Determination of percent solids for interior and exterior coatings

The determination of the solid content of interior and exterior wall coatings is the ratio of the mass of the remaining residue to the mass of the sample after the coating is heated and baked at a certain temperature, usually expressed as a percentage.

First bake the dry and clean Petri dish in an oven at (105±2)°C for 30 minutes, take it out and put it in a desiccator, and weigh it after cooling to room temperature.

Sampling with a ground drop bottle, weigh (1.5~2.0)g sample by decrement method, place it in a weighed petri dish, make the sample flow evenly on the bottom of the container, and then place it in a well-adjusted temperature [Latex paint is (120 ± 2) °C, 2 hours; or (105 ± 2 °C), 3 hours.] After baking in a blast constant temperature box for a certain period of time, take it out and put it in a dry operator to cool to room temperature , weighing. Until the error of the two weighings before and after is not greater than 0..01g (all weighing is accurate to 0.01g). The test measures two samples in parallel.

The solid content was calculated as follows:

In the formula, W is the mass of container, g;

W, the mass of the sample and container after baking, g;

G1-sample mass, g.

The test results take the average value of two parallel experiments, and the relative error of the two parallel experiments is not more than 3%.