摘要 |
<p>PAPER COATING METHOD AND APPARATUS This invention relates to a method, and apparatus of the blade type, for applying a coating material to a web of paper. A conventional coater of the blade type includes means for applying coating to a paper web supported and carried by a resilient backing roll, together with a flexible doctor blade located some distance from and on the trailing side of the applicator, which serves to level the applied coating. In order to achieve low coat weights, i.e., in the order of 3 to 4.5 grams per square meter per side of paper, it is necessary to increase the pressure of the blade against the web, which results in a high rate of wear, and increases the possibility of web breakage and streaking caused by foreign particles being caught between the blade and the web. The present invention utilizes a reservoir of liquid coating material between a forward liquid seal and a rearward doctor blade spaced a short distance from the seal. The coating material is applied under pressure to as to form and maintain the liquid seal. This provides a short dwell time, low coat weights, low blade pressures, and excellent results. Figure 5 is representative of the invention.</p> |