The physical and chemical properties of ink mainly refer to its density, fineness, transparency, gloss, light resistance, heat resistance and acid, alkali, water, solvent (alcohol) resistance. We know that once there is a problem with the ink, it will easily lead to poor printing leveling. Printing is to transfer the ink to the surface of the paper, fabric, leather and other materials through the processes of plate making, ink application, and pressure on the original manuscript such as text, pictures, and photos. Therefore, the material of heat transfer printing ink is very important!
In general, the main factor of ink composition affecting ink adhesion is that the resin used in the ink production process does not have better wetting properties for the substrate. Therefore, the ink produced with this type of resin has poor adhesion.
The surface of the printing material: In order to ensure a certain adhesion fastness, the surface of the printing material needs to be treated before printing, so that the surface energy can reach more than 0.038N/m (BOPP).
The relative humidity and temperature of the printing workshop will affect the ink adhesion. After long-term observation and experiments, it is believed that with the increase of the relative humidity of the environment, the adhesion tends to rise at the beginning, but as the humidity continues to rise, the adhesion begins to decline again. This shows that the relative humidity suitable for printing has a critical value, and temperature is an important condition in gravure printing, which affects both drying and the tension of the printing material. If the temperature is set too high, it will not only affect the vertical overprint accuracy but also cause the ink to dry too "fast" on the substrate, resulting in a decrease in adhesion. The ambient temperature suitable for printing should be controlled below 30°C. Due to the influence of factors such as printing materials, ink layer thickness, and printing speed, the drying temperature is not the same. The general principle is that it should not be set too high.
Ink layer thickness:The influence of ink layer thickness on ink adhesion, in order to clarify the relationship between the two, ink adhesion tends to decrease with the increase of ink layer thickness.
keywords:heat press printing