What Is Corona
Páginas: 8 (1828 palabras)
Publicado: 17 de noviembre de 2012
CORONA TREATMENT
Rohit Deshpande PBJ Industrial Electronics Pvt. Ltd
Introduction: There were many hurdles being faced in the past few years by the Plastic Conversion Industry one of which was inability of the water based and ultra based violate curable inks and coating, which adhere with the plastic substrates. This can now be achieved by plasma treatment or of using some form of surfacepreparation on to the plastic substrate with solvent based ink but this is subject to some form of surface preparation on to the plastic substrate. However this solution has some drawbacks such as short life of the viability etc. but when it comes to the water based or UV curable inks the above solution does not hold good. One perfect solution to this problem is using of Corona Treatment. In theModern days it is rare to find an Extruder, Laminator or wide web printer that does not come with one or more corona treaters in line.
What is Corona Treatment: In corona treatment the film is passed over the roller through the air gap between the fixed electrode and the dielectric whereby the film is exposed to a very high voltage potential at a very high frequency, which causes ionization of air.The equipment used to achieve this comprises of a generator, which converts the available 230V / 415V, 50Hz power supply a high voltage transformer and the treating station itself. Now under the influence of the electric field, the ionized air molecules are made to move about. As the electric field increases, so does the speed and hence the kinetic energy of the
PBJ Industrial ElectronicsPvt.Ltd. Mumbai 400067 www.pbj-ieec.com
ionized air molecules. The random collision of these ions with other charged ions result in increase in the number of ions. Thus when sufficient electric field is developed, then the air gap can be said to have broken down into an ionized current carrying conductor. During this process the atmospheric oxygen is broken down into nascent oxygen and Ozone.2O2
O
+
O3
The ozone is extracted out of the system where as the active nascent oxygen immediately oxidizes the film.
Components of a corona treatment system: The corona treatment system mainly comprises of a power generation source and a treating station. 1) Power generating source: - This consists of a high frequency generator which uses the normally available 230V / 415V. 50Hzmains power supply to a very high volt frequency (about 40-50 KHz) and a high voltage output transformer.
PBJ Industrial Electronics Pvt.Ltd. Mumbai 400067 www.pbj-ieec.com
2)
Treating station:- The treating stations comprises of a high voltage electrode and a grounded roll. In order to produce a conducting atmosphere, either the electrode or the ground roll should have dielectric covering.The treating station are broadly clarified in to two types: 1) Covered Roll 2) Bare Roll 1) Covered Roll: - In case of a covered roll, the ground roll is provided with a dielectric covering whereas the other high voltage electrode is a bare metal . The advantages of using a covered roll treating station are:i) ii) It is specifically designed for non-conducting substrates. Substrates with highslip are agents, which are difficulty to treat treated by using covered roll treatment stations.
PBJ Industrial Electronics Pvt.Ltd. Mumbai 400067 www.pbj-ieec.com
iii) Depending upon the customer specifications, variety of dielectric coverings ca is used. Following are the disadvantages of using covered roll treating stations. i) ii) Metalzed substrates cannot be treated. Fieldrepairability caused by the dielectric failures is very difficult.
2) Bare Roll: - Incase bare roll treating stations, the dielecting covering is provided on the high voltage electrode whereas the ground roll is just a bare metal.
PBJ Industrial Electronics Pvt.Ltd. Mumbai 400067 www.pbj-ieec.com
Advantages of bare roll treating station are: 1. No need of Dielectric roller sleeve or a dielectric...
Rohit Deshpande PBJ Industrial Electronics Pvt. Ltd
Introduction: There were many hurdles being faced in the past few years by the Plastic Conversion Industry one of which was inability of the water based and ultra based violate curable inks and coating, which adhere with the plastic substrates. This can now be achieved by plasma treatment or of using some form of surfacepreparation on to the plastic substrate with solvent based ink but this is subject to some form of surface preparation on to the plastic substrate. However this solution has some drawbacks such as short life of the viability etc. but when it comes to the water based or UV curable inks the above solution does not hold good. One perfect solution to this problem is using of Corona Treatment. In theModern days it is rare to find an Extruder, Laminator or wide web printer that does not come with one or more corona treaters in line.
What is Corona Treatment: In corona treatment the film is passed over the roller through the air gap between the fixed electrode and the dielectric whereby the film is exposed to a very high voltage potential at a very high frequency, which causes ionization of air.The equipment used to achieve this comprises of a generator, which converts the available 230V / 415V, 50Hz power supply a high voltage transformer and the treating station itself. Now under the influence of the electric field, the ionized air molecules are made to move about. As the electric field increases, so does the speed and hence the kinetic energy of the
PBJ Industrial ElectronicsPvt.Ltd. Mumbai 400067 www.pbj-ieec.com
ionized air molecules. The random collision of these ions with other charged ions result in increase in the number of ions. Thus when sufficient electric field is developed, then the air gap can be said to have broken down into an ionized current carrying conductor. During this process the atmospheric oxygen is broken down into nascent oxygen and Ozone.2O2
O
+
O3
The ozone is extracted out of the system where as the active nascent oxygen immediately oxidizes the film.
Components of a corona treatment system: The corona treatment system mainly comprises of a power generation source and a treating station. 1) Power generating source: - This consists of a high frequency generator which uses the normally available 230V / 415V. 50Hzmains power supply to a very high volt frequency (about 40-50 KHz) and a high voltage output transformer.
PBJ Industrial Electronics Pvt.Ltd. Mumbai 400067 www.pbj-ieec.com
2)
Treating station:- The treating stations comprises of a high voltage electrode and a grounded roll. In order to produce a conducting atmosphere, either the electrode or the ground roll should have dielectric covering.The treating station are broadly clarified in to two types: 1) Covered Roll 2) Bare Roll 1) Covered Roll: - In case of a covered roll, the ground roll is provided with a dielectric covering whereas the other high voltage electrode is a bare metal . The advantages of using a covered roll treating station are:i) ii) It is specifically designed for non-conducting substrates. Substrates with highslip are agents, which are difficulty to treat treated by using covered roll treatment stations.
PBJ Industrial Electronics Pvt.Ltd. Mumbai 400067 www.pbj-ieec.com
iii) Depending upon the customer specifications, variety of dielectric coverings ca is used. Following are the disadvantages of using covered roll treating stations. i) ii) Metalzed substrates cannot be treated. Fieldrepairability caused by the dielectric failures is very difficult.
2) Bare Roll: - Incase bare roll treating stations, the dielecting covering is provided on the high voltage electrode whereas the ground roll is just a bare metal.
PBJ Industrial Electronics Pvt.Ltd. Mumbai 400067 www.pbj-ieec.com
Advantages of bare roll treating station are: 1. No need of Dielectric roller sleeve or a dielectric...
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