Standard Test Method for Fineness of Grind of Printing Inks By the NPIRI Grindometer
Oversize particles in a printing ink may damage a printing plate, plug a cell, clog a nozzle and adversely affect the appearance of printed ink films. Fineness of grind measurements are useful for deciding when to stop the dispersion process and for determining if the test material meets specifications as agreed upon between the supplier and the customer.
This test method describes the procedure for determining the fineness of grind of printing inks using a NPIRI Grindometer. It evaluates the size of the largest particles in a finished dispersion but not average particle size or concentration of sizes.