Performance testing of powder coatings--melting contact fluidity measurement method, as follows:
(1) Horizontal mobility
①Dingwen horizontal fluidity is marked by the diameter of a national-shaped test piece that is pressed into a specified size by powder and melted at a certain temperature.
②Equipment Leveling instrument, constant temperature and humidity Test Chamber, oven, tinplate.
③Test procedure Weigh 0.8~1g powder sample (depending on the content of inorganic city material in the powder. 0.8g can be taken when there is no domain material at all). Put the mold sleeve on the lower mold, pour the powder sample carefully and make it flat, put the upper mold on it, and press the whole set of molds with a vise or a press until there is no gap between the upper and lower molds and the mold sleeve. Take out the upper and lower molds, push out the test piece in the mold sleeve with the discharge pressure head and the discharge groove, if the test piece has obvious edge burrs, use a blade to cut it off carefully.
After the Hot Plate is heated and kept at the required temperature, a thin layer of release agent is coated on the surface, and the test piece is placed on the Hot Plate and timed. When the test piece melts and cannot continue to flow, or after the specified time, use a divider Carefully measure the diameter of the test piece, then measure the size with a graduated steel ruler, and test two test pieces.
(2) Determination of inclined fluidity (refer to ASTM D345"-76)
1. Materials and Instruments
Constant temperature oven: 200°C, sensitivity ± 1°C.
Metal plate frame device: 50mmx120mrn metal frame, installed in the inner chamber of the oven, use the external joystick to keep it in a horizontal position or tilt at an angle of 65°.
Tinplate: 50rnmX120mmX(0.2~0.3)mm.
Analytical balance: Sensitivity 0.1 mg.
Stopwatch: scale 0. ls.
Steel ruler: the scale is 0.5mm.
Steel sample stamper, see Figure 6-4.
2. Determination steps Weigh 0.5~0.7g of powder and place it in a steel 1M sample mold, and press it into a powder test piece with a thickness of 6mm.
Put the powder test piece on the round field where the diameter line is drawn on the tin plate, and put it on the metal rice rack that has been kept at a constant temperature (150i2) ℃ for drying, quickly seal the oven door, and keep the metal rack device in a horizontal position for 3 minutes .
Under the condition that the oven door is not opened and the temperature of the oven is not lowered, the metal frame device fixed with the tinplate plate is tilted at an angle of 65° from the horizontal position. And keep at the position of the inclination angle: l0min.
After 30 minutes, take out the sample meal from the fuel tank, cool it to room temperature, draw a marking line with the maximum flow distance, and measure the distance from the diameter centerline originally drawn on the tin plate to the marking line, expressed in mm.
