How is perspiration fastness tested?

In the hot summer, are you troubled by the phenomena in the pictures? The occurrence of this kind of phenomenon not only affects the appearance of clothes, but more importantly, it affects your health to a certain extent. So what is the reason for this kind of phenomenon?

There are millions of effective sweat glands on human skin, and the forehead, armpits, chest, back and palms sweat more. Therefore, clothing commonly worn in summer, such as shirts, T-shirts and other clothing, will suffer from serious fading in these parts. As we all know, the composition of human sweat is complex. The main component is salt, which varies from person to person. Sweat can be acidic or alkaline. Short-term contact between textiles and sweat may have little effect on their color fastness, but long-term contact with sweat close to the skin will have a greater impact on certain dyes. Clothing with unqualified dye fastness can easily cause dyes to transfer from textiles to human skin through sweat, etc. Dyestuff molecules and heavy metal ions may be absorbed by the human body through the skin and endanger health.

For the health of consumers, the national mandatory standard GB 18401-2010 “National Basic Safety Technical Specifications for Textile Products” requires that the color fastness to (acid, alkali) perspiration resistance of Class A products (infant textile products) should be greater than or equal to 3- Level 4; the requirements for Category B products (products that directly contact the skin) and Category C products (products that do not directly contact the skin) are greater than or equal to Level 3 (the color fastness to perspiration is divided into levels 1 to 5. The larger the value, the lower the color fastness. The better the fastness).

Some textile dyes are not resistant to acid and some are not resistant to alkali. The perspiration color fastness test uses artificial sweat with different pH levels to simulate the human body sweating to test the dye fastness of textiles. Today we came to Meisheng Biological Laboratory to learn the test methods of GB/T 3922-2013 “Testing on Color Fastness of Textiles – Color Fastness to Perspiration”.