Crush-resistant disposable lid

Abstract

A crush-resistant, preferably thermoformed, disposable lid is provided for plates, platters, bowls and the like. The lid includes a dome and a downwardly extending sidewall provided with a plurality of outwardly convex flutes formed in the sidewall with a characteristic cylindrical diameter. The sidewall extends from the dome to an engagement portion adapted to be secured to the plate, platter or bowl about an engagement perimeter of the lid. There are typically fewer than about 1.85 flutes per inch of engagement perimeter and the flutes are characterized by a ratio of the characteristic cylindrical diameter of the flutes to the engagement perimeter of the lid of at least about 0.0125.

What is claimed is:  
     
         1 . A crush-resistant disposable lid made from a thermoplastic material for plates, platters, bowls and the like comprising a dome having a generally planar upper surface portion and a downwardly extending sidewall provided with a plurality of outwardly convex flutes formed in said sidewall, said flutes having a characteristic cylindrical diameter, said sidewall extending downwardly to an engagement portion of said lid adapted to be secured to said plate, platter or bowl about an engagement perimeter of said lid, wherein said lid includes about 1.85 or fewer flutes per inch of engagement perimeter.  
     
     
         2 . The crush-resistant disposable lid according to  claim 1 , wherein said lid includes from about 1.5 to about 1.85 flutes per inch of engagement perimeter.  
     
     
         3 . The crush-resistant disposable lid according to  claim 2 , wherein said lid includes from about 1.6 to about 1.75 flutes per inch of engagement perimeter.  
     
     
         4 . The crush-resistant disposable lid according to  claim 2 , wherein said lid includes about 1.7 flutes per inch of engagement perimeter.  
     
     
         5 . The crush-resistant disposable lid according to  claim 1 , wherein said flutes have a characteristic cylindrical diameter of from about 0.4 inches to about 0.6 inches.  
     
     
         6 . The crush-resistant disposable lid according to  claim 5 , wherein said flutes have a characteristic cylindrical diameter of about 0.5 inches.  
     
     
         7 . The crush-resistant disposable lid according to  claim 1 , wherein the ratio of the characteristic cylindrical diameter of said flutes to the engagement perimeter of said lid is at least about 0.0125.  
     
     
         8 . The crush-resistant disposable lid according to  claim 7 , wherein the ratio of the characteristic cylindrical diameter of said flutes to the engagement perimeter of said lid is from about 0.0125 to about 0.025.  
     
     
         9 . The crush-resistant disposable lid according to  claim 8 , wherein the ratio of the characteristic cylindrical diameter of said flutes to the engagement perimeter of said lid is about 0.018.  
     
     
         10 . The crush-resistant disposable lid according to  claim 1 , wherein the inward extension length of said flutes is at least about 0.35 inches.  
     
     
         11 . The crush-resistant disposable lid according to  claim 10 , wherein the inward extension length of said flutes is at least about 0.5 inches.  
     
     
         12 . The crush-resistant disposable lid according to  claim 1 , wherein the ratio of the inward extension length of said flutes to the engagement perimeter is from about 0.015 to about 0.04.  
     
     
         13 . The crush-resistant disposable lid according to  claim 12 , wherein the ratio of the inward extension length of said flutes to the engagement perimeter is about 0.02.  
     
     
         14 . The crush-resistant disposable lid according to  claim 1 , wherein said lid is thermoformed, thermoformed by the application of vacuum or thermoformed by a combination of vacuum and pressure from a sheet of thermoplastic material.  
     
     
         15 . The crush-resistant disposable lid according to  claim 14 , wherein said lid has a wall caliper of from about 8 to about 20 mils.  
     
     
         16 . The crush-resistant disposable lid according to  claim 15 , wherein said lid has a wall caliper of from about 8 to about 15 mils.  
     
     
         17 . The crush-resistant disposable lid according to  claim 16 , wherein said lid has a wall caliper of from about 10 to about 13 mils.  
     
     
         18 . The crush-resistant disposable lid according to  claim 14 , thermoformed by the application of vacuum.  
     
     
         19 . The crush-resistant disposable lid according to  claim 14 , thermoformed from oriented polystyrene sheet.  
     
     
         20 . The crush-resistant disposable lid according to  claim 14 , thermoformed from a sheet of thermoplastic material comprising polypropylene.  
     
     
         21 . The crush-resistant disposable lid according to  claim 1 , wherein said engagement portion of said lid includes an undercut groove extending substantially continuously about said engagement perimeter.  
     
     
         22 . The crush-resistant disposable lid according to  claim 1 , wherein said engagement portion of said lid includes a removal tab defining an upwardly extending cavity.  
     
     
         23 . The crush-resistant disposable lid according to  claim 22 , wherein said removal tab is a stepped removal tab.  
     
     
         24 . The crush-resistant disposable lid according to  claim 22 , wherein said engagement portion of said lid includes an undercut groove and said upwardly extending cavity of said removal tab extends upwardly with respect to the undercut portion of said groove.  
     
     
         25 . The crush-resistant disposable lid according to  claim 1 , wherein said sidewall extends downwardly from said dome portion to said engagement portion in a substantially linear manner.  
     
