Monday, January 25, 2010

Ultraviolet Protection Factor of Cellulosic Fabrics

It takes more than sunscreen to keep the sun's UV rays from harming your skin. The type of clothing you wear can offer protection, too—or not. It is not just the type of fiber and the weave of the fabric that matters, but also the color. Ascención Riva of the Polytechnic University of Catalonia and colleagues Inés M. Algaba, Montserrat Pepió have addressed the color issue, studying the effects of different optical brighteners and dyes on the UV protection provided by lightweight woven cottons.

The researchers chose three fabrics, not dyed, with different initial levels of UV protection based on the weave and other factors. Then they dyed them in varying shades of blue, red, and yellow and measured how much UV radiation was absorbed and transmitted.

They found that red and blue shades performed better than yellow, particularly in blocking UV-B rays, which are the most harmful. Protection increased as the shades were made darker and more intense. And if the initial protection level of the fabric was higher, the darker shades offered even greater improvement.

The researchers say the findings, reported March 29, 2007 in Industrial and Engineering Chemistry Research, should help fabric and garment manufacturers optimize their products for UV protection.

[Source: SPIE Professional January 2010]