Measurement of Water Absorption Thickness Expansion Rate of MDF
Medium density fiberboard-Determination of thickness swelling rate of eater absorption
1 Subject Content and Scope of Application
This standard specifies the method for determining the swelling rate of water absorption thickness of MDF.
This standard is suitable for indoor medium density fiberboard.
2 Reference Criteria
Preparation of MDF specimens in GB 11718.3
3 Equipment and measuring instruments
3.1 Water absorption constant temperature tank.
3.2 micrometer, accuracy 0.01 mm.
4 Sampling and specimens
Sampling and cutting of specimens are carried out according to GB 11718.3.
5 test methods
5.1 The thickness of the specimen is measured as shown in the figure, and the accuracy is 0.05 mm.
5.2 The specimen is placed in distilled water at 25 2 C. The water level is 30 mm higher than the top of the specimen, which makes the surface and water surface of the specimen straight and does not sink to the bottom of the water. There should be a certain gap between the specimens.
5.3 Immerse the specimen for 24 hours, absorb the water on the surface of the specimen, and immediately measure the thickness at the original measuring point.
Zmt5.bmp (8704 bytes)
6 test results
6.1 The swelling rate of water absorption thickness H (%) of each specimen is calculated according to the following formula, which is accurate to 0.1%.
In formula: thickness of specimen before immersion of h1, mm1;
The thickness of the specimen after H2 immersion is mm.
6.2 The swelling rate of water absorption thickness of each plate is the arithmetic average of three specimens, which is accurate to 0.1%.