We’d like to look at ways of saving energy on the factory floor. What are the main areas we should be improving?
As a sector, the print industry is energy-intensive, so it is the responsibility of all businesses involved to examine ways that they can consider their energy usage on the factory floor – and this can also bring substantial financial savings.

A good place to start is by monitoring energy consumption, ideally at half-hourly intervals during active hours, downtime and weekends to accurately assess ‘background’ energy use. This will help you analyse data from the electrical supplier and work out ways to reduce that usage.

It is essential to ensure that time-control settings of office and factory heating are correctly set. You can use heat recovery equipment to reduce the need for heating in the first place. It is also worthwhile improving detection of compressed air leakage, for example through the loading bay or factory doors. Installing a ventilation system incorporating a heat exchanger instead of air conditioning would also consume less energy.

Installing skylights in the factory roof allows daylight in; if you also install photovoltaic cells, these can sense when daylight is sufficient to switch electric lights off. Individual fluorescent tube ‘starters’ can be replaced by a more energy-efficient central system, and new energy-efficient style tubes can be bought when old tubes need replacing.

Energy-saving advice and assessments are available from the Carbon Trust (carbontrust.co.uk), or alternatively businesses can seek advice from an independent carbon management company such
as dcarbon8.com.

Lena Johansson

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I heard recently that so-called ‘alcohol-free’ founts can actually have a lot of alcohol, or alcohol substitute, in them, which isn’t any better for the environment. Can somebody explain?
There are a lot of myths around alcohol-free founts. Let’s start by clarifying the terminology. The term ‘alcohol-free founts’ actually refers to the practice of alcohol-free or IPA-free printing, where you don’t add volatile alcohols to the fount solution. Fount solutions that are used in alcohol-free printing are known as alcohol-replacement founts and use non-volatile glycols instead of isopropanol.

Glycols are still classified as alcohols, but the big distinction is their non-volatility. IPA is so volatile that it evaporates into the atmosphere very quickly, which makes the workplace unpleasant, but also adds to problems in the wider environment. IPA is also an inefficient chemical as although you dose the fount solution at between 5-20%, by the time it gets to the plate already quite a bit has been lost to evaporation. Non-volatile glycols remain more active for longer.

Glycols are biodegradable and are not considered to be environmental pollutants, although you still can’t dispose of an alcohol-replacement fount solution to drain because once it’s used on press it will contain other chemicals. The big benefit, other than the environmental one, is that replacing IPA brings down the hassle and the insurance premiums of handling fount solutions that contain it.

However, it’s worth bearing in mind that IPA is very good at what it does, and glycols are not so good – it’s important to choose a package of fount solution and ink that works well together so you get the ink/water balance correct.

Paul Hayden

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How would humidity control help our factory environment? What’s the typical ROI? Can it save us money?
Constant, optimum air humidity is one of the most important climatic parameters for print quality and trouble-free production.

A variety of systems and technologies are available and each has its pros and cons. It’s important to factor in costs for replacement and maintenance, additional costs for cleaning and sterilising these systems in order to reduce hygienic problems and health hazards for employees, as well as the energy costs needed to achieve optimal humidity levels.

High-pressure nozzle systems are rated among the best humidification technologies on the market, where water is atomised using a high-pulsation pressure. Such systems give superior power consumption, maintenance outlay and humidification performance; if they are properly designed and operated in tandem with a water treatment system, they will operate hygienically, silently, with no maintenance and savings on energy.

High-pressure nozzle systems are differentiated by nozzle size, humidity, distribution and versatility. Systems with extremely fine nozzles prevent droplet formation and humidity condensation. Systems with fans achieve maximum and speedy distribution of humidity. And due to the natural principle of evaporation and cooling, printers who install a humidification system can also make significant savings in energy costs by running their air conditioning on a lower setting in the summer.

Return on investment is difficult to quantify; a humidification system doesn’t contribute to the bottom line directly, but can rectify problems such as paper curl that can lead to downtime on the press or finishing equipment, or to problems with colour shift or misregister, as the paper size changes fractionally on its way through the press.

Low-humidity environments also generate much more static: in a properly humidified environment, the natural build-up of static is earthed through moisture droplets in the air. Static causes runnability problems on machinery too. Some printers eliminate this by aerating sheet stacks; if a humidification system is in place, it may not be necessary to do this, in which case a humidification system may pay for itself faster in terms of improved productivity, reduced manpower and reduced turnaround time.

John Barker