Electronics shielding from drinks cartons

Reutlingen University in Germany has developed a process that converts post consumer Tetrapak cartons into a conductive and electromagnetically shielding material.

Tetrapaks have a composite structure. While the paper content is recyclable, the remaining composite, consisting of 84% polyethylene and 16% aluminium, has not previously been considered recyclable.

Reutlingen University has devised a means to convert this mixed waste into a plastic material that can be moulded into a coloured, anti-static and electromagnetically shielding compound. The bright colours are an innovative feature, something that cannot be achieved with conventional electrostatically dissipative materials.

The concept has been proved at plastics recycling company Hiller and has been used in transport and storage containers moulded for electronic equipment by Daigler.

The parts were put on display at the Composites fair in Stuttgart and won second place in the AVK Federation of Reinforced Plastics environmental category.

DBU (Federal German Environment Foundation) supported the project. In its concluding report, it said a typical compound would be made of 14% ground carbon fibres, 10% aluminium, 6% LDPE and 15% talc to achieve shielding beyond 10dB.