Invisible pattern can put a stop to counterfeit designer clothing
06 May 2013
A researcher has produced a thread with optical properties that can be used to create invisible patterns in fabrics only visible under polarized light.
Using invisible thread can help clothing manufacturers create a logotype that is part of the actual fabric and that only becomes visible under polarized light (photo: Christian Müller)
Trade in counterfeit and pirated goods is rife; it impacts companies, their employees and unknowing consumers. And it is often difficult to see the difference between a genuine garment and a fake.
Christian Müller,a researcher in polymer technology at Chalmers University of Technology in Sweden, has found a solution to the problem. He has created a partially invisible thread made of polyethylene and a dye molecule that absorbs visible light. The thread can be weaved into a pattern that is invisible to the naked eye, but which can be seen using a polarization filter.
"The production process itself is uncomplicated," he says. "Clothing manufacturers could start using the thread right away to put a signature pattern in their garments. The equipment needed to see the pattern is fairly simple, and is already in place at Swedish Customs, for example."
The invisible thread can be created using several different dye molecules and several different synthetic fibre textiles such as nylon. The dye molecule can also be bonded to natural fibres such as wool and silk. The technology can be used both for clothes and for different types of expensive speciality fabrics such as the textile used in vehicles and caravans.
"It is very difficult for pirate manufacturers to copy the unique combination," says Müller. "They can obtain the equipment needed to read the pattern and ascertain the optical spectrum produced by a specific signature, but they cannot know which combination of components will produce the specific spectrum. And there are loads of different dye molecules available to use."
From a long term perspective, Christian Müller's discovery could also be used to manufacture 'smart textiles', such as clothing that changes colours based on electrical charge.