Packaging that minimises product waste

Shaking and tapping is often the only way to get the last drop of tomato sauce out of the bottle. But soon a special coating on the packaging will make every last, precious drop of sauce ooze out of the bottle with ease.

Up to 20% of some sauces are left in the packaging when it is dumped in the trash can, which, beyond being an annoyance to consumers, poses difficulties to recycling operations. The leftovers first have to be removed from the packaging, usually with an expensive, time-consuming procedure that uses a great deal of water. If the products in question are pharmaceuticals, chemicals or pesticides, the rinsed-out leftovers also have to be disposed of in a suitable manner.

A joint project by the German Fraunhofer Institutes for Process Engineering and Packaging IVV and the Interfacial Engineering and Biotechnology IGB, together with Munich University of Technology and various industrial partners, will put an end to this dilemma.

"We are developing packaging materials that reduce leftover traces to half or less," said Dr Cornelia Stramm, head of the Functional Films business field at the IVV.

The researchers apply thin films, no more than 20 nm thick, to the inside surface of the packaging.

"We make the coatings from plasma of the type already familiar from neon lamps," said IGB scientist Dr Michaela Müller.

"It is done by placing the plastics into a vacuum. We introduce gases into this vacuum chamber and ignite them by applying a voltage. We can deposit different coatings with defined properties on the surface of the packaging, depending on the proportions of electrons, ions, neutrons and photons in this luminous gas mixture."

The first samples of this new packaging will be presented to the public for the first time at K2007, the international trade fair for plastics and rubber held in Düsseldorf on 24-31 October.

The research scientists at the IGB are now working to optimise the coatings applied, improving properties such as adhesive strength.

"The coatings must not change the properties of the materials. They must remain capable of being industrially processed to form bottles, tubes or stand-up pouches of the kind typically used for liquid soap," said Müller.

The research team is continuing to analyse the film's resistance to mechanical stress, temperature fluctuations and contact with acids and alkalis.