The negative impact of plastics is manifold. Most frequently discussed is the issue of landfill; where cellulose products break down in a matter of months, plastics can take more than 400 years. But plastics can cause all manner of havoc other than by sticking around for a long time. Plastic buried deep in landfill can leach harmful chemicals into groundwater. And, crucially, the raw material of many plastics currently is oil, an unsustainable and fast diminishing resource.

These are all issues the popular imagination – unsettled by oft-reproduced images of plastic waste in, often sprawling third world, landfills – is more than familiar with in relation to plastic bags and packaging. In fact plastic packaging has done much to clean up its act over the past couple of decades, with increasingly stringent legislation to dictate what sorts of plastics can and can’t be used for what.

“If you go to buy something from a supermarket that’s plastic-based and has a plastic label, so cosmetics, etc, you’d be really hard pushed to find a vinyl. Typically it’ll be polyester, specifically PET,” says Andy Voss, managing director at Lintec Graphic Films. He explains that while polyester plastics are still oil-based, they don’t feature the same kinds of contaminates as those in the vinyl family of plastics, including PVC (polyvinyl chloride), and tend to be much more easily recyclable.  

And yet the same move from PVC to polyester hasn’t happened in the graphic arts market at large. The majority of wide-format and credit and loyalty cards are still made from this potentially more toxic material. 

The reason is the much lower visibility, to the average consumer, of these products’ disposal, explains sustainable material consultant Steve Lister. With an absence of legislative pressure responding to this, price has remained king. And for decades no other plastic has been able to touch PVC on this front, he explains.

“Packaging has a visible impact – when you go into a store, what do you leave with and then throw away?” says Lister. “People are bothered by things like shoeboxes, but how many people think about the sign hanging above the shoes, the acrylic display stand or the retailer’s tag?”

Out of favour

Admittedly, this lack of consumer and legislative pressure is partly down to these print items not being produced in the same volumes as plastic packaging and labels. But the print industry’s overwhelming predilection for PVC for many of the non-label plastic substrates it prints on, sits increasingly at odds, many feel, with the growing availability of greener alternatives.

“I work with the design team of a major retailer and I recently got around 50 products out and they said ‘we’ve never seen these’. When I spoke to their printer they said ‘you know, we just stick to what we already do’,” reports Lister. “I think the problem we’ve got is people make lazy decisions; they think ‘I’ve always printed on this product, it’s always worked, I’m going to stick with it’.”

He adds that many won’t be aware of the possibilities themselves: “There’s a huge education gap of what people should and shouldn’t be printing on in our industry,” he says.

So what plastic substrates should printers be getting more clued up about? A word springing to more environmentally aware minds will be ‘bioplastics’.

The term has cropped up in the mass media with fair regularity over the past few years, with reports on work to develop plastics from plant cell walls, and even potatoes, and reports on edible ‘blob’ water bottles, piquing curiosity.

The idea is to produce plastics that use as their base much more sustainable and degradable raw materials, such as corn or sugar, or even bacteria or methane. 

Certainly there is plenty of activity going on here in the graphic arts arena. 3A Composite’s recent launch of a Smart-X natura display board made of sugar-based PLA for example. Amari Plastics is in the process of releasing a similar PLA-based product, which it reports will be only 15%-20% more expensive than equivalent non-biodegradable substrates. 

But the fact that this higher cost is something of a selling point illustrates the key obstacle to uptake: most bioplastic substrates are, for most customers, still prohibitively expensive. 

“Corn-based products tend to cost double or more at the moment,” reports Lintec’s Voss. “The trouble is the market is extremely limited; there aren’t many suppliers and there’s not much demand so it ends up being an expensive product.”

This means that bioplastics have yet to make significant inroads into even the packaging and labels market. “Even if you look at labels, it’s not even 0.1% of those products,” says Voss. “You’ll get certain retailers, like the Body Shop, that are really hot on that, but they’re the exceptions.”

