This standard is applicable to the determination of the adhesion strength of paint films with a thickness of less than 250μm on the surface of wooden furniture and other wooden furniture parts, or the adhesion strength of the primer and topcoat. GB 4893.4-1985 Cross-cut test method for adhesion of paint films on furniture surfaces GB4893.4-1985 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Furniture-Assessment of adhesion of surface coatings-Cross cut UDC 684.4 : 667
GB 4$98. 4—85
This standard is applicable to the determination of the adhesion of paint films with a thickness of less than 250 μm on the surface of wooden furniture and other wooden furniture parts to the substrate, or the half degree of bonding between the primer and the topcoat. Use a sharp blade to cut two groups of grid-shaped cuts at right angles to each other on the surface of the paint film, and grade the damage of the paint film according to the cuts.
1 Equipment and materials
1.1 FE-paint film adhesion tester (see Appendix A). Other types of adhesion testers with equivalent test results can also be used. 1.2 Zinc oxide adhesive plaster (GB2771—81 "Medical adhesive plaster"). 1.3 Pig case paint brush.
1.4Observation lamp 60W white frosted bulb.
1.54x magnifying glass. www.bzxz.net
2Specimen
Specifications: 250mm×200mm.
2.2After the sample is painted, it should be stored for at least 10 days and completely dry before testing. 2.3The surface of the sample should be flat, and the paint film should be free of scratches, bubbles and other defects. 2.4When sending the sample, a test report should be attached, including the name of the paint, a brief coating process, production time, etc. 3Test conditions
Laboratory temperature 20±2℃, relative humidity 60%~70%. 4Test steps
4.1Take two test areas on the sample (try to choose different texture parts), the center of the test area should be no less than 40mm from the edge of the sample, and the center of the two test areas should be no less than 65mm apart. 4.2 According to GB4893.5-85 "Determination of paint film thickness on furniture surface", measure the paint film thickness at 3 points in adjacent parts of each test area. The result is the arithmetic average of the three readings. 4.3 Install the blade into the blade clamp so that the distance between the blade and the template is 0.3±0.02mm. 4.4 Cut the paint film surface of the test area with the blade in the blade clamp along the template to make two groups of right-angled grid cuts. Each group of cuts includes 11 parallel cuts with a length of 35mm and a spacing of 2mm. All cuts should penetrate the surface of the substrate. The cutting direction is approximately 45° to the direction of the pattern.
4.5 Use a paint brush to gently brush off the paint film debris, press the zinc adhesive tape on the test area with your fingers, and peel it off diagonally.
4.6 Under the observation light, use a 4x magnifying glass to carefully check the paint film damage in the test area from all directions. 4.7 The cutting edge of the blade should be checked frequently during the test. If any wear or chipping is found, the blade should be replaced immediately. Issued by the State Bureau of Standards on February 1, 1985
Implementation on April 10, 1985
5 Evaluation of test results and test report
Egg grade standard The following table and Figures 1 to 5
GB 93.4-B5
Smooth surface without paint peeling
Flament peeling at the intersection of cuts, a little intermittent peeling of paint film along the cut marks, and a little intermittent peeling of paint film along the cut marks.
In the cut grid below 5%, the paint film has large pieces peeling off or is completely removed. In the cut grid above 5%, the paint film has large pieces peeling off or is completely removed. Figure 1
GB 4893.4-85
Three inspectors must evaluate each test area separately, and take the majority of the same values ​​as the evaluation results. 5.2
5.3 The three test areas on the same test sample shall be evaluated separately, and the consistent evaluation values ​​of the two test areas shall be the final test values. In case of inconsistency, the test may be repeated…·times.
5.4 The test report shall include the following contents:
group, test date,
name of the coating material of the test sample and a brief coating process, bi
time after the coating of the test sample is completed
test results, film thickness (average value) of each test area, adhesion grade and description, type of film peeling, peeling from the substrate, peeling between the primer and topcoat layers, or both, and final test value. 577
GB4893.4—95
Appendix A
FE - Paint Adhesion Tester
(Supplement)
This instrument is based on the British Standard BS3962: Part 6: 1980 "Cutting Equipment in Test Methods for Surface Finishing of Wooden Furniture".
A.1 Components
Surface Resistance to Mechanical Damage"
A.1.1 The blade (dimensions see Figure A1) is made of Cr03 alloy tool steel or Cr06 material specified in GB1299—77 "Technical Conditions for Alloy Tool Steel". After heat treatment, the hardness of the blade should not be less than HV1750. A,1.2 The metal template (dimensions see Figure A2) is made of 45 steel and has eleven parallel cutting grooves with a spacing of 2±0.01mm in the middle. A,1.3 Blade clamp (dimensions see Figure A3). 25
Sum: 7 pieces thickness is 0.43±0.03
75 ×76
50 × 50
10,000 pieces size diagram
Metal template diagram
GB 4893. 4-- 85
Blade clamp diagram
Additional instructions:
This standard is proposed by the Ministry of Light Industry of the People's Republic of China and is technically managed by Shanghai Furniture Research Institute. This standard is drafted by Shanghai Furniture Research Institute. The main contributors to this standard are An Daiping.
This standard is formulated with reference to British Standard BS3962: Part 6: 1980 "Test methods for surface finishing of wooden furniture - resistance to mechanical damage of the surface".
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