Steve Katz, Editor10.13.15
There are certain components to the label converting workflow that would fit right in as science fair exhibits – static control, ink viscosity and adhesive technology, to name a few. Corona treating is another area that falls into the scientific realm, and it’s become increasingly more important to label converting.
The complex definition of Corona treatment could come straight out of a textbook: All materials have an inherent surface energy, and corona treatment is a technique used to modify the surface energy by using a low temperature corona discharge plasma to impart changes in the properties of a surface. A corona discharge is an electrical discharge brought on by the ionization of a fluid surrounding a conductor that is electrically charged. Surface treatment systems are available for virtually any surface format including sheets and roll goods that are handled in a web format.
In layman’s terms, “Corona treaters increase the surface energy of labelstock to improve wettability and adhesion of inks, coatings and adhesives,” explains Mark Plantier, vice president of marketing for Enercon Industries. “Generally speaking, polymer and foil labelstock have chemically inert and non-porous surfaces with low surface energy, causing them to be non-receptive to bonding with printing inks. While ink formulations may be optimized for specific applications, labelstock surface energy plays a key role in ensuring proper adhesion. Adhesion is also inhibited by surface contaminants and film additives which migrate to the film surface.”
Within the label converting industry, there are suppliers dedicated to the manufacture of corona treaters designed specifically for narrow web applications. What follows are corona treatment explanations and product descriptions from the experts themselves.
Enercon Industries
According to Plantier, labelstock that is corona-treated inline prior to printing, demonstrates improved print quality, while enabling faster press speeds and reducing scrap.
The development of highly engineered polymer materials for labelstock has increased the need for corona treating, Plantier says. “These materials provide labels with a unique set of performance features, but have also increased the challenge of getting inks to properly adhere. The development of these materials and the printing technologies used in the narrow web market have also enabled many label converters to enter the flexible packaging market. Many printing operations are now printing on a wider variety of materials, and corona treating inline provides them with greater capacity for printing success.
“Successful label converters know that minimizing printing variables leads to higher productivity and profits. Corona treaters provide high value for both flexographic and digital printing operations as they eliminate the variable of labelstock surface energy. And since corona treaters are inexpensive, simple to integrate and easy to operate, they provide an excellent return on their investment,” Plantier says.
Enercon’s newest innovation is the CoronaFlex corona treater, specifically designed for the narrow web converting industry. The design fits universally with all flexographic and digital printing presses. The system’s deluxe model features an intuitive touch screen control panel that guides users through operation and power settings. Integrated with this system is Enercon’s Watt Density control feature, which ensures consistent treatment by automatically adjusting the power level in accordance with changes in line speed.
Explains Plantier, “CoronaFlex is a breakthrough system architecture which allows more features to be provided to users at a lower cost than ever before possible. With the touch screen interface, Enercon is trying to take some of the mystery away from the corona treating process for operators.”
Within the CoronaFlex operating system is the ability to collect detailed system diagnostics and fault logs, and there is basic troubleshooting information incorporated as well. “We find that there are too many narrow web operations that have failed to properly train their operators to have an understanding of the basics of corona treating,” he says, adding that Enercon hosts numerous online webinars and provides technical papers to customers at no additional charge.
www.enerconind.com
QC Electronics
“The corona treating process is critical to successful label manufacturing,” states Ken Klein, president and CEO of QC Electronics. “The corona field provides a means of cleaning the surface, but, more importantly, it increases the surface energy. Increased surface energy makes film more compatible with inks; therefore increasing the wet-out and bonding of ink and topcoats.”
Klein points out that with label presses running faster and faster, it is important that the corona treater be capable of producing watt densities that keep up with these increased line speeds. “As I talk with label makers, they tell me they are looking for high power treaters that are compact and reasonably priced,” he says. “QC has answered this request with our new 4E narrow web corona treater. The 4E treater provides high watt densities at fast line speeds, ensuring reliable surface tensions and good ink bonding.”
The 4E treater is prewired for quick and easy installation. “It simply mounts onto the press and is ready to produce high definition corona,” explains Klein. “Having the 4E installed on press ensures that the surface energy of the film is adequate for good ink wet-out and good bonding, resulting in high quality labels. Owners of the 4E treater benefit from years and years of profitable treater operation due to the 4E’s reasonable price and low maintenance requirements.” - www.qcelectronics.com
Corotec
Corotec Corporation recently introduced the latest in its new family of fixed-width bare-roll corona treatment system designs for the narrow web processor. These systems feature Corotec’s new electrode design, which the company says is capable of delivering much higher power densities to the web than competitive designs due to unique HVC cooling architecture. Systems are available in single and double-sided treating configurations and can be ordered with an integral power supply (the Corotec Uni-Dyne system configuration), or a separate power supply. Uni-Dyne configurations are available with power ratings from 500 watts to 5,000 watts, while systems with a separate power supply have no power limitation.
