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Test Colour Fastness to Light using MBTL Fastness Tester

Poor colour fastness can be often observed in sports dresses which are mostly exposed to harsh lighting conditions or car seat fabric and carpets. Dyes used in such materials fade when exposed to sunlight or artificial light for a prolong time. Also it is possible for a dyed article to fade during drying on a washing line in bright sunlight or, more importantly, under display lighting conditions in a retail outlet. Any reputable retailer would take such level of performance as unacceptable. Hence, testing for light fastness is important and provides an objective framework for what is acceptable. This type of test can be conducted using an MBTL fastness tester.

Test Colour Fastness to Light using MBTL Fastness Tester
The chemistry behind colour fading

Fastness to light is generally a feature of the actual colourant molecule itself. It is the capability of the molecule to absorb radiation without being destroyed. In a dye with poor light fastness, the molecule will be broken down by the absorbed radiation. Light fastness is the degree to which a colourant resists fading due to light exposure. Different dyes have different degrees of resistance to fading by light.

Retailers are nowadays becoming more conscious of issues concerning colour fastness to light. Higher colour fastness is being demanded for apparel that will be worn predominantly outdoors. The criteria of light fastness are hence becoming a major concern amongst buyers and consequently with dyers.

The standard testing method for evaluation of colour fastness to light is BS EN ISO 105-G02:1997. This test can be conducted using an MBTL Fastness Tester, which is used to determine the color fastness and degradation of textiles to sunlight or artificial light.

MBTL Fastness Tester
The instrument comprises of a metallic hollow cylinder, which opens from both the ends. The testing apparatus is equipped with a 500 watt MBTL fading lamp which is installed centrally for constant light emission around the circumference. It also offers an hour meter with buzzer and an hour totalizer for time estimation of the test. There are four sample holders in the machine at an equal distance inside the cylinder along with a metal sheet to cover half portion of each sample. This adjustment can allow you to compare the half faded portion to the covered one. It offers cooling arrangements with water flow, in case the temperature rises up to or above 800°C. The machine is duly supplied with horizontal pump and a water tank.

For more information, kindly contact our technical team here.

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