GB/T17657-2013 Test Method for Physical and Chemical Properties of Wood-based Panels and Decorative Wood-based Panels: Determination of Internal Bonding (Bonding) Strength after 2-hour Boiling in Water
Determination of internal bonding strength after boiling in 12 2h water
12.1 Principle
Determine the internal bonding strength of the specimen after boiling in water
12.2 Instruments and equipment
12.2.1 Universal mechanical testing machine (see 11.2.1).
12.2. 2 Vernier calipers, with a division value of 0.1mm and a range of 0mm~150mm.
12.2.3 Water tank, capable of heating and keeping water boiling.
12.2.4 Water tank, capable of maintaining a water temperature of (20 ± 5) ℃
Boiling water tank. png
12.3 Test pieces
12.3.1 Specimen size
Length l=(50 ± 1) mm, width b=(50 ± 1) mm.
12.3.2 Specimen balance treatment
If necessary, place the test piece and hardwood or hardwood plywood clamp in an environment with a temperature of (20 ± 2) ° C and a relative humidity of (65 ± 5)% until the mass remains constant. The difference between the two weighing results after a 24-hour interval does not exceed 0.1% of the mass of the test piece, which is considered to be a constant mass.
Artificial board constant temperature and humidity box. png
12.4 Method
12.4.1 Measure the width and length of the specimen at the centerline of its length and width (see 1).
12.4.2 Place the test piece in a water tank with a pH value of 7 ± 0.5 and a temperature of (20 ± 5) ° C, with the upper end of the test piece (75 ± 25) mm away from the water surface. The distance between the test pieces, as well as between the test pieces and the bottom and wall of the water tank, should be at least 15mm, so that water can flow freely. Slowly and uniformly heat the water to the boiling point (about 100 ° C) within (90 ± 10) minutes, and immediately start timing. The test piece is boiled in boiling water for (120 ± 5) minutes, while the water remains slightly boiling to prevent rolling bubbles and strong water flow from eroding the test piece. Fresh water should be replaced for each test. After boiling water for 2 hours, remove the specimen and immediately place it in a water bath at (20 ± 5) ° C to cool for 1-2 hours.
12.4.3 Take out the test piece and wipe it dry. Immediately sand the surface of the test piece with fine sandpaper in a wet state, and then bond the test piece to the clamp head.
12.4.4 Determine the failure load according to 11.4.3 and 11.4.4. The test piece should not be taken out of cold water for more than 1 hour until the test is completed. If the test cannot be completed within 1 hour, the test piece can be sealed and stored in a plastic bag, and the internal bonding strength measurement must be completed within 4 hours.
12.5 Expression of Results
12.5.1 Calculate the internal bonding strength according to 11.5.1. The size of the test piece is calculated before boiling.
12.5.2 The internal bonding strength of a board after boiling is the arithmetic mean value of the internal bonding strength of all test pieces in the same board after boiling, accurate to 0.101MPa.
