Innovations in plastic packaging

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Barry Turner of the British Plastics Federation reviews some of the most recent developments in plastic food packaging.

Recent focus on the environmental impact of plastic packaging has drawn it onto centre stage in the debate on single-use items — a term many in the industry do not recognise. In most applications, plastic packaging already presents the most resource efficient way of preventing food waste, product waste and transporting goods. Nevertheless, the industry has responded by continuing to innovate its products to further reduce waste. Also, many producers have embraced the circular economy challenge to ensure even the most difficult functional packaging structure can be recycled.

Single layer materials

With many specifiers now focused on achieving the aims of the circular economy, it is inevitable that there has been a shift away from multiple material layers, where possible, to ensure ease of recycling and this has included a move to mono PET (polyethylene terephthalate) trays. This shift has been led by suppliers, including Klöckner Pentaplast and Coveris to name just two. Now an increasing number of packer fillers and retailers see mono PET trays as the norm as opposed to the former PE/PET (polyethylene/ polyethylene terephthalate) construction.

There have also been similar moves in the manufacture of flexible films, with RPC bpi protec’s new X-EnviroPouch stand-up pouch that is recyclable and comes with a good moisture and oxygen barrier. This is already finding applications in the cereal and pet food market. The pouch can achieve an oxygen transmission rate of below 3cc/ m2/day.

Klöckner Pentaplast meat tray

Collaborations

Polymer manufactures, major brands, converters, recyclers and waste management companies are all working together in industry-focused European initiatives. One example is Ceflex^[1], which has nearly 100 stakeholders and encompasses government-led initiatives, such as the UK Plastics Pact; it is the first of its kind anywhere in Europe. Ceflex, which is focused on flexible applications of plastic packaging, includes leading polymer manufacturers, polymer converters and brands, such as Nestle, PepsiCo, P&G, Unilever and M&S, as well as recyclers and waste management companies. The aim of Ceflex is to preserve the resource efficiency benefits of flexible films, while ensuring that best design principles preserve functional benefits and that flexible films are collected for recycling at end of life. Dow is already offering new film structures that fit with the aims and objectives of Ceflex. This sort of collaborative working will only intensify the rate of change and innovation and follows on from work started by Reflex (a collaborative project to improve the recyclability of flexible packaging)^[2] and PIRAP (Plastics Industry Recycling Action Plan)^[3]– both UK initiatives – to develop best practice in the design of plastic packaging and to ensure that it is collected and recycled.

As digital presses have continued to evolve, the industry now has the potential to offer short run packaging solutions. Ultimate Packaging and other companies have already stepped into this space, offering personalised packaging, for example a collaboration with KitKat printing digital personal images on the packaging. The principle has been extended to allow children to design their own flexible ‘lunch bags’.

Flow wraps with MAP and vacuum skin packaging are also starting to become more commonplace and the latter has been proven to reduce food waste from 12% to 3% for steak.

Composting

In response to the need to provide circular economy solutions regardless of the size of the packaging medium or the complexity, RPC is offering coffee capsules that will industrially compost. Small items of packaging have always posed a problem to mechanical recycling, especially those with high levels of food waste. The Bebo B2nature™ material features a special multilayer sheet that incorporates an effective oxygen barrier to deliver a long ambient shelf life and maintain the aroma and quality of the coffee in the capsule, thus resulting in no degradation in function but at the same time offering another route to recovery at end of life.

Other areas of innovation have included the use of cellulose in conjunction with board for products and packaging more typically used in ‘on-the-go’ applications, such as sandwich packs. Although sandwich packing switched to board some time ago, in many applications it continued to use OPP (orientated polypropylene) film. Coveris has brought to market a number of plastic-free products featuring this construction, which are compostable.

