Topic 8 - Designer Products
New materials are sometimes are invented by accident. Teflon is what the non-stick coating on non-stick saucepans is made from. It was discovered in 1938 by accident. Scientists were trying to make a new refrigerant and came up with Teflon. The glue on Post-it notes was also invented by accident. Scientists were trying to invent new glue for sticky tape, and it ended up with glue that didn’t stick permanently. Later on, someone came up with the idea of sticky-backed peel-off notes.
Carbon fibre is very strong and light. It’s combined with plastic to make a composite material, which is used to make the bodywork for formula one cars. It is also used to make bike frames, tennis rackets and fishing rods. Thinsulate is brilliant for thermal insulation because it’s got very thin fibres which trap a lot of air. It is used for ski clothes and other outdoor clothing. Lycra is very stretchy and crease resistant. It’s combined with other fibres and is used in tights, swimwear and sportswear, and in other clothes so they don’t get creased or go baggy.
Most waterproof materials trap sweat inside, making skin and clothes wet and uncomfortable. Breathable waterproof materials, e.g. Gore-Tex products, allow water vapour to escape, but still prevent liquid water coming in. Gore-Tex fabrics are made by laminating a thin film of a plastic called expanding PTFE onto a layer of another fabric, such as polyester or nylon – this makes the PTFE sturdier. Both liquid water and water vapour can pass through the nylon or polyester layer. The expanded PTFE film has tiny holes which let water vapour pass through, but these aren’t big enough to let water droplets through.
Kevlar is a synthetic polymer that is strong, light, flexible, heat resistant and electrical insulating. The strength lightness, lightness and flexibility of Kevlar make it ideal for protective clothing. Body armour made of woven Kevlar fibres is soft and comfortable to wear. Cut resistant gloves for worker in glass factories are made from Kevlar. It is also used in protective clothing worn by people working with chainsaws. The heat resistance of Kevlar means it is ideal for fire fighters’ helmets and protective clothing. It is also used in airplane manufacture and for some sports gear, such as canoes, skis, bike helmets and tennis rackets, because it is light and strong. Ropes made from Kevlar are used on ships and oil rigs.
Some materials behave differently depending on the conditions. Nitinol is a shape memory alloy. It is a metal, but when it is cool you can bend it and twist it like rubber. Bend it too far, though, and it stays bent. But if you heat it above a certain temperature, it goes back to a remembered shape. It is really handy for glasses frames because if you accidently bend them, you can put them into hot water and they will go back to their shape. Some dyes…