GB/T 12967.4-1991 Determination of ultraviolet light resistance of anodized aluminum and aluminum alloys GB/T12967.4-1991 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Anodizing of aluminium and aluninium alloys--Determination of thefastness to ultraviolet light of coloured anodic oxide coatings GB/T 12967.4 91
This standard is equivalent to the international standard 1SO6581-1980 "Determination of thefastness to ultraviolet light of coloured anodic oxide coatings of aluminium and aluminium alloys".
1 Subject content and scope of application
This standard specifies a reference test method for the ultraviolet light resistance of coloured anodic oxide coatings of aluminium and aluminium alloys. This standard is applicable to the fastness test of coloured anodic oxide coatings of aluminium and aluminium alloys. This standard is a relatively fast test method for fastness to light. This standard is not applicable to heat-sensitive coloured anodic oxide coatings. 2 Principle of the method
After the anodized sample is irradiated with ultraviolet light, it should be compared with the standard sample or control standard sample. By observing the changes in the sample after irradiation, its light resistance performance can be evaluated.
Note that the light source emitted by mercury vapor has the characteristics of spectral discontinuity and strong ultraviolet radiation, so the results of this test method must be compared and verified with the test results of sunlight irradiation. 3 Apparatus
The inspection apparatus mainly consists of an irradiation chamber, an ultraviolet light source, and a sample placement rack or a sample placement table. 3.1 Irradiation chamber
3.1.1 The irradiation chamber should be made of heat-resistant materials. The sample placement rack or sample placement table should be equidistant from the light source so that the exposed sample is equidistant from the light source.
3.1.2 For cylindrical irradiation chambers, the bulb should be placed in the center of the chamber; for rectangular irradiation chambers, the bulb should be placed horizontally on the sample rack. Both irradiation cases have good applicability. 3.1.3 Since the higher the test temperature, the faster the sample fades, the temperature of each part of the surface of the sample in the irradiation room should not exceed 100℃. The temperature of the irradiation room and the sample can be controlled by adopting a suitable air supply and air cooling method. At this time, the bulb should be prevented from being overcooled to avoid damaging the arc lamp. For specific methods, please refer to the instructions for use of the bulb. 3.1.4 Because ultraviolet light of a certain wavelength can damage the eyes, it is stipulated that the irradiation room should be fully enclosed or equipped with a suitable isolation device to avoid any possibility of ultraviolet light leakage. The revolving door of the irradiation room should be equipped with a micro switch, which can automatically cut off the light source when the revolving door of the irradiation room is opened
3.1.5 Under the test state, many ultraviolet lights can produce ozone (see Article 4.3), which is harmful to human health. If the ozone is produced by the light source, it is best to have a compressed air circulation device to discharge the ozone in the irradiation room to the outside. 3.2 UV light source
Approved by the State Administration of Technical Supervision in 199106-04
Implemented in 199203-01
GB/T12967.4---91
3.2.1 UV light bulb A medium-pressure mercury arc lamp with a silicon oxide coating on the outside of the bulb, controlled by a suitable transformer and switch. The bulb should not be covered with a glass cover, as the glass cover will lose a lot of UV light. 3.2.2 The power and arc length of the lamp should satisfy the following intensity relationship at a distance of 190 mm from the center of the bulb (see Table 1): Table 1
μw/cm
500 to 150
800 to 400
600 to 400
1000 to 800
1350 to 1200
1500 to 1700
800 to 1000
1300 to 1600
3.2.3500w commonly used bulbs have an effective arc length of 120 mm and are approximately 190 mm from the specimen. 3.2.4 Many bulbs have a rated life of 1000 hours. During use, especially when the wavelength is less than 313nm, the output light will generally decrease. At this time, a suitable intensity regulator should be selected to compensate for the loss of light intensity. 3.2.5 Do not touch the silica coating on the bulb with your hands to prevent the glass from losing its luster and affecting the radiant light intensity of the lamp source. 3.2.6 Although ozone has little effect on the test results, it is still desirable to use bulbs that do not produce ozone. This can also reduce exhaust devices and settings.
3.3 Sample placement
3.3.1 The sample should be placed on the fixture or bracket of the sample rack or sample table. And ensure that the distance between the sample and the light source is equidistant. 3.3.2 Cylindrical brackets and glass products will produce shadows. Be sure to prevent these shadows from blocking the sample to avoid loss of ultraviolet light. 4 Test steps
When the anodized sample is placed in the irradiation room for ultraviolet light irradiation, it should be kept until the color change of the sample or control sample reaches the predetermined standard. wwW.bzxz.Net
4.1 Sample Pasting
4.1.1 On the periphery of the sample surface, paste with opaque material to avoid ultraviolet light exposure. This is conducive to the inspection of color changes.
4.2 Control Sample
4.2.1 This test is very demanding. In order to achieve the purpose of comparative inspection, a standard colored anodized sample with known ultraviolet light resistance should be selected as a control sample.
4.2.2 During the test, the sample and the control sample should be subjected to ultraviolet light irradiation test at the same time, and the control sample should also be pasted in the same way for the final inspection and comparison.
4.3 Influence of Ozone
4.3.1 Some of the bulbs used may produce ozone. However, this has little impact on the inspection results of the anodized sample. 4.3.2 When there is ozone in the atmosphere, the surface of the anodized sample sometimes forms a layer of spots. Therefore, before evaluating the results of the sample, it should be wiped off with a soft abrasive. 463
4.4 Exposure time
12967.491
4.4.1 The exposure time mainly depends on the selected instrument and the evaluation degree of the colored anodized sample. 4.4.2 Compared with other sun resistance test methods, this test method is a more demanding test method. Therefore, when the exposure time is within 100h, the color of the colored sample can change significantly. 5
Test report
The test report should include the following contents:
This standard number;
Results and expression methods;
Some abnormal phenomena observed during the inspection; operating methods not included in this standard or considered to be optional. Additional notes:
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Northeast Light Alloy Factory. The main drafters of this standard are Gao Kangzhi and Wang Ziyi. 46.1
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.