In-folded fin seal end closure

Abstract From the Canadian patent

There is disclosed a flat end closure arrangement for a thermoplastic coated paperboard container and the blank, therefor, wherein four sets of dual oppositely skewed, supplementary score lines are formed on two sides of the resultant end closure, such that they are adapted to be folded into position just inside the usual horizontal score lines separating the end closure panels from the sidewall panels. These supplementary score lines provide a second, substantially 90° bend for the paperboard layers, supplementing a 90° bend about the respective horizontal score lines, in lieu of each usual 180° bend about the respective horizontal score lines thereby, diminishing the chances for cracking …