Automotive paint viscosity according to ASTM D7395

USE

Painting automobile exteriors, making their appearance more attractive.

TEST EQUIPMENT

Viscometer: CAP 2000 + L with high torque and low torque 1/23 CAP 2000 + L

Pin: Taper 10 (CAP-S-10)

Speed: 100 rpm

Temperature: 25 ° C

TEST METHOD

In our experience, we used the "Standard Test Method for Cone / Plate Viscosity at Shear Rate of 500 s-1" as described in ASTM D7395. This test method for measuring paint viscosity requires the material to be equilibrated at 25 ° C for one minute. The test method recommends using the solvent trap to help prevent evaporation of the material.

We used a CAP 2000 + L high torque viscometer and a CAP 2000 + L low torque viscometer with Capcalc software for automated instrument control and data acquisition. We used Cone 10 to get scale results with 170 L of fluid. The cone and plate were cleaned before dispensing each portion of paint. A new portion of sample was used for each test. Three tests were carried out for each paint color. Representative data from the analyzes are shown in Figures 1, 2 and 3.

The tolerance for the High Torque CAP 2000 + L viscometer operating at 100 rpm with the 10 cone is +/- 100 cP, for the Low Torque CAP 2000 + L viscometer is +/- 4.4 cP. Figures 1 and 2 show that the results obtained with the Low Torque CAP 2000 + L and High Torque CAP 2000 + L viscometer were reproducible within the tolerance of the viscometers.

Figure 1

Figure 2

Figure 3 plots run 1 of Figures 1 and 2. Figure 3 shows the big difference in the viscosities of the black and white automatic finishing paints. This difference required the use of different viscometers for each paint. For the black paint, we used a Low Torque CAP 2000 + L viscometer in order to obtain scale results with a lower viscosity. For the white paint we used a High Torque CAP 2000 + L viscometer to get scaled results with higher viscosity.

Figure 3: Comparison of test methods:

black and white automatic finishing paint