It is summer now. Whether you are distressing about the phenomenon occurred in the picture? Appear this kind of fading phenomenon, not only affect the appearance of the clothes, but will affect your health, then what is the reason for this kind of phenomenon?
As we all know, the sweat of the human body composition is complicated, the main ingredients for salt, vary from person to person, sweat is acidic, and alkaline. If textiles contact with sweat closely for a long time, it will produce great influence on some dyes.
For consumer health, national mandatory standard GB 18401-18401 "national textile product basic safety technical specifications" for (acid, alkali) perspiration fastness rating of A product (infant textile products) require greater than or equal to 3-4; Class B products (Direct contact with the skin products) and class C products (without direct contact to skin product) are greater than or equal to 3 (the color fastness to perspiration was divided into 1 ~ 5, the larger the value, the better color fastness ).
Some textile dyes are no acid resistance, or no alkali resistance, perspiration colorfastness test is to use different PH value of artificial sweat, simulate the human body sweating in textiles for color fastness test.