Inventors:
Ronald P. Marx - Lakewood WI
Patrick H. Wnek - Menasha WI
Denny R. Garns - Appleton WI
Assignee:
James River Corporation of Virginia - Richmond VA
International Classification:
B31B 128
Abstract:
A method of forming a container from a flat, substantially homogeneous blank of fibrous substrate, comprising the steps of shaping the blank into a formed container having a bottom wall, an up-turned side wall extending from the bottom wall, a rim outwardly extending from the side wall and a lip downwardly curving from the rim and including a plurality of radially-extending, circumferentially-spaced pleats formed in the side wall, rim, and lip, each pleat including at least three layers of the blank; and applying sufficient heat and pressure to the side wall and rim to decrease the thickness thereof to less than that of the blank and to transform each pleat into a substantially integrated fibrous structure in which the constituent layers generally lack individual identity, each structure having a density greater than and a thickness substantially equal to adjacent areas of the side wall and rim.