There are also question marks surrounding the functionality of bioplastics currently. “Often biodegradable products haven’t been developed enough to do the job as well as standard products. I’m just not sure they’re quite there yet,” says Steve Buffoni, group director of operations at specialist plastic printer Ryedale Group.

It’s generally accepted that the most viable alternatives to vinyls currently are polyesters, polypropylenes and polystyrenes, the materials that most packaging and plastic labelling has now switched to. These are again more expensive than PVC. But at on average around 30% more expensive, it is a price brands are increasingly willing to pay. 

“When we set out our stall five or six years ago we decided we wouldn’t produce any PVC products for the window graphics market because we were getting more requests, from the likes of H&M, John Lewis, Waitrose and banks, for non-PVC graphics,” says Voss, adding: “Year on year there are more retailers asking for this.”

Topping the list of non-vinyl plastics on a recyclability front is polypropylene, reports Lister. “Polypropylene is 100% recyclable back into itself and it never loses its properties, whereas PVC loses about 80% of its strength even the first time its recycled, so you have to add more plasticisers to reinvigorate it into being a new plastic,” he says, reporting that PET and HDPE come a close second from a closed-loop perspective.

Polyester and polypropylene can also be incinerated to produce energy without giving off the toxic fumes associated with burning vinyls. And both materials also boast many useful properties that most bioplastics currently don’t, including durability and good transparency.

Material gains

There are plenty who would argue, however, that it’s only a matter of time before bioplastics catch up. “There are now more companies creating more durable fibre-based products that can mimic plastic. So there are companies now doing waterproof cardboard,” reports Lister.

Voss reports that several are also currently experimenting with coatings to counteract potential drawbacks with durability and control of degrading timescales. “With varnishes – either on press or liquid laminate – you can potentially delay degrading. The chemistry’s not quite there yet, but you can see the potential of using the chemistry of inks,” he says.

And as bioplastics become more viable and more people start ordering them, economies of scale mean the prices will start to come down.

But there are still those who would argue that, even so, highly recyclable and already recycled polyesters, polypropylenes and polystyrenes are still best. The raw materials used for bioplastics are not completely controversy-free, points out Neville, taking over land that could perhaps be better used for food production. He points out that many plastics are made from the by-products of other oil uses such as heating and fuel, and feels that encouraging a throwaway culture by promoting biodegradability could be the wrong way to go.

Lister agrees that as long as they’ve been made where possible from recycled material and are recyclable, oil-based plastics shouldn’t be overly demonised. He points out that much waste recyclable plastic will today make it to a recycling plant.

“Plastic recycling is actually pretty good,” he says. “The old adage of ‘it’s in a skip, it’s going to landfill’, I don’t believe anymore. Because in a waste sorting centre the machines are intelligent enough to be able to sort different plastics.” 

In light of this, Lister adds that for him the rule of thumb should always be: “you’ve just got to find the right material for the right application and recycle responsibly”.

He and Voss explain that in some situations, use of less environmentally friendly plastics, such as PVC, will still be necessary, and printers shouldn’t be afraid of this. “The main advantage of PVC is its flexibility. Polyester will go in one direction but it’s not stretchy,” says Voss, adding that print processes such as eco-solvent don’t print well on non-PVC plastics.

“We still use flexible PVC for a number of customers who weld parts together, so for products like Oyster card holders, that sort of thing,” adds Buffoni. “There’s a groundswell against PVC, but I’m not sure there’s a product that does that as well.”

Printers’ approach to greener plastics has, then, to be pragmatic. It will also depend ultimately on what the customer wants. And yet plenty of buyers are apparently eager for their printers to influence and inform what they want by showing them a greener way when it comes to wide-format and other plastic substrates. 

Certainly greener plastics isn’t a straight- forward area, with raw material, biodegradability and recyclability all complex issues to take into account. But, with a bit of extra knowledge, printers could be helping to boost the environmental reputation of graphics arts in line with packaging and labels. And, crucially, improving their own green credentials too.