초록 ▼

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 dow

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.

대표청구항 ▼

A method of forming a container from a flat, substantially homogeneous blank of fibrous substrate, comprising the steps of: (a) shaping said 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 l

A method of forming a container from a flat, substantially homogeneous blank of fibrous substrate, comprising the steps of: (a) shaping said 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 said rim and including a plurality of radially-extending, circumferentially-spaced pleats formed in said side wall, rim, and lip, each said pleat including at least three layers of said blank; and (b) applying sufficient heat and pressure to said side wall and rim to decrease the thickness thereof to less than that of said blank and to transform each said pleat into a substantially integrated fibrous structure in which the constituent layers generally lack individual identity, each said structure having a density greater than and a thickness substantially equal to adjacent areas of said side wall and rim.