The dryness index actually measures the extent to which the sample coated on the iron sheet becomes a solid coating film under specified baking conditions, and uses it to measure the dry quality of the iron printing ink.
1. Appliances
(1) Minor ink knife;
(2) Small rubber rollers (preferably made of synthetic rubber);
(3) oven;
(4) Glass plate for ink distribution.
2. Materials
The size of tinplate and aluminum sheet should be appropriate.
3. Method
First adjust the oven to the desired temperature and keep it constant.
Apply a small amount of test ink on a small rubber roller, and roll it on a glass plate to make the ink fully even. After rolling to a certain thickness, roll the ink on the rubber roller to the tinplate. Then put it in an Incubator. Baking conditions depend on requirements.
For primer, white cocoa and varnish, dilute a certain amount of sample with a certain amount of solvent, stir it evenly, and flow coat it on the tinplate to measure its dryness. The heating conditions provided in Table G-12 are for reference. In actual application, they can be specified separately according to the type of coating.
4. Matters needing attention
When rolling a layer of ink or flow coating a layer of primer, varnish, or white codine on the iron sheet, the thickness of the coating film is the key to the measurement, and it is required to be thin and uniform, which requires rich experience.
