Clothing Definitions — definitions of garments and clothing terms from Apparel Search
Sun protective clothing is clothing specifically designed for sun protection and produced from a fabric rated for its level of ultraviolet (UV) protection. A novel weave structure and denier, related to thread count per inch, may produce sun protective properties, and some textiles are pre-treated with UV-inhibiting ingredients during manufacture to enhance their UV-blocking capacity. Design matters as much as fabric: long sleeves, full collars and full-length trousers are common styles, covering the skin most susceptible to UV damage. Some fabrics in common use need no enhancement, thanks to inherent fibre structure, density of weave and dye components, especially darker colours and indigo dyes.
Not only limited to UV-inhibiting textile use, sun protective clothing may also adhere to specific design parameters - including styling appropriate to full coverage of the skin most susceptible to UV damage. Long sleeves, full collars and full length trousers (not shorts) are common styles for clothing as a sun protective measure.
A number of fabrics and textiles in common use today need no further UV-blocking enhancement based on their inherent fiber structure, density of weave, and dye components - especially darker colors and indigo dyes. Good examples of these fabrics contain full percentages and/or blends of heavy weight natural fibers like cotton, linen and hemp or light-weight synthetics such as polyester, nylon, lycra and polypropylene. Natural or synthetic indigo dyed denim, twill weaves and canvas are also good examples. However, a significant disadvantage is the heat retention caused by heavier weight and darker colored fabrics.
As sun protective clothing is usually meant to be worn during warm and humid temperatures, some UV-blocking textiles and clothing may be designed with ventilated weaves, moisture wicking and antibacterial properties to assist in cooling and breathability.
History
The original UPF rating system was enhanced in the United States by the ASTM (American Standards and Testing Methods) Committee D13:65 at the behest of the FDA (Food and Drug Administration) to qualify and standardize the emerging sun protective clothing and textile industry. The UPF rating system may eventually be adopted by interested apparel and domestic textile/fabric manufacturers in the industry at large as a "value added" program strategic to complement consumer safety and awareness.
Factors that affect the level of sun protection provided by a fabric, in approximate order of importance, include weave, color, weight, stretch, and wetness. In addition, UV absorbers may be added at various points in the manufacturing process to enhance UV protection levels.
There is some indication that washing fabrics in detergents containing fabric brighteners, which absorb UV radiation, might increase their protective capability. Studies at the University of Alberta also suggest that darker colored fabrics can offer more protection than lighter colored fabrics.
A relatively new rating designation for sun protective textiles and clothing is UPF (Ultraviolet Protection Factor). Unlike SPF (Sun Protection Factor) that measures only UVB, UPF measures both UVA and UVB.
Developed in 1998 by Committee RA106, the testing standard for sun protective fabrics in the United States is the American Association of Textile Chemists and Colorists (AATCC) Test Method 183. This method is based on the original guidelines established in Australia in 1994.
AATCC 183 method defines the UPF rating for a fabric/textile as the ratio of UV measured without the protection of the fabric (compared to) with protection of the fabric. For example, a fabric rated UPF 30 means that if 30 units of UV fall on the fabric only 1 unit will pass through. A UPF 30 fabric that blocks or absorbs 29 out of 30 units of UV is therefore blocking 96.7% UV. UPF tests are normally conducted in a laboratory with a spectrophotometer or a spectroradiometer.
AATCC 183 should be used
in conjunction with other
related standards including
American Society for Testing
and Materials (ASTM) D 6544
and
ASTM D 6603. ASTM D
6544 specifies simulating
the life cycle of a fabric
so that a UPF test can be
done at the end of a fabric's
life cycle
which is when most fabrics
provide the most reduced
level of UV protection.
ASTM D 6603 is a consumer
format recommended for visible
hangtag and care labelling
of sun protective clothing
and textiles. A manufacturer
may publish a test result
to a maximum of UPF 50+.
While there is some correlation between the amount of visible light that passes through a fabric and the amount of UV that passes the same fabric, it is not a strong relationship. Based on some of the new-technology fibers and textiles designed for the sole purpose of UV blocking, it is not always possible to gain a good understanding of the UV protection level of a fabric simply by holding it up and examining how much visible light passes through the fabric.
Sun protective clothing and textile/fabric manufacturers are currently a self-regulating industry in North America, prescribed by the AATCC and ASTM methods of testing.
Gies, H.P., Roy, C.R., Elliot, G., & Zongli, W. (1994). "Ultraviolet Radiation Protection Factors for Clothing". Health Physics 67 (2): 131-139.
Gambichler, T., Rotterdam, Altmeyer, P., & Hoffmann, K. (2001). "Protection against ultraviolet radiation by commercial summer clothing: need for standardized testing and labelling.". BMC (BioMed Central) Dermatology I: 6-9.
American Association of Textile Chemists and Colorists (AATCC) Test Method 183
American Society for Testing and Materials (ASTM) Standard D 6544
American Society for Testing and Materials (ASTM) Standard D 6603
Stanford, Duncan G., Georgouras, Katherine E. & Pailthorpe, Michael T. (1997). "Rating clothing for sun protection: current status in Australia". Journal of the European Academy of Dermatology & Venereology 8 (1): 12-17.
| The above article is licensed under the GNU Free Documentation License. From Wikipedia, the free encyclopedia (https://en.wikipedia.org/wiki/sun_protective_clothing). 9/4/07 Modified by Apparel Search |
Sun protective clothing is sold on a measured rating, the ultraviolet protection factor, which states what fraction of UV radiation reaches the skin through the fabric. A tightly woven, dark, undamaged fabric can rate very highly; a thin white T-shirt rates low, and lower still when wet or stretched, because stretching opens the weave. That measurability is what separates the category from ordinary clothing advice: a rated garment carries a tested number, and the number lets buyers compare a fishing shirt, a rash guard and a pair of sun trousers on the same scale. Treatments that add UV absorbers to the fibre can raise a fabric's rating, and the rating approach also explains the design rules: high collars protect the neck, long sleeves the arms, and hats with real brims the face and ears.
The category grew around people who cannot simply stay out of the sun: anglers, sailors, hikers, gardeners, construction and agricultural workers, lifeguards, and children in outdoor programmes, together with anyone whose skin or medication makes UV exposure a medical issue. For those wearers, clothing has practical advantages over sunscreen alone: it does not wash off, need reapplying, or miss a spot, and it works the same at the end of the day as at the start. Modern sun protective garments hide the technology inside ordinary-looking shirts, trousers, dresses and swim cover-ups, in lightweight knits and wovens chosen so that full coverage stays comfortable in the heat that makes the protection necessary.
Protection comes from the fabric itself: a dense weave structure and suitable denier leave few gaps for UV to pass, fibre structure and dye, especially darker colours and indigo dyes, absorb UV, and some fabrics are pre-treated with UV-inhibiting ingredients during manufacture to raise their blocking capacity. The fabric is rated for its level of UV protection.
Because a fabric can only protect the skin it covers. Sun protective garments follow design parameters for coverage of the skin most susceptible to UV damage, so long sleeves, full collars and full-length trousers rather than shorts are common styles in this category.
Some do, without any special treatment. Fabrics with inherently dense weave, suitable fibre structure and strong dye components, darker colours and indigo-dyed fabrics are good examples. Thin, pale, loosely woven summer fabrics are the opposite case, which is why rated sun protective clothing exists.