The setting speed of heatset printing inks is important because it influences the efficiency of the drying process. This test method provides a means for comparing the setting of a heatset ink directly against a standard at the same conditions of temperature and exposure time. While the method does not determine the setting speed of an ink on a production press, it is useful for specification acceptance between the supplier and the customer.

The setting speed of a printing ink depends on a number of variables such as the substrate on which it is printed, the film thickness on the print, the temperature of the forced air, the rate of air flow, and the time that the print is subjected to heat. For these reasons, it is important to conduct the tests under conditions that are controlled and as realistic as practical.

1.1 This test method describes the procedure for determining the relative setting speed of heatset inks using a tester consisting of a forced hot air oven and print delivery system.

1.2 This test method is applicable to printing inks intended to be dried by the application of heat and for which a suitable reference standard is available.

1.3 Although heatset inks are normally printed by the offset process, this test method specifies the direct letterpress mode because the higher ink film thicknesses obtained tend to amplify subtle differences in ink setting speed. Prints are prepared by a flatbed printing apparatus using a constant depth printing gage.

1.4 This tester reads temperature and belt speed in nonmetric terms; therefore, instrument settings in this test method are stated first in U.S. Customary Units (inch pound units of measurements). The values given in parentheses are for information only.

1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.6 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.