Method and an Apparatus for Sterilizing Packaging Material

Abstract

A method and an apparatus for sterilizing packaging material for use in packaging for protein containing products, such as food products or medical drugs. The packaging material is sterilized by irradiating it using a beam of ionizing radiation, such as an electron beam or a beam of gamma rays. Afterwards, the packaging material is processed in such a manner that protein reactive substances or compounds formed in the packaging material during the irradiation step are at least partly removed or rendered inreactive with respect to proteins. The processing step may advantageously be performed by heating the packaging material. Preferably, the processing step involves accelerating diffusion from the packaging material of protein reactive substances or compounds. Since the protein reactive substances or compounds are removed or rendered inreactive with respect to proteins, degradation of the product which is later stored in the packaging material is considerably reduced. The packaging material needs to be stored under sterile conditions for a shorter period of time. Thereby the space needed for sterile storage, as well of the risk of contamination, is considerably reduced.

1 . A method of processing a material containing protein reactive substances or compounds, the method of processing the material comprising: 
       accelerating diffusion from the material of protein reactive substances or compounds, 
       wherein the processing is performed in such a manner that an impurity level in the protein containing product after storage in the packaging for 10 weeks at 5° C. is within 1.5% of a corresponding impurity level in a comparable protein containing product positioned in a packaging made from a sterilized glass material under similar storage conditions. 
     
     
         2 . A method according to  claim 1 , wherein accelerating diffusion from the material is performed by emitting ionizing radiation toward the material. 
     
     
         3 . A method according to  claim 2 , wherein the emitting ionizing radiation comprises an gamma ray generator. 
     
     
         4 . A method according to  claim 2 , wherein the emitting ionizing radiation comprises an electron beam emitter. 
     
     
         5 . A method according to  claim 2 , wherein the emitting ionizing radiation comprises a UV generator. 
     
     
         6 . A method according to  claim 1 , wherein accelerating diffusion from the material is performed by heating the packaging material. 
     
     
         7 . An apparatus for sterilizing packaging material in packaging for protein containing products, the apparatus comprising:
 an irradiation station comprising means for emitting ionizing radiation towards the packaging material,   a processing station comprising means for processing the irradiated packaging material in such a manner that diffusion of protein reactive substances or compounds formed in the packaging material during irradiation is accelerated, and   means for conveying the packaging material at least between the irradiation station and the processing station.   
     
     
         8 . An apparatus according to  claim 7 , wherein the processing station is structured to process the material such that an impurity level in the protein containing product after storage in the packaging for 10 weeks at 5° C. is within 1.5% of a corresponding impurity level in a comparable protein containing product positioned in a packaging made from a sterilized glass material under similar storage conditions. 
     
     
         9 . An apparatus according to  claim 7 , wherein the means for emitting ionizing radiation comprises an gamma ray generator. 
     
     
         10 . An apparatus according to  claim 9 , wherein the gamma ray generator is structured to process the material such that an impurity level in the protein containing product after storage in the packaging for 10 weeks at 5° C. is within 1.5% of a corresponding impurity level in a comparable protein containing product positioned in a packaging made from a sterilized glass material under similar storage conditions. 
     
     
         11 . An apparatus according to  claim 7 , wherein the means for emitting ionizing radiation comprises an electron beam emitter. 
     
     
         12 . An apparatus according to  claim 11 , wherein the electron beam emitter is structured to process the material such that an impurity level in the protein containing product after storage in the packaging for 10 weeks at 5° C. is within 1.5% of a corresponding impurity level in a comparable protein containing product positioned in a packaging made from a sterilized glass material under similar storage conditions. 
     
     
         13 . An apparatus according to  claim 7 , wherein the means for emitting ionizing radiation comprises an UV generator. 
     
     
         14 . An apparatus according to  claim 13 , wherein the UV generator is structured to process the material such that an impurity level in the protein containing product after storage in the packaging for 10 weeks at 5° C. is within 1.5% of a corresponding impurity level in a comparable protein containing product positioned in a packaging made from a sterilized glass material under similar storage conditions. 
     
     
         15 . An apparatus according to  claim 7 , wherein the processing means comprises means for heating the packaging material. 
     
     
         16 . An apparatus according to  claim 15 , wherein the means for heating is structured to process the material such that an impurity level in the protein containing product after storage in the packaging for 10 weeks at 5° C. is within 1.5% of a corresponding impurity level in a comparable protein containing product positioned in a packaging made from a sterilized glass material under similar storage conditions.