GB789816A - Improvements in or relating to the manufacture of bottles and other hollow articles from plastic material - Google Patents

Abstract

789,816. Blow-moulding hollow plastic articles. AMIGO, A. Dec. 21, 1955 [Dec. 22, 1954], No. 37094/54. Class 87(2). A tube of organic plastic material is extruded, then the tube is sheared from the extrusion head and simultaneously its sheared end is closed, the shearing and closing being effected by movement of one mould half. Then the said mould half, together with the sheared tube, is moved into contact with another mould half (which is stationary during the movement of the first mould half) to form a mould, and the tube is blown in the mould to form a bottle &c. Fig. 2 illustrates a procedure in which a tube 5 of polythene &c. is extruded downwardly from a head 2 over a blowing pipe 1. A mould half 4 carrying a knife 6 then sweeps across the underside of the head to cut off the tube, that side of the tube which is first severed being brought into contact with and sealed against the other side, which is then severed. At the same time the lower end of the tube is clamped against the blowing pipe by the lower end of mould part 4. The mould part, tube and pipe then move to the left towards stationary mould part 3, the tube being sealed at top and bottom, and the tube is blown to shape. Mould part 4 then retracts to the right, as shown in Fig. 4, the blowing pipe with the blown article retracts a little to the right to clear mould part 3, and a stripping ring 8 ascends to discharge the blown article and the neck waste. In a modification (Fig. 5, not shown) the mould part 4 has pins which penetrate the tube to prevent it falling away from the nozzle. Fig. 6 shows a modification in which two movable mould parts 4 are arranged back to back on a reciprocating member 14 and co-operate in turn with two fixed mould parts 3.