(1) Definition
The softening temperature is the temperature when the powder coating just appears to melt, and the unit is expressed in degrees.
(2) Equipment
A Hot Plate is a kofle, a Hot Plate or a Hot Plate with similar properties, which is characterized by a temperature gradient from one side to the other when heated. Generally it is from room temperature to 200°C. Install a temperature scale along the Hot Plate, which can be measured with a material with a known melting point (such as azobenzene 68°C±1’C’, 80°C±0.5°C, benzoic acid 122°C±1°C or a thermocouple). Temperature instrument to calibrate.
Paintbrush bristles are 12.7mm long.
(3) Test steps
Heat to equilibrate the Hot Plate temperature. Select a material with a known melting point close to the melting point of the material to be tested or use a thermometer to check the indicated value of the temperature scale.
Apply a small sample of the powder to be tested on the plate L to form a thin and narrow powder belt, with a length of about 20°C across the temperature range, so that the expected melting point is near the center of the temperature range for 1 minute. Brush the unmelted powder from the high temperature side to the low temperature side, and then adjust the pointer to the position where the traces of melted powder just appear, this temperature point is the softening point.
(4) Results
The middle value of the three measured values is used as the brake inspection result, and the other two values are also included in the report as a reference.
