Non-stick ceramic slow-cooker and method for making the same

Abstract

A method for making a non-stick ceramic cooking vessel for a slow-cooker, the vessel having glazing defining a seal over a cooking surface of the ceramic vessel, the method comprising the steps of removing at least a portion of the glazing while preferably maintaining at least a portion of the seal of the vessel and applying a non-stick coating over the cooking surface. The step of removing the glazing is preferably achieved by grit-blasting at least a portion of the glazing with aluminum oxide. Additionally, the cooking surface preferably includes a bottom surface and a wall surface wherein the glazing is preferably removed from the bottom surface such that the seal is substantially removed, and a portion of the glazing is preferably removed from the wall surface such that the seal there remains substantially intact. The method preferably also includes the steps of applying a first layer of a non-stick coating over the cooking surface, drying the first layer, cooling the first layer and applying a second layer of a non-stick coating over the first layer. Additionally, the method preferably includes the steps of applying a third layer of non-stick coating over the first and second layers, drying the second and third layers, and curing the layers of non-stick coating.

1 . A slow-cooker for the preparation of food comprising: 
 a housing;    a ceramic cooking vessel received within the housing, the ceramic vessel having interior surfaces defining a cavity and having a non-stick coating covering at least a portion of the interior surfaces;    a heating element mounted within the housing for supplying heat to the ceramic vessel.    
     
     
         2 . The slow-cooker of    claim 1   , wherein the non-stick coating is multi-layered.  
     
     
         3 . The slow-cooker of    claim 2   , wherein the non-stick coating includes a first layer having a dry film thickness of approximately 0.3-0.5 mils.  
     
     
         4 . The slow-cooker of    claim 3   , wherein the first layer has a dry film thickness of approximately 0.4 mils.  
     
     
         5 . The slow-cooker of    claim 2   , wherein the non-stick coating includes a second layer having a dry film thickness of approximately 0.3-0.6 mils.  
     
     
         6 . The slow-cooker of    claim 5   , wherein the second layer has a dry film thickness of approximately 0.4-0.5 mils.  
     
     
         7 . The slow-cooker of    claim 2   , wherein the non-stick coating includes a third layer having a dry film thickness of approximately 0.05-0.5 mils.  
     
     
         8 . The slow-cooker of    claim 7   , wherein the third layer has a dry film thickness of approximately 0.1-0.2 mils.  
     
     
         9 . The slow-cooker of    claim 1   , wherein at least of portion of the interior surfaces is glazed.  
     
     
         10 . The slow-cooker of    claim 1   , further comprising: 
 a cover removably located over the ceramic vessel.    
     
     
         11 . The slow-cooker of    claim 1   , wherein the ceramic cooking vessel is removable from the housing.  
     
     
         12 . A method for making a non-stick ceramic cooking vessel for a slow-cooker, the method comprising the steps of: 
 (a) applying a first layer of a non-stick coating over a ceramic cooking surface of the vessel;    (b) drying the first layer;    (c) cooling the first layer; and    (d) applying a second layer of a non-stick coating over a portion of the first layer.    
     
     
         13 . The method of    claim 12   , wherein step (a) includes applying a first layer of a non-stick coating at a dry film thickness of approximately 0.3-0.5 mils over the ceramic cooking surface.  
     
     
         14 . The method of    claim 13   , wherein step (a) includes applying a first layer of a non-stick coating at a dry film thickness of approximately 0.4 mils over the ceramic cooking surface.  
     
     
         15 . The method of    claim 12   , wherein step (b) includes flash drying the ceramic cooking vessel for approximately 2-6 minutes at a temperature of approximately 180-270 degrees Fahrenheit.  
     
     
         16 . The method of    claim 15   , wherein step (b) includes flash drying the ceramic cooking vessel for approximately 3-5 minutes at a temperature of approximately 200-250 degrees Fahrenheit.  
     
     
         17 . The method of    claim 12   , wherein step (d) includes applying a second layer of a non-stick coating at a dry film thickness of approximately 0.2-0.6 mils over at least a portion of the first layer.  
     
