GB1411837A - Transfer moulding - Google Patents

Abstract

1411837 Injection moulding apparatus GENERAL TIRE & RUBBER CO 19 Nov 1973 [18 Dec 1972] 53660/73 Heading B5A Transfer moulding apparatus comprises a plunger 16, a transfer pot 32 located in a plate 30, a mould 40, runner-defining means adapted to be placed in open communication with a mould cavity 52 and with the transfer pot 32, and temperature-controlling means 70 for maintaining the transfer pot and a contiguous portion of the runner R at a temperature sufficient to allow the moulding material to flow, but below the temperature required to cure the material within the curing cycle time. The temperature controlling means 70 comprises a heat insulating plate 76 disposed between a heating plate 72 and a "cooling" plate 74. Steam is circulated through bores 82 in the plate 72 and hot water through bores in the plate 74. A series of bores 78 extend through the means 70, each bore containing an insert 90 (not shown in Fig. 1). As seen in Fig. 5 each insert defines a runner R and comprises upper and lower cylindrical members 92, 94 joined together to form an insulating annular space 96. The mould 40 comprises plates 44, 46, 48, a core form 50, and a pair of runners 54, for each cavity 52. When the mould is opened separation between cured and uncured material occurs along a line S (Fig. 5) and material above this line and in the pot 32 can be used in the next moulding cycle. The apparatus can be used for making rubber inserts for automotive bushings.