GB637654A - Improvements in or relating to methods of packing congealing substances - Google Patents

Abstract

637,654. Enclosing in bags; paper bags. LEVER BROS. & UNILEVER, Ltd. March 13, 1947, No. 7027. Convention date, July 24, 1940. [Classes 94(i) and 94(ii)] A method of packing a congealing substance such as margarine comprises pouring the substance in a liquid or semi-liquid state into a bag with leakproof seams made of a thin foil consisting of material (other than rubber hydrochloride) which is impermeable by the substance, e.g. foil made of vinyl resins, said bag having a flat base of pre-determined shape and size and joined without seams to one or more of the walls, or being so constructed that such flat base is formed by the action of filling, and closing the opening of the bag after filling by means of a leak-proof external seam. During filling at least two opposite sides of the bag may be held between flat surfaces to give the packed material the desired shape, the bag being left between said surfaces until the substance is sufficiently hard to retain its shape. A number of examples of bags suitable for use according to the invention are described, e.g. as shown in Specification 539,044. After filling, a bag is closed by tightly pinching the opening together, preferably along a straight edge, and joining the two pieces of foil, e.g. by using adhesives or agents which dissolve the material of the foil or by using thermoplastic foils joined by pressing them together by means of heated flat instruments. In one method to close a bag it is not quite filled and filling is preferably effected by putting the bag in a carton of the desired shape into which the material is poured. The sides projecting above the filling are now folded along the centre line (Fig. 22), the seam being then made by joining the edges. The projecting part can be folded over so that the bag fits into a carton which is not much bigger than the mould formed by the flat surfaces referred to above. When using a carton container the empty bag is placed in the carton after the latter has been folded into shape. Fig. 1 shows a cross-shaped piece of foil the arms 1 of which are folded up until they stand perpendicularly on the base, the adjacent strips 2 being joined to form seams 3 (Fig. 1 and 2). In a modification the piece of foil is obtained from two bands placed crosswise one on top of the other, joined together where they overlap. In another modification a bag is obtained by folding a rectangular sheet in half and joining two edges together. A rectangular block 6 is pushed into this bag which leaves " ears " 7 projecting. These are then folded on to the base and fastened to it. The ears can, if desired, be seamed before folding. Specifications, 539,044, 637,655 and U.S.A. Specifications 2,074,277 and 2,149,872 also are referred to. The Specification as open to inspection under Sect. 91 states also that the bags may be made of rubber hydrochloride. This subject-matter does not appear in the Specification as accepted.