How is film heat resistance measured?

The heat resistance of the coating film can be determined by the method in the national standard GB1735-79 "Determination of Heat Resistance of Paint Film". This standard applies to the determination of the heat resistance of paint films. Use blast constant temperature oven or high-temperature furnace to heat, after reaching the specified temperature and time, the heat resistance performance of the paint film is indicated by the physical properties or the surface changes of the paint film.

(1) Materials and equipment

Tin plate 50mmX120mmX(0.2~0.3)mm.

Thin steel plate (GB708-65) 50mmX120mmX (0.45~0.55)mm.

Blast constant temperature oven

High temperature furnace

(2) Measurement method

According to GB1727-79 "general preparation method of paint film", prepare paint film on four thin steel plates (or the model specified in the product standard). After the paint film is hard-dried, place the three painted samples in the blast constant temperature oven (or high-temperature furnace) that has been adjusted to the temperature specified by the product standard. Another painted panel was kept for comparison. After the specified time has elapsed, take out the painted sample, cool it to room temperature 25°C±1°C, and compare it with a previously left painted sample to check whether it has peeling, wrinkling, bubbling, cracking, discoloration, etc. phenomenon or inspected according to the product standards, if not less than two samples can meet the requirements of the crystal production standard as qualified.