In the ink industry, the word "set" is a concept that has only gradually become clear in the past 20 years. Its definition refers to the meaning that when the fluid ink is printed on the paper, it is fixed and attached and cannot be transferred.
Fixation, in fact, can be regarded as the initial drying content of an ink, that is, the process of ink changing from a fluid state to a semi-solid state is called fixation.
The so-called imprint fixation method introduced here to measure fixation is actually basically similar to the principle of the dryness instrument method mentioned above .
(1) Equipment and materials.
①Apparatus.
(i) Printability Tester.
(ii) Scissors.
(iii ) stopwatch.
② material. 100g or 1.50g coated paper.
(2) method.
Use the printability Tester to print the oil to be tested on the coated paper. At the same time start the stopwatch. Use scissors to cut a small piece of printing sample about 0.5 × 1 cm in size, and repeat the pattern on another white coated paper (the printed oil og layer is in contact with the white coated paper), and after one minute, use a pressure device ( For example, printing suitability Tester, etc.) press it, remove a small piece of printing, and then a small piece of printing about 0.5 × 1 cm appears on the white coated paper. In this way, the above-mentioned operation is repeated every one minute, so that pieces of blots with lighter and lighter colors (less) are left on the white coated paper until the blots no longer appear on the white coated paper.
The time required from the beginning of the printing to the time when the imprint no longer appears on the white coated paper is the fixation and drying time of the tested ink.
(3) Precautions.
① The determination of fixed drying is closely related to the thickness of the ink layer of the printed sample. Therefore, the thickness of the oily layer of each printed sample needs to be strictly controlled, and the imprint needs to be uniform.
②The pressure during embossing also has a certain influence on the drying of the solid, so the pressure during printing should also be strictly controlled.
③The measurement should be carried out under the condition of constant temperature and humidity, the temperature is 25±1 ℃. The relative humidity is 65%±5%. The paper used for the measurement should be stored under this condition for more than 24 hours in advance. Different papers will give different results, so the quality of the paper should be strictly fixed.
