METHOD FOR WATERPROOF PROCESSING AT END SURFACE OF CONTAINER BLANK

摘要

PROBLEM TO BE SOLVED: To perform a waterproof processing against an end surface of a blank in such a way that paper powder or the like is not generated and the entire blank can be sterilized uniformly. SOLUTION: A waterproof processing against an end surface of a plate-like container blank covering both surfaces by each of thermoplastic synthetic resin layers 21, 23 and having a paper layer 22 is comprised of a melting step for melting a non-processed thermoplastic synthetic resin layer 21 in at least one blank end surface adjoining portion and a flowing step in which the melted processing thermoplastic synthetic resin layer is flowed in such a way that the end surface 24 is covered by the synthetic resin layer.