Secretary of State for Business, Greg Clark, recently announced the winners of the UK innovation fund awards. One of the 11 winners securing part of a £4m fund, Skipping Rocks Lab in London, is developing alternative materials to be used for sauce sachets. The company is working on a scheme that would see single-use condiment sachets on takeaway counters made from seaweed. The material, which has successfully been trialled as an alternative to the plastic water bottle, biodegrades as fast as a piece of fruit and is said to be cheaper than conventional plastics. However, care will be needed to ensure such solutions, if successfully brought to market, do not encourage consumers to litter with impunity as products will just biodegrade!

Other similar developments include the use of bio materials in the manufacture of polymer, including the use by Dow of bio naphtha in the manufacture of LDPE (Low-density polyethylene) film for beverage cartons, collation shrink and other multilayer applications.

Reducing food waste

Efforts to ensure reduced food waste — a topic that some green campaigners seem to be all too willing to sacrifice in pursing their goal of reducing the use of plastic — have continued to receive attention. Examples include Ultimate Packaging’s Adapt MAP (modified atmosphere packaging), where companies can download live information about a crop’s journey to their factory to ensure the correct level of laser perforation to provide optimum food life. In another example, RPC’s X-Hance film prevents the greening of potatoes.

Flow wraps with MAP and vacuum skin packaging are also starting to become more commonplace and the latter has been proven to reduce food waste from 12% to 3% for steak. When you bear in mind the vastly higher resources required to put meat on our plates compared to the minute amount to produce the packaging, this is a ‘no brainer’ to those in the industry. Sealed Air has extended this concept with its Cryovac® Darfresh® Barrier Packaging, which claims to have reduced the amount of film required by up to 40%.

The industry continues to further boost its resource efficiency credentials by reducing the amount of polymer required to do a given job and a good example of this is in stretch film, where companies like Dow have reduced the amount of film per pallet by 50% over the last decade.

RPC Massmould High Secure Flip Pports Closure

Recycling plastic packaging

There has been a move to use significantly more recycled content in packaging and good examples include the PET tray market, where Klockner Pentaplast boasts up to 95% recycled content. Also, leading brands, such as Coca-Cola, have committed to increase the level of recycled content in their bottles to 50% with others in the bottled water market committed to go further still.

There are also exciting developments in the UK that offer the potential to make recycling of plastic packaging so much easier for the consumer, with the development of new chemical recycling plants. Once adopted at scale, this would enable UK householders to place plastic packaging in the recycling bin at kerbside, safe in the knowledge that it would be recycled by a combination of mechanical and chemical processes.

On-the-go applications of packaging have also come under scrutiny in terms of design to ensure components of the packaging, such as tear off pieces and caps, are less likely to be discarded. In fact, legislators in the EU have stepped into the space, calling for tethered caps to become the norm, which will be challenging due to the way bottles have been light-weighted, particularly in the neck area. Nevertheless, leading brands of bottled water have already started to adopt this for sizes typically associated with the on-the-go market and Highland Spring is working with cap manufacturers, such as RPC Massmould with its Secure Flip sports cap, to bring this innovation to market.

Other innovations in plastic recycling include moves by polymer manufacturers to introduce recycled content pre-blended with virgin feedstock for food packaging and the move by waste management companies to step in and buy plastic recyclers, for example resource management company Veolia has acquired the Dagenham Plastics Facility, which recycles milk bottles into HDPE (High-density polyethylene) pellets. These moves will ensure the building of efficient, joined-up plastic recycling plants in the UK, ensuring that the benefits of plastic as a material are maintained in a circular economy.

New packaging materials are continuously appearing in the UK marketplace. Aquapak now offers the possibility of using polymeric material in laminated structures — particularly those involving paper —which can be recycled. Marketed under the name Hydropol, the material is available at scale and can be used on a multitude of standard processing lines.

The industry continues to further boost its resource efficiency credentials by reducing the amount of polymer required to do a given job and a good example of this is in stretch film, where companies like Dow have reduced the amount of film per pallet by 50% over the last decade.