Serving Tray with Inner Raised Surface Incorporating Thermoplastic Polyurethane and Methods for Manufacturing the Same

Abstract

A serving tray comprised of at least one synthetic material and an insert which provides a non-slip top surface of the serving tray. The textured relief is preferably made of thermoplastic polyurethane (TPU) which allows a glass or other item to be placed on the serving tray without the item sliding or slipping while the tray is in motion. As the tray is being fabricated, the TPU is mechanically bonded with the top surface of the tray while a textured relief is simultaneously defined into the top surface. The textured relief provides adequate frictional force to an item being placed on the tray so as to substantially prevent its lateral movement. The tray also includes an inner support structure disposed on its inner surface. The inner support structure provides an upward facing edge which allows a plurality of trays to be easily and efficiently stacked or nested on one another.

We claim: 
     
         1 . A serving tray comprising:
 a top surface;   a bottom surface disposed on an opposing side of the top surface;   a raised edge disposed about the top surface;   an inner support structure disposed circumferentially around the top surface;   at least two elongated lips disposed within the raised edge; and   a textured relief defined into the top surface,   wherein the top surface and the bottom surface are comprised of at least one synthetic material, and   wherein the textured relief is comprised of an insert integrally bonded with the at least one synthetic material.   
     
     
         2 . The tray of  claim 1  where the insert integrally bonded with the at least one synthetic material is comprised of a sheet of thermoplastic polyurethane (TPU). 
     
     
         3 . The tray of  claim 1  where the inner support structure comprises a protrusion in its surface which provides an upward facing edge around the circumference of the top surface. 
     
     
         4 . The tray of  claim 1  where the inner support structure is disposed on the raised edge and above the top surface. 
     
     
         5 . The tray of  claim 1  where the tray is comprised of a plurality of synthetic layers comprising at least two layers of randomly distributed and continuous glass fiber filament sheets, at least two layers of crisscrossed interlocking glass fiber sheets with a chemical binder, and an interstitial layer of polycarbonate resin. 
     
     
         6 . The tray of  claim 1  further comprising a shaped smooth boundary portion disposed between the textured surface and the inner support structure on the raised edge on the top surface. 
     
     
         7 . The tray of  claim 1  where the textured relief comprises a plurality of raised protrusions and a plurality of recessed indentations asymmetrically disposed over the top surface. 
     
     
         8 . An improvement in a method of making a friction enhanced tray in a compression molding apparatus comprising:
 placing an insert on top of a lower tool portion of the compression molding apparatus;   layering at least two layers of randomly distributed and continuous glass fiber filament sheets on top of the insert;   layering at least two layers of crisscrossed interlocking glass fiber sheets with a chemical binder on top of the insert;   disposing an interstitial layer of polycarbonate resin between the at least two layers of crisscrossed interlocking glass fiber sheets with a chemical binder;   compressing the insert, the least two layers of randomly distributed and continuous glass fiber filament sheets, the at least two layers of crisscrossed interlocking glass fiber sheets with a chemical binder, and the interstitial layer of polycarbonate resin against the lower tool portion of the compression molding apparatus and defining an inner support structure in the friction enhanced tray; and   defining a textured relief within the insert.   
     
     
         9 . The method of  claim 8  wherein defining the textured relief within the insert comprises impressing a chemically etched mold surface disposed on the lower tool portion into a surface of the insert. 
     
     
         10 . The method of  claim 8  where compressing the insert and defining an inner support structure in the friction enhanced tray comprises defining the inner support structure above the insert on a raised edge disposed around the circumference of the insert. 
     
     
         11 . The method of  claim 10  where defining the inner support structure above the insert on a raised edge disposed around the circumference of the insert comprises defining a protrusion along the length of the inner support structure. 
     
     
         12 . The method of  claim 8  further comprising defining a shaped smooth boundary portion disposed around the textured relief defined in the insert and beneath the inner support structure. 
     
     
         13 . The method of  claim 8  wherein placing the insert on top of a lower tool portion of the compression molding apparatus comprises placing a sheet of thermoplastic polyurethane (TPU) on top of the lower tool portion of the compression molding apparatus. 
     
     
         14 . The method of  claim 8  wherein defining a textured relief within the insert comprises asymmetrically defining a plurality of raised protrusions and a plurality of recessed indentations into a surface of the insert. 
     
     
         15 . An improvement in a method of making a friction enhanced tray in an injection molding apparatus comprising:
 placing an insert on a first half of a mold of the injection molding apparatus;   enclosing the insert by bringing a second half of the mold against the first half of the mold, the first and second halves of the mold forming a completed mold tool;   injecting a liquid interstitial resin into the completed mold tool;   forming a tray around the insert within the completed mold tool;   forming an inner support structure in the tray; and   defining a textured relief within a surface of the insert.   
     
     
         16 . The method of  claim 15  wherein defining the textured relief within a surface of the insert comprises impressing a mold surface disposed on the first half of the mold into the surface of the insert. 
     
     
         17 . The method of  claim 15  where forming an inner support structure in the tray comprises forming the inner support structure above the insert on a raised edge disposed around the circumference of the insert. 
     
     
         18 . The method of  claim 17  where forming the inner support structure above the insert on a raised edge disposed around the circumference of the insert comprises forming a protrusion along the length of the inner support structure. 
     
     
         19 . The method of  claim 15  further comprising defining a shaped smooth boundary portion disposed around the textured relief defined in the surface of the insert and beneath the inner support structure. 
     
     
         20 . The method of  claim 15  wherein placing an insert on a first half of a mold of the injection molding apparatus comprises placing a sheet of thermoplastic polyurethane (TPU) on the first half of the mold of the injection molding apparatus.