PROCESS AND APPARATUS FOR SURFACE STERILIZATION OF MATERIALS

• US 3,780,308 A
• Filed: 06/07/1971
• Issued: 12/18/1973
• Est. Priority Date: 06/07/1971
• Status: Expired due to Term

• Current Assignee: Sam V. Nablo
• Original Assignee: Sam V. Nablo
• Inventors: Nablo, Sam V.
• Primary Examiner(s): Lawrence, James W.
• Assistant Examiner(s): Church, C. E.
• Application Number:
  US05/150,464
• Time in Patent Office: 925 Days
• Field of Search: 250/49.5TE,43 21/102 99/253
• US Class Current: 250/492.3
• CPC Class Codes: A23L 3/263 with corpuscular or ionising radiation, i.e. X, alpha, beta or omega radiation laser plasma radiation A23L3/26
• CPC Class Codes: A61L 2/08 Radiation
• CPC Class Codes: B65B 55/08 by irradiation
• CPC Class Codes: B67C 7/0073 Sterilising, aseptic filling and closing B67C3/2642 takes precedence
• CPC Class Codes: G21K 5/10 with provision for relative movement of beam source and object to be irradiated
• CPC Class Codes: Y10S 148/023 Deep level dopants

Abstract

This disclosure deals with the surface sterilization and/or surface treatment of containers and other articles the walls of which have a high specific energy absorption for relatively low energy electrons, by transmitting such low energy electrons to such containers as they move through a sterile gaseous zone, only slightly to penetrate the container walls to effect surface sterilization or treatment thereof, while substantially absorbing the electrons within the walls to minimize X-ray generation.

Claims

2. A process as claimed in claim 1 and in which the further step is performed of maintaining the said zone substantially sterile.

3. A process as claimed in claim 1 and in which said articles are disinfested by exposure to said beam.

4. Apparatus as claimed in claim 13 and in which means is provided for successively pulsing the successive guns.

5. A process as claimed in claim 4 and in which the electron beam pulses are adjusted to be of duration of the order of a micro-second and less.

6. A process as claimed in claim 1 and in which said electron beam generating step is repeated at successive spaced regions along said zone.

7. A process as claimed in claim 6 and in which said articles comprise containers and the containers are filled between such successive regions of said zone.

8. A process as claimed in claim 7 and in which the containers are closed after filling, with the closure subjected to a sterilizing electron beam at one of said regions of said zone.

9. A process as claimed in claim 1 and in which said articles comprise container material prior to formation into containers, and in which the further step is performed of forming the material, after the electron beam has penetrated the same, into containers while maintaining the containers sterile.

10. Apparatus for achieving surface sterilization of a moving line of articles by utilization of low energy electrons with energy in the range of the order of from about 50 to about 150 keV at the surface of said articles, with article penetration depths of up to the order of about 6 mils and with energy transfer efficiency such that the electron energy is substantially completely absorbed within such penetration depths, the articles having walls of high enough specific energy absorption for said low energy electrons to provide said energy transfer efficiency, that comprises, means for moving said articles successively through a gaseous irradiation zone, means for generating a single substantially uniform large-area low energy electron beam and transmitting the same in said zone to said surface of said articles with said electron energies at said surface as said articles move through said zone, in order to cause said electrons to penetrate said article walls to said depths over such large area and to effect such surface sterilization with said substantially complete absorption within the walls that minimizes X-ray generation, and means for absorbing such X-rays as may be generated in said zone along the line of movement of the articles there-through.

11. Apparatus as claimed in claim 10 and in which means is provided for maintaining the said zone substantially sterile.

12. Apparatus as claimed in claim 10 and in which said articles comprise container material prior to formation into containers, and in which there is further provided container-forming apparatus for receiving the electron-beam treated material and forming a container therefrom while maintaining the container sterile.

13. Apparatus as claimed in claim 10 and in which said electron beam generating means comprises a plurality of successive electron guns and corresponding windows positioned to irradiate successive regions of said zone along the line of movement of said articles.

15. Apparatus as claimed in claim 10 and in which said articles comprise containers, and there are provided means for filling said containers as they move through the said zone while maintaining the containers sterile.

16. Apparatus as claimed in claim 15 and in which means is provided for subjecting the filling of said filling means to electron beam irradiation.

17. Apparatus as claimed in claim 16 and in which said last-named electron-beam irradiation subjecting means is coaxially disposed about said filling means.