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Stable humidity improves productivity

27 January 2021

When digital and screen print company VGL needed stable relative humidity levels in order for its machinery to run optimally and ensure stock was maintained in the the best possible condition, it turned to Humidity Solutions for the answer

READING-BASED VGL – Vinyl Graphics manufactures vinyl graphics, from vehicle or building wraps to branded pop up stands. The company's warehouse facility occupies approximately 15000m³, with several printing machines within it generating considerable heat. The building has three large roller shutter doors that are often open, allowing outside temperature and humidity levels into the factory. VGL knew that stable conditions of 55%-65% relative humidity were required within the space to eliminate static and paper curl while also providing dust suppression of any airborne particles.

Relative humidity needs to be maintained at between 55-65% rH for machines to run at optimum efficiency and also ensure stock is maintained in best condition whilst ensuring dimensional stability required for high quality finishing. However, having monitored and collected over a month’s worth of data, they could see that levels varied considerably over the period, and had only reached a maximum of 50% once, hence the call to Humidity Solutions.

Due to the large factory size and the fresh volumes coming into the environment, a system with good capacity and the ability to deliver the moisture over the areas of concern was needed: Humidity Solutions recommended the Airtec Hydrosens system as the most effective and appropriate solution. This system uses a high-pressure pump to run water through flexible pipework at high level out of the way of production, which branches off into sections of the production area with the water atomized through nozzles that produce a fine mist over target areas.

Tom Barker, sales executive at Humidity Solutions, commented: "This localised approach means that even when the roller doors are open the required relative humidity levels are achieved in the key areas of the production facility. A further benefit of this system is the ‘free’ cooling effect of anything up to 4–8˚C which occurs as the water is evaporated."

Low ongoing costs

Once installed, the Hydrosens system has some of the lowest ongoing costs of any alternative humidification options such as steam or compressed air systems.

As an example up to 600 litres of water can be delivered from one control panel which uses less than 1.5kw of energy whilst providing up to 410kw of cooling as a product of the adiabatic evaporation process which changes the state of the water to a gas which is the humid air. A similar steam humidifier for 600 litres/hr output would be around 500kw of electrical energy and no cooling effect.

Due to the sensitive nature of the print heads to any form of dust, a reverse osmosis plant was also included on the system to remove all the minerals from the water to prevent the minerals from precipitating out in the air after atomization of the water. Water hygiene is ensured by use of the standard water hygiene sequence included in the control panel to ensure no stagnant water in the pipes plus the use of an inline ultraviolet steriliser.

Due to the high demand for VGL's products, no factory shutdown was possible, so Humidity Solutions were happy to work with the customer to manage full installation of the system as operation continued. In fact, the on-site presence of VGL staff as a result meant that operators could quickly become familiar with the Hydrosens system, and full collaboration and training could be achieved from the outset with Humidity Solutions’ team of experienced engineers.

Issues resolved

Rupert Dadd from VGL confirmed that the new system has been ‘doing a great job’ and has resolved all the previous issues they experienced.  Productivity has improved as machines are working under optimum conditions. VGL has also taken out a Planned Maintenance contract with Humidity Solutions. This is a cost effective way of ensuring that all the equipment is maintained regularly, spares are replaced as required, reducing the need for costly emergency callouts and giving peace of mind to the production team.

The result is a trouble-free system that supports the company’s production quality and productivity, reducing downtime and allowing VGL to focus on their printing without worrying about environmental issues.