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(11) | EP 0 870 583 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Water jet edge trimming station for use in papermaking machine |
| (57) A water jet edge trimming station 12 for trimming the edges 54 of coated paper web
14 during on-machine operation including backsplash compensating features. The edge
trimming station 12 has a cutting station 13 over which the web 14 travels to be cut.
The water jet travels along a water jet axis 48 to a point of impingement 52 to cut
the web 14. The cutting station 13 has an effluent receiving aperture at the point
of impingement 84. A negative pressure mixing zone 90 located below the aperture draws
effluent by-products or backsplash associated with cutting of the web 14 below the
cutting surface 82. The water jet axis 48 is offset a first predetermined angle 62
chosen relative to a normal axis 61 passing at right angles through the point of impingement
84 to reduce backsplash. The water jet axis 48 is rotated about the normal 61 axis
by a second predetermined angle 58 to direct the effluent by-products away from the
water jet nozzle 33 and the traveling web 14. The water jet nozzle 33 has a positive
air pressure chamber 64 surrounding the nozzle head 64 to maintain an air flow over
the nozzle head 64 driving effluent backsplash away from the nozzle head 64. |