| 摘要 |
A calibration plate for the cooling of thermoplastic sheet material comprises a plurality of passageways for chilled fluid characterised in that at least part of the or each passageway is open to the operative surface of the plate. As with traditional calibration plates, vacuum passages may also be provided to draw a vacuum and maintain the sheet to be cooled in close contact with the plate during the cooling operation. The calibration plate of the invention therefore allows chilled fluid, in particular chilled water, into direct contact with the sheet surface. This has two beneficial effects: firstly, it lubricates the sheet surface, cutting down the friction; and, secondly, with direct contact between the cooling medium and the sheet surface the cooling effect is much more rapid and marked. The calibration plate of the invention therefore enables much higher throughput speeds to be achieved, speeding up the entire process of the production of the sheet material. |
