The pressure of environmental protection has accelerated the development and application of domestic thin film flexo printing ink, and flexo printing will welcome new development opportunities under the pressure of this market.But in this market opportunity, flexo printing machinery needs to make the following four improvements.
First, the improvement of the medium expansion
Second, establish rules for regulating printing pressure
Third, the need to improve the ink film printing on the unit type
Fourth, the improvement of closed scraper and cleaning mechanism
Today, I would like to talk about the third improvement – the improvement needed to print thin films with ink on the machine set.
First of all, because there is no increased risk of satellite type, unit type printing film is a good choice.But the domestic unit type flexo printing machine mostly printing paper, used to the large tension under the condition of adjustment, after changing the tension control of the film must be very careful, before using a hand to pat the paper tape tension can be determined by the size of the operation habit, it is likely not suitable.
Attention must be paid to the concept of unit line tension.Under the limit condition, the maximum or minimum unit line tension is calculated according to the full width, and then the unwinding tension, feeding tension, discharging tension and winding tension are calculated according to the type, thickness and width of the film used.This is very similar to gravure film printing.
Due to the environmental requirements of the use of ink, very worried about the film ink drying slower, so I want to change the original unit type flexo printing machine down paper structure to up paper.In this way, the oven turns over the fuselage, similar to the shape of a gravure printing machine.This improvement is reasonable, because by moving the paper, the center of gravity of the whole machine moves downward and the machine is more stable at high speed.The drying way can also be lengthened for better drying effect.However, one thing must be noted: when the film is printed, the first corner guide roller encountered in the drying path, please pay attention to the surface friction coefficient, not too rough.Otherwise, the ink film has not been completely cured, ink film is tender, too rough guide roller surface, easy to pull the ink film.
Unit type ink printing film, can be used with gravure the same film.As long as the intaglio printing can achieve accuracy, the unit flexo printing can also achieve.Because the structure of these two models is similar, the tension control requirements for the film are similar.And, because the flexography pressure than gravure pressure is much smaller, by the positive pressure caused by the reverse friction also have a lot of difference, flexography thin film material coil compensation is much smaller than gravure, therefore, gravure transmission and film compensation in the empirical data, may be more fuzzy than flexography data.This is the advantage of flexo printing.But if you have to print on the machine than gravure print thinner, this has a certain difficulty.
Post time: Sep-24-2020