abstract |
A security paper is provided in which identifying material is contained as an intercalary layer within the thickness of a bonded, nonwoven, polyethylene-film-fibril sheet having an opacity of at least 70% and a delamination resistance of at least 60 grams per centimeter. A process for making such paper includes forming an assembly of two unbonded, lightly consolidated, nonwoven, polyethylene film-fibril sheets containing identifying material between them, compressing the assembly in an unheated nip at 17 to 85 kilograms per centimeter of assembly width and then self-bonding the compressed assembly while under restraint by contact with a heated drum. Such security paper is useful for bank notes, stock certificates, paper currency and the like. |