Selection Guide for Light Fastness Tester

 


What is color fastness to light?

As we all know, textiles are usually exposed to light during their use life, and light has the potential to destroy the dye, resulting in the effect of “fading,” which causes colored textiles to change color, usually light or dark. We call the degree of resistance to the fading effect of light as color fastness to light. The color fastness to light is a very important index in physical testing of textiles. And light fastness tester is the machine for the test.

How to test the color fastness to light?

The test method of color fastness to light is exposing a set of reference samples along with the specimens at the same time and under the same conditions; the color fastness to light is assessed by comparing the change in color of the test specimen with that of the reference materials used.
Color fastness to light can also be divided into: sunlight (which can be exposed to several different colors of sunlight) and artificial light (xenon arc or carbon arc). In order to control the test conditions in the laboratory and speed up the testing process, the labs generally use artificial light source, so they need a color fastness tester which can simulate and strengthen the natural environmental factors such as the light irradiance, humidity, temperature, light and dark cycle and spray etc.
At present, ISO 105 B02 and AATCC 16 are the two commonly used standards to test the textiles’ color fastness to light internationally. Below the writer give the key control parameters of two test methods.

Types of light fastness tester

There are three kinds tester for textile color fastness to light if dividing by light source: The tester with xenon arc lamp as light source, the tester with carbon arc lamp as light source and the tester with mercury lamp as light source.

Xenon arc lamp tester

Xenon lamp has been used as an artificial light source for the color fastness test for a long time, because the spectral power distribution curve of xenon arc lamp is close to sunlight, and at the same time, the ultraviolet, visible and infrared wavelength generated by xenon arc lamp are the closest to sunlight at present.
The xenon arc tester also have two types according to different cooling method for xenon arc lamp, air cooled and water cooled models.

Carbon arc lamp tester

Carbon arc lamp is the earliest light source for color fastness to light test in textile industry. Carbon arc lamp is divided into two kinds, one is closed carbon arc lamp, the other is solar carbon arc lamp. Both of these carbon arc lamps are used in early equipment, the former is initially used for textile light resistance test, the latter is initially used for coating light resistance test. The luminescent body of the enclosed carbon arc lamp is a group of carbon rods. However, the spectral energy distribution (SPD) of the arc light emitted by carbon rods is quite different from natural sunlight. There is neither short wave ultraviolet radiation nor high intensity energy of sunlight between 400-800nm in natural sunlight. The SPD matching between solar carbon arc lamp and natural sunlight is improved, but the spectral distribution between the two is still different between 50nm and 350nm. Therefore, in general, the correlation between the carbon arc lamp test results and the actual weather resistance of the product is poor. So the carbon arc lamp has is not so popular compared with xenon arc lamp tester.

Mercury lamp tester

Mercury lamp’s spectral lines are mainly in the ultraviolet part, the wavelength concentrate around 365mm. It is mainly used for outdoor products durability test.
The more information about how to choose light fastness tester can be found here.

Comments

Post a Comment

Popular posts from this blog

Twist Test Methods and Influencing Factors

Image
  Twist test is an important part of yarn inspection. It is related to the strength, elongation, appearance, style, etc. of yarns and fabrics. Different yarns have different structural characteristics, and their twist testing methods are also different. Basic concept To understand twist testing, you must first understand what twisting is. Twisting is a necessary condition for yarn formation. Short fibers can be made into yarns with certain physical and mechanical properties through twisting; filaments often need to be twisted in order to increase the tightness between single filaments, facilitate processing, and improve fabric properties. Number of twists Twisting is to cause two cross-sections of parallel straight fiber slivers to rotate relative to each other. The number of relative rotations of the two cross-sections is called the number of twists. Twist Twist refers to the number of twists per unit length of yarn . Twist coefficient In actual production, the twist coefficient is of
Read more

Combing Process in Spinning

Image
Before processing cotton, wool, and silk fibers into fabrics, the process of removing impurities and short fibers in the fibers with a combing machine is called combing. The texture, washability and durability of the fabric produced through this process are greatly improved compared with carded fabrics. The following introduces the composition of the combing machine and the combing process. The kinematic coordination relationship of the main parts on the combing machine is indicated by a dial. The disc is mounted on the combing machine and rotates synchronously with the cylinder, which is generally called the indexing disc. The index plate is divided into 40 equal parts along the circumference, and each equal part is 9°, which becomes one index. The working cycle refers to the time interval between the combing cylinder of the intermittent combing machine corresponding to the two actions of combing the whiskers. That is: the first row of needles in the combing cylinder goes to the botto
Read more

Garment Dyeing-Special Dyeing Method In Textile

Image
Garment dyeing is a relatively special dyeing process for textiles and garments. Many people may not know much about this dyeing process. In the impression of most people, textile and clothing products are dyed in the fabric period, and garment dyeing is a dyeing process that breaks people’s cognitive limitations on textile dyeing. ​What is garment dyeing ​Garment dyeing means that dyeing the one not in the fabric type but in the garment type itself. The garment type mentioned above include socks, towels, sportswear, shirts, plush toys (without fillers), T-shirts, pants, bathrobes, handkerchiefs, bath mats, carpets, scarves, etc. The material of these garments can be wool, linen, silk and cotton of natural fibers. But most garments are made of cotton or a cotton-rich blends. Garment dyeing imparts vibrant colors to garments. The clothes such as denim garments, tops, sportswear and casual clothing with garment dyeing can provide a distinctive special effect. Garment dyeing method Garmen
Read more