Overcap with method for making the same

Abstract

A one-piece paper lid and container system using the one-piece paper lid is provided herein. The one-piece paper lid comprises base having a central portion and peripheral portion, and a circumferential bead disposed adjacent the peripheral portion of the base. The circumferential bead is radially extendable between an inward position defining a first inner diameter and an outward position defining a second inner diameter. The one-piece paper lid further comprises a skirt extending downward from the circumferential bead. The skirt comprises an outer sidewall, an inner sidewall and an upwardly extending curl connecting the outer sidewall and the inner sidewall, wherein the inner sidewall comprises an inner protrusion extending radially inward.

What is claimed is: 
     
         1 . A method of making a paper-based lid, the method comprising:
 placing a blank onto a deep draw device, wherein the blank comprises a central portion and a peripheral region;   applying a force to the peripheral region of the blank with a blank holder;   deep drawing the blank with the deep draw device;   forming a circumferential bead about the perimeter of the peripheral edge, between the base and skirt, wherein the circumferential bead is radially extendable between an inward position and an outward position;   folding a bottom portion of the skirt inward wherein the fold forms an upwardly extending curl connecting an outer sidewall and an inner sidewall of the skirt;   knurling the folded skirt; and   forming an inner protrusion within the inner sidewall of the folded skirt.   
     
     
         2 . The method of  claim 1 , wherein forming the circumferential bead comprises:
 compressing the deep drawn blank into a mold.   
     
     
         3 . The method of  claim 1 , wherein forming the inner protrusion comprises:
 compressing the outer sidewall and the inner sidewall of the skirt, wherein a first pressure is applied above the inner protrusion, a second pressure is applied below the inner protrusion, and a third pressure is applied to the inner protrusion.   
     
     
         4 . The method of  claim 3 , wherein the first pressure and the second pressure are greater than the third pressure. 
     
     
         5 . The method of  claim 3 , wherein the first pressure is greater than the second pressure. 
     
     
         6 . The method of  claim 1 , wherein the blank is made from at least 95% paper material. 
     
     
         7 . The method of  claim 1 , wherein the outer sidewall is linear between the upwardly extending curl and the circumferential bead. 
     
     
         8 . The method of  claim 1 , wherein the circumferential bead is configured to extend into the outward position upon application of the lid to a container. 
     
     
         9 . The method of  claim 1 , wherein the inner sidewall comprises an inner protrusion extending radially inward, wherein when the circumferential beach is in the inward position, the skirt defines a first diameter, and when the circumferential bead is in the outward position, the skirt defines a second diameter. 
     
     
         10 . The method of  claim 1 , wherein the forming a circumferential bead step forms a circumferential bead which is biased to the inward position. 
     
     
         11 . The method of  claim 1 , wherein the circumferential bead defines a height above the base, and wherein when the circumferential bead is radially extended to the outward position the height of the circumferential bead decreases. 
     
     
         12 . The method of  claim 1 , wherein the circumferential bead defines a cross-section of a half-cylinder in the inward position. 
     
     
         13 . The method of  claim 1 , wherein the inner protrusion is continuous about the inner sidewall of the skirt. 
     
     
         14 . The method of  claim 1 , wherein the skirt defines an upper portion comprising extending between the circumferential bead and the inner protrusion, and a lower portion extending between the upwardly extending curl and the inner protrusion, wherein the upper portion and the lower portion are configured with different flexion. 
     
     
         15 . The method of  claim 14 , wherein the upper portion exhibits a larger outward flex than the lower portion. 
     
     
         16 . The method of  claim 14 , wherein the lower portion is configured for minimal outward flex. 
     
     
         17 . The method of  claim 14 , wherein the flex between the upper portion and the lower portion is linear.