GB/T 8427-2019 Textiles－Tests for color fastness－Color fastness to artificial light：Xenon arc English
1 Scope
This standard specifies a method intended for determining the effect on the color of textiles of all kinds and in all forms to the action of an artificial light source representative of natural daylight (D65).
This standard is applicable to colored and also white (bleached or fluorescent brightened) textiles.
Note: this standard allows the use of two different sets of blue wool reference materials. The results obtained may not be identical.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 250 Textiles - Tests for color fastness - Grey scale for assessing change in color (GB/T 250-2008, ISO 105-A02: 1993, IDT)
GB/T 730 Textiles - Tests for color fastness - Quality control of blue wool reference materials 1to 7 (GB/T 730-2008, ISO 105-B08: 1995, MOD)
GB/T 6151 Textiles - Tests for color fastness - General principle of testing (GB/T 6151-2016, ISO 105-A01: 2010, MOD)
GB/T 6682 Water for analytical laboratory use - Specification and test methods (GB/T 6682-2008, ISO 3696: 1987, MOD)
GB/T 8431 Textiles - Tests for color fastness - Detection and assessment of photochromism (GB/T 8431-1998, eqv ISO 105-B05: 1994)
GB/T 32616 Textiles - Tests for color fastness - Instrumental assessment of change in color for determination of grey scale rating (GB/T 32616-2016, ISO 105-A05: 1995, MOD)
FZ/T 01047 Standard light sources and conditions for visual assessment of textile color fastness
ISO 105-B01: 2014 Textiles - Tests for color fastness - Part B01: Color fastness to light: Daylight
ISO 9370 Plastics - Instrumental determination of radiant exposure in weathering tests - General guidance and basic test method
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
3.1
test specimen
portions of the textile samples to be tested and which are representative
Note: this is used for comparison between the exposed and the original (unexposed) state.
3.2
reference specimen
portion of a reference material that is to be exposed simultaneously with the test specimen
Note: multiple reference specimens may be required to determine the test results.
3.3
blue wool reference material
one of a series of blue wool textile materials with a known reaction to light
3.4
test chamber
area within the device capable of meeting and maintaining the requirements for temperature, light and humidity
3.5
chamber relative humidity
ratio of the actual water vapor pressure in the test chamber to the saturation water vapor pressure at the same temperature
Note: the chamber relative humidity is expressed as a percentage.
3.6
effective humidity
combination of air and surface temperatures and air relative humidity which governs the moisture content at the surface of the test specimen during exposure
3.7
humidity-test control fabric
a red azoic dyed cotton fabric of known sensitivity to humidity and light
Note: this red azoic dyed fabric is used as a reference material to ensure that the effective humidity requirements are met.
3.8
photochromism
change in color of a test specimen after brief exposure to light, which is substantially returned to its original color after storage in the dark
3.9
flip-flop mode
mode of operation whereby the test specimen holders revolve around the central light source and on alternate rotations the test specimen holders are automatically rotated 180° about their vertical axis so that the test specimens face towards the light source only every alternate revolution
4 Principle
A test specimen of the textile is exposed to artificial light under controlled conditions, together with a set of blue wool reference materials. The color fastness is assessed by comparing the change in color of the test specimen with that of the blue wool reference materials used.
Note: Annex A gives a brief description of color fastness to light.
5 Materials and devices
5.1 Reference materials
5.1.1 General
Either of two sets of blue wool reference materials may be used. The rating of color fastness to light is obtained by comparison with either blue wool reference materials 1 to 8 (preferred in Europe) or blue wool reference materials L2 to L9 (preferred in America). The results from different references are not interchangeable. Information on the relationship between the two sets of blue wool reference materials may be found in 4.1, ISO 105-B01: 2014.