All systems include Corotec’s instant speed switch protection to automate treating system start-up with the machine, while reducing untreated material to an absolute minimum. All configurations can include an integral power density control system and automatic exhaust blower control. For added convenience, the systems can be supplied customized to “bolt on” to an existing press, saving installation headaches. - www.corotec.com
3DT
“Many label manufacturers have been printing for years on paper or labelstock materials which didn’t require corona treatment,” says Gary Kohlnhofer, 3DT’s sales engineer. “But as more and more label converters are getting into printing film-based materials such as polyethylene and polypropylene, there is a need for inline corona treatment.”
Because of low surface energy, Kohlnhofer says film-based labelstock often needs retreatment, especially with some of the water-based and UV cured inks that are being used in the printing process. “Inline corona treatment can also provide a level of insurance and allow converters more flexibility with regard to sourcing their filmstock,” he says, adding that another use of corona treatment is in the coating process that is being done after the labels are printed with digital inks.
3DT’s most popular system for the label industry is its CLNE narrow web treating system with compact station and Softal 9000 series generators. These systems are provided in standard treatment widths of 260, 360 and 460mm with other widths also available upon request. The treating stations feature a very compact design and are built for easy installation into the printing presses. On the 9000 series, the generator is mounted behind the press and out of the way. All cables are included and the system is controlled through a digital operator panel that is mounted on the operator side of the press. “This allows for complete operation of the corona treating system from a convenient operator location,” Kohlnhofer says. “As this system is software based, it is very easy to operate and change configurations based on plant location and language used. All systems are supplied with CE certification.”
Softal CLNE systems are supplied with the electrodes mounted in a removeable cartridge system for removing the electrode assembly for cleaning. This allows for easy cleaning of the electrode assemblies and less downtime of the press. - www.3DTLLC.com
Vetaphone
The Danish company Vetaphone was founded by Verner Eisby, who in 1951 invented the corona treating process. According to CFO Jan Eisby, “In more recent times, our EASI-plasma technology has extended our capability wherever high-quality surface treatment is required.”
The new Vetaphone VE1A model is designed for the specific needs of the narrow web printing press, with its compact and user-friendly design and output of up to 6 kW. All stations are equipped with four to six ceramic electrodes for treating conductive and non-conductive substrates. The patented Quick Change electrode system on Vetaphone treaters enables simple thread up of the material, easy cleaning, and changing of the complete set of electrodes in seconds. This provides a boost to productivity and a significant reduction in maintenance costs.
Eisby says the combination of quality, low price and reliability of Vetaphone equipment has made it a trusted OEM supplier to manufacturers of narrow web technology, including Mark Andy, for whom John Howard, director of product Development, stated recently: “Vetaphone equipment is universally acknowledged as top quality, and I am more than happy to have it fitted to any Mark Andy press.” - www.vetaphone.com
“A corona treater is basically a capacitor with an electrode – either ceramic or metallic – discharging voltage into the air directly above the film which is running over a covered roll,” explains Fred Paonessa, sales and marketing Manager for Impreglon Cellramic. “The cover material is non-conductive and serves to ground the metallic roll. Different cover materials are used from rubber, epoxy and ceramic.”
Ceramic thermal-sprayed applied coatings are the most durable of these materials due to their high hardness of 62-65 Rc and dielectric strength of 500 v/mil. These attributes make ceramic covers more wear resistant to scratches and abrasion due to the high hardness, Paonessa says. “It also will not break down as quickly as the epoxy or rubber due to the high dielectric strength. Also, if a pinhole does occur, it can be effectively patched in the field unlike the other materials. The most common ceramic materials used are pure aluminum oxide and aluminum oxide with titanium dioxide,” he says.
Impreglon Ceramic has developed its P-Series coating, P-10 and P-11, for corona treater rolls. These aluminum oxide-based coatings have very low porosity, 2-3%, which is sealed with the company’s proprietary sealer, ensuring the coating is pinhole free. Impreglon tests for pinholes as the last step of the process. “Our P-Series coatings have successfully tested by major OEM’s. These coatings add to Impreglon’s anilox roll services which include manufacturing and resurfacing of anilox rolls as well as provide traction and release coatings for idler rolls.”
