The perfect foil

Either on its own or else increasingly working in conjunction with a wide variety of plastics polymers, aluminium foil is the essential component of a broad span of flexible packaging applications ranging from self-adhesive labels to stand-up pouches, and for which the material is equally as adept in providing dazzling good looks and quietly efficient covert protection.

The global packaging industry demand for aluminium foil in varying thicknesses is well in excess of 2 million tonnes per annum; two-thirds of the total amount produced annually. Over 75% of it goes to the packaging of food products, for which it guarantees an absolute barrier to light, oxygen, gases and moisture.

Its lightweight characteristics and capability for infinite recycling also tick precisely the right sustainability boxes close to the hearts and minds of brand owners, retailers and consumers alike.

Even so, according to the European Aluminium Foil Association (EAFA), demand has dipped slightly in Europe this year. Thinner gauges for flexible packaging and household foil have declined by almost 6%, while shipments of the thicker foil segments typically used for semi-rigid container and technical applications were down by almost 10% in the first quarter.

On the plus side, however, exports from Europe – the world’s second largest producer, generating 25% of total output (behind China at 40%, and ahead of the USA at 14%) – rose by 9%.

This is a ‘swings and roundabouts’ effect that is more reflective of the economic downturn rather than an arrested trend, and certainly no erosion of foil’s continuing contribution towards extending product life expectancy or facilitating a more convenient consumer life-style.

Through thick and thin

Working in combination with a range of plastics polymers, foil provides the integral barrier protection element within co-extruded multilayer stand-up pouches (SUPs); a format that currently achieves global sales of just under €2 billion, and is predicted to be in excess of €3.3 billion by 2016. In the meantime, it’s estimated that demand for SUPs throughout Europe alone will total over 30 billion by the end of next year, accounting for approximately 5% of the flexible market.

Notwithstanding the clear evidence that foil as a substrate solution is patently about as fit for purpose as it can possibly be, there is still room for improvement, says Protective Packaging sales director Simon Jolly: “The lower the micron thickness, the less material being used and the lower the weight; fractional though these differences might be, they all help to improve upon both margin and sustainability.

“Whereas a micron thickness of 12 used to be the norm, now anywhere between 7 and 9 is typical for a bag or an SUP. The challenge is that there’s more likelihood of pin-holing taking place, the thinner the material,” he adds.

The drive towards elevating performance standards while shedding unnecessary weight is equally applicable for more rigid foil structures, such as the ‘Canny’ food bowl developed out of two years of R&D by Amcor Flexibles as a potential replacement for the steel can – and 30% lighter than a standard aluminium bowl with ring-pull, and targeting applications for which both lightweighting and convenience are strongly involved in the buying decision.

On doctor’s orders

A blister pack based on aluminium cold-formed bottom material with a paper-free, child resistant, peelable lidding foil is just one of a string of innovative new solutions introduced this year for the pharmaceuticals sector by Vienna-based Constantia Flexibles.

The blister lidding foil used by Constantia for Bayer’s Staxyn product contains two layers of alufoil due to the excellent temperature transmission characteristics of the material, which also functions as a barrier layer. Due to the paper-free make-up of the blister lidding foil, the sealing temperature on the blister line is lower than for conventional alu/paper laminates. In turn, this means energy consumption is reduced and, as dwell times in the sealing section can be reduced, the blister machine can operate at higher speeds.

Constantia is also helping to extend the use of ‘stick packs’ within the sector, a format that’s not only bringing advantages for packaging manufacturers and pharmacists, but also for the consumer, who finds it significantly easier to use because of its portability. The foil laminate comprises PET/Al/sealing medium or even paper/Al/sealing medium to protect the contents against moisture, oxygen and light, while a laser perforation below the seal ensures easy opening of the stick. Unlike a conventional stick pack with a tear notch, the sticks with the opening aid can be emptied completely because there is no need for the seal to protrude to accommodate the tear notch.

Functioning under pressure

While foil-based packaging is helping to facilitate a healthier life on the home front, an ambitiously innovative application developed by Protective Packaging on behalf of a team of ex-armed forces personnel has the potential to save lives under far more testing conditions. The Survivastill is said to be the world’s first-ever multi-function solar still, whose four-layer laminate construction can make 2 litres of safe, drinkable water a day out of literally anything that contains moisture. It operates by trapping heat from the sun within an inflated chamber where a layer of foil sheeting of 7-15 micron thickness reflects the sun’s rays back into the chamber to increase the internal temperature of the distilling reservoir.

The Survivastill has additional functionality in being able to pump up into an inflatable life-raft by reversing the purpose of the tap fitments, and to attract help from the air thanks to the foil’s reflective properties. It may not be product packaging per se, but it certainly underlines the possibilities opened up by foil’s natural properties.

A bright future

In total contrast to its formidable barrier properties, there’s nothing to match foil when used as an external decorative embellishment for attracting rather than repelling attention, says API Foils marketing manager Pamela Cairns.

“Designers are looking for something that’s new and exciting and different that’s going to make products stand out even more, not least in the current climate where it’s difficult to get people to spend money,” says Cairns. “And something that’s exciting for designers is also exciting for consumers.

“There are a lot of brave brand managers out there, so while it might add a penny onto the cost, if it can guarantee that your product is going to appeal to consumers ahead of a competitive one, then it’s not worth quibbling about.”

Far from being limited to top-end applications and, indeed, encouraged by the example set across a number of premium product categories, foil effects are becoming more the norm for morecommodity items, especially in the personal care sector. One way of reining in that on-cost could be greater adoption of coldfoiling, an inline process for both sheetfed and rotary printing, says Cairns.

“Coldfoiling sits in very well with the prevailing economic trends,” she says. “While the original coldfoils weren’t as bright and shiny as hot stamping foils – or never will have quite that mirror effect – the latest developments are bringing them much closer via a good quality finish, plus printing inline realises obvious cost savings.

“Designers are particularly interested in the possibilities of over-printing conventional or UV inks on a silver background that give almost an unlimited range of colours to play with and gradations that can’t be achieved in any other way,” says Cairns.

“It’s not just that it’s cheaper; it’s also an attractive way of printing to achieve shelf stand-out.”

Canny foil bowl developed by Amcor Flexibles as an alternative to the can Canny Blister lidding foil used by Constantia Flexibles for Bayer’s Staxyn Staxyn ‘Stick packs’ such as these by Constantia beginning to make an impact in the pharmaceuticals sector are Constantia API Foils: coldfoiling is eye-catching and affordable for commodity items API Foils

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Protective Packaging
Constantia