| 摘要 |
<p>Mould for transferring and preshaping a semi rigid sheet lining for a thermoforming mould cavity comprises a sleeve coaxial with the stem of a reciprocating plug for the base of a mould cavity tool having an open base slightly smaller than the cavity section and itself also able to withdraw axially to allow lateral removal of successive mouldings complete with the external linings. The sheet lining is initially shaped between the plug sleeve and a casing which comprises an extension to the base of the walls of the cavity but with a reduced bore. The lining is supported by a collar on the sleeve until it can extend on to the rim of the base of the cavity when the latter is retracted. As the cavity tool complete with lining rises into position to receive the next moulding, the head of the plug is raised to an intermediate level and provides lateral support for the lining, opt. also thrusting it towards the more remote parts of a non-circular cavity section. Used esp. for positioning plain or printed sleeves for thermoformed thermoplastic beakers or containers. Involves a minimum of different moving parts to allow the shaping and transfer operations for the liner to be sepd. sequentially and to minimise the incidence of buckling of the unsupported lining material.</p> |
