| 摘要 |
The machine for the continuous production of polyurethane foam panels lined with outer layers has two endless conveyor belts, defining a mould cavity between them, and a lining gantry, on which there are arranged two mixing heads (11, 12), which can be moved independently of each other into a production position above the lower conveyor belt or the lower outer layer. To each mixing head there leads a component supply line (14, 15) from the metering station 13. Provided between the two component supply lines is a permanently open connecting line (16). In the foaming position, the mixing heads preferably oscillate transversely to the direction of production. According to the invention, it is possible always to have one mixing head in operation when the other is being cleaned or maintained. It is not necessary to interrupt production for this purpose. The component lines are connected in such a way that, when changing over, no metering errors occur due to pressure fluctuations. If one mixing head is switched off, each component continues to flow through the corresponding supply line to this switched-off mixing head, but instead of flowing into it flows into the connecting line and on to the other mixing head. Consequently, there is a permanent throughflow through each component supply line to each mixing head, irrespective of whether the mixing head is switched on or not. The direction of flow through the connecting line depends on which mixing head is switched on (Fig. 2). <IMAGE> |
