envelope to distend into contact with the walls of the chamber, a perforated partition 7 limiting the downward expansion. In order to ensure even stretching of the rubber a plunger'may be provided to press it downwards, but a pin 10 may, be provided for the same purpose. The pin also shapes the envelope when a part of the envelope is to be inserted into the interior of a packed article, as shown in Fig. 3. The stretched rubber is stiffened, to cause the envelope to maintain its shape, by chilling it by means of an air jet, or by circulating cooling fluid through a jacket 27 in the container 1. The article is then inserted in the envelope, the vacuum about the envelope is relieved, the upper end of the envelope is gathered about a nozzle 11, and air is exhausted from within the envelope. Finally, the neck of the' envelope is sealed, and the rubber is subjected to the action of heat to restore its elasticity before the package is put into cold storage.