I. Scope of the Standard

This standard specifies the test methods, expression of protection level, evaluation and labeling for the performance of textiles against solar ultraviolet radiation.

This standard is applicable to the evaluation of the performance of fabrics in protecting against solar ultraviolet radiation under specified conditions.

II. Introduction to the Standard

The national standard Textiles - Evaluation of Ultraviolet Protection Performance includes ten aspects, such as explanations of terms, testing principles, testing instruments, sample preparation, result calculation, etc.

Now we will focus on explaining the "testing principles" and "evaluation and labeling".

a. Testing Principle
Irradiate the sample with monochromatic or polychromatic UV rays, collect the total spectral transmitted rays, determine the total spectral transmittance, and calculate the Ultraviolet Protection Factor (UPF) value of the sample.

A parallel light beam can be used to irradiate the sample, with an integrating sphere collecting all transmitted light; alternatively, a hemispherical light source can be used to irradiate the sample.

b. Evaluation and Labeling

The standard stipulates that a product can only be called an "ultraviolet-proof product" if both of the following conditions are met: the UPF value of the sample is greater than 40, and the average transmittance of UVA (T(UVA)AV) is less than 5%. These two conditions are indispensable and serve as the indicators for determining whether a product is an "ultraviolet-proof product".

UV-protective products should be labeled with the following information:

National standard number: GB/T 18830-2009;
UPF value: 40+ or 50+

(1) When 40 < UPF ≤ 50 and the UVA transmittance is less than 5%, label as: 40+;
(2) When UPF > 50 and the UVA transmittance is less than 5%, label as: 50+;
(3) The protective performance provided by the product may decrease with long-term use, or when stretched or wet.

III. Explanation on UPF Value

UPF is the abbreviation of Ultraviolet Protection Factor, which refers to the ultraviolet protection coefficient. As defined in the national standard, UPF is "the ratio of the average effect of ultraviolet radiation calculated when the skin is unprotected to that calculated when the skin is protected by textiles." This definition is relatively abstract. We can understand the physical meaning of UPF as follows: for example, if the UPF value is 50, it means that 1/50 of the ultraviolet rays can penetrate the fabric. The higher the UPF value, the better the ultraviolet protection effect. However, the highest UPF label specified in the national standard for textiles is 50+, that is, UPF > 50. This is because when UPF exceeds 50, its impact on the human body can be completely ignored.

It should be added that the national standard Textiles - Evaluation of Ultraviolet Protection Performance is a recommended standard rather than a mandatory one. Enterprises can choose whether to produce UV-protective products according to their actual conditions. However, if a product is claimed to be an "ultraviolet-proof product," it must comply with this standard.

IV. Testing Instruments

UPF Ultraviolet Transmittance Performance Tester (for detailed product information, please click the product link UV-2000)

Standards Compliance: GB/T 18830, AS/NZ 4399:1996, etc.

For more detailed technical standard information, please contact Luozhong Technology.