Testing of wear resistance of new elastic lacquer solid wood flooring film

At present, China's market for lacquered wood flooring, mostly using UV paint coating, UV has a fast curing speed, environmental protection, paint film wear resistance is good, high hardness, scratch resistance, transparency and high advantages, but the paint film is more brittle, and the local plate affected by the ambient temperature and humidity and dry shrinkage or wet expansion, easy to cause paint film wrinkle, cracking and even peeling, thus affecting the appearance, performance and service life of the product. To this end, the author developed an elastic lacquer solid wood floor, the width direction of the local plate (120 to 150 mm) to produce < 3 mm of dry shrinkage and swelling, the paint film will not wrinkle and crack. In addition, elastic paint film has a certain shape memory function, under the impact of the paint film surface indentation, after a period of time will automatically restore flat, and thus applied to solid wood flooring and other high-end flooring products . Due to the large differences in wear resistance between elastic paint film and general U V paint film, there are some differences in the evaluation of wear resistance between the two by different test methods. Therefore, the author has tested and compared the wear resistance of the two lacquered solid wood floors in order to find more accurate and practical test methods for the performance of flooring products.
1. Materials and methods
1. 1 Test material
1) Conventional UV lacquered solid wood flooring, elastic lacquered solid wood flooring, all made of disc beans (Cy l icodi scus spp.), specifications (long x width x thick) 910 mm x 122 mmx18 mm, Kusheng Floor Co., Ltd.
2) Conventional UV wear-resistant primer, model 318030511, viscosity (2. 0- 0.2) Pa.s; Elastic paint, model 128400511, viscosity (4.2 plus 0.2) Pa.s; Are provided by Jiangsu Haitian Technology Co., Ltd.
3) sand belt, particle size 80 􀀁m; Rough sand, pure gold (Al3 O2), granularity 45 to 75 um.
1. 2 Production process
using U V curing technology, using multiple sand →red coating→ curing production process, to obtain the specified thickness and uniform paint film. According to the actual production process paint coating volume range, in this test, the amount of elastic paint coating is set to 20, 45, 80, 120, 150 g/ m2; The amount of coating of conventional UV paint is 11. 4, 14, 16, 20, 26 g/m2.
1. 3 Test instruments
JM-IV wearer (Figure 1), produced by Shanghai Modern Environmental Engineering Technology Co., Ltd., for GB/T 17657􀀁 test methods specified in 1999; T aber 5135 type wear meter (Figure 1), produced by Shanghai Shouli Industrial Co., Ltd., for the test method in EN 14354􀀁 2004; Type 155 coarse sand supply, etc.
1. 4 Test Method
Theoretically, when other conditions remain unchanged, the wear resistance value of the paint film surface is linearly related to the thickness or coating volume of the wear-resistant functional layer (the paint film layer). Therefore, the stronger the linear correlation between the wear resistance value of the paint film surface and the thickness or coating amount of the lacquer film, the more accurate the test method used for the paint film. According to GB/T 15036. 2-2009< Solid wood flooring Part 2: Test method >, GB/T 17657-1999<> (sand belt method) and European standard EN 14354-2004 < Wood-base panels-wood veneer f loorcov ering > (sanding method) respectively.the main differences between the
2 detection methods: sand belt method sand particles adhere to the sand belt, sand belt and rubber wheel rotation together, used to simulate the furniture drag on the floor paint film produced by the direct wear process;
1) Sample 5 pieces of elastic lacquer flooring and conventional UV lacquer flooring, sawing 1 test piece at each end of each floor in sizes (100-2) mm x (100-2) mm.
2) Balanced treatment Puts test parts, grinding wheels, sand belts and coarse sands in relative humidity (65 s-5) and temperature (23 s- 2) oc until the mass is constant.
3) Wear resistance determination a sand belt method: see GB/T 15036. 2-2009 and GB/T 17657-1999.
b sanding method: (1) adding coarse sand to the rough sand supply; (2) Secure the test piece to the support plate, lower the grinding wheel to the surface of the test piece, and ensure that the grinding wheel shaft level; (3) Adjust the sand-falling speed to (21 s- 3) g/min; (4) Turn on the vacuum cleaner, while starting the test part rotation, every 200 r
to check the wear degree of the test piece, when the remaining paint film is thin, close to the wood, every 100 r check, until the test piece paint film through, record the number of turns.
5) Maximum wear-resistant torsion calculation􀀁 According to the standard, for UV lacquer flooring, the number of turns in the event of paint damage is calculated; For elastic lacquer flooring, the test piece is divided into 16 areas, all accurate to 100 r in terms of the number of turns when the paint surface is worn through 12 consecutive areas.
