L&L turns 40: Developments in packaging films

Packaging films are on a path of constant research and development (R&D) to enhance their key characteristics and improve suitability for use in a variety of applications. As such films take on the mantle of primary packaging, this ranges from their strength and preventing migration, to maximizing both shelf life and shelf appeal.

And for those producing such films, R&D is focused around a handful of ‘megatrends’, namely the environment and performance.

A number of recent developments showcase this work, such as the launch of Propafilm RCU by Innovia Films. Propafilm RCU is a BOPP film that has been officially proven to provide up to 1.5 years protection from mineral oil migration, and was developed after research indicated foods were being contaminated by the migration of mineral oil from recycled paper-board.

KM Packaging Services has introduced KPeel 3G, a user-friendly lidding film designed to reduce instances of ‘wrap rage’. A survey by The Grocer in 2014 found that nine out of 10 British consumers are regularly gripped by ‘wrap rage’ – frustration with impenetrable or poorly functioning food packaging. KM Packaging says KPeel 3G will be ‘music to the ears of consumers who proactively seek out foodstuffs that are easier to open’.

KPeel 3G is a heatsealable polyester film which peels cleanly from trays in ambient or chilled conditions. Available in 21-, 25- and 40-micron thickness, KPeel 3G is suitable for printing using the flexo and gravure processes. Additional features include macro hole and laser perforation. KPeel 3G films seal to CPet and APet trays and provide superior cold peel in one piece without shredding, even direct from the freezer, KM Packaging says. It is also suitable for microwave and conventional oven cooking, and chillable.

KM Packaging commercial director Graham Holding says: ‘[We are] constantly looking to innovate, not just for the sake of it, but to really seek out ways to make the consumer experience better and thus keep our customers – food manufacturers – happy.’

Amcor’s I-Peel is another heatsealable polyester lidding film which is said to answer consumer demand for packaging that is easy to open by hand with a smooth peel designed to minimize sharding.

Amcor says I-Peel delivers a consistent seal whether the packaging is heated or has come direct from the freezer, and is suitable for dual ovenability with all foodstuffs. It is available in 19, 26 and 40 microns. It is suitable for P-Plus – Amcor’s flagship tailored permeability films designed to maintain freshness and extend shelf life.

I-Peel is designed to stay sealed through the distribution chain ensuring the product arrives safely on shelf in stores, with the hermetic seal protecting food and preventing leaks. It can be sealed to aPET, rPET and cPET.

Further, I-Peel’s high clarity coupled with anti-mist performance ensures the customer has a clear view of the product.

I-Peel can be printed using Amcor Prism, Amcor Vivid technologies or conventionally.

Barrier properties

One of the fundamental requirements of packaging films is their barrier capabilities. They must take on the characteristics of primary packaging, like glass and metals, while maintaining the lightweight and flexible credentials that make them a growing choice in so many product categories. Fatty foods, dry foods, fresh foods, frozen foods, beverages and dairy products can all be easily purchased in one of any number of flexible packaging structures. And each of these brings their own specific application requirements.

‘One of the biggest trends in packaging today is the quest to improve shelf life and reduce food waste,’ says Andy Sweetman, marketing manager for packaging and sustainability at Innovia Films.

‘As such, oxygen, moisture and light barriers are growing demands. A few years ago, crisp packs moved to metallized films for this very reason, as they provide barriers to stop the product spoiling.’ Crisps/ chips contain fats that oxidize rapidly if exposed to air and light, which makes them taste rancid. They also quickly become soft if exposed to moisture.

Cosmo Films is working to enhance the barrier characteristics of its films through the use of new coatings and metallization, which its chief executive officer Pankaj Poddar says are allowing it reduce the transmission of gases and moisture.

Functional films

As part of its R&D work, Cosmo Films is also paying close attention to the seal and burst strength of its films, which Poddar says will allow packaging films to be able to hold heavier products without their structure being compromised.

This will benefit the distribution supply chain as it will ensure spillages, leakages and pack failures are kept to a minimum, he says. ‘We are working in partnership with our supply chain partners to this end and to bring new products to market, as it is not possible to make such advances when working alone.’

Sweetman adds: ‘We are a specialist supplier, so a lot of what we develop at Innovia Films is specific to a certain application, and to meet new market dynamics. For instance, digital printing, which has established itself in the label market, is starting to crossover into the packaging world, so we have developed films suitable for that process. We also have products that offer functionality for fresh produce, where anti-misting and anti-fogging are requirements.’

A further trend within this element is cook-in packaging – that is those that can be used in the preparation of foods. Sirane’s Sirlon is one development suited to this growing market trend for convenience, and where packaging films are playing an integral part of the evolving interaction between consumers and products.

A sustainable future

‘I once heard someone describe packaging’s biggest issue as being “fundamentally everything we produce is rubbish”,’ says Sweetman, ‘by which they meant what consumers mostly see is the leftover waste once a product has been unpacked and/or consumed.

