Cold plasma application on packaging materials
- Identification
- How does it work?
- What can it be used for?
- What can it not be used for?
- Implementation
- Related Facilities
- Further Information
Identification
| Key words | Cold plasma, sterilisation, microorganisms, bottle, antimicrobial, non-thermal plasma, decontamination, RF |
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| Latest version | 2011/08/05 |
| Completed by | FRIP |
How does it work?
| Primary objective | Rapid and effective sterilization and deodorization of surfaces e.g. of PET or glass bottles before filling and dielectric surfaces . | |||
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| Working principle | Generally cold plasma technology is used for inactivation of micro-organisms (vegetative and sporulent form) on the surface of products and packaging materials [5]. The oxidative radicals are released that acts on biological targets and damage their cell membrane.
It is a non-thermal sterilization and can be used for heat sensitive packaging materials. It is energy-efficient way with a minimum of damage to the product. For products such as cut vegetables and fresh meat there is no mild surface decontamination technology available at the moment. | |||
| Images | | |||
| Additional effects | deodorization of the inside of PET bottles before filling | |||
| Important process parameters | Ignition voltage, frequency of RF pulses, length of pulses, main input power, mean pulse current, exposure time, type of gas, density, temperature, size | |||
| Important product parameters |
What can it be used for?
| Products | surface of packaging materials (bottles) |
|---|---|
| Operations | Sterilisation of bottles before filling of a product. |
| Solutions for short comings | This technology is mainly suitable for PET bottles because of low temperature and high speed of sterilisation. |
What can it NOT be used for?
| Products | - |
|---|---|
| Operations | - |
| Other limitations | Bacteria in deeper biofilm layers survive better after the plasma treatment than without or at small layer of biofilm. It was found that the rate of inactivation e.g. of S. typhimurium is inversely proportional to initial bacterial concentration [2]. There can be problem with spores of some microorganisms - no significant inactivation e.g. for Geobacillus stearothermophilus [6]. |
| Risks or hazards | Electrodes that are used in gas discharges degrade over time. Metals that are evaporated at the electrode surface may end up as unintended additives. |
Implementation
| Maturity | There exist many lab scale plasma jet equipments, but experiments with RF Flash Plasma for industrial use have been performed as well. The device was integrated into an industrial-filling machine for in-line sterilization and deodorization of the inside of PET bottles before filling and for caps and bottle neck sterilization before closing. The method allows cold, aseptic filling [3]. |
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| Modularity /Implementation | There is no problem with implementation of this technology to industrial-filling machine. The estimated cost (investment and operating cost) of this system is substantially lower than systems based on other methods. |
| Consumer aspects | The process has no harmful effect on treated bottles or on beverages filled into the bottles after treatment. |
| Legal aspects | The system can generate UV photons and ozone gas, thus the local legislation on UV and ozone must be applied. Generally speaking novel food legislation can be applied if the technology was not broadly used before July 12, 2002.
Regulation (EC) N°258/97 of the European Parliament and of the Council as of 12/07/2002 |
| Environmental aspects | Small quantity of ozone and nitrogen dioxide and possibly NH3 are produced during the RF flash discharge in a PET bottle, which causes a characteristic odour after treatment. Experiments with filling of distilled water showed that there was neither detectable ozone nor ammoniac and that the concentration of nitrogen oxide ions was much lower than the allowed limit. |
Facilities that might be interesting for you
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Further Information
| Institutes | Institute for plasma technology, INP Greifswald, VITO |
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| Companies | OMVE Netherlands, AURION, K-Plasma |
| References | [1] Deilmann M, Halfmann H, Bibinov N., Wunderlich J., Awakowicz P (2008): Low-pressure microwave plasma sterilization of polyethylene terephthalate bottles, JOURNAL OF FOOD PROTECTION, volume 71 (10), 2119-2123
[2] Fernández A., Shearer N., Wilson DR., Thompson A. (2011): Effect of microbial loading on the efficiency of cold atmospheric gas plasma inactivation of Salmonella enterica serovar Typhimurium, Int J Food Microbiol., in Press [3] Koulik P., Begounov S., Goloviatinskii S (1999):Atmospheric plasma sterilization and deodorization of dielectric surfaces, PLASMA CHEMISTRY AND PLASMA PROCESSING, volume 19 (2), 311 -326 [4] Messerer P., Halfmann H., Czichy M., Schulze M., Awakowicz P (2005): Plasma sterilisation and surface modification of thermolabile materials, Symposium on Surface Engineering in Materials Science III, p. 205-214 [5] Moreau M., Orange N. and Feuilloley M.G.J (2008): Non-thermal plasma technologies: New tools for bio-decontamination, Biotechnology Advances, volume 26(6), 610-617 [6] Morris A., Akan T., McCombs G. B., Hynes W. L., Laroussi M. (2009): Bactericidal effects of non-equilibrium cold plasma on Geobacillus stearothermophilis and Bacillus cerus, J Dent Hyg., 83(2), 55-61 [7] Leipold, F., Schultz-Jensen, N., Kusano, Y., Bindslev H., Jacobsen, T. (2011): Decontamination of objects in a sealed container by means of atmospheric pressure plasmas, Food Control, 22( 8), 1296 |