(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
Hot plate: Use a Kofler Hot Plate or a Hot Plate with similar performance. Its characteristic is that there is a temperature structure from one side to the other side when heating, generally from room temperature to 200 ℃. A temperature scale is installed along the Hot Plate. The temperature scale can be used for known melting points. The material (such as azobenzene 68°C ± 1°C, naphthalene 80°C ± 0.5°C, benzoic acid 122°C ± 1°C) or use a thermocouple temperature measuring device to calibrate.
Paint brush: bristle length 12.7mm.
(3) Test procedure
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 indication value of the temperature scale, apply a small amount of the powder sample to be tested on the board, and make it into a thin and long loose strip .Span the temperature range of about 20°C, and make the expected melting point near the center of the temperature range. After 1 minute, brush the unmelted powder from the high temperature to the low temperature. Then adjust the pointer to just melted For devices with traces of powder, this temperature point is the softening point.
(4) Results
Take the median value of the three measured values as the result, and the other two values are also included in the result.
