Ink has three basic components: varnish, oil, and pigment. Most people believe ink to be a pigment, but pigment often accounts for only 20% of its volume.
What’s the environmental impact of ink?
The type of ink used to print on packaging will ultimately impact the biodegradability, compostability, and recyclability of the packaging. There’s two key things to consider when assessing the environmental impact of packaging ink:
- The sustainability of the ink printing process
- The impact of the ink – and the packaging it’s printed on – at the end of it’s life
Of the 78 million tonnes of plastic packaging we produce each year – 14% is recovered for recycling, 14% incinerated, 40% goes into landfill, and 32% leaks into the wider economy. 100% of this packaging will contain ink and if this ink isn’t biodegradable, compostable, or recyclable – the environmental footprint of the packaging will inevitably be greater. Most non-eco inks have toxic elements that cause further harm to the environment, and human health too. Oils often contain minerals, whilst the pigments often contain heavy metals like lead, mercury or cadmium – meaning when the paper is left to biodegrade in the soil, they pollute the soil and its wider ecosystem.
Most widely used inks are now VOC-free. VOCs, or Volatile Organic Compounds, are a by-product of traditional inks and a potential hazard for the environment and human health.Thought not all VOCs have detrimental health effects, particularly not in small doses, many are carcinogenic and pose possible damage to the central nervous system. In terms of environmental damage, they react with nitrogen oxides to produce ozone pollution, the nation’s most widespread outdoor pollutant.
But it’s not all doom and gloom! Governments are now adopting environmental regulations which specifically address the content of ink, like the European Union’s EN 134323 standard on packaging compostability. The elimination of these heavy metals is now compulsory in many markets – though not yet in packaging heavyweight’s like China.
What are the alternatives?
These inks contain oils that are based on naturally biodegradable vegetables oils such as soya or rapeseed. There’s a misconception that environmental alternatives such as biodegradable inks are more expensive. In fact, many biodegradable alternatives are more cost effective as they flow and spread more efficiently than conventional ink, ultimately reducing the amount of ink needed in the printing process. Biodegradable inks often produce more satisfying, vivid colours; and, as they’re not mineral based, they don’t have that off-putting smell most traditional inks have.
EnNatura recently developed a completely biodegradable ink called ClimaPrint using a solvent based on vegetable oil and castor oil. Central to the appeal of this ink is that the main resin is solvent-free, so that it can be washed off printing plates using a non-toxic solution, eliminating the need for chemicals in the printing process.
But even soy-based inks are not without their environmental impact. Some have been criticised for changing the agriculture in the developing countries their crop is cultivated in, directing local ambitions away from food and leading to forestry-clearance for cash-crops.
Water-based inks are often called flexographic inks as they are printed by a flexographic printing press – essentially a modern letterpress. Water-based inks include a biodegradable polymer called PHA, and all but eliminate the use of petroleum-based solvents, which increase VOC-emission.
Any ink that removes petroleum from the printing process is an improvement not just environmentally but also economically, as many markets now incur costly abatement programmes on the use of petroleum. There is, though, some contention to the summarised costs of water-based inks, as they require more energy to dry – resulting in a possibly higher carbon footprint than some of its alternatives.
UV and EB curable inks
Inks which are UV and EB curable (EB stands for electronic beam) are printed by polymerisation upon exposure. Meaning they have no solvents and emit no VOCs. The latest UV lamps provide fantastic energy efficiency, reducing energy consumption by as much as 50% without sacrificing speed. Plus, as UV inks do not dry on the plate, they’re cleaner and require less wastage.
EB printing processes can only cure solvent-free inks, and their technological complexity can sometimes be restrictive – so their cost is relatively high. However, EB costs are reducing due to their environmentally positive impact and overall lower energy consumption compared to UV and traditional thermal curing systems.
Other alternative inks
Ever heard of algae ink? Algae ink is one of the more niche alternatives to veg or water-based inks (which are still not 100% renewable or harmless to the environment). LivingInk are a bioresearch company that produce Algae ink. They grow algae on a large scale, then purify the pigment so it can be used in the packaging industry and domestically for printer ink.
Where to now?
As public awareness grows and more of a spotlight is put on sustainability it’s become essential packaging inks are in line with your environmental goals. The eco-friendly ink market is growing 4.5% each year – so the future is looking bright for those choosing eco-friendly packaging solutions for their supply chain.
Yet, as with most aspects of the supply chain, there is no one-size-fits-all solution. All inks have some drawbacks. And at the moment, sourcing eco-friendly components to your packaging like inks, glues etc can be a fragmented process. We need greater communication within industries, and across projects to bring cohesion to the supply chain process for businesses with the right intentions.