Method and Apparatus for Sterilizing Containers

Abstract

A method ( 20 ) and apparatus ( 100 ) for sterilizing packaging ( 102 ) is disclosed herein. The method ( 20 ) applies a solution of hydrogen peroxide onto the packaging ( 102 ) and an alkaline solution to react with the hydrogen peroxide to generate hydroxyl radicals to kill microorganism. The use of an alkaline solution allows the sterilization process to proceed at a lower temperature and a faster rate. A solution of sodium hydroxide is the preferred alkaline solution. The temperature of the process is preferably below 100° C.

1 - 25 . (canceled) 
     
     
         26 . A method for sterilizing packaging, the method comprising:
 applying a hydrogen peroxide solution having from 1% to 50% hydrogen peroxide to packaging, the hydrogen peroxide solution applied at a temperature of approximately 60° C. and permitting the hydrogen peroxide solution to activate on the packaging;   applying an alkaline solution to the packaging subsequent to the activation period, the alkaline solution having a pH in the range of 10-14, the alkaline solution applied at a temperature ranging of approximately 60° C.;   rinsing the packaging with sterile to remove the residue alkaline solution and residue hydrogen peroxide; and   hot filling the packaging with a flowable food product, the packaging filled at a temperature ranging from 60° C. to 80° C.   
     
     
         27 . The method according to  claim 26  wherein the flowable food product is orange juice. 
     
     
         28 . The method according to  claim 26  wherein the alkaline solution is a solution of 0.05 Normal sodium hydroxide having a pH of approximately 12.5. 
     
     
         29 . The method according to  claim 26  wherein the hydrogen peroxide solution has a concentration of approximately 35% hydrogen peroxide. 
     
     
         30 . The method according to  claim 26  wherein the packaging is a PET bottle, a polyethylene bottle or a polypropylene bottle. 
     
     
         31 . A method for sterilizing a plastic bottle, the method comprising:
 applying a hydrogen peroxide solution having from 30% to 40% hydrogen peroxide to an exterior surface of the plastic bottle and an interior surface of the plastic bottle, the hydrogen peroxide solution applied at a temperature of approximately 60° C.;   permitting the hydrogen peroxide solution to activate on the exterior surface of the plastic bottle and the interior surface of the plastic bottle for an activation period;   applying a solution of 0.05 Normal sodium hydroxide to the exterior surface of the plastic bottle and the interior surface of the plastic bottle subsequent to the activation period, the solution of 0.05 Normal sodium hydroxide having a pH in the range of 11-13, the solution of 0.05 Normal sodium hydroxide applied at a temperature of approximately 60° C.;   rinsing the packaging with sterile water to remove the residue sodium hydroxide and residue hydrogen peroxide; and   hot filling the packaging with a flowable food product, the packaging filled at a temperature ranging from 60° C. to 80° C.   
     
     
         32 . The method according to  claim 31  wherein the flowable food product is orange juice. 
     
     
         33 . The method according to  claim 31  wherein the alkaline solution is a solution of 0.05 Normal sodium hydroxide having a pH of approximately 12.5. 
     
     
         34 . The method according to  claim 31  wherein the hydrogen peroxide solution has a concentration of approximately 35% hydrogen peroxide. 
     
     
         35 . The method according to  claim 31  wherein the plastic bottle is a PET bottle, a polyethylene bottle or a polypropylene bottle. 
     
     
         36 . The method according to  claim 31  wherein the solution of hydrogen peroxide is applied as a vapor. 
     
     
         37 . The method according to  claim 31  wherein the flowable food product is hot filled at a temperature less than 70° C. without heat distortion of the plastic bottle. 
     
     
         38 . The method according to  claim 31  wherein the flowable food product is hot filled at a temperature ranging from 60° C. to 70° C. without heat distortion of the plastic bottle. 
     
     
         39 . An apparatus for performing the method of  claim 26  or  claim 31 .