摘要 |
Air bubbles which are entrapped within the cells of an engraved applicator roller are displaced from the cells by wiping the surface of the engraved applicator roller with the bristles of a brush. An elongated brush mounted on a doctor blade head projects into a doctor blade reservoir. The bristles of the brush are disposed for wiping engagement against the engraved surface of an applicator roller which is wetted by liquid coating material. As the engraved applicator roller rotates in contact with the liquid material in the doctor blade reservoir, the bristles of the brush puncture the entrapped air bubbles and sweep the entrapped air away from the cells. The sweeping action of the bristles induces a relatively low pressure condition within the cells, which promotes the flow of liquid material into the cells. The elongated brush, which extends from one end of the doctor blade head to the other, serves as a baffle which blocks the transfer of dispersed air bubbles from the liquid material in the upper reservoir chamber above the brush to the lower reservoir chamber below the brush where the cells are being filled.
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