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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard is revision of QB/T 2727-2005 Leather - Tests for Colour Fastness - Colour Fastness to Artificial Light: Xenon Arc.
In addition to a number of editorial changes, the following technical changes have been made with respect to QB/T 2727-2005:
——The standard name is adjusted to "Leather - Tests for Color Fastness - Color Fastness to Artificial Light: Xenon Art Fading Lamp Test";
——The normative references are revised, for the purpose of which, the year of references are cancelled, making the references the current documents, and the GB/T 6682 Water for Analytical Laboratory Use - Specification and Test Methods is added;
——The description of the principle is revised;
——The descriptions of water-cooled xenon arc lamp in equipment are revised;
——Black panel thermometer is added for the temperature sensor in the equipment;
——The descriptions of the specimens are detailed;
——The exposure conditions are added;
——The exposure methods are detailed;
——The descriptions on the assessment for color fastness to light are made more detailed.
This standard is proposed by China National Light Industry Council.
This standard is under the jurisdiction of SAC/TC 252 the National Technical Committee on Leather of Standardization Administration of China.
The previous edition of the standard superseded by this standard is as follows:
——QB/T 2727-2005.
Leather - Tests for Color Fastness -
Color Fastness to Artificial Light: Xenon Art Fading Lamp Test
1 Scope
This standard specifies the methods for testing the color fastness of leathers to artificial light and heat.
This standard is applicable to various leathers with color fastness requirements to light and high temperature.
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 Colour Fastness - Grey Scale for Assessing Change in Colour
GB/T 730 Textiles - Tests for Colour Fastness - Quality Control of Blue Wool Reference Materials 1 to 7
GB/T 6682 Water for Analytical Laboratory Use - Specification and Test Methods
GB/T 8432 Humidity Test Control for Colour Fastness to Light
3 Principle
The specimen is exposed to artificial light together with blue wool reference material under specified conditions. After the specimen is exposed to meet the specified requirements, its color fastness to light is assessed by comparing it with the blue wool reference material or grey scale used.
4 Reference Material and Equipment
4.1 Reference material
4.1.1 Blue wool reference material, which is in accordance with GB/T 730.
4.1.2 Humidity test control sample, which is in accordance with GB/T 8432.
4.1.3 Gray scale for assessing change in color, which is in accordance with GB/T 250.
4.1.4 Coverings, made of opaque materials such as hardcard being white inside and outside and aluminum flake.
4.2 Equipment
4.2.1 Light fastness apparatus with xenon arc lamp (air cooled or water cooled)
The specimen and the blue wool reference material may be exposed to the xenon arc lamp simultaneously in any of the following equipment (see 4.2.1.1 and 4.2.1.2); the difference between the light intensity on the illuminated faces of both the specimen and the blue wool reference material shall not exceed ±10% of the average value; the radiant exposure (the radiant energy per unit area), which is measured with an irradiance monitoring meter (4.2.2.3), should be 42W/m2 if the wavelength is 300 nm~400 nm, or it should be 1.1W/m2 or 1.2 W/m2 if the wavelength is 420 nm; the distance from the xenon arc lamp to the specimen surface and the blue wool reference material surface shall be kept the same; the light source shall be placed vertically on the central axis of specimen mounting which rotates at the speed of (1±0.1) r/min.
4.2.1.1 Light fastness apparatus with air-cooled xenon arc lamps
The light fastness apparatus with air-cooled xenon arc lamps shall be in accordance with the following requirements:
a) Optical filter: placed between the light source and the specimen/blue wool reference material, so that the ultraviolet spectrum is attenuated stably .The light transmittance of the filter glass used shall be no less than 90% between 380nm~750nm, and shall be reduced to 0 when it is between 310nm~320nm.
b) Heat-reducing filter: which is placed between the light source and the specimen/blue wool reference material and may allow the stable attenuation of infrared radiation contained in the xenon arc spectrum; a glass filter is used to eliminate the excess infrared radiation so that the temperature condition specified in the standard is reached;
c) Humidity test control sample: for the humidity test control sample in accordance with GB/T 8432, the color fastness to light shall not be less than Grade 6.
4.2.1.2 Light fastness apparatus with water-cooled xenon arc lamp
The light fastness apparatus with water-cooled xenon arc lamp shall be in accordance with the following requirements:
a) Optical filter: which consists of the inner and outer filter glass to contain and guide the flow of cooling water; the filter is placed between the light source and the specimen/blue wool standard sample, so that the ultraviolet spectrum and part of the infrared spectrum can be stably attenuated; and the transmittance is no less than 90% between 380nm~750nm and drops to 0 around 310nm. or it is equipped with quartz light filter inside and S-shaped silicon-bromine light filter outside;
b) It is able to control the temperature and relative humidity automatically;
c) Cooling system: Class 3 water circulation (in accordance with GB/T 6682) passes between the internal and external filter glass of the xenon lamp and is cooled by the heat exchange device.
4.2.2 Temperature sensor
4.2.2.1 Black panel thermometer (BPT), which consists of a metal plate with a size of at least 45 mm×100 mm. The temperature of the metal plate is measured with a temperature measuring device, and the thermometric measurement point is located at the center of the metal plate. As for the metal plate, the side facing the light source is black, so that the reflectivity of the light reaching the specimen on the blackboard is less than 5%.
4.2.2.2 Black standard thermometer (BST), consisting of a stainless steel plate approximately 70 mm× 30 mm in size and 0.5 mm in thickness, the temperature of which is measured with a temperature measuring device. The metal plate is fixed with a plastic plate for insulation and is coated with a black coating, so that an absorptivity of no less than 95% can be obtained even in the range of infrared spectrum.
4.2.2.3 Irradiance monitoring meter: since the irradiance of the specimen surface changes as a function of xenon lamp, light intensity and the distance from the xenon lamp to the specimen, the consistency of the exposure shall be controlled with the irradiance monitoring meter.
Foreword i
1 Scope
2 Normative References
3 Principle
4 Reference Material and Equipment
5 Specimen
6 Exposure Conditions
7 Operating Procedures
8 Exposure Methods
9 Assessment on Color Fastness to Light
10 Test Report
