May 12, 2021
How to improve the combined color fastness to light and sweat?
What is the combined colour fastness of light and sweat
Combined color fastness of light and sweat refers to the color fastness of textile to artificial light under the action of artificial sweat. It reflects the resistance of dye molecules in textile to sunlight in the presence of sweat.
In the case of textile, the fading will be more intense because the dyes on the clothing will inevitably be exposed to the combined action of light, oxygen and other chemicals. Especially in our daily wearing, summer clothes are affected by sunlight, sweat and high temperature, which are more likely to fade or redness.
Test to combined colour fastness of light and sweat
At present, there are test standards GB/T 14576-2009, ISO 105-B07:2009 and so on for color fastness to light and sweat at home and abroad.
Do you want to know your clothes to color fastness of light sweat qualified? I'm going to show you a set of experiments.
Take GB/T 14576-2009 Test for Textiles Combined Colour Fastness to Light and Sweat as an example.
The principle is: after the artificial sweat treatment sample and blue wool standard sample at the same time in the light resistance testing machine, expose to the sun under specified conditions. When the color fading of the blue wool standard sample reached the end point, the sample was taken out and evaluated the coloue change with a gray sample card or instrument.
The artificial sweat used is divided into acid sweat and alkaline sweat.
1.Prepare test samples, ensure that the samples are clean and tidy, avoiding defects and stains. Weigh the mass of the sample, accurate to 0.01g.
2.Put the sample into the sweat box and add 50ml of freshly prepared sweat. The sample is completely immersed in sweat and soaked at room temperature for about 30min, during which the sample should be slightly pressed and agitated to ensure that the sample is completely wet.
3.Take out the sample from the sweat, remove the excess sweat on the sample, and weigh the mass of the sample so that the liquid carrying rate is (100±5%)
4.The sample is fixed on the waterproof white board, and then a grade 4 blue wool standard sample fixed on another white board.
5.The blue wool standard sample is covered with a half shielding plate, and the sample to be tested is not covered.
6.The fixed samples and blue wool standard samples are placed in the exposure chamber of the light resistant testing machine, and the exposure conditions is carried out according to GB/T 8427 (medium effective humidity, humidity control standard sample level 5, maximum black label temperature 50℃)
7.Continuous exposure until the discoloration of grade 4 blue wool standard sample reaches grade 4-5 of gray card, the exposure can be terminated. Take out the sample, wash it with three-level water at room temperature for 1min, and then hang it in the air to dry at no more than 60℃
8.Use gray sample card or instrument to evaluate the sample color. Then according to the corresponding product standard of light and sweat composite color fastness assessment index to determine the sample qualified or unqualified.
It can be clearly shown from the picture that, after the experimental test, except the orange sample of the original sample did not produce too much discoloration, the remaining three samples showed relatively large discoloration compared with the original sample. However, for the assessment index of color fastness to light and sweat of many products, the discoloration of these three samples could be judged as unqualified.
Do you understand the test process after reading it? Then how to improve the textile ‘s combined colour fastness of light and sweat?
Let us introduce the color fastness tester from Haida , he can solve all your troubles !