Method of finishing screen plates

摘要

A screen plate and method of making a screen plate for the pressure screening of papermaking stock in pressure screening apparatus includes slots which have been cut therethrough by a machining laser beam focused at the inlet side of the plate, to provide slots with nearly straight walls with minimum taper, and which are recast and have a "glassy" appearance by reason of the melting and resolidification of the immediate wall surface, to provide a low friction path for the stock. Straight, curved and inclined or slanted slots are disclosed including slots which are at a diagonal to the axis of the cylinder. Slots or openings are disclosed which are inclined to a radius line therethrough both with and against the direction of flow of the stock along the inlet surface. Wear bars are applied to the plate for coaction with the rotating foils on the screening apparatus, in the form of strips of weld material of high hardness applied directly to the plate.