Views:0 Author:Site Editor Publish Time: 2020-08-24 Origin:Site
How to ensure the curing quality of UV ink?（一）
UV ink is suitable for offset printing, gravure printing, flexo printing and other printing methods, no matter what kind of printing, I believe we are most concerned about the fundamental problem is the curing quality of UV ink.
UV ink can be in ultraviolet radiation photochemical reaction, thus achieving the purpose of curing. From this curing principle can be known, UV ink before and after receiving UV light irradiation has different properties, namely UV ink before receiving UV light radiation, can maintain stable rheological property, and after receiving UV radiation, it will quickly cure. It is conceivable that the effect of UV radiation factors, will also affect the curing quality of UV ink. Therefore, in order to ensure the radiation effect of ultraviolet light, the following three aspects must be achieved.
The first aspect is to do the ink balance control well. In offset printing process, UV ink is weak polarity, if the ink balance control is not good, easy to occur emulsification phenomenon, resulting in the ink film becomes opaque, which directly affects the UV light transmittance, thereby slowing down the curing speed of UV ink, resulting in the formation of the ink film after its internal still not fully cured.
In this case of printed matter for folding friction or the use of adhesive tape to pull the surface of the text and text, the surface of printed matter will appear scratches or wire drawing phenomenon. Therefore, controlling the ink balance in the printing process is one of the important factors to ensure the quality of UV ink curing.
Due to UV ink viscosity is large when the adhesion between the molecules, UV ink water resistance will become stronger, therefore, in order to reduce the UV ink emulsion value, in the printing process must grasp the principle of small water, so as to ensure the printing color, thick ink layer, clear and full dot.
The second aspect is to maintain appropriate workshop temperature and humidity. In the printing process, the workshop temperature and humidity changes will affect the performance of UV ink and substrate, such as when the workshop temperature is low, high humidity, UV ink light curing reaction is slow, and the ability to combine with substrate will be reduced. Therefore, in the use of UV ink printing must be in the workshop temperature and humidity control in the appropriate range, the general workshop temperature should be controlled in 20 ~ 25℃, relative humidity should be controlled in 50% ~ 65%.