The complex definition of Corona treatment could come straight out of a textbook: All materials have an inherent surface energy, and corona treatment is a technique used to modify the surface energy by using a low temperature corona discharge plasma to impart changes in the properties of a surface. A corona discharge is an electrical discharge brought on by the ionization of a fluid surrounding a conductor that is electrically charged. Surface treatment systems are available for virtually any surface format including sheets and roll goods that are handled in a web format.
In layman’s terms, “Corona treaters increase the surface energy of labelstock to improve wettability and adhesion of inks, coatings and adhesives,” explains Mark Plantier, vice president of marketing for Enercon Industries. “Generally speaking, polymer and foil labelstock have chemically inert and non-porous surfaces with low surface energy, causing them to be non-receptive to bonding with printing inks. While ink formulations may be optimized for specific applications, labelstock surface energy plays a key role in ensuring proper adhesion. Adhesion is also inhibited by surface contaminants and film additives which migrate to the film surface.”
Within the label converting industry, there are suppliers dedicated to the manufacture of corona treaters designed specifically for narrow web applications. What follows are corona treatment explanations and product descriptions from the experts themselves.
Enercon Industries
According to Plantier, labelstock that is corona-treated inline prior to printing, demonstrates improved print quality, while enabling faster press speeds and reducing scrap.
The development of highly engineered polymer materials for labelstock has increased the need for corona treating, Plantier says. “These materials provide labels with a unique set of performance features, but have also increased the challenge of getting inks to properly adhere. The development of these materials and the printing technologies used in the narrow web market have also enabled many label converters to enter the flexible packaging market. Many printing operations are now printing on a wider variety of materials, and corona treating inline provides them with greater capacity for printing success.
“Successful label converters know that minimizing printing variables leads to higher productivity and profits. Corona treaters provide high value for both flexographic and digital printing operations as they eliminate the variable of labelstock surface energy. And since corona treaters are inexpensive, simple to integrate and easy to operate, they provide an excellent return on their investment,” Plantier says.
Enercon’s newest innovation is the CoronaFlex corona treater, specifically designed for the narrow web converting industry. The design fits universally with all flexographic and digital printing presses. The system’s deluxe model features an intuitive touch screen control panel that guides users through operation and power settings. Integrated with this system is Enercon’s Watt Density control feature, which ensures consistent treatment by automatically adjusting the power level in accordance with changes in line speed.
Explains Plantier, “CoronaFlex is a breakthrough system architecture which allows more features to be provided to users at a lower cost than ever before possible. With the touch screen interface, Enercon is trying to take some of the mystery away from the corona treating process for operators.”
Within the CoronaFlex operating system is the ability to collect detailed system diagnostics and fault logs, and there is basic troubleshooting information incorporated as well. “We find that there are too many narrow web operations that have failed to properly train their operators to have an understanding of the basics of corona treating,” he says, adding that Enercon hosts numerous online webinars and provides technical papers to customers at no additional charge.
www.enerconind.com
QC Electronics
“The corona treating process is critical to successful label manufacturing,” states Ken Klein, president and CEO of QC Electronics. “The corona field provides a means of cleaning the surface, but, more importantly, it increases the surface energy. Increased surface energy makes film more compatible with inks; therefore increasing the wet-out and bonding of ink and topcoats.”
Klein points out that with label presses running faster and faster, it is important that the corona treater be capable of producing watt densities that keep up with these increased line speeds. “As I talk with label makers, they tell me they are looking for high power treaters that are compact and reasonably priced,” he says. “QC has answered this request with our new 4E narrow web corona treater. The 4E treater provides high watt densities at fast line speeds, ensuring reliable surface tensions and good ink bonding.”
The 4E treater is prewired for quick and easy installation. “It simply mounts onto the press and is ready to produce high definition corona,” explains Klein. “Having the 4E installed on press ensures that the surface energy of the film is adequate for good ink wet-out and good bonding, resulting in high quality labels. Owners of the 4E treater benefit from years and years of profitable treater operation due to the 4E’s reasonable price and low maintenance requirements.” - www.qcelectronics.com
Corotec
Corotec Corporation recently introduced the latest in its new family of fixed-width bare-roll corona treatment system designs for the narrow web processor. These systems feature Corotec’s new electrode design, which the company says is capable of delivering much higher power densities to the web than competitive designs due to unique HVC cooling architecture. Systems are available in single and double-sided treating configurations and can be ordered with an integral power supply (the Corotec Uni-Dyne system configuration), or a separate power supply. Uni-Dyne configurations are available with power ratings from 500 watts to 5,000 watts, while systems with a separate power supply have no power limitation.
