The agglomeration degree (commonly known as fineness) of noble metal paste refers to the size of solid aggregates in the paste, and its thickness directly affects the printing performance and sintering characteristics of the paste. Fineness is an important index that needs to be detected and controlled in the production and use of slurry, and the measurement of fineness is of great significance to the quality control of slurry.
Methods and Instruments
The fineness of the precious metal paste was measured with a QXD-50 scraper Fineness Meter produced by Tianjin Materials Experimental Factory. The operation process is to place the sample on the fineness gauge, scrape the scraper from top to bottom, and determine the particle size according to the position where the longitudinal stripes appear in the groove.
Experimental sample
Fully stir the samples of silver series paste, silver palladium series paste and silver platinum paste evenly, and take 5 balanced , 2g for each sample.
test steps
① Wash carefully with chloroform and dry the scraper fineness gauge;
②Put the prepared sample on the upper end of the fineness gauge;
③ Hold the scraper with both hands, place it on the upper end of the fineness of the scraper (at the edge of the sample), and move the scraper from the scraper to the surface of the Fineness Meter at a suitable speed.
Pull the deep part of the groove to the shallow part, so that the sample fills the groove without leaving excess slurry on the plate;
④ After the scraper is pulled, immediately (not more than 5 s) hold the fineness gauge horizontally and tilt it so that the line of sight and the groove plane form an angle of 15° to 30° and observe the light to find out that there are two vertical lines in the groove.
The position shown to the stripes, read and recorded;
⑤Environmental temperature 15～35℃, relative humidity 25%～85%.
