How to test the covering power of Titanium dioxide:

In Plastic

Test method for hiding power of titanium dioxide in plastics

Disperse titanium dioxide and resin in a ratio of 4:100 and mix to obtain a white plastic sheet, which is pressed into a 0.1mm thin sheet.

The transmittance of the sheet is measured to indicate the hiding power of titanium dioxide in plastic. Covering power = (1-minus transmittance) X 100

In Paint

Test method for hiding power of titanium dioxide in coatings:

Stir titanium dioxide and varnish sample evenly to form a mill base, the ratio is 1:10

Put titanium dioxide mill base on the whiteboard and blackboard respectively to form a coating film and air-dry at room temperature for 3 hours.

Measure the reflectance of the painted whiteboard and blackboard, and divide the reflectance on the blackboard by the reflectance on the whiteboard to calculate the contrast ratio.

Covering power =reflectance of blackboard/whiteboard

So the paint grade TiO2 covering power and plastic grade, it should be test with different way.

If compare the plastic grade TiO2 hiding power, We must use plastic test method

If compare the paint grade TiO2 hiding power, We must use paint test method