| 摘要 |
<p>Two or more water jet nozzles (4, 5), have different nozzle diameter, spacing from the web (1) and/or differing inclinations relative to the web surface. The nozzles are operated at differing pressures. There are two or three of them, arranged in succession and in precise alignment, in the direction of web motion. They are alternatively offset slightly across the direction of web motion. Spacing between adjacent nozzles is at least 25 mm. The nozzle water pressure is 400-1500 bar, preferably 800-1500 bar. Nozzle diameter is 0.1-0.3 mm, preferably 0.1-0.2 mm. At least one water jet nozzle is inclined against the direction of the web. The angle between the water jets and the normal to the surface of the web, is 50 degrees to 80degreesC, preferably 60 degrees to 70 degrees. All water jet nozzles are inclined against the direction of web travel.</p> |
