Apparatus for coating moving strips of material
AssigneeJ. M. Voith GmbH
InventorFranz Krautzberger, deceased
Life of this patent
Estimating the term…
Abstract
A coating material is transferred to the surface of a spreader-roll from a spreader-mechanism. The spreader-roll is partly wrapped by a strip of material. In the location where the said strip of material is lifted off the spreader-roll, a doctor-element, comprising a doctor-blade, is arranged to rest tangentially on the spreader-roll. The doctor-element thereby forms a rubbing distributing surface which faces the strip of material and ensures a smooth and uniform coating of the coating material on the strip of material. The strip of material is then carried away over a sharp tear-off edge on the doctor-element at an angle of less than 20.degree.. In this way a coating of any desired thickness may be applied to a strip of material, more particularly as a coating for a strip of paper.
Claims45
An apparatus for coating moving strips of material by transferring the coating material from a spreader-roll, over a doctor, to the strip of material, characterized in that:
- (a) over a distance along its coated periphery, the spreader-roll is wrapped by the strip of material and, arranged in the notch formed where the strip of material is lifted off the said spreader-roll, is a doctor-element in the form of a blade or leaf-spring, the apex thereof extending substantially tangentially into the apex of the notch and pressing against said spreader-roll;
- (b) the doctor-element exhibits, on the side remote from the spreader-roll, a substantially flat transfer- and rubbing-distributing surface running parallel with the strip of material, for the purpose of transferring the doctored coating material to the strip of material;
- (c) arranged at the outlet end of the doctor-element is an abruptly falling stripping edge which runs parallel with the axis of rotation of the spreader-roll.
A method for coating moving strips of material with a coating material by transferring the latter to the strip of material from a spreader-roll by means of a doctor-blade, which comprises:
- (a) guiding the strip of material over a portion of the periphery of the spreader-roll;
- (b) scraping a predetermined amount of coating material off the spreader-roll and transferring the scraped material to the strip of material guided along the doctor-blade;
- and
- (c) effecting additional regulation of the amount of coating material applied, with a view to increasing the thickness of the coating, by controlling the r.p.m. of the spreader-roll which is immersed in a bath of coating material.
Dependencies are inferred from the claim text.