Paper pulp defibering or refining plate and method of manufacturing it
AssigneeTechnogenia S.A.
InventorGuy Maybon
Life of this patent
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Abstract
A paper pulp defibering or refining plate in accordance with the invention comprises a comminuting surface having a large number of ridges separated by grooves. The plate body is made from a first material such as stainless steel or cast iron providing the overall mechanical strength of the plate in use. The upper part of the ridges is a layer of an abrasion resistant material based on grains of tungsten carbide bound in a metal alloy whose melting and brazing characteristics are appropriate to laser resurfacing on the plate body. The ridges are resurfaced successively by scanning a laser beam and a powder spray nozzle in one or more passes.
Claims4
A method of manufacturing a paper pulp defibering or refining plate, the plate comprising a comminuting surface having a plurality of ridges, each of the ridges having an upper surface, the ridges being separated by grooves, the method comprising the steps of:
- a) directing a laser beam onto an impact area on the upper surface of one of the ridges,
- b) spraying onto said impact area a powder made of grains of an abrasion-resistant material and a brazing alloy, and
- c) moving the plate so that the laser beam and powder are scanned over a region to be coated with said abrasion-resistant material,
- wherein the laser beam has an intensity sufficient to melt said upper surface and to melt the brazing alloy powder in the impact area, but not sufficient to melt the grains of the abrasion-resistant material, wherein the brazing alloy becomes brazed to the upper surface of said one of the ridges, wherein the brazing alloy also becomes brazed to the abrasion-resistant material.
Dependencies are inferred from the claim text.