Treaters review

Self cleaning electrodes raise productivity
Corona Supplies, the UK manufacturer of corona systems and distributor of the Sherman brand of treaters, offers a system to avoid contamination build-up within the discharge treater. The RAF Reverse Air Flow corona system, working on many lamination lines in Europe, is said to have “clearly demonstrated” increased performance and reliability.

The RAF system provides filtered and conditioned air directly into the corona discharge face, said to result in a more uniform corona, improved treat levels, and self cleaning for the discharge electrodes, whether ceramic or metal electrodes are fitted. The corona produced ozone is then extracted from the hood compartment surrounding the electrode assemblies.

This system avoids contamination build-up directly on the electrode, as with more conventional stations where only ozone extraction is fitted, avoiding frequent electrode failure and system shutdowns, the company states. If high atmospheric moisture is present, an in-line air-duct heater can be fitted to ensure all dampness is removed before corona is switched on.

Pneumatic opening of the two halves of the treater station provides access for web threading, and pneumatic actuation of the electrode bridges ensures electrode removal during passage of substrate splice/join. Hinged access doors also provide access for electrode gap adjustment.

All done in a day
At relatively short notice, The Schleising Consultancy was required to provide a hire treater for Taylor McIntosh, a UK company specializing in technology transfer and innovation. This project required corona discharge treatment to be carried out in developing a method of modifying products for preserving the integrity of wines and extending their shelf life.

Schleising provided a treater, specially adapted to deal with the 50mm wide substrates, to Protos Packaging, Gloucester. The equipment was set up on a line specifically dedicated for the day, in preparation for a series of material treatments. A representative from the consultancy attended throughout the day to monitor the performance of the equipment and make any necessary adjustments, while Protos staff ran the line, following instructions from Taylor McIntosh. On completion of the trials the equipment was dismantled and removed by Schleising.

“This is an example of our ability to respond quickly to a particular need with the minimum interference with production, says Eddie Schleising. “In this case, three companies were involved in combining their diversified expertise to complete a whole series of tests, with equipment being installed and removed within the one day.”

Protos managing director Phil Fussell adds: “Printing a 50mm wide film through a flexo press proved to be quite demanding, however during the one-day trial we were able to come to terms with several pitfalls that might have occurred when we get down to running production volumes”.

Segments solve problems

New segmented electrodes from Enercon are claimed to eliminate the three main drawbacks in corona treatment of blown film: segments binding on each other and sticking together; treatment 'lines' on the film surface; and segments becoming loose and falling down, causing treatment where it is not needed or wanted.

The electrodes are made from stainless steel using a new casting process said to produce a uniform and repeatable size. The faces between the segments are designed to remove the possibility of them sticking together. They have also been 'tilted over' to prevent lines in the treatment from forming.

Briefly...
Corotec has introduced a combination roll-to-roll and sheet-fed corona treating system with integral HFT-Series power supply, power density control, and adjustable speed control, all pre-wired and mounted to a portable frame. The self contained system is designed to process a wide variety of materials in either sheet-fed or roll-to-roll format.

Vetaphone now applies an easy clean coating to the components on its corona stations for the label and narrow web market. The company offers a range of compact stations for single or double-sided treatment of web widths up to 560mm. All have the patented Quick-Change electrode system as standard.

Pilar and Simco, both divisions of ITW, have teamed up to offer a narrow web corona treater/web cleaner combination. Available in contact and non contact configurations, it is prewired, ready to plug in and run.

A new corona treatment system from Ferrarini & Benelli features interchangeabl electrode groups, for processing all types of materials with the best results. It can be equipped with aluminium and with ceramic electrodes, as required.