Efficient heating of thermoplastic plate using radiating heat source

摘要

In a process for optimum heating of a thermoplastic plate (1) using a radiating heat source heater (2,3) output is varied during the heating period to account for changing characteristics in the plate and involves: (a) recording the surface temperature(TO) of one or both sides of the plate(1) with a sensor (5,6) and comparing(TO) with a set value(TS); (b) reducing the heater output from a high initial value so that the plate surface temperature(TO) is stabilised at the set temperature(TS); (c) maintaining the set temperature(TS) or a slightly lower post heating temperature(TG) for a prescribed post heating time(TN) at the reduced heating output.