Environmentally Conscious Printing Pt. 1 of 3: Inks
Businesses looking to reduce their environmental footprint can make a big difference by making educated choices when it comes to printing and packaging. Understanding the impacts of different inks, what is recycled/recyclable/
We begin by looking at inks, where the options range from eco-friendly water-based inks right through to environmentally hazardous petroleum-based inks, and many in between. There are different pros and cons to each type of ink, and we will take you through those so you can select the most environmentally friendly ink for your particular project.
The eco-friendliest inks currently on the market are water-based inks and vegetable-based inks. Also, at the fairly environmentally friendly end we have UV-curable inks and latex inks. Down the bottom of the list we have eco-solvent inks and, most harmful of all, solvent inks.
Water-based inks (or aqueous-based inks) are amongst the most environmentally friendly inks and are a great solution for food, beverage, beauty, and baby products as they are non-toxic, odourless, food-safe, and free of UV-reactive chemistries therefore guaranteeing customer safety. Due to these properties there is no requirement for an additional layer of protective material or film to prevent the ink from being transferred thus meaning that corrugated packaging printed with water-based inks can be fully recyclable. Also, at both the printing and handling level, water-based inks provide for a safer working environment by reducing the amount of harmful chemicals in the workplace. On the downside, these inks require a longer drying time than other inks, and they can only be applied to a limited range of surfaces due to the energy of the water component and the way in which it sits on top of the surface. Water based ink can also be an inferior solution when it comes to its waterproof properties and its susceptibility to fading in sunlight, however water-based pigmented inks perform better than water-based dye inks (yes there are different types of water-based inks). They also lack in the saturation and brilliance of the final printed outcome, although dye inks will outperform pigmented inks in this aspect.
Soy-based ink was developed in the 1970s in response to the oil crisis. It is made from soybean oil, which is relatively clear, delivering more vibrant colours than petroleum-based ink and was therefore used for purposes such as newspaper printing. Since then, soybean oil has been combined with oil from other plants (most notably linseed) to create what is called vegetable-based ink which is growing in popularity today due to its environmental credentials and range of other benefits. Vegetable-based ink boasts vibrant colours, a low release-rate of VOC’s (volatile organic compounds), comes from a renewable source, and is just as cost-effective as solvent inks. The low rate of VOC’s into the atmosphere (only around 2-4%) means it provides a safer workplace for those involved in the printing process as well as reducing its effect on the ecosystem. Additionally, vegetable-based ink is easier to de-ink during the recycling process meaning it creates less hazardous waste. It should be noted however that vegetable-based inks generally have a longer drying time which may add delays to a project.
UV-curable ink is water-based which means it emits low levels of VOC which are considered harmful to the environment. The point of difference with this ink is in the process, in which the ink is subjected to strong ultra-violet light immediately after printing which reduces the drying time down to seconds. Traditionally UV-curable ink was cured under mercury lamps, however LED technology has lately been replacing this and providing a less energy intensive process. LED lights offer an additional benefit in that they last 10-20 times longer, thus reducing lamp wastage due to replacements. The main advantage of UV-curable ink is that is that it can be applied to almost any material you can put through the press due to its unique process which does not require the ink to soak into the media. Additionally, it is waterproof and known to maintain its colour consistency making it especially popular for outdoor applications such as billboards. The main disadvantage of UV-curable ink is the cost and the print quality is not as good as traditional solvent and water-based inks. It can also be sometimes susceptible to cracking when applied to flexible substrates due to a high volume of ink sitting on the surface.
The latex ink process involves using print heads to distribute water-based inks onto media, however the difference is the ink also contains small particles of latex. Once applied, heat is used to evaporate the water away and melt the latex particles into the media, binding the pigments to the surface. Latex is amongst the most waterproof and colourfast solutions, and has emerged as an alternative to solvent ink (and eco-solvent ink), especially for the printing of outdoor media. It is commonly used for posters, banners, signage, vehicle wraps, and billboards. Using a water-based solution and quick drying, latex printing doesn’t produce harmful gases or odours that are damaging to the environment, and is therefore fairly environmentally friendly, although its use of energy related to the heat applied for drying is a factor that keeps it from being completely eco-friendly. The fast drying time, means quick turnarounds on projects and the printers are quite user friendly. On the downside, latex printers have parts which need replacing more often than solvent printers, and combining this with their use of energy become a couple of reasons why latex printing can often add up to being a little more expensive. However as latex printing technology becomes more established it will likely continue to replace solvent and eco-solvent inks as a solution for outdoor media with high quality image results.
SOLVENT & ECO-SOLVENT INKS
Solvent printing technology has been around for quite some time and produces high quality graphics which are durable, waterproof, sunlight resistant, and scratch resistant, making it ideal for a wide variety of applications, especially outdoor media. The shortcoming of solvent inks is the environmental impacts. The liquid involved is chemical based, derived from petroleum, which is known to release a high level of VOC’s into the air and is also non-renewable and non-biodegradable. It is also therefore unsuitable for certain destinations, such as food retailers. Another drawback is that it doesn’t dry as fast as latex or UV-curable inks, which therefore may add time to your project.
Eco-solvent ink later emerged as an answer to some of the environmentally hazardous aspects of solvent ink, whilst still producing high quality, durable, waterproof graphics. Unfortunately it is not biodegradable either, however it does provide big wins on the strong smell and harmful odours of its predecessor, making it considerably more environmentally friendly. It is still derived from petroleum though, and is by far and large the least eco-friendly ink solution of those we’ve covered excluding solvent ink.
In summary, if you require the benefits of solvent inks such as water resistance for your project, choose eco-solvent ink (or latex ink if you can) over solvent ink to reduce the harm it will cause to our eco-system. However water-based, vegetable-based or UV-curable inks are more environmental solutions if you can make them work for your particular needs.
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