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Process for making secure paper product

  • US 4,964,951 A
  • Filed: 04/13/1989
  • Issued: 10/23/1990
  • Est. Priority Date: 05/29/1987
  • Status: Expired due to Fees
First Claim
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1. A process for making a paper product from which images cannot be copied by use of a xerographic photocopier that reproduces an image defined by print on the paper product by a process that includes sensing light received from the paper product upon the paper product being exposed to high intensity light within a predetermined portion of the light spectrum that is absorbed by the print, said paper making process comprising the steps of(a) mixing paper ingredients with a material selected from a group consisting of materials that totally absorb light within said predetermined portion of the light spectrum so that no light is received from the paper product by the light sensing means of the photocopier;

  • and(b) processing the mixture of step (a) to provide a sheet of the mixture wherein step (a) comprises mixing the paper ingredients with a said selected material having light absorption characteristics that are dependent upon the orientation of such material with respect to incident light, wherein said selected material is uniformly oriented in a medium that can be oriented in accordance with the orientation of an applied electric field; and

    further comprising the step of(c) applying an electric field during step (b) to orient said selected material to provide a paper product having selected light absorption characteristics.

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