When it rains it pours … and corrugated leaks. The importance of anilox dead bands and good quality chamber end seals that tweak the leaks cannot be overemphasised. For those willing to recognise that pound foolish waits at the end of penny wise, they can mean reduced ink waste and improved press efficiencies.
In recent times, we’ve noted some unfortunate on-press problems, which we identified as the result of short-term cost cutting without long-term focus. Decent savings were achieved, but big spending may be just around the corner.
Sure, cheaper foam-end seals save money initially, but ink is far more expensive and chamber leaks can cost dearly. Technical performance requirements are often overlooked, but not all seals are created equal.
All the ink chamber leaks we observed shared a cause – cheaper-end seals, which appear to do the trick until they don’t, after which deficiencies in quality, tolerances and design manifest in the drip, drip, drip of valuable and expensive ink.
In almost all cases where our recommendations were accepted to switch to the correct seal and go for pre-soaked chamber felt seals or rubber seals, ink wastage dropped and anilox wear was lowered and correct pressure settings from blade to anilox were also achieved reducing anilox wear and tear, which in the long term yields improved anilox and doctor blade lifespans.
A good soak to ease the pressure
The focus should always be on the quality of the anilox, ink and ink seal. Pre-soaking is important for adequate lubrication between the seal and the anilox surface, which ensures that ink doesn’t leak from the chambers and operators don’t have to over-pressure to compensate for a poor seal. The savings are impressive.
Rubber and felt-end seals (as seen in the picture below) are oversized for a snug fit and pre-soaked in petroleum (for felt only) to reduce friction and prevent build-up. Felt-end seals are compatible with all ink and coating types, provide a tighter seal and typically last longer than rubber and foam seals. Keeping felt seals lubricated with seal grease is key to their superior performance and longer life.
Also helpful in extending seal life are anilox dead bands. For many years, CAE has produced these unengraved ceramic bands to reduce ink spitting and ensure sound seal between the anilox and the ink chamber seal. They not only stop ink leaks, but eliminate over-pressure caused by leaks.
More cells by the centimetre
Over recent years, we have also refined our eCell anilox transfer cell technology with local and international customers to bridge the gap between production considerations of modern plate trends and technology, and brand owner requirements for sharp, clean graphics. Many brand owners opt for recycled liners but still want high-quality graphics and good coverage of their spots.
eCell transfer anilox technology can print higher screen tonal ranges due to its elongated cell shape. This allows more cells per centimeter, thus higher anilox screen counts. This is better for plates and offers smooth print coverage not seen when using conventional 60° ycell- or yhex-type cell geometry.
The image below of a corrugated print sample, created in a production environment, shows how eCell holds perfect dot reproduction – in this case to the required 5% minimum dot (smallest dots on this cliché/plate) – and produces perfect print coverage due to the eCell’s advanced transfer properties and low cell turbulence. This satisfies not only production and marketing but is music to the finance team’s ears as advanced transfer properties extend ink millage.
CAE has completed many banded anilox trials with every type of plate and dot-processing technology, producing excellent results globally within the corrugated industry. We can streamline anilox specifications not only for press and ink, but for various liners, because eCell produces equally high-quality results on recycled and virgin white liners, while offering the on-press flexibility the market seeks.
Through our focus on the corrugated market, we’ve grown locally and export to many corrugated OEMs and end users around the world. We believe that shared knowledge is power; hope you can benefit from our experiences and consider them when the ink well is empty.
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