Reinforced paperboard cartons and method for making same
AssigneeThe Mead Corporation
InventorsDonald F. Hiscock, Joe A. Jacomet, Deborah H. Carter
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Abstract
A selectively reinforced paperboard carton having areas of reinforcement formed by impregnating the uncoated paperboard carton blank in patterned areas with a polyisocyanate which reacts with hydroxyl groups within the paperboard to form a cured polyurethane reinforcement. The preferred polyisocyanate is polymethylene polyphenylisocyanate.
Claims16
A reinforced paperboard carton blank comprising a paperboard blank having therein a pair of fingerholes, fold lines, and a series of openings for receiving a plurality of liquid containers, said blank being impregnated with a polyisocyanate in areas located to increase the tensile strength of said blank adjacent said fingerholes and/or openings such that said container does not readily break when liquid containers are carried therein, said polyisocyanate being a polyisocyanate which reacts with hydroxyl groups in said paperboard to form a cured polyurethane reinforcement.
A method of reinforcing paperboard carton blanks comprising:
- providing a paperboard blank having fingerholes, fold lines, and a series of openings therein for receiving a plurality of liquid containers, and
- impregnating selected areas of said blank with a polyisocyanate which reacts with hydroxyl groups within said paperboard to form a cured polyurethane reinforcement, said selected areas being located to increase the tensile strength of said paperboard adjacent said fingerholes and/or said openings such that when said blank is folded into a carton and liquid containers are carried therein, said blank does not readily tear.
Dependencies are inferred from the claim text.