摘要 |
An apparatus and a method for controlling the thickness of coatings on webs at a plurality of cross-directional positions while a coating procedure is taking place. The deflection of the metering element is controlled automatically in response to measurements of the uncoated and coated web that determine the thickness of the coating being applied at a plurality of cross-directional positions. In one preferred embodiment, a bimetallic member having a plurality of separated tongue-like extensions corresponding to cross-directional positions along the blade is used, the tongue-like extensions pressing on the back of the blade at their ends in response to heat applied dependent upon the determined thickness of the coating being applied. In another embodiment, pneumatic actuators whose pressure may be varied in response to the determined thickness are used to adjust the position of the metering element at a plurality of cross-directional positions to locally vary the thickness of the applied coating.
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