防晒织物UPF的评价

UPF（紫外线防护系数）用于表示织物产品的紫外线防护性能。UPF值表示在有和没有织物材料或产品保护的情况下被紫外线辐射晒伤的时间比率。例如，如果在没有UPF 50布的情况下用紫外线照射皮肤10分钟，则使用布产品需要500分钟才能获得相同量的晒伤（50 UPF x 10分钟）。UPF测量程序可以客观地比较紫外线屏蔽的性能，通过对织物产品的紫外线屏蔽性能的数值计算。除AS/NZS 4399：2016标准外，还包括以下标准： BS EN 13758-1：2002、AATCC测试方法183：2010和GBT18830：2009。Application NoteUV-0036 2/4Application NoteUPF Evaluation of Sun Protection Fabrics UPF Evaluation of Sun Protection Fabric s In t ro d uc t ion UPF (Ult r aviolet Protect i on Factor) is u s ed to in dicate the UV shielding per f orm a nce of sun protect i on for fabric prod u cts. T he UPF va l ue re p resents the rat i o of t im e f or s u n b urn by UV radiation wi th and wi t hout t h e prot e c t i on of th e f abric mater ia l or product . For example ， i f s k in i s i rr adiated by ultravio l e t light i n 10 m i n utes without a UPF 50 cloth ， i t tak e s 500 minut e s to o b tai n t he sam e amoun t of su nb urn u sing t h e cloth prod u ct (50 UPF x 10 m in ). V-750 This a pplication n ote eva l u a t es UPF， UPF r at i ng， and UVA a n d UVB tr a n sm i t t ance of sun protec t io n fiber products using a UV-Visible spec t rophotometer an d the UPF calculation system. Fluorescence me a surements were also obtai n ed to cor r oborate the UV-Visible results UV -Visible Spectrophotomete r K eywor d s V -750，U V -V is i ble /NIR S pe ctr o p h o t o m e t e r ， UPF C a l c u lati o n prog r a m ， Flu o r e s ce nc e ， Ma t er ia l s Exp e r i m e ntal The UPF can be calculated using the fol l owing equation： where E(X) i s the CIE r eference erythema d o se spectr u m， S() i s t he radiatio n intensity distribution of sunlight， and T(X) i s the di f f use transmit t ance spec t rum (%). To calculate th e UPF r ati n g， the transm itt a n ce spec t ru m at more than four d i ffere n t wavele n gths i s measured for the sampl e UPF rating = UPFave 一E UPFL+UPF2+…+UPFn UPF ave where t i s the value which provides 0.5% of the border value of probabili t y of one side i n the t distribut i on， a is the probabil i ty of o n e side (0.005)， and k i s the d e gr e e of f r e edom (n-1). If t h e UPF rating i s s m al l e r th a n the mi nim u m of eac h UPF， the calculated value is rounded down by 5. I f the UPF rating i s more than 50， the UPF rating is defined at 50+. UVA trans m ittance i s ca l culated by the equat i o n be l ow usi n g t h e ave r age t r ansmittance from 315 to 410 nm： UVB transmittance i s calculated by the equation below using the average transmitta n ce from 290 to 315nm： Fluorescence* Transmittance Excitation Bandwidth 5nm Bandwidth 5nm Emission Bandwidth 5nm Scan Speed 100 nm/min Scan Speed 5000 nm/min Response 0.96 sec Response 10 msec Data Interval 1nm Data Interval 0.5nm *a fluo rescen ce cut f i l t e r b loc k a nd c u t f i lter (U-330) a r e r e q ui r ed t o m eas u re sa m p les w hi c h e mi t fl uor esc ence fr o m 450-650 n m R esu l ts Figure 1 i ll u strates the 3D fluorescence measurements of the t-shir t . No f l u o r escence was obse r ved for the excitation wavelength from 290 to 400 nm. The sports shirt and arm cover also did not show a n y fluo r escence (data not shown). Figure 1. F l uorescence spectra of t -shi r t. Th e transmi s sion spectrum of e ac h sample i s shown in F i gure 2 a n d t he ca l culated UPF and UPF r ati n g r e sults are showr in Table 1. Figure 2. Tra n s m itta n c e s p e c t r um of t h e t -sh i r t (r e d)， spo r ts s hi r t (blue)， and a r m cove r (gr ee n) JASCO INC. 28600 Mary's Cour t ， E a s to n ， M D 21601US A UASGO A ppli c a tio n Lib r ary： htt p：//www.jas co in c .c o m/a pp l icatio n s Table 1. A nal y s i s res ul ts calc ul ated us i ng t h e UPF M e asu re m en t pr ogram a n d de f in e d b y A S /NZS 4399：1996. Sample Number UPF UPF Rating UVA Transmittance (%) UBV Transmittance (%) 1 30.0 4.4 3.1 T-Shirt 2 30.0 4.4 3.1 3 30.0 25 4.3 3.1 50+ 50+ 4 30.0 4.4 3.1 1 114.3 1.2 0.8 Sports Shirt 2 114.2 1.2 0.8 3 114.1 1.2 0.8 4 114.4 1.2 0.8 1 68.2 2.1 1.3 Arm Cover 2 68.0 2.1 1.3 3 68.1 2.1 1.3 4 68.0 2.1 1.3 C onclusion The UPF Measurement program can objectively compare the performance of the ultravio l et sh i elding as a result of the numer i cal ca l culation of the UV sh i elding perfor m of the fabric products. Aside from the AS/NZS 4399：2016 standard， the following standards a r e also i ncluded ： BS EN 13758-1：2002，AATCC Test Method 183：2010， and GBT18830：2009. 28600 Mary's Cour t ， E a s to n ， M D 21601US A