摘要 |
<p>The start-up of a free-falling liquid curtain (12) in the coating of objects or a moving web (18) using curtain coaters is considerably improved by the controlled retraction of a catch pan device (30) positioned in close proximity to the moving web (18). The catch pan device which includes a primary lip (32), and a secondary lip (44), is positioned so that it can be retracted through the falling curtain at a predetermined speed and direction relative to the moving web (18). The device (30) is retracted at the start of a coating process so that the falling curtain is interrupted first by primary lip (32) and then secondary lip (44). Primary lip (32) prevents the coating liquids from flowing onto the moving web (18) during the start-up process and secondary lip (44) retains the coating liquids of an extended falling curtain resulting from contact between the curtain and primary lip (32). The start-up method and apparatus including the catch pan device (30), having a plurality of spaced lips on the trailing end of said device, the orientation of the catch pan device relative to the falling curtain (12) and moving web (18), the retraction speed of the catch pan device and the direction of retraction of the catch pan device relative to the moving web (18), provide a considerably improved uniform coating start-up.</p> |