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ASTM D8020-15(R2020) pdf free download

ASTM D8020-15(R2020) pdf free download.Standard Test Method for Freeze-Thaw Viscosity Stability of Water-Based Inks and Ink Vehicles
1. Scope
1.1 This test method covers a procedure for evaluating the effect of freeze-thaw cycling on the properties of water-based inks and ink vehicles. 1.2 This test is based on a similar standard test for coatings; Test Method D2243. 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 all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.5 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Summary of Test Method
3.1 The waterborne ink or ink vehicle is placed into two 237-mL plastic jars. One jar is stored at room temperature, while the other jar is subjected to cycles of freezing and thawing. After cycling, the ink or ink vehicle is examined for changes in viscosity and uniformity.
4. Significance and Use
4.1 When waterborne inks and ink vehicles are shipped during cold weather, these materials may experience cycles of freezing and thawing. This can damage the material rendering it unusable. 4.2 Cycles of freezing and thawing can cause more damage to waterborne inks or ink vehicles than when the inks or ink vehicles are subjected to steady freezing.
5. Apparatus
5.1 Test Chamber, a suitable cabinet, room, or enclosure space large enough to contain the specimens to be tested permitting at least 25 mm (1 in.) of air space between the sides of adjacent jars and capable of being maintained continuously at a temperature of –18°C (0°F). N OTE 1—Although a variation ofthe test chamber temperature of62°C (3.5°F) is allowed, the test chamber temperature should be maintained as near –18°C (0°F) as practicable and the amount of variation should be recorded and reported. 5.2 Viscometer, a dip-type viscosity cup as described in Test Method D4212 or a Brookfield type viscometer as described in Test Methods D2196. 5.3 Recirculating Water Bath, capable of maintaining a temperature of 25 6 1°C (77 61.8°F). 5.4 Cylindrical Container, with a capacity of 0.5-L (1-pt), 85 mm (3 3 ⁄ 8 in.) diameter to contain the test specimen during testing. 5.5 Spatula.
7. Procedure
7.1 Stir the specimen by hand and measure its viscosity in accordance with Test Methods D4212 or D2196. 7.2 Store the control specimen at room temperature. 7.3 Place the test specimen in the chamber maintained at –18°C (0°F) in such a manner that it does not touch the walls or bottom of the chamber and air circulates around it freely. Placing jars on racks that raise them off the bottom of the chamber or upon pieces of insulating board resting on the bottom is suggested. In the case of several test specimens, maintain a minimum of 25 mm (1 in.) of air space between adjacent jars and between jars and the chamber walls. 7.4 Remove the test specimen from the chamber after 17 h. Place it adjacent to the control specimen and allow it to stand for 5 h undisturbed at room temperature, followed by 2 h in a recirculating water bath for a complete freeze-thaw cycle of 24 h. 7.5 Examine both the test and control specimens for any evidence of settling, gelation, and coagulation. 7.6 Stir the test and control ink or ink vehicle by hand using a spatula. Stir carefully so as to avoid air entrainment and foam. Measure the viscosities in accordance with Test Methods D4212 or D2196. Record the temperature at which the viscos- ity is measured. 7.7 Repeat 7.2 – 7.6 for two additional freeze-thaw cycles, or as many as agreed on between cooperating laboratories or buyer and seller. If any test specimen more than doubles in viscosity compared to the control the test is stopped.

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