     
         18 . The method of    claim 17   , wherein step (d) includes applying a second layer of a non-stick coating at a dry film thickness of approximately 0.4-0.5 mils over at least a portion of the first layer.  
     
     
         19 . The method of    claim 12   , further comprising the step of applying a third layer of a non-stick coating over at least a portion of the first and second layers.  
     
     
         20 . The method of    claim 19   , wherein the step of applying the third layer includes applying the third layer at a dry film thickness of approximately 0.05-0.5 mils over at least a portion of the first and second layers.  
     
     
         21 . The method of    claim 20   , wherein the step of applying the third layer includes applying the third layer at a dry film thickness of approximately 0.1-0.2 mils over at least a portion of the first and second layers.  
     
     
         22 . The method of    claim 19   , wherein the step of applying the third layer occurs before the second layer of non-stick coating is dry.  
     
     
         23 . The method of    claim 19   , further comprising the step of drying the second and third layers by flash drying the ceramic cooking vessel for approximately 2-6 minutes at a temperature of approximately 180-270 degrees Fahrenheit.  
     
     
         24 . The method of    claim 19   , further comprising the step of drying the second and third layers by flash drying the ceramic cooking vessel for approximately 3-5 minutes at a temperature of approximately 200-250 degrees Fahrenheit.  
     
     
         25 . The method of    claim 19   , further comprising the step of curing the layers of non-stick coating.  
     
     
         26 . The method of    claim 25   , wherein the step of curing the layers includes heating the ceramic cooking vessel for approximately 20-35 minutes at a temperature of up to approximately 900 degrees Fahrenheit.  
     
     
         27 . The method of    claim 25   , wherein the step of curing the layers includes heating the ceramic cooking vessel for approximately 25-30 minutes at a temperature of up to approximately 850 degrees Fahrenheit.  
     
     
         28 . A method for making a non-stick ceramic cooking vessel for a slow-cooker, the vessel having glazing defining a seal over a cooking surface of the ceramic vessel, the method comprising the steps of: 
 (a) removing at least a portion of the glazing while maintaining at least a portion of the seal of the vessel; and    (b) applying a non-stick coating over the cooking surface.    
     
     
         29 . The method of    claim 28   , wherein step (a) includes grit-blasting at least a portion of the glazing with aluminum oxide.  
     
     
         30 . The method of    claim 29   , wherein a 44-64 grit aluminum oxide blast is used to create a glazing profile measuring approximately 160-240 micro inches on at least a portion of the vessel.  
     
     
         31 . The method of    claim 29   , wherein a 54-grit aluminum oxide blast is used to create a glazing profile measuring approximately 180-220 micro inches on at least a portion of the vessel.  
     
     
         32 . The method of    claim 28   , wherein the cooking surface further includes a bottom cooking surface and a wall cooking surface and step (a) includes removing at least eighty-five percent of the glazing over at least a portion of the bottom cooking surface and removing at least fifty percent of the glazing over at least a portion of the wall cooking surface.  
     
     
         33 . The method of    claim 28   , wherein the cooking surface further includes a bottom cooking surface and a wall cooking surface and step (a) includes removing at least ninety-five percent of the glazing over at least a portion of the bottom cooking surface and removing at least seventy-five percent of the glazing over at least a portion of the wall cooking surface.  
     
     
         34 . The method of    claim 28   , wherein step (b) farther includes the steps of 
 (c) applying a first layer of a non-stick coating over the cooking surface;    (d) drying the first layer;    (e) cooling the first layer; and    (f) applying a second layer of a non-stick coating over at least a portion of the first layer.    
     
     
         35 . The method of    claim 34   , wherein step (b) further includes the steps of 
 (g) applying a third layer of non-stick coating over at least a portion of the first and second layers;    (h) drying the second and third layers; and    (i) curing the layers of non-stick coating.    
     
     
         36 . The method of    claim 28   , wherein the cooking surface includes a bottom surface and wherein step (a) includes removing the glazing from the bottom surface such that the seal is substantially removed.  
     
     
         37 . The method of    claim 28   , wherein the cooking surface includes a wall surface and wherein step (a) includes removing a portion of the glazing from the wall surface such that the seal remains substantially intact.