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Need To Know


You may not be able to see it, but the air in the printroom is extremely important. Genevieve Lewis finds out what is better for your business – a bespoke or generic system?

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How important is humidity to the print industry?

Up in the air

Hygroscopic – this means a tendency to absorb water from the air and is a very important word in the industry.

Humidity in the printroom is just as important as the paper, ink and machinery itself. In this case, the paper is very hygroscopic, meaning that it can absorb and lose moisture if in the wrong setting. This of course, can offset some serious issues for your print job.

Dry air can cause paper curl, web breaks and static build-up. It can also mean that paper can be misfed and therefore end up creased and damaged. Tight edges can also occur as the exposed edges shrink. Paper sizes can also transform, and this would then affect how the colours line up in printing runs of two or more colour processes.

The SKR Open is an Electric Resistive humidifier, which generates steam to serve a digital print room

Humidity is also important for different areas of the industry – digital, sheetfed offset and even platemaking. Poor humidity can mean that plates attract grit and dust, which obviously creates issues further down the line. The humidity levels are also important in many industries across the country, from hospitals to museums to art galleries. It is imperative in the latter industries for preserving certain items at optimum condition.

Therefore, it is necessary that the temperature and the humidity in the printroom is correct. But how can you make sure that your factory is primed and ready for print?

Humidity Solutions is based in Leatherhead and is active in a number of sectors, including charcuterie and cheese production, pharmaceuticals and wood processing through to print and packaging. It is now in its 12th year of business, with teams including experienced engineers on hand to provide a bespoke service. This can include surveying, designing, installing and maintaining humidification and dehumidification systems across the aforementioned industries.

John Barker is the managing director of Humidity Solutions, and he explains why humidification is so important to the print industry: “Dry air in the printing industry can cause paper curl, web breaks and static build up; issues that are ever more regular in the winter months. When spooling the paper, printing presses may generate electrostatic charges, this can then mean that the pages become hard to separate.”

John Barker is the managing director of Humidity Solutions in Leatherhead

Barker also says that the optimum humidity for printing and paper stage conditions should be between 50-60% RH.

“Once the humidity solution has been applied, the separation of sheets of paper is improved, paper curl is avoided and productivity increases,” says Barker. “The machinery will be able to work at a higher speed as the feed will be more efficient as less paper will be rejected.”

The machinery will be able to work at a higher speed as the feed will be more efficient as less paper will be rejected

Bespoke vs Generic

The question on one’s mind when looking at investing is when to go bespoke, and when to choose an off-the-shelf solution. Both options have serious perks, including fitting to your own bespoke set-up or having help on call.

O Factoid: The optimum humidity for printing and paper storage conditions should be between 50-60% RH.  O

“Every print or press room is different: size, height of ceilings, number of windows, ventilation, amount of machinery and people, and – of course – budget,” says Barker, before continuing: “All these factors will influence the levels of relative humidity and therefore a system needs to be designed to suit each specific building. At Humidity Solutions, we listen to our customers’ requirements, carefully asses the conditions, and choose from a range of equipment to design the ideal solution for each project.”

Humidification is important in a number of industries, including hospitals, museums, galleries, manufacturing and of course the print industry 

So, over on the other hand, what could be the benefits of investing in a standard off-the-shelf humidity solution? Barker argues: “Whilst, as mentioned above, each system will be designed to suit the specific conditions for that building, many of our products are standard but modular so that they can be added to or adapted with minimal extra cost. Controls, water treatment and other add-ons can be applied where necessary.”

After making the decision of whether or not to invest in a bespoke or off-the-shelf solution, how will your latest investment help your business to grow and improve? “By establishing the conditions, dimensional stability of paper and other hygroscopic materials in the printroom is improved and therefore machine breaks and downtime is significantly reduced,” explains Barker. “Machinery will also be able to work at higher speeds. Not to be forgotten either is the positive effect of appropriate and stable humidity levels on the health and wellbeing of employees – thereby reducing sickness and absenteeism. All of these clearly have a significant effect on productivity.”

Electrode boiler steam humidifier installed in a digital print room

Barker also warns that humidity in the printroom is so important, that some manufacturers’ warranties on their products can become invalid if there is no control in place. This is because of the obvious detrimental effects that having the wrong humidity levels can have on equipment. “We are not the only ones stating that humidity control is essential,” explains Barker. “Warranty from leading digital print machine manufacturers is not valid if the machine is not operating in the correct environmental conditions, plus paper suppliers constantly refer us to where paper is stored in uncontrolled areas and has caused production concerns.”

He adds: “We are always happy to discuss a particular issue or project and offer a free site survey where appropriate.”

Access all areas

It’s not just the traditional litho areas of the print industry where having the correct humidity levels is of high importance. While we think of perhaps the very specific paper that is used for newspaper printing, or mesmerising we press printing in need of help with humidity, but it is all sections that require a little bit of air. Barkers says that Humidity Solutions regularly supplies to those in digital printing, wide-format and even label printing on top of the more traditional service providers.

An Airtec induct – this is an Airtec adiabatic spray humidifier in an air movement system serving a reel stand area

Barker explains: “We regularly supply to digital print, litho, gravure and web press printing, not to mention wide-format and label printing as well, so we serve all sectors of the print and packaging industries. This also serves a variety of product types such as paper, card or plastics.

“Humidity is a variable that the print sector can eliminate quickly and without incurring a great deal of cost, so payback is often short by reducing waste and speeding up production.”

As a human being, you will be well air how important air, temperature and your environment are to your wellbeing.

The wrong humidification levels can result in paper being misfed, exposed edges shrinking, which in turn affects the print run

It is the same with your printroom – while travelling in Thailand and Singapore, experiencing humidity like never before with the heat, it was hard to function. Just think of it as the same way with your printroom and how important the correct level of humidity can be – neither too little or too much. While one didn’t become crinkly and experience paper misfeeding, it was still extremely difficult to function at 100% without a break every ten minutes.

So, make sure your humidity systems are up-to-date and your printroom will be fully functioning and performing like a dream.

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