Conduct a freezing and heating test on the ink for a certain period of time to observe whether the ink is gelled or thickened.
(1) Iron box that can hold 20 grams of ink;
(2) Self-controlled thermostat;
(3) Self-controlled freezer;
(4) Fluidity Tester;
(5) Ink adjusting knife;
(6) Transparent volume scale (the scale value is 1mm)
(1) Put the ink samples into two iron boxes respectively, and each box contains no less than 15 grams of ink. The ink in the iron box should remove air bubbles, then mark the upper cellophane, cover the iron box, and then separate Put it in a 75~80°C self-control thermostat and a -15~-20°C freezer, take it out after 72 hours, and store it at room temperature.
(2) Measure the fluidity of the tested ink that has been stored at room temperature for more than 3 hours according to the QB560-83 flow test method and compare the fluidity of the ink that has not been subjected to heating and freezing tests.
(3) Based on the difference in the fluidity of the ink sample and the change in the performance of the ink, determine whether the oil quantity is stable according to the following regulations.
a. The fluidity after the test is not much different than that of the untested one, which means that the ink is stable.
b. The fluidity after the test is much larger than that of the untested one, and the ink property is still good, so the possibility of the oil becoming the most wavy is not great. But it is not stable enough.
e. The fluidity after the test is much smaller than that of the untested one, and the ink becomes "shorter", which means it has a tendency to gel. Generally, this kind of ink is easy to gel after a long time.
(1) The freezing test method is mainly to determine whether it returns to coarse.
(2) The heating test is mainly to determine whether there is a possibility of gelling.