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US 4,534,398 AGranted
Security paper
AssigneeCrane Co.
InventorTimothy T. Crane
Life of this patent
Estimating the term…
Abstract
This invention relates to a security paper document incorporating counterfeit deterrent, optical variable devices that display their optically active properties in reflectance when there are changes in the angle of incodent light with respect to the eye of the viewer. The devices are applied by means of a carrier paper and a base web format during the papermaking process. An embedment roll presses the device within the base web while the base web fibers are unconsolidated and pliable.
Claims11
A method of forming a security paper on a paper making machine comprising the steps of:
- attaching a water impervious security device to a surface of a non-water dispersible porous carrier paper;
- passing said carrier paper and security device between the outer surface of an embedment roll and wet base paper fibers to wet and press said carry paper and security device within said wet base paper fibers while drawing some of said wet base fibers and some of said water up to within said carrier paper to form a composite paper;
- and
- pressing and heating said composite paper to form a composite paper having said security device coextensive with a surface of said composite paper.
1 more element
Dependencies are inferred from the claim text.