Patent GB-1394917-A (GB)
Title: Aseptic packaging of materials
IPC: B29C51/24
Filed: 1973-07-17
Abstract: 1394917 A method and apparatus for the aseptic packaging of materials TETRA PAK DEVELOPPEMENT SA 17 July 1973 [11 Aug 1972] 33890/73 Heading B8C In a method of aseptic packaging while one side only of a first web 2 of packaging material is maintained in an aseptic state by exposure to sterile conditions, a second web 3 of packaging material, having a surface maintained in asceptic condition, is partially attached to said first web with the aseptic surfaces of the webs facing one another in order to form a pocket-like receptacle into which is then loaded material being packaged, whereafter unattached zones of selected areas of the web are bonded together to form, and to enclose and seal, the material in a package. According to the invention also apparatus for aseptic packaging of materials comprises means for maintaining the surface on one side only of a first web 2 of packaging material in aseptic condition, means for presenting to said aseptic surface of said first web, the aseptic surface of a second web 3 of packaging material, and for partially sealing together said two webs to form a pocket-like receptacle open only to a sterile environment, means for loading material to be packed into said receptacle and means for completing the bonding of the webs to form a package with loaded material enclosed, and sealed therein. As shown, webs 2, 3 of thermoformable material, such as e.g. polyvinylidene chloride coated-P.V.C. or polystyrene, are fed respectively from rolls 7, 27, through vats 8, 28, filled with washing and/or sterilizing equipment and preferably through pretreatment chambers 5, 6 and into the chamber 4 which is supplied with pressurized sterile air through an inlet 18. A forming tool 19, Fig. 1, for forming at least one, but preferably several cavities 21 in the web 2, is adapted to move with the web 2, vacuum draw the material, and then rapidly return to its original position for repeating the process. A tool 20 may also be employed to provide a positive forming effect on the web 2. A filler 22, to fill the container bodies 21 with sterile material, co-operating heat-sealing rollers 43, 44 for heat-sealing the webs together along their longitudinal edges 45, heat-sealing pressure plates 23, 24 for completely sealing the sterile material in the containers 21, and a cutter 38, for separating container packages, are also accommodated in the chamber 4. The web 2 is heated to a temperature suitable for thermoforming by heating elements 12, Fig. 1, accommodated in the pretreatment chamber 16 which has an extractor 17, for removing to atmosphere, any vapour given off the web. The chambers 5, 6 are also provided with elements for washing and sterilizing the web 2, 3 as well as an element 71 adapted to irradiate the webs 2, 3 with ultraviolet light and an element 34 for electron spraying, or bath and spray devices for spraying liquid medium such as hydrogen peroxide, alcohol &c., on to the webs 2, 3, traces of liquid being removed from the webs by heaters, not shown. The entrances to the chambers 5, 6 and the outlet of the chamber 4 are, in order to prevent ingress of the surrounding atmosphere, provided with a sluice consisting, e.g. of a sterilizing or disinfecting fluid, or sterile air, curtain, a liquid curtain, e.g. of hydrogen peroxide, or alcohol, or a sleeve. Screen walls 14, 15, or sluices, not shown, separate the chambers 5, 6 from the chamber 4, the pressurized air in the chamber 4 flowing out to the chambers 5, 6 respectively through openings 13, 36. The washing and/or sterilization process must be carried out, outside the sterile chamber 4, and if liquid, or gaseous agents are used, these processes must be carried out outside the pretreatment chambers 5, 6. In a modification, Fig. 3, the moulding tool comprises moulding bodies 52 which are carried out by an endless chain 47, tools 20<SP>1</SP> being arranged on a second endless chain 50 for also forming the web 3. The web 2 may consist e.g. of polyvinylidene chloride-coated P.V.C. web and the web 3 of a multi-layer comprising metal foil, a polyethylene layer, and a more rigid layer consisting of fibres of polyester and a peroxylene-based coating which is heat-sealable.