Three test methods for light fastness and how to improve textile color fastness?

Test method for color fastness to light

The color fastness of textiles refers to the degree of fading and dyeing of textiles during processing and use. The principle of photofading of textile dyes is very complicated: the structure of the dye is destroyed mainly because the dye absorbs photons, is stimulated and undergoes a series of photochemical reactions, resulting in color fading. The color fastness to light of textiles mainly depends on the chemical structure of the dye, as well as its aggregation state, combination state and mixed color matching. Today, we discuss the test methods for color fastness to light and 3 ways to improve textiles.

Comparison of Test Methods for Color Fastness to Light

Textiles are often exposed to light as they are used, and the light energy extinguishes the dye and causes the familiar "fade" of colored textiles, which often lightens and darkens, and some of them also experience color changes. If you want to know more about lightfastness testing, you can check out Lightfastness Tester.

Common methods for lightfastness testing

ISO 105 test methods (ISO 105 B01, ISO 105 B02, ISO 105 B04, ISO 105 B06, etc.)

AATCC 16 – Test Methods by Light Source Type

ISO 105 test method

Method 1 : Control the exposure time by checking blue wool reference standards, each sample should be equipped with a set of blue wool reference standards, usually used in case of disputes.

Method 2 : Control the exposure time by checking the blue wool reference value, a batch of different samples only need one set of blue wool reference value, you can save the blue wool reference value.

Method 3 : This method is used to check that the sample is consistent with known performance specifications. According to the requirements, the sample only needs to be equipped with two blue wool benchmarks, and the exposure period can also be controlled by checking the blue wool benchmarks.

Method 4 : This method is used to check that one or more samples correspond to an agreed reference sample. The essential feature is to control the exposure time by checking an agreed reference sample. Allows samples to be exposed using reference samples only, and blue wool references are not used.

Method 5 : This method is suitable for checking compliance with agreed radiation levels. The sample can be exposed alone, or the blue wool reference. Samples shall be exposed until the specified radiant energy is achieved.

AATCC 16 – Test Methods by Light Source Type

Method 1 : Xenon arc lamp, alternating light and dark

方法2：氙弧灯，连续光，黑标温度计

方法3：氙弧灯，连续光，黑板温度计

部分耐光色牢度测试标准的技术要求比较

如何提高纺织品的耐光色牢度？

通过研究和实践发现：选择具有良好耐光性的染料是提高纺织品耐光性的关键。纺织品的耐光色牢度主要取决于化学结构，聚集态，结合态和染料的混合物。现在我们分析如何提高染料对光的色牢度。

According to纤维特性和纺织品用途选择染料

• 对于纤维素纤维纺织品，应选择具有更好抗氧化性的染料    。

• 对于蛋白质纤维，应选择具有良好抗还原性能或弱氧化性添加剂的染料。

• 对于其他纤维，请According to褪色效果选择染料。

According to颜色深度选择染料

活性染料在纤维素纤维上的色牢度与所染颜色的深度成正比，也就是说，颜色越深，光色牢度就越好。

例如，在对浅色品种进行染色时，应选择耐光性稳定的染料。另外，添加许多整理剂，例如柔软剂和抗皱整理剂，也会降低产品的耐光性。这些织物应选择对整理剂不敏感的染料。

选择具有良好耐光稳定性和颜色组合兼容性的染料

不同染料的褪色特性不同，甚至光褪色的原理也不同。有时，一种染料的存在会引起另一种染料的褪色。

When the color is a combination color, we should choose dyes that are not sensitive to each other or even improve light stability, which is especially important when dyeing black and other black varieties. If one of the three primary colors disappears too quickly, it will quickly discolor the dyed fiber or fabric, and the faded dye residue will also affect the light stability of the other two dyes. Reasonably control the dyeing process to fully combine the dyes with the fibers, and try to avoid hydrolyzed dyes and unfixed dyes remaining on the fibers. This is an important way to obtain stable light fastness.

Due to the complexity of light and climate in reality, it is difficult to simulate color fastness testing. In order to make the results close to reality, the operator needs to master the test process proficiently and with the help of a stable weather instrument (light fastness Tester).