GB945234A - Machine for manufacturing bottles or similar hollow articles from thermoplastic materials - Google Patents

Abstract

945,234. Blow moulding hollow plastic articles. S.A.S. LAVORAZIONE MATERIE PLASTICHE (L.M.P.) DI. M.I. COLOMBO & CO. June 22, 1962 [April 6, 1962], No. 24091/62. Heading B5A. In a machine for making thin-walled thermoplastic bottles wherein an extrusion head 10 feeds a heated tubular blank between the jaws of a mould, which close to form a hollow, one end of the jaws closing the blank completely while the other end, fitted with rubber pads, presses the blank round a blower tube 42 extending from the extrusion head, after the blank has been inflated to fill the hollow and the mould has been withdrawn from the blower tube, the pressurized blank is pierced to release the pressure before the mould is opened. Fig. 1 shows a series of moulds A, B, C, D mounted on an endless chain 12, and an extrusion head 10 with blower tube 42 projecting. The blower tube is much narrower than the tubular blank T extruded by the head 10 (see Fig. 3). Each mould comprises two jaws A 1 , A 2 which may be cooled and which close on part of the hot blank T<SP>1</SP> (see Fig. 4), enclosing it in a moulding hollow 20, the lower end of the blank closed by clamping jaws 511, 51<SP>11</SP> the upper end pressed round the blower tube 42 by rubber pads 53<SP>1</SP>, 53<SP>11</SP>. As the mould moves away from the extrusion head, the section T<SP>1</SP> of the blank is inflated by compressed air entering through the blower tube, finally T<SP>1</SP> slides off the blower tube, the rubber pads close the hole, as in the lower half of Fig. 4, and the pressure within the formed bottle is retained until the mould on its chain passed a fixed cam 90 (Fig. 1), which causes the section P (Fig. 4), of the bottle to be pierced by a hollow needle 65, immediately prior to the mould being opened.