(1) Principle
Gravure ink is a low-viscosity dispersion, due to the reactivity of the resin and pigment used in this system, and also due to the performance of the resin and pigment itself, especially when the external conditions change drastically, gelation, delamination, etc. may occur The situation directly affects the usability and durability of the ink. Therefore, it is necessary to control the stability of the ink.
(2) Tools and materials
Tools: electric heating box (constant temperature), scraper clock "processed polyethylene film.
(3) method
a. The print is thermally blocked. In the case of plastic ink, use a scraper to make a print on PE film (polyethylene). After two minutes, fold the print against each other and sandwich it between two 20X20X2 mm glass sheets. Under the condition of 60°C plus 300~500g/c㎡pressure, for 24 hours, depending on the adhesion of the imprint, no adhesion is qualified.
b. The ink is resistant to freezing. Use a 150ml triangular flask, fill it with 50ml ink and seal it. It is better if it does not gel at -5°C for 24 hours.
c. Ink delamination inspection, the ink is stored at 25°C for 7 days, and the oil slick is regarded as qualified.
