Significance and Use
Coarse particles in printing inks reduce the efficiency of the dispersion process, requiring not only extra milling passes, but also frequent changes in pump filters. In printing processes, they may cause excessive wear to metal plates, piling or localized retention of ink on blankets and plates, and water balance problems. Coarse particles also reduce color strength and the gloss of printed matter.
This test method is suitable for quality control. The precision may be improved by the use of a specimen size larger than that prescribed.
Test results are sensitive to the type of washout solvent used. Strong solvents are to be avoided because they may dissolve large particles of resin in the ink vehicle.
1. Scope
1.1 This test method covers the determination of the weight concentration of coarse particles in printing ink dispersions by sieve retention.
1.2 This test method is applicable to printing inks, flushed pigments, and other pigment dispersions that contain particles larger than 45 μm. With proper choice of solvent, it is applicable both to paste and liquid inks.
Note 1—This test method is similar in principle to Test Methods D185. For particles under 25 μm, see Test Method D1316.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately)
The documents listed below are referenced within the subject standard but are not provided as part of the standard.
ASTM Standards
D185 Test Methods for Coarse Particles in Pigments
D235 Specification for Mineral Spirits (Petroleum Spirits) (Hydrocarbon Dry Cleaning Solvent)
D1316 Test Method for Fineness of Grind of Printing Inks By the NPIRI Grindometer
E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves
E145 Specification for Gravity-Convection and Forced-Ventilation Ovens
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
Keywords
coarse particles; dispersions; pigment dispersions; printing inks; wire-cloth sieve; Coarse particle analysis; Dispersion; Nonheatset printing inks; Pigment dispersion (paints/related coatings/materials); Printing inks/vehicles; Sieve analysis;
ICS Code
ICS Number Code 87.080 (Inks. Printing inks)
DOI: 10.1520/D2067-97R08E01
ASTM International is a member of CrossRef.
Citing ASTM Standards
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