Determination of Coating Fineness

equipment

1) Ink adjusting knife

2) The scraper fineness gauge complies with the regulations in GB/T 1724-79.

Detection method

Use the scraper Fineness Meter to test the paint fineness as shown in Figure 21-6, and its unit is expressed in µm. The readings when measuring the paint fineness are shown in Figure 21-7.

①Fineness meter Divided into the following three types: 0~50µm; 0~100µm; 0~150µm.

②Scraper fineness measurement range selection If the fineness is below 30µm, use a Fineness Meter with a range of 0~5oµm.

The fineness is 31~70µm, use a Fineness Meter with a range of 0~100µm.

If the fineness is above 71µm, use a Fineness Meter with a range of 0~150µm.

③The scraper fineness gauge needs to be cleaned and dried with solvent before use, and a soft cloth should be used for scrubbing. During operation, drop the sample into the deepest part of the groove (it is advisable to fill the groove with a little excess), hold the scraper with both hands, and place it horizontally on the upper end of the polishing plate (at the edge of the sample), so that the scraper and the polishing The flat surfaces are in vertical contact. Within 3 seconds, pull the scraper from the deep part of the groove to the shallow part, so that the paint sample fills the groove without leaving any residual paint on the plate. Immediately (not more than 5s) after the scraper is pulled, make the line of sight and the groove plane form an angle of 15°~30°, and observe the scale line (accurate to the minimum division value) where the particles in the groove are evenly exposed to the light. If there are individuals exposed on other graduation lines, there shall not be more than 3 particles within the range of the reading and adjacent graduation lines.

calculate

Three parallel experiments were performed, and the arithmetic mean of the two similar readings was taken as the test results. The error of the two readings should not be greater than the minimum division value of the instrument. 

notes

① After the scraper fineness gauge is worn out, it should be calibrated by the national measuring instrument verification agency before it can be used;

② When measuring the fineness of thick paint, the paint should be adjusted with clear oil that meets the product standards before measuring.