2 Results and Analysis
2. 1 Wear resistance of elastic lacquer flooring
results of the test results of lacquer film wear resistance of flexible lacquer flooring, see Figure 2.
Figure 2 the sanding method and the sand belt method on the elastic lacquer floor wear performance characteristics
as can be seen from Figure 2, the wear-resistant functional layer coating volume and wear-resistant to the number of turns are linearly related, the linear measurement coefficient between the two obtained by the sand-falling method is 0.9958, higher than the sand belt method (0.8936), indicating that for the elastic lacquer floor, the sanding method is more accurate evaluation of its wear resistance.
In the scope of this test, when the amount of elastic paint coating is 20 g/m2, the wear-resistant transitions measured by the sanding method and the sand belt method are 1 100 r and 100 r, respectively; For the elastic lacquer floor of the same paint coating amount, the amount of wear-resistant transition measured by the sand-dropping method is about 10 times the test result of the sand belt method. This is mainly due to the principle of the two test methods are different, and the characteristics of elastic paint surface: 1) the sanding method is the use of rubber wheels with a certain load, in the process of rotation, through the free scattered sand particles on the floor surface, to achieve the friction of the paint film. In the wear process, the sand grain relative to the rubber wheel and test piece is moving, the wear is more moderate, the paint film per turn wear consumption is also small; The sand belt method is the use of the sand belt wheel with a certain load applied, because the sand is fixed to the sand belt, directly with the paint film friction, so that each turn of the paint film wear consumption increased.
2) The hardness of the paint film of the elastic lacquer floor is low, when the sand drop method is used for testing, the sand grain does the work on the paint surface, most of which is converted into the thermal energy generated by the elastic deformation of the paint film, which reduces the energy consumed in the form of wear, therefore, the wear consumption is reduced; When using the sand belt method, the sand grain fixed to the sand belt can easily break through the paint film, resulting in tearing, greatly improving the wear consumption of the paint film. According to the amount of wear-resistant functional layer coating of the elastic lacquer floor obtained by the sanding method, and the linear equation between the wear-resistant transition, combined with the requirements of the wear-resistant grade in EN 14354, it is necessary to calculate the floor of the applied elastic paint, the amount of coating required for different wear grades, and provide the basis for the formulation of the actual production process parameters (Table 1).
the wear performance rating of the floor paint film in meter 1 EN 14354 is
2. 2 Wear resistance of conventional U V lacquer flooring
test results for wear resistance of conventional U V lacquer floor surfaces, as shown in Figure 3. Figure 3 shows that the coefficient of measurement between the amount of coating of the wear-resistant functional layer and the amount of wear-resistant transition is 0. 9523, greater than the sanding method (0.8304), indicating that conventional UV lacquer flooring should use sand belt method to evaluate the wear resistance of its paint film surface. The amount of UV paint is 11. At 4 g/m2, the grinding number of paint film measured by the sand-falling method and the sand belt method is 1,300 r and 200 r, respectively; The coating amount is 26 g/m2, and the wear-resistant turns measured by the sanding method and the sand belt method are 2,300r and 800 r, respectively. For conventional UV lacquer flooring of the same paint film thickness, the number of wear-resistant turns measured by the sand-dropping method is 3 to 5 times the measured result of the sand belt method, the main reason is that the principles of the two test methods are different. Comparing Figures 2 and 3, it is found that when using the sand-falling method, the measured wear-resistant turn of the elastic lacquer floor is significantly higher than that of the UV lacquer floor.
analysis: 1) the amount of paint coating of elastic lacquer flooring, about 2 to 5 times the UV lacquer floor, the coating is thick; 2) U V lacquer floor paint film hardness is high, brittle, regardless of the use of sand or sand belt method, sand work on the paint surface, not converted to heat, but all in the form of paint wear consumption.
3 . Conclusion
1) Due to the use of elastic paint, and a large amount of coating, so the wear resistance of elastic lacquer flooring is better, should be tested according to EN 14354-2004, conventional UV paint floor wear resistance is suitable for reference to GB / T 15036.2-2009 test.
2) Based on the amount of coating of the wear-resistant functional layer of the elastic lacquer floor and the linear equation between the wear-resistant transitions, the minimum amount of coating required for floor coating at different wear-resistant grades can be calculated to save production costs.
3) GB/T 15036. 2-2009 only specifies the wear resistance requirements of the home grade floor, in the future standard system revision, the introduction of EN14354-2004 according to different uses, the floor paint film surface wear performance testing and evaluation methods.
4) It is recommended to further study the performance testing methods of elastic lacquer flooring, and to draw up the corresponding industry or national standards with reference to EN14354-2004 and other standards.