All systems include Corotec’s instant speed switch protection to automate treating system start-up with the machine, while reducing untreated material to an absolute minimum. All configurations can include an integral power density control system and automatic exhaust blower control. For added convenience, the systems can be supplied customized to “bolt on” to an existing press, saving installation headaches. - www.corotec.com
3DT
“Many label manufacturers have been printing for years on paper or labelstock materials which didn’t require corona treatment,” says Gary Kohlnhofer, 3DT’s sales engineer. “But as more and more label converters are getting into printing film-based materials such as polyethylene and polypropylene, there is a need for inline corona treatment.”
Because of low surface energy, Kohlnhofer says film-based labelstock often needs retreatment, especially with some of the water-based and UV cured inks that are being used in the printing process. “Inline corona treatment can also provide a level of insurance and allow converters more flexibility with regard to sourcing their filmstock,” he says, adding that another use of corona treatment is in the coating process that is being done after the labels are printed with digital inks.
3DT’s most popular system for the label industry is its CLNE narrow web treating system with compact station and Softal 9000 series generators. These systems are provided in standard treatment widths of 260, 360 and 460mm with other widths also available upon request. The treating stations feature a very compact design and are built for easy installation into the printing presses. On the 9000 series, the generator is mounted behind the press and out of the way. All cables are included and the system is controlled through a digital operator panel that is mounted on the operator side of the press. “This allows for complete operation of the corona treating system from a convenient operator location,” Kohlnhofer says. “As this system is software based, it is very easy to operate and change configurations based on plant location and language used. All systems are supplied with CE certification.”
Softal CLNE systems are supplied with the electrodes mounted in a removeable cartridge system for removing the electrode assembly for cleaning. This allows for easy cleaning of the electrode assemblies and less downtime of the press. - www.3DTLLC.com
Vetaphone
The Danish company Vetaphone was founded by Verner Eisby, who in 1951 invented the corona treating process. According to CFO Jan Eisby, “In more recent times, our EASI-plasma technology has extended our capability wherever high-quality surface treatment is required.”
The new Vetaphone VE1A model is designed for the specific needs of the narrow web printing press, with its compact and user-friendly design and output of up to 6 kW. All stations are equipped with four to six ceramic electrodes for treating conductive and non-conductive substrates. The patented Quick Change electrode system on Vetaphone treaters enables simple thread up of the material, easy cleaning, and changing of the complete set of electrodes in seconds. This provides a boost to productivity and a significant reduction in maintenance costs.
Eisby says the combination of quality, low price and reliability of Vetaphone equipment has made it a trusted OEM supplier to manufacturers of narrow web technology, including Mark Andy, for whom John Howard, director of product Development, stated recently: “Vetaphone equipment is universally acknowledged as top quality, and I am more than happy to have it fitted to any Mark Andy press.” - www.vetaphone.com
“A corona treater is basically a capacitor with an electrode – either ceramic or metallic – discharging voltage into the air directly above the film which is running over a covered roll,” explains Fred Paonessa, sales and marketing Manager for Impreglon Cellramic. “The cover material is non-conductive and serves to ground the metallic roll. Different cover materials are used from rubber, epoxy and ceramic.”
Ceramic thermal-sprayed applied coatings are the most durable of these materials due to their high hardness of 62-65 Rc and dielectric strength of 500 v/mil. These attributes make ceramic covers more wear resistant to scratches and abrasion due to the high hardness, Paonessa says. “It also will not break down as quickly as the epoxy or rubber due to the high dielectric strength. Also, if a pinhole does occur, it can be effectively patched in the field unlike the other materials. The most common ceramic materials used are pure aluminum oxide and aluminum oxide with titanium dioxide,” he says.
Impreglon Ceramic has developed its P-Series coating, P-10 and P-11, for corona treater rolls. These aluminum oxide-based coatings have very low porosity, 2-3%, which is sealed with the company’s proprietary sealer, ensuring the coating is pinhole free. Impreglon tests for pinholes as the last step of the process. “Our P-Series coatings have successfully tested by major OEM’s. These coatings add to Impreglon’s anilox roll services which include manufacturing and resurfacing of anilox rolls as well as provide traction and release coatings for idler rolls.”