The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 16, 1979
Filed:
Jan. 25, 1978
Hans Friess, Linnich, DE;
Fritz Kettenbach, Huckelhoven, DE;
Jurgen Farber, Kaarst, DE;
Karl T Witter, Linnich, DE;
Ulrich Strole, Titz, DE;
Papier- und Kunststoff-Werke Linnich G.m.b.H., Dusseldorf, DE;
Abstract
In a cardboard blank for a gas-tight and liquid-tight folding box, especially one printed externally, carrying on the cardboard surface which is to be the inside of the box a full-surface layer of heat-sealable plastic, the improvement which comprises an additional plastic layer positioned between the full-surface plastic layer and the cardboard, the additional layer being provided only over portions of the surface including the seam areas, the thickness of the full-surface plastic layer together with the local additional plastic layer being sufficient for tight, hot-sealed seams. The additional layer can be hot melt printed onto the cardboard, before application of the full-surface layer, at the same time the cardboard is printed and/or die cut. By providing the additional layer only in critical areas such as seams or fold lines, a thinner full-surface layer can be provided with an overall economy of plastic.