Narrow Web Corona Treaters – and the importance of correct maintenance

Vetaphone Support Technician Karsten Ahlmann Jensen gives a brief tutorial on how to look after your corona treater to ensure top performance and a long working life.

With a narrow web market share of more than 80% in the developed regions, Vetaphone is best placed to advise converters on how to make the most of their investment.  The company’s range of corona treaters for narrow web applications spans widths from 350mm to 850mm, with single- or double-sided models, and generator power ratings from 1kW to 10kW, fitted with remote control and a variety of interfaces to integrate with the existing press controls. With a small footprint, and the ability to be mounted in any position on the line, including at right-angles or inverted, Vetaphone corona treaters are universal in their application.

But, like all machinery, good and regular maintenance is the key to ensuring optimal performance and reliability, so here are a few important points that all narrow web converters need to know.

Before you start:

·Make sure the initial set-up is secure – the unit is properly located and connected, and all adjustments are made prior to operation.  Where a web cleaner is fitted, we recommend the corona treater is fitted afterwards so you are treating a cleaned web

·Each treater is connected to its generator by a thick insulated high-power cable, which prevents electrical interference.  These cables are available in various lengths to suit different installations and should not be shortened on-site.

·Before starting the corona treater, check the starting Dyne level of the substrate being used and the Dyne level required – our corona stations are adjustable to ensure the correct level of treatment

Optimising performance:

·We recommend inspecting the removable cartridge once a week and giving it a quick and simple clean if necessary.  A more thorough clean is needed once a month.  Gently use a soft cloth with a small quantity of alcohol to wipe both sides of the electrodes – if you prefer you can use soap and water but be careful to dry the electrodes completely before re-installing to avoid flashovers

·Before re-installing, ensure the wiring to the electrodes is clear of any obstruction and check the gap between the electrodes and backing roller is 1.5mm.  We provide a flexible tool for this

·If there are any burn marks, these parts cannot be cleaned and should be replaced. Likewise, damaged electrodes are cheaper to replace than repair

·The backing rollers should be inspected regularly and cleaned on the same basis and using the same method

·Always ensure the backing roller has its carbon brush attached – this will avoid corona treatment of the ball bearings and subsequent failure.

·Each corona treater is supplied with its own precision air system for cooling the electrodes and extracting the Ozone produced in the process, based on its power rating.  We advise a regular inspection to ensure efficient operation

Other facts you need to know:

·Our corona treaters are suitable for conductive and non-conductive substrates and are fitted with ceramic electrodes and stainless-steel backing rollers.  These require less maintenance because they do not corrode, which is especially important in humid production environments

·The encoders and sensors should be checked periodically but are generally low maintenance – the Operation Manual incudes advice on this

·Where moisture build-up is an issue, for example after the system has stood unused for a period such as a weekend shutdown, an air blower can be fitted to dry the electrodes prior to operation – this is usually applicable only under conditions of high humidity

·Electrodes can be disengaged but must be left in place and the power adjusted

·Typical life-expectancy of an electrode is 3-4 years and for a backing roller around 8 years – but both will last longer with regular maintenance

·You can run narrow web through a wider corona treater without problem

·You can use a small vacuum cleaner to remove the dust and compressed air to clear the filters in the cabinet

Help is always at hand:

·If something goes wrong with your corona treater, we can usually help you without the need for a technician to visit.  There is the capability of remote analysis via a laptop and in many cases, we can get you back up and running quickly.

I hope these guidelines are useful and allow you to get maximum benefit from your Vetaphone technology.  If you’d like more information, we’re always available at:

www.vetaphoneservice.com