China Printing Solutions-UV ink can be applied to offset, gravure, flexo printing way, no matter adopt what kind of printing way, believe that the industry's most concerned about the fundamental problem is the quality of the solidified UV ink.UV ink can occur under the radiation of ultraviolet photochemical reaction, so as to achieve purpose of curing.From the principle of this kind of curing, UV ink has different performance in before and after exposure to ultraviolet light, or UV ink before accepting ultraviolet radiation, can maintain the stability of the rheological property, and after receiving ultraviolet radiation, fast curing.Predictably, factors that influence the effect of ultraviolet radiation will affect the quality of the UV ink curing.Therefore, in order to guarantee the effect of ultraviolet radiation, the following three aspects must be done.
1. The ink balance control
In the process of offset printing, UV printing ink is weak polarity, if ink balance control is not good, easily happened emulsifying phenomenon, cause the ink film become opaque, which directly affect the transmittance of ultraviolet light, then slow down the UV ink curing speed, cause the ink film formation are still not completely cured after their internal.For this case, the printing quality of folded friction or use sticky tape pull its surface graphic, printing quality surface will be chafed or drawing.
Therefore, good control in the process of printing ink balance is one of the important factors to ensure the quality of the UV curing ink.Because of its high UV ink viscosity adhesive force between the molecules is large, the UV ink water resistance will be stronger, therefore, in order to reduce the emulsification value of UV ink in the printing process must hold good principle with small amount of water, so as to guarantee the print color bright, clear ink layer thick, branches full.
2. Keep the workshop temperature and humidity is appropriate
In the printing process, the workshop temperature and humidity changes will impact on the performance of UV ink and substrates, such as when the workshop low temperature, high humidity, UV printing ink light curing reaction is slow, the combination of substrates and capacity will reduce.Therefore, when using UV ink printing workshop temperature and humidity must be controlled in appropriate range, general workshop temperature should be controlled in 20 ~ 25 ℃, relative humidity should be controlled in 50% ~ 65%.
3. Ensure that the UV lamp intensity of UV light
First of all, on the basis of printing speed, the product type to select suitable power on UV lamp is the important premise.UV light intensity of the UV lamp directly affects the UV ink curing time, it is also the key factors affecting ink film internal sclerosing.When UV light intensity become low, even by increasing the irradiation time to improve the cumulative amount of light, also can't improve the inside of the ink film sclerosing, so more than the actual service life of the UV lamp can't make the UV curing ink completely.Usually, UV device fitted with UV lamp use timer, import UV lamp actual service life of 1000 hours, domestic actual service life of the UV lamp is 600 hours.To ensure the quality of the UV ink curing, UV lamp should be replaced in a timely manner after to real life.
Second, if the ink contains impurities or the dust attached on the surface of UV lamp, in the process of production will be less UV light intensity, thus greatly reduce the curing quality of UV ink, UV lamp to use after a period of time, therefore, should be removed the light box, use clean soft cotton cloth dipped in the foot gently wipe the surface of UV lamp, anhydrous ethanol in place to ensure that its clean and bright.
Finally, in the bowels of the UV lamp box reflector can concentrate 80% of UV light effect on printing quality, if the paper powder or dust attached on the reflector, would affect the reflection effect of ultraviolet light.So, in the daily production, must be carried out on the reflector cleaning and maintenance in time, to maintain the best Angle of reflection and reflective ability.This work can be, at the same time of cleaning the UV lamp which use clean soft cotton cloth dipped in ethanol to clean.When cleaning and maintenance, should also be closed manually reflector, check whether the closed state in good condition, if necessary, also check the closing device integrity, average closing device adopts pneumatic components, can use magic eye or electromagnetic to detect the working condition.In addition, also check of the condition of the fire board, once the reflection surface appear hair black or not smooth phenomenon, should be replaced in a timely manner.
In addition, the purity and dosage of UV ink system of pigment, printing color sequence arrangement, such as printing speed to impact of UV ink curing.China Printing Solutions-
(Gold Printing Group) |
