How Bobst and partners are pioneering high-barrier mono-materials laminates as environmentally friendly alternatives to traditional plastic
There is perhaps nothing which defines our consumer-driven society of recent decades better than plastic.
Its staggering growth since the 1950s has been driven largely by our industry, which recognises its versatility, durability and impermeability. But these very same qualities are what makes it non-biodegradable and difficult to recyle – in other words, environmentally unfriendly.
Reports and projections of environmental damage have changed attitudes. No longer are sustainable alternatives an aspiration – they are a necessity. Accordingly, many major brands have set their suppliers the challenge of producing 100% reusable, recyclable or compostable packaging by 2025.
“The shift in mindset over the last two years has been huge,” says Eric Pavone, Business Development Director, BU Web-fed at Bobst.
“The sense of urgency, the political will, the resources are all now in place. The packaging industry is at the forefront of making alternatives a reality, and the progress in innovation in a short space of time has been extraordinary.”
Finding alternatives to plastic is difficult, particularly for food packaging, for which high-barrier protection against oxygen and water is a must. Any alternative needs to have similar properties, at a similar price while remaining visually pleasing. Part of the challenge can be found in the variability of flexible plastic packaging – stand-up pouches, sachets, films, bags, liners, wraps and so on – which generally consist of several layers of different types of plastics.
“Plastic is not one single material – it comes in many varieties, and most flexible packaging is a combination of these,” says Mr Pavone. “When we talk about replacing plastic, we are actually talking about replacing a wide range of laminate materials, all with different benefits for different types of packaging. Finding high-barrier alternatives with only one polymer is not easy, but we believe we are making a breakthrough.”
A watershed moment for our oceans?
Because it is the combination of various polymers that makes recycling plastics so difficult, the ultimate aim is to create functional mono-polymer materials. But mono-polymers traditionally don’t perform to the level of multi-polymer materials, and even if serviceable mono-polymers are found, they need to be produced with the same machine efficiency throughout the whole value chain of packaging.
At the K 2019 trade show, Bobst and partners presented what they believed to be a watershed moment – new high-barrier mono-material laminate solutions designed for recyclability.
The project involved using different high-barrier mono-material structures, each thoroughly tested to guarantee all industry requirements were met. The different types of mono-material standup pouches on show – machine direction-oriented (MDO) polyethylene, biaxially oriented polyethylene (BOPE), biaxially oriented polypropylene (BOPP) and cast polypropylene (CPP) – were the outcome of considerable investment and intense research.
“The feedback at K was phenomenal,” says Mr Pavone. “Sustainability is such a clear focus for so many companies, now that we are starting to demonstrate tangible solutions, the excitement is really growing.”
A partnership bringing real progress
The development came about thanks to an industry partnership of some of the leading innovators in the field. Bobst provided the use of its Competence Centres for high-barrier, printing and lamination to test the viability of the new materials.
Other partners in the project include Dow, a PE resin supplier for the first step in the production chain, Brückner Maschinenbau for the production of the biaxial stretched polypropylene and polyolefin-based films, Hosokawa Alpine for the production of MDO linear density polyethylene (LDPE), ELBA to convert the finished reels into pouches, and Constantia Flexibles to produce metallised high barrier LDPE standup pouches.
As well as its Competence Centers, Bobst brings expertise in metallisation and clear coating technology, and has pioneered improvements in metallisation and clear coating technology to allow mono polymer materials to be processed.
“We have a huge amount of expertise to contribute to this enterprise, but we wanted to establish partnerships because it makes sense to pool our engineering know-how” says Mr Pavone. “By bringing the best minds together, we are making real progress – fast. Now we want to take these materials to the next level and start producing them on a more industrial scale.”
Are we on track for 100% reusable, recyclable or compostable packaging by 2025?
“At Interpack and Drupa this year, Bobst and its partners will announce exciting next stages, including full high-barrier PLA and paper packaging structures, moving us one step closer to our goal,” says Mr Pavone.
Polypropylene (PP) high-barrier mono-material laminates are now available worldwide. LDPE, MDO and BOPE have greater recyclability potential but still require major research and investment to convert into industrial-scale operational solutions. But the feeling in the industry is positive.
“We are on the right path to developing reusable, recyclable biofilm or paper alternatives on an industrial scale in the next few years,” says Mr Pavone. “Even just a few years ago this would have been almost unimaginable, but Bobst and its partners are making it a reality. We are confident the work we are doing will ultimately have a tremendously positive impact on the industry and the environment.”