Sony Recycled Speakers
In 1997 Sony’s European audio group came up with a technique for making loudspeaker boxes from Tectan®, a material made from recycled Tetrapak milk cartons. Tectan consists of 75% paper, 20% polyethylene foil and 5% aluminum. The front of the box is a medium pressure fiber plate, which is attached to the Tectan panels with screws for easy dismantling.
Using alternate materials selection Sony created a product which boasts outstanding acoustic characteristics.
Tectan® is a completely new chipboard like material made from recycled Tetrapak drinks cartons. Once sorted the cartons are shredded, heated and turned into small particles. The material is then formed into sheets which are compressed, heated and pressed between two plates. A foil is applied to give a lacquered finish. Once it has cooled the board is pressed again to strengthen it. The finished board can be used in a number of applications. Tectan also produces Tectan-Form - recycled paper/polyethylene pellets which can be used for injection moulding.
The information about the Sony speakers came from: https://www.c-direct.ne.jp/japanese/divide/10106758/6758er/6758e_09.pdf
For further information about Tectan® visit: http://www.tectan.de/page55.html