The method of measuring levelling with levelling agent deliberately refers to GB/T17.50, JB3998 and American ASTM D4062 standards. Taking GB/T17.50 as an example, the principle of determination mainly uses Mayer-Rod to scrape Printing ink on the ink film, and observes the ability of self-laying Development to eliminate surface irregularities during fluid drying. The operation method is also very simple. Drop the fluid into the tinplate, and then use the levelling agent around Mayer-Rod to evenly scrape the sample to obtain a coating with a uniform film thickness, which is expressed in min as the result of the disappearance of the coating pattern and the formation of a smooth ink film. This method is more suitable for offset ink and solvent type Printing ink.
In addition, JB3998 deliberately passes the levelling scraper, usually called the levelling Tester. This levelling Tester generally has multiple grooves with different film thicknesses. One scraping can prepare multiple wet films with different Film thicknesses. The number of parallel strips that have flowed together on the test cardboard, and the levelling level is determined against the standard pattern, 10 is better, and 0 is the worst.
American ASTM D4062 also adopts the Mayer-Rod scratch coating method, using 40 ° light to observe the light-dark contrast formed by the temperature adjustment of the film surface, so as to judge Leveling. Printing ink is applied to the Paint Chart through the coating bar to produce uniform parallel stripes on the entire ink film surface. There are 9 standards. Find the standard number that is the same as a certain dark-bright contrast. If it is worse than NO1, it will be No. 0, and Leveling will be the worst; if it is better than NO9, it will be No. 10, and Leveling will be better.
Which method do you think is more convenient and accurate? Welcome to discuss with nbchao.
