In European flexo printing companies, conductive sleeves and adapters are primarily used when solvent-based inks are utilised, and there are good reasons for this: Conductive sleeves conduct electrostatic charges, which can occur in the printing area and go into the grounded printing press. These electrostatic charges can happen when the anilox rollers are shut down. If solvent-based inks are used with a flash point below 55°C, highly flammable vapours can arise, which can result in an exhaust ignition within the printing unit.
Therefore, measures must be taken against the danger of fire and explosions, which call for special requirements. Besides grounding of all conductive parts of the printing press, this applies also for the sleeves and adapters. As per EU Directive No. 94/9/EG (also known as ATEX 95) different parts of the printing press, and especially the printing unit, are classified as areas with potential explosion danger of zone 1, as the risk of an explosive atmosphere through gases or vapours cannot be ruled out.
In Germany, there exists a clear directive of the “Berufsgenossenschaft ETEM” (Printing and Converting Insurance Association), which was issued 10 years ago; it explains the correct handling with sleeves and solvent-based inks in flexo printing (BG-leaflet No. 453). This directive regulates that only sleeves with an electrical leakage resistance on the surface of less than 106 ohm are allowed. In general, safety at work and plant safety are matters of high importance. This subject was implemented with the European level via directive no. 94/9/EG and firmly anchored in more and more countries.
For ten years, the Omega Surface Technology for rotec® Sleeves and Adapters has been on the market. Introduced for the first time at drupa 2004 in Duesseldorf, this technology still sets the benchmark in electrostatic conductivity. The complete rotec® Sleeve contributes to the conductivity. Different to many products on the market, with the rotec® Omega Surface Technology, the sleeve surface as well as the complete glass-fibre reinforced base sleeve are produced in a conductive version. Thus the electrostatic charge can be conducted from the outside to the complete inner surface and thereby permanently ground the machine.
“This special construction enables absolute reliability and consistent electrostatic conductivity to the printer. The full-surface conductivity provides huge advantages compared with selective conductivity. An isolating impact due to contamination or abrasion of the conductivity spots will be prevented”, explains Nico Jasper, Product Manager rotec® Sleeves & Adapters. The rotec® Omega Surface Technology was recently certified by the DEKRA (organisation for technical product testing and certification), and it shows high performance and meets all requirements concerning the ATEX 95. If handled correctly, Flint Group Flexographic Products assures the electrostatic conductivity for ten years.
Nico Jasper points out: “A non-compliance with the directive due to use of non-conductive (isolating) sleeves and adapters could have far-reaching consequences in the event of a claim – from health risks over missing insurance coverage to the point of loosing warranty of machine components.” With rotec® Sleeves and Adapters, which are manufactured with the Omega Surface Technology, Flint Group Flexographic Products significantly contributes to safety in the printing process.
Source: Flint Group