| 摘要 |
While the machine is stationary, the material sheet (4) is protected from the radiation from the heaters (5), which run at reduced power, by a shield (8). At start-up the heaters are brought to full power and the shield (8) is withdrawn as the sheet (4) accelerates. The movement of the shield is controlled so that the edge (9) of the shield exposes sufficient radiation to give the correct sheet temperature at molding. An independent claim is also included for the analogous procedure at stopping the machine to synchronize the shield movement with the deceleration of the sheet (4). The power of the near-infra-red heaters (5) is also reduced. Deceleration of the sheet (4) is only started once the last sheet section to be utilized has left the heating station. |
