Initial drying crack resistance tester

QKL typeInitial drying crack resistance testerScope of application:

The QKL type initial drying crack resistance test designed and manufactured according to the national standard GB/T9779 is mainly applicable to the initial drying crack resistance test of building coatings and indoor and outdoor building putty under specified wind speed conditions.

QKL typeInitial drying crack resistance testerWorking principle and structure:

Working Principle:

There is a test panel rack parallel to the direction of air flow in the wind tunnel. After starting the axial flow fan, the wind speed is controlled within 3 ± 0.3m/s using an air volume control device. The coated test panel is placed on the test panel rack in the inspection wind tunnel, and the drying control time is adjusted according to the product standard requirements. After the time is up, the machine automatically stops and the surface of the test panel is visually inspected for cracks.

Structure:

It mainly consists of an axial flow fan, a test wind tunnel, a test specimen rack, an air volume control device, a timer, an anemometer, etc.

Operation Method:

Operation of anemometer: (see anemometer manual for details)

Operation of timer:

① The delay range of this timer is 0.01 seconds, 99 hours, and 99 minutes, which can be preset arbitrarily. The three windows in the middle are time switches, with h (hours), m (minutes), and s (seconds).

② Select hours, minutes, and seconds by flipping the black window on the right side of the middle.

③ Adjust the timer within the required time.

Note: This task is pre-set before starting up, and the preset key of the timer cannot be changed without authorization after starting up, otherwise the timer will be invalid.

According to the instructions for the putty product, apply the main coating in the specified amount onto the surface of the prepared test panel (above the base coating), and immediately place it on the test panel rack in the wind tunnel, parallel to the airflow direction. This testing machine can generally place two specimens for parallel testing.

Turn on the power of the testing machine, the power indicator light will turn on, the axial flow fan will start, and the timer will start counting.

Adjust the wind speed control knob with a handheld anemometer, observe the anemometer display screen to adjust the wind direction within 3 ± 0.3m/s, and start air drying.

When the timer reaches the preset time, the testing machine stops working, the test panel is taken out, and the surface is visually inspected for cracks.