Slurry ink dry test (on)

The dryness (dryness) of the ink is an important quality indicator and cannot be conceived as a consequence of the slow or even dryness of an ink printed on the substrate. We know that many printing failures during the printing process are caused by poor ink drying. For example, the printed matter is dirty (back stained), which is caused by poor ink dryness. Therefore, almost all ink manufacturers are making efforts to study it.
There are many types of drying inks, and the method of determination is also different. For example, ultraviolet drying inks need to be irradiated with ultraviolet rays, and thermosetting inks need to be heated. Due to the relatively large number of methods for measuring ink dryness, its standard level is poor. Here are some of the more common methods that can be used as needed.
(1) Dry Instrument Method (QB562-83):
1 Test principle. Ink based on oxidized conjunctiva drying can generally be measured by this method, but since the ink is measured by scraping (or printing) on ​​paper, the influence of osmotic drying on drying time cannot be practically eliminated.
The time required for adding the sulfuric acid to the sulfuric acid paper coated on the scraped sample under the certain pressure conditions is the dry operating time of the ink, expressed in hours. Samples were compared under conditions.
2 tools and materials a, automatic drying analyzer;
b, analytical balance;
c, ink transfer knife d, squeegee;
e, scraping paper;
f, standard white dry oil;
g, sulfuric acid paper;
h, standard ink samples.
3 test methods:
a, the test should be carried out at a temperature of 25±1°C and a relative humidity of 60-70%.
b. Weigh the sample and the standard white dry oil on the analytical balance in the following proportions, mix thoroughly, and weigh the standard sample and standard white dry oil in the same way. Ratio of ink sample to dry oil: Resin ink sample (or standard sample) and standard white dry oil is 95:5; oil type ink sample (or standard sample) and standard white dry oil is 90:10.
c. Blend the ink sample and sample together and scrape them into a scraping sample of about 30 cm long. Record the time immediately. Cover the paper with sulfuric acid and wrap it in the cylinder of the automatic drying tester. Clamp the paper with the molding.
d. Move the press wheel with 100 g weight to the left side of the screw rod, press it on the scraping paper covered with sulfuric acid paper, turn on the power supply, and place the speed regulator at a position of 10 minutes per revolution as required. On the top, turn on the push button, the cylinder will start to rotate at this moment, the pressing wheel begins to scribing, and moves to the left slowly, so that the time required for the pressing wheel to go is completed.
e. Examine the sulfuric acid paper that has been pressed by the pressurizing roller so as not to be stained with ink marks, indicating that the ink has dried (it has been stained with ink marks before it has dried). When the pressurizing wheel turns to the end, the sulfuric acid paper is removed for inspection, the number of ink marks on the paper is converted into hours, and the difference between the drying time of the sample and the standard ink can be determined to see if it meets the standard.
4 Note:
a, dry oil, ink should immediately dry testing;
b, the test must not be interrupted.
(2) Natural conjunctiva method (QB563-83):
1 Test principle. This method is also suitable for the drying of ink mainly composed of oxidized conjunctiva. The principle is to make the surface of the tested ink with a certain thickness become a solid film, which means that the conjunctiva is dry and expressed in hours.
2 tools and materials;
a, standard scraping paper;
b. Adjust the ink knife;
c, squeegee;
d, pin;
e, glass plates;
f. Scissors.

(To be continued)