The main reason for the slow drying of offset printing products
1: The temperature of the environment: The temperature of the environment is too low and the humidity is too high to dry the ink slowly.
2: Ink properties: In general, organic pigments dries slower than inks prepared from inorganic pigments, the thinner binder material dries slower than the thicker binder material, and the oil content is much slower than the less oil content.
3: Diluting agent and dissolving agent: Both diluting agent and dissolving agent have the property of inhibiting the ink drying, so it is necessary to add a small amount.
4: The nature and structure of the paper: If the paper is acidic, the print will dry slowly. The surface of the paper is rough, the structure is loose, and the permeability is large. A small degree of sizing will promote the drying of the ink, and vice versa, the drying will be slow.
5: The pH of the fountain solution: the pH of the fountain solution is low: the hydrogen ion (H+) concentration in the fountain solution is large, and it will have a substitution reaction with the metal salt in the dry oil, thus inhibiting the ink on paper. The surface is dry.
6: Layout Moisture: In the printing process, if the plate surface moisture is too large, not only will the paper absorb too much moisture and stretch out, but also will form oil-in-water type Lulu emulsion ink, which will affect the drying of the print.
7 Add too much desiccant: Add too much desiccant, then make the ink thicker, dirty plate, expanded mesh deformation, with hair thorns, imprinting is difficult to dry.
8: Excessive stacking of printed sheets: If the sheet area is large, the paper surface is smooth, and the stack of sheets is too high, it is difficult for the air to come in contact with the printed ink traces. This will necessarily make the prints dry slowly.