26 Jul 2005
Indian scientists exploit the light scattering properties of protruding fibers to determine the hairiness of yarn.
Tiny, light scattering fibers that protrude from the body of yarn are enabling researchers in India to measure the hairiness of textiles. Hairiness is of great interest to the textile industry as it affects the tactile feel and look of fabric, and can influence selling price. (Rev. Sci. Instrum. 76 076104-1
Currently, most firms use projection methods to determine hairiness, which involve examining an enlarged view of the yarn profile. Unfortunately, these techniques can be expensive and complicated to implement, especially in a production environment, and the industry is keen to find an affordable alternative.
"A local textile equipment manufacturer asked us whether we could make an efficient, cost-effective and fast hairiness measurement meter," Arun Anand, from the Maharaja Sayajirao University of Baroda's Photonics Laboratory, told Optics.org. "It occurred to us that we could use the light scattered from the yarn hairs to measure hairiness if we could block out the direct light by some means."
In their set-up, Anand and his colleagues use two crossed polarizers as a method of isolating scattered light from the hairy fiber. Placed in between the polarizers, the hairy fiber scatters and depolarizes a portion of an incident He-Ne laser beam, which can then pass through the system on to a photodiode.
Static testing on unprocessed vegetal yarns revealed that the amount of scattered light hitting the detector was proportional to the hairiness of the fiber. The researchers found good agreement between their scattering technique and image analysis data gathered using projection methods.
The Gujarat-based team is currently developing a dynamic version of its hairiness meter that will suit yarn speeds of several hundred meters per minute. Anand expects the work to be complete within the next 2 - 3 months and is hoping to commercialize the Indian government sponsored research.