GB/T 4893.2-1985 Determination of resistance to moisture and heat of furniture surface paint films

GB/T 4893.2-1985 Determination of resistance to moisture and heat of furniture surface paint film GB/T4893.2-1985 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Furniture--Assessment of surface resistance to wet heat
UDC 684.4 : 667
GB 4893.2--85
This standard is applicable to the determination of the resistance to wet heat of paint films on the surfaces of wooden furniture and other wooden furniture parts. A container containing a medium is placed on the surface of the sample at a specified temperature with a wet cloth in between. After a specified time, the container and wet cloth are removed and the paint film is rated according to the degree of damage. Instruments and materials
Copper test cup (see Appendix A).
1.2 Electric furnace.
1.3 Balance with a graduation value of 0.1g.
Crusher tongs.
Thermometer 0～100℃ mercury thermometer, accuracy 1℃. Insulation pads should be no less than 100mm×100mm×10mm wooden board. Nylon spun white, product number 21156, product name 112/62, 53g/m2. Specifications are 70mm×70mm. Stainless steel pointed tweezers.
Distilled water.
Qualitative filter paper (GB1915---80 "Qualitative filter paper"). Heating medium Mineral oil with an ignition point of not less than 250℃. 1.12
2 Sample
Observation box (see Appendix B).
Specifications are 250mm×200mm.
After the sample is painted, it should be stored for at least 10 days and completely dried before testing. 2.2
2.3 The surface of the sample should be flat, and the paint film should be free of defects such as scratches and bubbles. 2.4 When sending samples, a test report should be attached, including the name of the paint, a brief coating process, production time, etc. 3 Test conditions
3.1 The test room temperature is 20±2℃. Relative humidity is 60%~70%. 3.2 The test temperature is based on the product standard or the agreement between the supply and demand parties. Recommended test temperatures: 55℃, 70℃, and 85℃. 4 Test steps
4.1 Select three test areas on the sample, each with a diameter of 50mm. The center of the test area is not less than 40mm from the edge of the sample, and the centers of the three test areas are not less than 65mm apart. 4.2 After the test area is determined, mark it. Before the test, the test data records of color, gloss, and paint film appearance must be made according to the following requirements:wwW.bzxz.Net
The color selection of the contrast area is consistent with the color of the tested area. a.
National Bureau of Standards Issued on February 1, 1985
Implementation on April 10, 1985
GB 4893.285
Gloss Use a photoelectric gloss meter to measure the gloss value of the tested area. b.
Surface Visual inspection The tested area should have no obvious defects. c.
4.3 Check the bottom of the copper test cup. There should be no surface damage and adhesion. Then inject 100±1g of mineral oil. 4.4 Place the copper test cup on an electric furnace and heat it until the oil temperature exceeds the specified temperature by 10℃ (safety must be ensured during the heating process). Use pliers to place the test cup on an insulating pad, let the oil temperature drop slightly, and stir the mineral oil continuously to make the temperature evenly distributed. 4.5 Soak a 70mm×70mm single-layer nylon spun in distilled water, and then place it in the test area with tweezers, but there should be no water drops next to the test area.
4.6 When the oil temperature in the copper test cup reaches the specified temperature, move the test cup to the test area and let it stand for 15 minutes. 4.7 After the specified time, remove the copper test cup and nylon spinning, absorb the surface with filter paper, mark the test temperature, and let it stand for 16 to 24 hours. Note: If an electric heating cup is used, it should comply with the provisions of 1.1, and its heating effect is the same as that of the copper test cup containing oil. 4.8 Wipe the test area with filter paper and inspect according to the requirements of 4.9. 4.9 Place the test area on the sample in the observation box at the center of 550mm from the back, with a visual distance of 0.5 to 1m, and observe the marks made by the test cup and nylon spinning on the sample. 4.10 Then place the sample under natural light in the room, check whether the test area has discoloration, bubbling, etc., and compare and analyze with the test data in 4.2. For example:
The color difference between the visual test area and the comparison area is discoloration, the actual measured value is 5-10% lower than the original measured value, which is a slight discoloration, and the small bubbles visible to the eye are paint film blistering. 5 Evaluation of test results and test report
Grading standard
No test cup mark
Intermittent slight mark and slight discoloration
Almost complete ring mark or circle mark and slight discoloration Obvious ring mark or circle mark, discoloration
Severe ring mark or circle mark, discoloration or blistering
5.2 Three inspectors must evaluate each test area separately, and take the majority of the same values ​​as the evaluation results. 5.3 The three test areas on the same sample must be evaluated separately, and the consistent evaluation values ​​of the two test areas shall be the final test values. If there is inconsistency, the test can be repeated once.
5.4 The test report shall include the following contents:
Test date,
The name of the coating material of the sample and a brief coating process; the storage date after the sample coating is completed,
Test time and test results, etc.
GB 4893.2-85
Appendix A
(Supplement)
The copper test cup is used to determine the moisture and heat resistance of the paint film on the surface of wooden furniture. It is a container for holding the heating medium. A.1 Material and surface requirements
A.1.1 The material is made of ZH62 brass.
A.1.2 The surface of the cup bottom ring must be finely processed with a finish of √6. A.1.3 The surface must be polished before electroplating, and there must be no defects such as organic processing knife marks, burrs, scratches, sand holes, etc. The surface must be polished after electroplating.
The weight of the copper test cup is 440±25g.
A.2 Dimensions
The dimensions of the copper test cup are shown in the figure below.
$50 ±0.1
$44 = 0. 1
e48 ± 0.1
Schematic diagram of the copper test cup
GB 4893.2—85
Appendix B
(Supplement)
The observation box is used to observe the imprint and tarnish of the test area on the test piece. Structure and materials
The box is made of 15mm thick solid wood or particle board. B.1.1
B.1.2 A hole with a diameter of 25mm is opened on the inclined surface of the box. A 60W white frosted bulb is fixed above the hole by a hinge through the lamp holder plate. The angle of light projected onto the sample is 30°~60°. B.1.3 The inner wall is painted with black matte paint.
B.2 Dimensions
The dimensions of the observation box are shown in the figure below.
60W white frosted bulb
Observation point
25mm hole
Observation area
Additional instructions:
Schematic diagram of the observation box
This standard was proposed by the Ministry of Light Industry of the People's Republic of China and is technically managed by the Shanghai Furniture Research Institute. This standard was drafted by the Shanghai Furniture Research Institute. The main drafter of this standard is Xiao Zhengming.
This standard is formulated with reference to the British Standard BS3962: Part 2: 1980 "Test methods for surface finishing of wooden furniture - surface resistance to moisture and heat test"
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