| 摘要 |
1, 048, 829. Coating webs. ILFORD Ltd. Nov. 26, 1964 [Dec. 10, 1963], No. 48765/63. Heading D1L. A method of applying a thin coating to a flexible web travelling at high speed e.g. applying gelatin or other colloid material to a film base, comprises passing the web 33 about a backing roller such that it passes adjacent the liquid application which comprises at least three parallel plates 25, 26, 27, 28 defining at least two narrow slots 29, 30, 31. The coating liquid is pumped through slot 29 on the upstream side of the applicator and a fraction of this liquid, e.g. a half, is pumped away through the next slot 30, the remaining liquid forming the coating. Ir this way a high pressure zone is created in the upstream portion of liquid lying between the applicator and web so that this portion of liquid remains against the web at high web speed. In the embodiment shown a second layer of coating is applied through slot 31. The applicator may be adjacent the web when it is travelled upwardly (as shown), horizontally or vertically. Preferably the surfaces of the blades facing the web are parallel to the web and not more than three times the wet thickness of the applied coating. Metering pumps are preferably used to supply and extract liquid from the applicator so that the quantity of applied coating is known. |
