| 摘要 |
<p>1463290 Extrusion blow moulding J A ZABALETA 21 April 1975 [22 Feb 1975] 16336/75 Heading B5A An extrusion blow moulding machine includes a cutter 20 downstream of the extrusion die 11 for severing tubular parisons in synchronism with the continuous rotation of a pair of plates 22 carrying the opposite halves 23 of a series of blow moulds, the half moulds 23 being moved together to enclose a severed parison causing it to rotate with them while inflating air is introduced, e.g. by piercing with a blow needle 24 which is advanced hydraulically into the mould. The extruder 4-10 is mounted via longitudinally and transversely adjustable carriages 3 and 4 on a platform 2 which can be vertically adjusted by an hydraulic ram. A crosshead die 11 contains a tubular core 12, Fig. 3, through which a mandrel 14 having a tapered end 13 is slidable to adjust the width of the die outlet. The mandrel 14 is mounted on a block 15 mounted via hydraulic rams 26 (Figs. 4, 5, not shown) to the extruder barrel 8. One of the rotary plates 22 carries a cam (not shown) which operates a valve (17) carried on an arm attached to the block 15 to control the rams (16) and hence the thickness of the parison. The extrudated is heated by a corona discharge between two half rings 18 below the die and a central electrode (19) attached to the die face. The moulds are opened by hydraulic rams and grippers 25 engage the neck of the article. The gripper head rotates about its support shaft 27 to discharge the article on to a stand 29, Figs. 11, 13, where cutters 30 remove the neck flash and members 32 engage and twist the tail flash to remove it. Alternatively the tail flash is removed by a member 34 (Fig. 13, not shown) positioned between the mould halves so that it becomes embedded in the tail flash and on withdrawal pulls off the flash.</p> |
