Sterilising material

Claim 2

1 A method of sterilising a web or sheet of material, more especially of packaging material, wherein the web or sheet is 110 moved past a first station where it is subjected to a preliminary sterilisation, and thereafter to a second station where under suitably controlled conditions vapour of a liquid sterilising agent is deposited as a 115 condensate upon the web or sheet, and removed therefrom after a prearranged period.

Claim 3

2 A method as claimed in Claim 1 wherein at said first station the web or 120 sheet is immersed in and passes through a bath of a liquid sterilising agent.

Claim 4

3 A method as claimed in Claim 1 or 2 wherein the condensate is removed from the web or sheet by a stream of hot sterile 125 gas, such as air.

Claim 5

4 Apparatus adapted to sterilise a web or sheet of material, more especially a web or sheet of packaging material, comprising a first station provided with means 130 1 574 488 1 574488 for applying a preliminary sterilising treatment to the web or sheet, and a second treatment station provided with means for supplying a vaporised liquid sterilising agent, e g 'hydrogen peroxide, to the sheet or web under conditions which ensure deposition of some of the vapour as a condensate on the sheet or web, and means for removing said condensate from the sheet or web after a prearranged period of time.

Claim 6

4 Apparatus adapted to sterilise a web or sheet of material, more especially a web or sheet of packaging material, comprising a first station provided with means 130 1 574 488 1 574488 for applying a preliminary sterilising treatment to the web or sheet, and a second treatment station provided with means for supplying a vaporised liquid sterilising agent, e g 'hydrogen peroxide, to the sheet or web under conditions which ensure deposition of some of the vapour as a condensate on the sheet or web, and means for removing said condensate from the sheet or web after a prearranged period of time.

Claim 7

Apparatus as claimed in Claim 4 comprising at said first treatment chamber a bath of liquid sterilising agent, and guide means for causing the web or sheet to be temporarily immersed in the bath in the course of its advance.

Claim 8

6 Apparatus as claimed in Claim 5 comprising adjacent to and downstream of the bath scraper or wiper means adapted to remove a substantial proportion of the sterilising agent from the web or sheet after it leaves the bath.

Claim 9

7 Apparatus as claimed in Claim 4, 5 or 6 comprising screeing or cover means adapted to co-operate with said web or sheet in order to ensure that at least one face of the web or sheet is exposed to substantially closed space, and means for establishing an atmosphere charged with a vaporised sterilising agent in the said closed space to which the web or sheet surface is exposed.

Claim 10

8 Apparatus as claimed in Claim 7 wherein said vaporising means comprise a nozzle from which the sterilising agent is emitted as a spray.

Claim 11

9 Apparatus as claimed in Claim 7 or 8 wherein said vaporising means comprise a heated surface to which said agent, or the spray thereof, is directed, and which effects atomisation of the agent making contact with it.

Claim 12

Apparatus as claimed in Claim 9 wherein said heated surface is part of a heatable body.

Claim 13

11 Apparatus as claimed in Claim 9 or wherein the temperature of the surface is within the range 1600-250 TC.

Claim 14

12 Apparatus as claimed in any of Claims 7-11 wherein the rate of supply of sterilising agent for vaporisation is controlled.

Claim 15

13 Apparatus as claimed in Claim 8 or in any of Claims 9-12 when appendant to Claim 8 wherein the supply of said agent 55 and said nozzle is subject to a timecontrolled valve in the supply line upstream of said nozzle.

Claim 16

14 Apparatus as claimed in any of Claims 4-13 wherein the condensate is 60 removed from the web or sheet by a stream of hot sterile air.

Claim 17

Apparatus comprising means to form a web of packaging material into a tube, means to load the tube with a liquid 65 to be packaged, means to effect transverse seals at positions spaced longitudinally of the tube, and means as claimed in any of Claims 4-14 for sterilising at least the face of the web which forms the inner surface 70 of the tube, before and during the time the web is being formed into a tube prior to receiving the intended contents.

Claim 18

16 Apparatus as claimed in Claim 15 when appendant to Claim 14 wherein 75 means are provided to direct hot sterile air downwards into said,tube, and means to deflect this air stream in order to flow upwards adjacent to the inner surface of the tube, and out at the open top of the tube 80 17 A method of sterilising a web or sheet of material, more especially packaging material, substantially as described herein with reference to the accompanying drawings 85 18 Apparatus for sterilising a web or sheet of material more especially packaging material, substantially as described herein with reference to the accompanying drawings 90 19 Web or sheet material, more especially of packaging material, substantially as described herein with reference to the accompanying drawings. W H BECK, GREENER & CO, Chartered Patent Agents, 7, Stone Buildings, Lincoln's Inn, London, W C 2. Agents for the Applicants. Printed for Her Majesty's Stationery Office by The Tweeddale Press Ltd, Berwick-upon-Tweed, 1980. Published at the Patent Office, 25 Southampton Buildings, London, W C 2 A l AY, from which copies may be obtained.