| 摘要 |
An apparatus for casting sheets of plastic is shown. It includes a casting zone defined by two glass surfaces and a marginal sealing gasket, and an adjacent temperature control cell. The cell is an enclosed chamber comprised of a rigid frame having two extended, semi-rigid sides which may be of sheet metal or glass and which are flexible and responsive to pressures acting upon them. In one embodiment, the cell frame has a rigid brace attached within it, positioned adjacent to the inner surface of its sheet metal or glass side. The brace prevents inward deflection of that side so that the casting zone adjacent to that side is not distorted by the hydrostatic pressure of the liquid charged to it. In this embodiment, there is no need for charge measuring apparatus, the side of the casting zone is free to deflect outwardly and follow the cast sheet as it shrinks during polymerization and higher temperature and higher pressure media can be used in the temperature control cell. In the preferred embodiment the side of the temperature control cell is glass bonded to the sides of the frame at a series of novel bonding zones. The amount of liquid plastic charged to the casting zone is controlled by first adjusting the head of temperature control liquid in the adjacent control cell to a height which just balances the head of liquid plastic in the full casting zone.
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