Composites

The idea of a composite is simple enough – take two or more materials and combine them in a new, super-material with much better properties than the ingredients on their own. It’s not a new idea – already thousands of years ago, mud and straw was combined to make adobe bricks. Since then, mud has been replaced with high-performance plastic resin and the straw with some super-strong, ultra-lightweight fibre, although natural plant-based fibres and resins are making a big comeback in the emerging field of bio-composites.

We recently visited the JEC Composites Show in Paris (www.jeccomposites.com), Europe’s largest trade show for composite materials and technology, and we thought we’d share some of our highlights from the show.

Seismic wallpaper

A team of engineers from the consultancy D’Appolonia had been working on a ‘seismic’ wallpaper for some time when an earthquake struck the Italian town L’Aquila in 2009. The team promptly redoubled their efforts and managed to produce a working prototype of the textile in time to scoop up first prize in the construction category at the JEC Awards Programme. This remarkable product is made using a special multi-axial weaving technique and very strong textile fibres that has proved ideal for withstanding the large forces and complex material behaviour that are associated with earthquakes.

Used throughout a building, the textile can improve the structural strength and ductility of unreinforced walls by 200% – quite impressive, considering that the material is essentially a wallpaper. The material also contains sensors that give engineers lots of information about how best to manage the building and how it reacts to earthquakes and other events. Read more about the material here –www.dappolonia.it

Auxetic composites

If you didn’t know about auxetic materials before, you’re in for a treat. For an idea of how they work, think of an elastic rubber band – the more you stretch it, the thinner it gets. This is how most elastic materials work, but Auxetic materials behave in the exact opposite way – stretch them and they get fatter! Although this type of materials exist in nature (both cork and human skin are auxetic to a degree), synthetic auxetic materials are only starting to find uses in real life applications outside research labs, so naturally we were thrilled to find a new auxetic material at JEC.

Chismatec, another Italian company in the construction industry, have come up with an auxetic core material for composite sheet materials that can replace conventional honeycomb cores in a variety of lightweight applications such as construction and transport for example. If you were to bend a honeycomb core composite sheet, it tends tend to warp and go concave in one direction and convex in the other, but Chismatec’s new auxetic core material is reportedly much easier to form into complex, three-dimensional shapes. Unfortunately, there isn’t much by way of information on the Chismatec website (www.chismatec.com), but you can read more about the material on the Veneto Nanotech Polymerchallenge competition website, where Chismatec won first prize –www.venetonanotech.it/en/news-events/nanotech-news/the-era-of-nano-writing-and-of-super-polymers-begins,3,8111

Filament winding

This exciting process is perhaps best described as three-dimensional, structural weaving – long strands of fibre are saturated in resin and wound around a form, or mandrel, before being left to cure and taken off the form, producing incredibly strong and lightweight shapes. Originally developed for the aerospace industry, designers have enthusiastically experimented with filament winding and taken it in new directions.

We wrote about Wieki Somers Bellflower light in Ingredients 4 (download it here – www.moreingredients.com) and London-based Danish designer Mathias Bengtsson has done some amazing things with filament winding – check out his extendable Spun Bench for Future City and St James Group featured here for example. We were delighted to find Seifert Skinner & Associates at JEC, the company that produced some of Mathias’ pieces, for a first hand view of these beautiful products. For some inspiration in terms of what’s possible to achieve with the process, have a look at www.wiekisomers.com, www.bengtssondesign.com and www.seifert-skinner.com.

Image captions –

Mathias Bengtson’s Spun Bench, commissioned by Future City and St James Group. Image courtesy of the designer.

Bellflower light, designed by Wieki Somers. Photography by Fabrice Gousset