GB759202A - Flexible container and method and apparatus for making the same - Google Patents

Abstract

759,202. Dip-moulding flexible containers. SHAPERO, W. H. March 19, 1954, No. 8018/54. Class 87(2) [Also in Group XVII] A flexible container having a threaded outlet is made by attaching a threaded closure cap (or a former in the shape of such a cap) to a mandrel having the shape of the container, and dipping the mandrel and cap (or former) into a bath of resin, latex, &c., the thread on the cap (or former) forming a corresponding thread on the container. As described, a container comprising a body portion 10, Fig. 4, a shoulder 11 and a screw-threaded closure cap B having a central core 18 that fits into the neck 12 of the container, the material of the body covering the cap, is made by attaching the cap to a mandrel C and dipping the assembly of mandrel and cap into a bath of latex, vinyl plastisol, &c. As shown in Fig. 2 the cap is attached to the mandrel by sliding a bore 19 in the cap over a projection 25 on the mandrel. In operation, first the mandrel (or gangs of four mandrels) is hung on a conveyer 36, Fig. 12, and passes through station I where it is heated, II where the cap is attached, III where the assembly is dipped in a bath 21, IV where the dipped container is heated to cure or set it, and V where it is stripped from the mandrel, e.g. by compressed air passing through grooves in projection 25. During the dipping operation the neck 12 (see Fig. 5) is formed in the annular space between the cap core 18 and the screw-threaded interior of the cap, and a thin skin 16 is formed over the cap: this thin skin may be broken at a sharp edge when the cap is to be removed. The shoulder part 11 of the container is made thicker than the body part 10 by reason of the fact that the corresponding part 23 of the mandrel is thicker than the part 22 and retains more heat: alternatively this thickening may be achieved by dipping at different levels (Fig. 13, not shown). The mandrel may be heated by infra-red lamps 44, Fig. 12, or by immersion (with the cap) in a bath of powdered or liquid material (Fig. 14, not shown), or by gas burner or H.F induction. In modifications:-(1) (Fig. 7) the cap B<1> has a long stem 18<1> which forms a long container neck 12<1>. (2) (Fig. 10, not shown). The cap has a small central pip by which it is attached to the mandrel. (3) (Fig. 8, not shown). The mandrel has air passages for removal of the container by blowing.