Smart packages - with built-in freshness watchdogs

The latest packages are not only stronger but also require fewer materials and permit efficient handling - integrated time-temperature indicators and microchips constantly indicate the product’s state of quality. Active systems are even capable of improving the quality of the contents during storage. For product manufacturers, smart packaging therefore ought to be a big talking point.

When it comes to ‘Güggeli’, their much-loved grilled chicken, the Swiss are not willing to make any compromises. Unless the chickens are reared in humane conditions, subjected to regular health checks and are absolutely fresh, they don’t make it to the table. The Ernst Kneuss Geflügel poultry company in Switzerland has therefore come up with something original for the fastidious Swiss. On the cardboard boxes of its ‘Bachofe-Güggeli’ grilling chickens, the company prints an OnVu label, a time-temperature indicator, that accompanies the chickens on their journey to the shops. A special pigmented ink in the interior of an apple symbol is irradiated with UV light during packaging and turns blue. From then on, the colour gradually fades in relation to time and temperature. The longer a ‘Güggeli’ is stored in a warm place, the faster the colour changes. When the colour in the apple becomes paler than the surrounding reference colour, the consumer knows that it’s better not to eat the chicken.

“By enabling our customers to check the freshness and quality of our products, our labels underline our quality philosophy,” explains Kneuss CEO Daniel Kneuss. The poultry producer introduced the OnVu label in 2008, and other companies now aim to follow its lead. “We’re negotiating with fast-food and retail chains worldwide,” says Martin Angehrn, in charge of OnVu at BASF. In 2008, the German chemical corporation purchased the Swiss paint specialist Ciba that had developed the indicator, together with the German machine manufacturer Bizerba.

‘Best before’ date not enough

To assure customers of absolute product safety, the entire logistics chain has to be monitored from production through to the consumer. This applies particularly to perishable foods and to pharmaceutical products. Experience has shown, repeatedly, that spoilt foods and medicines pose a huge risk. So far consumers had only had the ‘best before’ date to go by, a date that indicates how long a product can be used without loss of quality if correctly stored. The problem is that, in the event of breaks in the cooling chain or of moisture penetration, the product spoils prematurely and may put the consumer’s health at risk. On the other hand, foods are often still fresh beyond the ‘best before’ date, but are thrown away for safety’s sake - an unnecessary waste of resources. Time-temperature indicators show the precise degree of freshness and can prevent waste. “They thus also contribute to sustainability,” says Angehrn.

Because more and more consumers are attaching importance to healthy and green products with added value, experts anticipate strong growth in the smart packaging market. The US market researcher MarketsandMarkets expects global turnover with smart packages to grow by 8.2% annually to around US$24,000 million from 2010 to 2015. Analysts see not only colour labels on the advance, but also radio frequency identification technology (RFID). Via sensors, microchips integrated in the packages constantly gather data on the product’s condition, such as moisture and temperature, and issue an alarm when the values move outside the programmed upper and lower limits. Or there are chips that help patients take medicines in the correct dosage and punctually, emitting an audible signal indicating when it’s time to take the medicine. However, the microprocessors are capable of more: fed with such data as the filling location or date of manufacture, their products can be continuously traced - an important feature in the battle against piracy.

Industry sees huge potential in chips and is eagerly pursuing their development. The Organic Electronics Association (OE-A), a work group at the German Engineering Federation (VDMA), is working on the commercialisation of printable organic electronics. “Inexpensive, thin, flexible electronics which, attached to flexible polyester substrates, can be easily integrated into packaging, will soon be a familiar feature in the retail industry,” says OE-A Chairman Wolfgang Mildner. With RFID, large volumes of information on goods can be retrieved or uploaded in a flash. The technology thus stands for a guarantee of authenticity and for distribution security. At interpack from 12-18 May 2011, the world’s foremost event in the packaging industry, ‘communicative’ packaging will also be high on the agenda.

Freshness straight from the pack

Packages of the future are expected to have even more functions: they will interact with their contents, eliminate harmful oxygen and microbes and thus improve the product’s keeping properties and quality. In Japan, oxygen-absorbing sachets have been in use for years to help vegetables and fish stay fresh for longer. However, Europeans and Americans are not so willing to accept the conspicuous packaging elements bearing the words ‘Do not eat’. Researchers at the Fraunhofer Institute for Process Engineering and Packaging (IVV) in Freising have therefore developed more elegant preservation solutions. “We integrate oxygen absorbers like iron in the package’s polymer matrix,” says IVV materials developer Sven Sängerlaub. Oxygen-sensitive beverages like beer and fruit juices stay drinkable for longer in PET bottles processed in this way, he adds. The IVV also offers industry an antimicrobial film that releases sorbic acid onto the surface of the food, the prime point of attack for contamination, and thus preserves it. Product manufacturers can gain a detailed impression of the IVV’s innovations at interpack.

Critics now argue that the extra chemicals in active packaging impair the product’s ‘naturalness’. “Only harmless odour- and flavour-neutral substances are employed for food protection,” Sängerlaub counters. Furthermore, antimicrobial substances like sorbic acid are capable of rendering preservatives in the product superfluous. “This in fact promotes a healthy lifestyle.” The scientist sees a bigger problem in the high cost of launching new packaging solutions on the market. Industry would have to modernise its packaging lines and exhaustively test its new packages. “This hampers the step from the laboratory to mass production,” says Sängerlaub.

Machine manufacturers equip themselves

Packaging specialists and their suppliers are nevertheless speculating on powerful growth in industry demand for ‘smart packs’ - and are investing in the extension of their product portfolios. “Although new products and campaigns call for high investment, growing consumer demand for goods with added value promise companies economic benefits in the long term,” says OE-A Chairman Mildner. The Hamburg plastics specialist Albis Plastic, for instance, is offering packaging material producers what it claims to be a ‘highly efficient’ iron-based oxygen absorber by the name of Shelfplus O₂ that is added to the natural polymer in quantities suitable for the food and type of package. The Austrian can manufacturer Pirlo, on the other hand, conceals a silica gel pad in a perforated plastic insert in the lid of its new steel DryCan for coffee and tea. “By regulating humidity, this new packaging element prevents the formation of lumps in powdered products,” explains Pirlo Managing Director Julius Lüthi.

Innovation in smart packages is also proceeding apace. The German Bosch Group’s Smart Wallet is a secondary package for capsule- or tablet-type medicines that can be additionally equipped with a microchip. The Bosch wallet gains its name not only from the possibility of integrating intelligence, but also because production is said to be particularly easy and inexpensive. “The plant for producing Smart Wallets has a smaller footprint and requires less capital expenditure than conventional wallet packaging machines,” explains Bosch Product Manager Helmut Deichert. The key to the efficiency of the Smart Wallet can be found in its pre-glued outer which is placed upright on a conventional cartoning machine and filled with a transparent blister pack for tablets. Depending on the machine type, up to 300 wallets can be produced per minute, according to Deichert.

Producing complex packages swiftly - this is something that machines from Körber in Germany, IMA in Italy and Pago in Switzerland are also capable of. The latter manufactures RFID-compatible labelling machines that attach microchips to the products not flat but as projecting flags. This way, there is no interference of the radio signal where liquids and metal packages are involved. The companies’ innovations demonstrate that smart and active packages have long ceased to be just a bold vision. At interpack in Düsseldorf, packaging specialists and product manufacturers can gain their own impressions live.