‘For plastic films, there is an issue that it is very hard to visually differentiate between different types, whether PE, PP, BOPP, so they become hard to sort, and recycling becomes impractical.’

Innovia has a long-standing history in working to make recycling of films a reality, having launched its NatureFlex range over a decade ago. Now in its fourth generation, NatureFlex is a range of specialty packaging films manufactured from renewable resources – wood pulp from managed plantations – and are certified to the European (EN13432), American (ASTM D6400) and Australian (AS4736) norms for compostable packaging. In addition, the majority of grades have been certified by Vinçotte to the OK Compost Home standard for home composting and certain grades have been proven to biodegrade in a waste-water environment. Further testing has proven that most NatureFlex grades are also suitable for anaerobic digestion.

‘What is often the case is people try down-gauging and using thinner films, however you quickly end up in a situation where you can’t go any thinner without compromising performance. What we are focusing on is using renewable raw materials and compostability, so embracing sustainability at both the creation and end-of-life stages of packaging materials.’

‘A big challenge for compostable materials has always been moisture transmission,’ Sweetman adds, ‘so we have looked at how to drive in the required barrier characteristics and still offer compostability. This is why the NatureFlex portfolio now includes a range of products offering different characteristics.’

At Amcor, work in this area has included the launch of a new bread bag for Hovis made with predominantly renewable polyethylene, and which offers a 75 percent lower product carbon footprint than traditional bread bags made with plastic from non-renewable fossil sources. Seed Sensations, the most premium product in the Hovis range, was the first to be relaunched using renewable PE bags.

‘It has the same performance characteristics of the old style, but with a much lower impact on the environment,’ says Dean Stanford, FLDC flexo development manager at Amcor Flexibles Europe and Americas.

Cosmo Films is developing BOPP that is printable with water-based inks, so allowing the majority of its films to be printed using a variety of process and offering environmental and safety benefits. To overcome BOPP’s low dyne level, and resulting difficulty with water-based inks, Cosmo Films is modifying the film’s structure so it is receptive to such products without the need for corona treatment.

‘Most products can be purchased in films and pouches nowadays,’ says Poddar. ‘They offer multiple environmental benefits, such as reducing pack weights and cutting emissions throughout the supply chain, and can play a part in reducing waste through food spoilage.’

‘Weight reduction is a big thing and will continue to be so as packaging moves away from heavier types and those that are not recyclable or compostable,’ says Amcor’s Stanford.

‘With the development of more sustainable and recyclable films, coupled with the improvements in performance characteristics in various applications, we will see market penetration of flexibles continue to grow,’ says Sweetman. ‘All the developments we have in the pipeline at Innovia are being designed to suit functionality, performance or sustainability, or a combination of the three.’

The recent collaboration of Treofan and Stora Enso brings another dimension to the sustainability debate. The fiber-based packaging specialist and the film manufacturer have been working together for over 18 months on a new hybrid packaging material, HybraPack, which combines the benefits of paper and BOPP.

Marco Holst, business development manager at Treofan, says the development is a major innovation in making stand-up pouches by bringing a semi-rigid packaging material to the market. Different grades are achievable by customizing different weights and volume of paper and BOPP, and it is printable and convertible on all existing machinery. Currently, around a dozen prototypes have been produced, with work now going on to secure real-life application trials and to continue testing what is possible with the combination of paper and BOPP. This includes the integration of zippers and spouts for usability.

‘HybraPack brings together the best of both worlds by allowing us to offer the structural rigidity of fiber with the barrier properties of BOPP.

‘This helps reduce the overall pack weight, while also not requiring any additional converting steps, such as laminating, as is the case when dealing with complex multi-layer films. Its two-layer construction can also be easily recycled, similar to how other metallized board waste streams are handled.’

Stora Enso’s Marcus Weise, business development manager for specialty papers, adds: ‘Semi-rigid doesn’t really exist as a product category yet. With HybraPack, we offer a new type of packaging material. We see big opportunities in dry food products and have seen interest in the market already.

Printing of films

Stanford says that developments in different print processes are helping to advance the role of films in today’s packaging market. This includes new ways of achieving high and consistent quality using flexo that is comparable to gravure in some instances, coupled with price.

‘What is now being achieved using flexo is incredible, and we’re seeing the number of colors being used reducing while giving brand owners what they want at little extra cost. New inks and imaging techniques are helping too.

‘There is no compromise in quality any longer, while the costs savings are potentially very large. The flexo printing process has, over recent years, advanced technically with many new developments, and the flexo print format is now capable of printing in markets considered beyond the process’s reach. It’s all about convincing the customer now and showing them a technology that many are not very knowledgeable about.

‘What was being printed in flexo using seven, eight or nine colors a few years ago can now be achieved with four, so opening up the ability to add embellishments and other elements using the freed up print stations, and having the potential to enhance shelf appeal.

‘We have to work to keep brand owners informed and ahead of the game, and show that flexo can be used to consistently achieve the print results they are looking for.’

*This article was first published in Labels & Labeling issue 1, 2015

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