ASTM D4942-20
(Test Method)Standard Test Methods for Water Pickup of Lithographic Printing Inks and Vehicles in a Laboratory Mixer
Standard Test Methods for Water Pickup of Lithographic Printing Inks and Vehicles in a Laboratory Mixer
SIGNIFICANCE AND USE
3.1 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.
3.2 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.
3.3 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.
SCOPE
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.
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4942 − 20
Standard Test Methods for
Water Pickup of Lithographic Printing Inks and Vehicles in a
1
Laboratory Mixer
This standard is issued under the fixed designation D4942; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Significance and Use
1.1 These test methods cover two procedures for determin- 3.1 The lithographic printing process requires that some
ingtheamountofwaterpickedupbylithographicprintinginks dampening solution be emulsified into the ink. These test
in a laboratory mixer. methods provide a rapid means for determining water pickup
under laboratory conditions. Test results may be useful for
1.2 Test Method A covers single-point water pickup; Test
specification acceptance between the supplier and the cus-
Method B covers the rate of water pickup. Both test methods
tomer.
are applicable to any printing ink and vehicle intended for the
lithographic printing process. 3.2 In order that results be comparable, the tests must be run
at the same temperature and with the same type and quantity of
1.3 The values stated in SI units are to be regarded as
liquid added prior to mixing.
standard. No other units of measurement are included in this
standard. 3.3 The emulsions obtained in these test methods are of
larger particle size than those typically produced in printing
1.4 This standard does not purport to address all of the
nips. Because of these and other variables in the printing
safety concerns, if any, associated with its use. It is the
process, water pickup results do not by themselves predict
responsibility of the user of this standard to establish appro-
lithographic printing performance.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4. Apparatus
1.5 This international standard was developed in accor-
4.1 Laboratory Mixer, equipped with a stainless steel speci-
dance with internationally recognized principles on standard-
men bowl 83 mm wide and 88 mm high, mixer blades that
ization established in the Decision on Principles for the
rotate at 90 r/min, and a timing device.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
4.2 Balance, accurate to 0.1 g, 600-g capacity.
Barriers to Trade (TBT) Committee.
4.3 Palette knives, two.
2. Summary of Test Methods
4.4 Thermometer, quick response.
2.1 Thesetestmethodsutilizealaboratorymixerforbeating
4.5 pH Meter (optional).
water or other agreed upon fluid into the test ink.
4.6 Conductivity Meter (optional).
2.2 For single-point water pickup (Test Method A), 50 mL
4.7 Graduated Cylinder, 50 or 100-mL.
of water is normally added to 50 g of ink and mixed in for 5
min. The water picked up is determined from volumetric
5. Reagents and Materials
measurements of free water.
5.1 Water—Deionizedordistilledwater,preferably having a
2.3 Forrateofwaterpickup(TestMethodB),waterisadded
pH of 5.0 to 7.0 (100 to 200 mL per sample); alternatively,
to 50 g of ink in increments of 20 mL and mixed in for 1 min
fountain solution or other aqueous medium as agreed upon
or more over a cumulative time period totaling 10 min. The
between the supplier and the customer may be used.
water taken up by the ink after each mixing interval is
5.2 Cleanup Materials—Naptha and rags or tissues.
determined gravimetrically.
6. Test Specimen
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These test methods are under the jurisdiction of ASTM Committee D01 on
Paint and Related Coatings, Materials, and Applications and are the direct
6.1 A minimum of 100 g is sufficient for two determina-
responsibility of Subcommittee D01.56 on Printing Inks.
tions. Before removing ink from the can, stir or otherwise
Current edition approved June 1, 2020. Published June 2020. Originally
ensure that the ink specimen is representative. Close the can
approved in 1989. Last previous edition approved in 2011 as D4942 – 11 which was
withdrawn January 2020 and reinstated in June 2020. DOI: 10.1520/D4942-20. and replace sealing tape immediately after each ink removal.
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D4942 − 20
7. Conditioning 8.11 Discard ink left in the bowl. Clean the bowl and the
mixer blades with tissue wetted with naphtha. Discard the
7.1 Condition the instrument, water, and ink samples in
...
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