Structural and surface properties tester for paper
AssigneeWeyerhaeuser Company
InventorYuri A. Bery
Life of this patent
Estimating the term…
Abstract
A method and apparatus for analyzing the structural formation and surface properties of fibrous sheet materials, particularly printing papers, are described. The method requires advancing a marker over a substantial area of the sheet to be tested. The marker is urged into contact with the sheet so that it exerts a pressure on it, typically of printing process magnitudes. The marker is any material which produces an image the intensity of which is proportional to the pressure exerted upon it by the test sheet. A preferred marker is graphite. The image produced is equivalent to those produced by Beta ray formation analyzers and may be evaluated by a missing dot technique commonly employed in rotogravure print quality evaluations.
Claims22
A method of evaluating the internal structure and surface properties of a sheet material which comprises:
- securing a sample of the sheet material to a supporting means;
- providing a solid marker means having an elongated sample contacting surface adapted to transfer a visible marking to any portion of the sample surface contacted by the means;
- conditioning the sample contacting surface of the solid marker means prior to contacting the sample in order to remove any surface-irregularities;
- providing a loading means so that the marker means will bear against the sample with a predetermined pressure;
- contacting the sample with the marker means;
- uniformly advancing the conditioned marker means across the sample while under said pressure so that the marker means contacts and marks a substantial portion of the sample surface;
- and
- relating the pattern of markings on the sample surface to the property being determined.
Apparatus for evaluating the internal structure and surface properties of a sheet material which comprises:
- a base means for supporting a sample of the sheet material;
- a solid marker means having an elongated sample contacting portion adapted for marking a substantial area of the sample surface;
- conditioning means to remove any irregularities from the sample contacting surface of the marker means;
- loading means for exerting a predetermined uniform pressure on the marker means while in contact with the sample surface;
- and
- traversing means for advancing the marker means so that the marker means is first lowered from a disengaged position over the conditioning means and conditioned, then raised and moved over the sample supporting area of the base means, then lowered onto the sample and moved across the sample at a predetermined pressure and uniform rate of speed while under load so as to mark a substantial area of the sample surface and produce an image on said surface relatable to the surface or internal structural properties of the sheet material.
Dependencies are inferred from the claim text.