     
         26 . The crush-resistant disposable lid according to  claim 1 , wherein said flutes have a flute height of greater than about 0.075 inches.  
     
     
         27 . The crush-resistant disposable lid according to  claim 26 , wherein said flutes have a flute height of from about 0.075 to about 0.125 inches.  
     
     
         28 . A thermoformed, crush-resistant disposable lid for plates, platters, bowls and the like comprising a dome having a generally planar upper surface portion and a downwardly extending sidewall provided with a plurality of outwardly convex flutes formed in said sidewall, said flutes having a characteristic cylindrical diameter and said sidewall extending downwardly to an engagement portion adapted to be secured to said plate, platter or bowl about an engagement perimeter of said lid, wherein said lid includes about 1.85 or fewer flutes per inch of engagement perimeter, said flutes being characterized by a ratio of the characteristic cylindrical diameter of said flutes to the engagement perimeter of said lid of at least about 0.0125.  
     
     
         29 . A thermoformed, crush-resistant disposable lid according to  claim 28 , wherein said flutes have a characteristic cylindrical diameter of from about 0.4 inches to about 0.6 inches.  
     
     
         30 . A thermoformed, crush-resistant disposable lid according to  claim 29 , wherein said flutes have a characteristic cylindrical diameter of about 0.5 inches.  
     
     
         31 . The crush-resistant disposable lid according to  claim 28 , wherein said lid includes from about 1.5 to about 1.85 flutes per inch of engagement perimeter.  
     
     
         32 . The crush-resistant disposable lid according to  claim 28 , wherein said lid includes from about 1.6 to about 1.75 flutes per inch of engagement perimeter.  
     
     
         33 . The crush-resistant disposable lid according to  claim 32 , wherein said lid includes about 1.7 flutes per inch of engagement perimeter.  
     
     
         34 . The crush-resistant disposable lid according to  claim 28 , wherein the ratio of the characteristic cylindrical diameter of said flutes to the engagement perimeter of said lid is from about 0.0125 to about 0.025.  
     
     
         35 . The crush-resistant disposable lid according to  claim 31 , wherein the ratio of the characteristic cylindrical diameter of said flutes to the engagement perimeter of said lid is about 0.018.  
     
     
         36 . The crush-resistant disposable lid according to  claim 28 , wherein the inward extension length of said flutes is at least about 0.35 inches.  
     
     
         37 . The crush-resistant disposable lid according to  claim 36 , wherein the inward extension length of said flute is at least about 0.5 inches.  
     
     
         38 . The crush-resistant disposable lid according to  claim 28 , wherein the ratio of the inward extension length of said flutes to the engagement perimeter is from about 0.015 to about 0.025.  
     
     
         39 . The crush-resistant disposable lid according to  claim 38 , wherein the ratio of the inward extension length of said flutes to the engagement perimeter is about 0.02.  
     
     
         40 . The crush-resistant disposable lid according to  claim 28 , wherein said lid is thermoformed by the application of vacuum or thermoformed by a combination of vacuum and pressure from a sheet of thermoplastic material.  
     
     
         41 . The crush-resistant disposable lid according to  claim 40 , wherein said lid has a wall caliper of from about 8 to about 20 mils.  
     
     
         42 . The crush-resistant disposable lid according to  claim 41 , wherein said lid has a wall caliper of from about 8 to about 15 mils.  
     
     
         43 . The crush-resistant disposable lid according to  claim 42 , wherein said lid has a wall caliper of from about 10 to about 13 mils.  
     
     
         44 . The crush-resistant disposable lid according to  claim 40 , thermoformed by the application of vacuum.  
     
     
         45 . The crush-resistant disposable lid according to  claim 40 , thermoformed from oriented polystyrene sheet.  
     
     
         46 . The crush-resistant disposable lid according to  claim 40 , thermoformed from a sheet of thermoplastic material comprising polypropylene.  
     
     
         47 . The crush-resistant disposable lid according to  claim 28 , wherein said engagement portion of said lid includes an undercut groove extending substantially continuously about said engagement perimeter.  
     
     
         48 . The crush-resistant disposable lid according to  claim 28 , wherein said engagement portion of said lid includes a removal tab defining an upwardly extending cavity.  
     
     
         49 . The crush-resistant disposable lid according to  claim 48 , wherein said removal tab is a stepped removal tab.  
     
     
         50 . The crush-resistant disposable lid according to  claim 48 , wherein said engagement portion of said lid includes an undercut groove and said upwardly extending cavity of said removal tab extends upwardly with respect to the undercut portion of said groove.  
     
     
         51 . The crush-resistant disposable lid according to  claim 28 , wherein said sidewall extends downwardly from said dome portion to said engagement portion in a substantially linear manner.  
     
     
         52 . The crush-resistant disposable lid according to  claim 28 , wherein said flutes have a flute height of greater than about 0.075 inches.  
     
     
         53 . The crush-resistant disposable lid according to  claim 52 , wherein said flutes have a flute height of from about 0.075 to about 0.125 inches.