Method of manufacturing plastic-coated packages to hold liquids

Claim 1

Process for the manufacture of a printed coated cardboard blank for use in forming a package for liquids which package has a perforated or rip-out opening preformed there-through at a predetermined position with respect to the printed message on the package; said process comprising the steps of advancing a cardboard web past a punching or perforating and registration mark applying station; punching or perforating a portion of said cardboard web and applying registration marks at the station in said cardboard web at a predetermined position with respect to said portion; keeping substantially constant the distance between successive registration marks by monitoring said distance between successive registration marks downstream from the station, and in response to such distance adjusting the punching or perforating and registration mark applying speed at the station relative to the speed at which the web advances past the station; thereafter coating said cardboard web with a suitable liquid resistant coating before further processing; and thereafter applying the printed message at a predetermined position with respect to said registration marks whereby said printed message is applied in a predetermined position with respect to said punched or perforated portion of said cardboard web, and cutting said printed coated cardboard web into blanks.