Molded fiber lid for a container

Abstract

A container lid formed of cellulose material is provided for mating with a base container to securely hold various items, such as food items. The container lid includes a body having a main portion and a perimeter, and a skirt extending substantially around the perimeter of the body. The skirt includes a shoulder and an intermediate member connected with the shoulder. The intermediate member extends inwardly towards the base container when mating therewith. The intermediate member and skirt cooperatively form a channel or undercut for receiving the base container so that the base container and lid may be interlocked together.

1 . A container lid formed of cellulose material and adapted to mate with a base container, comprising: 
 a body having a main portion and a perimeter; and    a skirt extending at least substantially around the perimeter of the body, the skirt having, 
 a shoulder, and  
 an intermediate member connected with the shoulder and extending inwardly towards the base container when mating with the base container;  
   wherein the shoulder and intermediate member cooperatively form a channel.    
   
   
       2 . The container lid of  claim 1 , wherein the cellulose material is at least partially composed of recycled paper fiber.  
   
   
       3 . The container lid of  claim 1 , further comprising an end flange extending outwardly from the intermediate member and away from the central region.  
   
   
       4 . The container lid of  claim 1 , wherein the shoulder has an upper portion and a lower portion, the upper portion extending from the perimeter of the body outwardly and away from the central region.  
   
   
       5 . The container lid of  claim 1 , wherein the container lid is formed as a monolithic structure.  
   
   
       6 . The container lid of  claim 1 , wherein the body and skirt cooperatively define a container lid inside surface facing the base container when mated therewith and a container lid outside surface, and wherein the channel is formed on the inside surface of the container lid.  
   
   
       7 . A container lid formed of cellulose material, comprising: 
 a body having a main portion and a perimeter; and    a skirt extending at least substantially around the perimeter of the body, the skirt having an inside surface into which an undercut is formed, the undercut defining a lateral dimension extending from a first portion of the undercut to a second portion of the undercut directly opposite and across the skirt from the first portion, the lateral dimension between the undercut first and second portions being greater than a second lateral dimension defined as extending between portions of the skirt immediately above the first and second portions of the undercut and greater than a third lateral dimension defined as extending between portions of the skirt immediately below the first and second portions of the undercut.    
   
   
       8 . The container lid of  claim 7 , wherein the cellulose material is at least partially composed of recycled paper fiber.  
   
   
       9 . The container lid of  claim 7 , wherein the container lid is a monolithic structure.  
   
   
       10 . The container lid of  claim 7 , wherein the undercut is concave in shape.  
   
   
       11 . In combination, a base container and a lid therefor, the base container including a peripheral portion, and the lid formed of cellulose material and comprising: 
 a body having a main portion and a perimeter; and    a skirt extending at least substantially around the perimeter of the body, the skirt having a shoulder and an intermediate member connected with the shoulder to cooperatively form an undercut;    wherein the skirt is adapted to accept the peripheral portion of the base container in the undercut with the intermediate member providing an interference fit to interlock the lid with the base container.    
   
   
       12 . The combination of  claim 11 , wherein the peripheral portion of the base container includes a cantilevered flange, and wherein at least one of the cantilevered flange of the base container and the skirt of the lid is sufficiently resilient to allow for deflection thereof when the lid is placed in covering relation over the base container and the lid and base container are pressed together to force the cantilevered flange past the intermediate member of the skirt.  
   
   
       13 . The combination of  claim 11 , wherein the cellulose material is at least partially composed of recycled paper fiber.  
   
   
       14 . The combination of  claim 11 , wherein the undercut is concave in shape.  
   
   
       15 . The combination of  claim 11 , wherein undercut defines a lateral dimension extending from a first portion of the undercut to a second portion of the undercut directly opposite and across the skirt from the first portion, the lateral dimension between the undercut first and second portions being greater than a second lateral dimension defined as extending between portions of the skirt immediately above the first and second portions of the undercut and greater than a third lateral dimension defined as extending between portions of the skirt immediately below the first and second portions of the undercut.  
   
   
       16 . The combination of  claim 11 , wherein the container lid is formed as a monolithic structure.  
   
   
       17 . The combination of  claim 11 , wherein the body and skirt cooperatively define an outside surface and an inside surface for the container lid, and wherein the undercut is formed on the inside surface of the container lid.  
   
   
       18 . The combination of  claim 11 , wherein the skirt further comprises a free end extending outwardly from the intermediate member.  
   
   
       19 . A container lid formed of cellulose material and adapted to mate with a base container, comprising: 
 a body having a main portion and a perimeter; and    a skirt extending at least substantially around the perimeter of the body, the skirt having a shoulder and an intermediate member connected with the shoulder to cooperatively form an undercut adapted to interlock with a rim of a base container to releasably lock the container lid with the base container.    
   
   
       20 . A container lid formed of cellulose material comprising: 
 a body having a main portion and an elliptically-shaped perimeter; and    a skirt extending at least substantially around the perimeter of the body, the skirt including a shoulder and an intermediate member connected with the shoulder to cooperatively form an undercut therebetween;    wherein the intermediate member is disposed at least partially beneath both of the shoulder and the undercut.    
   
   
       21 . A container lid formed by the process, comprising: 
 providing a vacuum die base with an article molding region;    overlying the article molding region of the vacuum die base with a vacuum wire;    placing a vacuum die ring against at least one of the vacuum die base and the vacuum wire, the vacuum die ring including a channel formed thereon;    placing a cellulose material lay up to be molded into an article on the vacuum wire and the vacuum die ring; and    overlying the cellulose material lay up with a finishing die to press the cellulose material lay up against the vacuum wire and against the vacuum die ring and into the channel;    applying heat to the cellulose material lay up with at least one of the finishing die and the vacuum die ring;    wherein the vacuum die ring facilitates the formation of the cellulose material lay up as a container lid having an undercut.    
   
   
       22 . The container lid of  claim 21 , further comprising drawing a vacuum on the cellulose material lay up through the vacuum wire.  
   
   
       23 . The container lid of  claim 21 , wherein the vacuum wire and the vacuum die base are perforated to allow the vacuum to be drawn on the cellulose material lay up.  
   
   
       24 . The container lid of  claim 21 , wherein the channel of the vacuum die ring has a concave configuration, and wherein the vacuum die ring further includes a convex shoulder region above the channel.