Process and apparatus for coating webs and adjusting the wet application weight of the coating material

A process for coating a traveling web of paper, or the like, with a coating material, comprising:

• passing the traveling web over the circumferential, peripheral surface of a roll-shaped support;
• the support having an axis of rotation;
• the surface of the support being elastic where the traveling web passes over it;
• applying excess coating material to the outward surface of the traveling web which is passing over the support;
• scraping off excess coating material from the surface of the traveling web using a scraper having a curved entrance flank that faces toward the outward surface of the traveling web, wherein the entrance flank has a sharp edged end downstream in the motion of the web past the scraper;
• the scraper being movable with respect to the support for moving the position of the sharp edged end thereof with respect to the support;
• pressing the sharp edged end of the entrance flank against the surface of the coating material traveling by with sufficient force that the support is pressed inward by the scraper;
• the axis of the support roll and the swivel axis of the scraper generally define a plane between them, and before adjustment, the sharp edged end of the entrance flank is normally pressed against the surface of the coating material at the line across the web in the said plane,
• for selecting the application weight of coating material on the outward surface of the web, adjusting the length of the pressing zone at which the entrance flank presses upon the coating material by swiveling the scraper with respect to the support about a respective axis for shifting the position of the sharp edged end of the entrance flank with respect to the support so that the sharp edged end of the entrance flank is moved out of the said plane, and thereby adjusting the amount of the entrance flank that will be contacted by the coating material within the pressing zone.