Testing pure cotton fabrics with a light color fastness tester

The color fastness to light tester is suitable for testing the color fastness to light and perspiration of pure cotton fabrics, and can be used to evaluate the factors influencing the color fastness to light and perspiration. perspiration of fabrics. Qisnun Precision Electromechanical Technology Co., Ltd. can provide light color fastness tester, Welcome customers who need to inquire.

The colorfastness to light and perspiration of pure cotton fabrics is greatly affected by the variety of dyes, and the colorfastness to light and perspiration of light-colored fabrics is generally lower than that of dark colored fabrics; Sweat has some influence, and the color fastness to light and perspiration of the fabric is good when the surface of the fabric is neutral; the colorfastness to light and perspiration of the corresColor weight is determined by dyes with low colorfastness to light and perspiration.

Test standard:

Fabric colorfastness to light and perspiration is tested by GB/T 14576—2009 \"Test of Textile Colorfastness to Light Composite color fastness and perspiration; The fabric pH value is tested by GB/T 7573-2009 \"Determination of pH value of water extract of textiles\".

Test Results:

1. Effect of dye concentration on fabric light fastness and colorfastness to light and perspiration

Select 6 kinds of different color reactive dyes, use the two-bath pad dyeing method to dye, and test and classify dyed fabrics according to national standards.

It can be analyzed that the color fastness to light and trThe aspiration of the resulting fabric will increase to some extent with increasing dyeing concentration of reactive dyes of different colors. It can be seen from Table 1 that the test results of different concentrations of the two varieties of yellow reactive dyes, Golden R-4RFN and Golden RES, show that their lightfastness and sweatfastness can reach level 4 or more, and they have good resistance to light and perspiration. For the two varieties of reactive red, as the dye concentration decreases, their lightfastness performance decreases to some extent, especially when the dye concentration is reduced to 0.3g/L, the resistance to acid sweat and alkaline sweat resistance have a relatively obvious decline. The test results of blue reactive dye show that the light fastness and color fastness to light perspiration of its blue turquoise G cannot meet the demands of everyday use. Compared with the original sample, the tested sample has obvious discoloration, which is consistent with the concentrated appearance of consumers. Complaints are relatively consistent. In addition, reactive dyes are sensitive to the composition of sweat and alkaline sweat has a greater impact on it than acidic sweat.

It can be seen that the colorfastness to light and perspiration of reactive dyes is not only related to the dye concentration, but also to the natural color type of the dye. The different natural color structure of the dyes causes the difference in color fastness to light and perspiration.

2. The effect of pH on the color fastness to light and perspiration of fabrics

The acidity and alkalinity of the surface of the fabric have a great influence on the performance of the tfrom. Since pure cotton fabrics usually have to go through mercerizing and washing procedures during the finishing process, the pH of the fabric surface changes significantly. The pH of the fabric affects its resistance to light and perspiration to some extent. In this test, the pH value of the fabric surface was adjusted by buffering a sodium carbonate solution and an acetic acid solution, and the pH value was tested. The effect of value on the colorfastness to light and perspiration of the fabric.

By changing the pH of the surface of the fabric and retesting the color fastness to light and perspiration of the fabric according to the national standard method, we find you the pH has some influence on the test to light and perspiration of the fabric. When the surface of the fabric becomes neutral again, its resistance to light and perspiration is good. When the pH of the fabric surfaceu is adjusted, its colorfastness to light and perspiration decreases to some extent. When the fabric surface is adjusted to be acidic, the color fastness to acid and perspiration decreases significantly; when the fabric surface is adjusted to be alkaline, the color fastness to alkali and perspiration decreases significantly. The reason for this pattern may be that the acidic and alkaline substances on the surface of the fabric strengthen or weaken the effect of acid and alkali on the fabric during the test, resulting in changes in the resistance to light and perspiration of the fabric.

3. The effect of color matching on the color fastness to light and perspiration of fabrics

In the actual dyeing process, it is usually necessary to mix several basic colors and use them to meet the needs. the colour. Howeverdant, due to the ratio of different dyes to R-4RFN golden and R-2BF red dyes, as well as RES golden and RES scarlet, which have a better effect on lightfastness and sweatfastness, the fastness colors in the light and sweat of the fabric is better; When the dyes are added with blue C-R and turquoise blue G, which have poor color fastness to light and perspiration, the color fastness to light and perspiration of the fabric shows obvious fading and fading . Therefore, if a variety of colors are dyed after color matching, even if there are several dyes with good color fastness to light and sweat, the color fastness to light and sweat of the fabric is determined by the dye with poor performance.

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