ASTM D4942-89(2006)

1.1 These test methods cover two procedures for determining the amount of water picked up by lithographic printing inks in a laboratory mixer.

1.2 Test Method A covers single-point water pickup; Test Method B covers the rate of water pickup. Both test methods are applicable to any printing ink and vehicle intended for the lithographic printing process.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

This standard does not purport to address all of 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.

The lithographic printing process requires that some dampening solution be emulsified into the ink. These test methods provide a rapid means for determining water pickup under laboratory conditions. Test results may be useful for specification acceptance between the supplier and the customer.

In order that results be comparable, the tests must be run at the same temperature and with the same type and quantity of liquid added prior to mixing.

The emulsions obtained in these test methods are of larger particle size than those typically produced in printing nips. Because of these and other variables in the printing process, water pickup results do not by themselves predict lithographic printing performance.