Patent EA-000597-B1 (EA)
Title: A method and apparatus for surface sterilizing items and a system suitable for sterilizing bottles
Inventor: SEGAARD SEREN PETER
IPC: B65B55/08
Filed: 1997-02-10
Abstract: 1. A method for surface sterilising an item made from a polymeric material and finished by hot deformation such as blow moulding or vacuum moulding, said method comprising treatment with high-frequency electric energy such as microwaves, characterised in that: - a substantially continuous liquid film is provided on the item by applying to the item a liquid which is not repelled by the material of which the item consists, said liquid being preferably water to which de-tensioning agent has been added, in particular a surface-active agent, and the liquid is led away from the item and allowed to drip off, following which - the item is subjected to high-frequency electric energy for heating the liquid film and sterilising of at least a definite part of the surface of the item. 2. A method according to Claim 1, in which the item is a packing. 3. A method according to Claim 2, in which the packing is a returnable bottle for beverages, said bottle being manufactured by blow moulding. 4. A method according to Claim 2, in which the packing is a tray or a box, manufactured by vacuum moulding and intended for packing or storing of food like for instance meat products. 5. A method according to any of the preceding Claims, characterised in that the liquid film at least locally is heated to the boiling point. 6. A method according to any of the preceding Claims, characterised in that the item is still subjected to high-frequency electric energy after the boiling or evaporation away of the liquid film. 7. A method according to any of the preceding Claims, characterised in that the high-frequency electric energy is supplied in the form of microwaves, and surplus microwave energy preferably is removed from the energy treatment place, particularly preferred by circulation of a liquid absorbing the surplus energy. 8. A method according to any of the Claims 1-6, characterised in that the high-frequency electric energy is supplied at a frequency of 3-300 MHz, preferably one of the frequencies 13.56 MHz, 27.12 MHz or 40.68 MHz, and preferably by placing the item between two capacitor plate means, across which a high-frequency electric voltage is applied. 9. A method according to any of the preceding Claims, characterised in that the sterilising is carried out immediately after a preceding washing or rinsing of the item, and in that the liquid is left on the item in a step of the washing or rinsing process, respectively. 10. A method according to Claim 9, characterised in that ultrasound is being applied to the liquid used in the washing or rinsing process during the process. 11. An apparatus for surface sterilising items like for instance packagings, including returnable bottles for beverages, which items are manufactured from a polymeric material and finished by hot deformation like blow moulding or vacuum moulding, the apparatus being provided with wetting means for applicating liquid to the items, dripping off means for removing liquid from the items and heating means for subjecting the items to high-frequency electric energy, characterised in: - that the dripping off means are substantially constituted by transport means for transporting the items from the wetting means to the heating means under simultaneous dripping off of liquid from the items, - that the transport means are adapted to turn and/ or move the items such that all liquid readily drips off therefrom, and - that the transport time from the wetting means to the heating means is measured out such, relative to the prevailing temperature and air humidity, that a substantially complete dripping off of the items is ensured without the liquid film on the items completely or partially drying away. 12. An apparatus according to Claim 11, characterised in that the dripping off means comprise members for blowing air across the items, preferably sterile and/or cooled air. 13. An apparatus according to Claims 11 or 12 characterised in that the wetting means are substantially constituted by a washing or rinsing device for washing and/or rinsing of the items. 14. An apparatus according to Claim 13, characterised in that the washing or rinsing device is provided with means for applying ultrasound to the washing or rinsing liquid, respectively. 15. An apparatus according to any of the Claims 11-14 characterised in that the heating means are substantially constituted by a continuous flow microwave oven. 16. An apparatus according to any of the Claims 11-14, characterised in that the heating means are substantially constituted by a high-frequency heating system, preferably comprising capacitor plate means connected to an electric high-frequency generator for applying to said capacitor plate means a high-frequency electric voltage, and between which means the items are conveyed by means of conveyor means. 17. A system for sterilizing bottles made from a polymeric material, said bottles being manufactured by hot deformation like blow moulding, which system comprises: - a rinsing section for rinsing the bottles with water, preferably water to which a detensioning agent has been applied, and preferably under application of ultrasound, a heating section for applying high-frequency energy to the bottles, like for instance a through-flow microwave oven or a high-frequency heating installation, and - first transport means for conveying the bottles from the rinsing section to the heating section, said transport means being adapted to allow the bottles to drip off substantially completely during transport and to protect the bottles against even partial drying, preferably by being constructed with a short transport path. 18. A plant according to Claim 17 and further comprising: - a washing section for washing the bottles with water or lye before the rinsing, preferably under application of ultrasound. 19. A plant according to Claim 17 or 18 and further comprising: - second transport means for conveying the bottles from the heating section to a bottling or packing section or machine under aseptic conditions, the transport preferably taking place in encased surroundings and in an atmosphere of sterile air under overpressure.