The most popular overview of the new technology of

2022-07-27
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In recent years, one of the most successful new technologies in the flexo printing industry is the UV (ultraviolet)/eb (electron beam) curing technology. This new curing technology plays a vital role in improving the quality of flexo printing products

we know that UV flexo is widely used abroad, and its development and promotion in China are also quite rapid. It can be called the most influential technological innovation in the flexo printing industry

the components of water-based ink or alcohol based ink include: colorant, resin, amine, surfactant, solvent, etc; UV curing ink contains colorant, resin, surfactant, photoinitiator and diluent (a reactive monomer, non-volatile). We can see the difference between UV ink and water-based ink. UV ink has bright color, almost 100% solid content, and is non-volatile. It will cure only when it meets ultraviolet light with a certain wavelength and sufficient work. The short process of turning a liquid into a solid is called solidification. It is different from drying. Drying refers to the process in which the volatile solvents (water, alcohol) contained in the ink volatilize from the ink under the external action (heat, infrared, etc.), and the remaining part slowly becomes a solid

the UV light source used on the flexographic press is the UV curing system, which is generally composed of three parts: light box (lamp tube, reflector, etc.), power controller and operation panel. When high voltage electricity passes through the UV lamp, the lamp tube will emit ultraviolet, infrared, visible light, etc. Generally, the temperature of UV lamp is very high when it works, which will lead to the shrinkage of film materials and affect the overprint accuracy. It is especially unsuitable for some thermal materials, so the cold UV technology came into being. The cold UV adopts a dichroic reflector, which can reflect ultraviolet light and absorb infrared (heat). In addition, a transparent cooling plate is added between the light source and the substrate. Cold UV technology can reduce up to 80% of the heat to ensure that the substrate surface temperature will not exceed 45 degrees. Cold UV technology not only solves the problem of ink adhesion, but also avoids the problem of overprint accuracy caused by the thermal shrinkage of thin film materials

eb curing technology is similar to UV curing. The ink is cured rapidly after being irradiated by the electron beam since his first competition in 2009. Because the application cost of EB curing is high, it has not been popularized on a large scale

II: rapid replacement technology

the rapid replacement technology referred to here has been extended to include rapid replacement of ink and embossing roller, rapid replacement of printing plate, embossing cylinder and die-cutting tool. Adopting the rapid replacement technology can greatly shorten the time required for each process link, minimize the downtime preparation time and improve the utilization efficiency of the machine

the technology of quickly replacing the stripper roll and cleaning ink generally adopts a drawer structure. Pull out the stripper roll and ink tray together, remove the stripper roll, clean the ink lifting roll and ink tray, and then put in the new stripper roll and ink. When the Aquaflex flexo press pulls out the drawer, the motor that independently drives the wrinkle roll does not stop working, which can prevent the ink from drying on the wrinkle roll

quick change of printing plate refers to the quick change of printing plate after the completion of an order in the case of different printing plates with the same size of plate cylinder. Generally, for a limited number of plate cylinders, thin sleeve (1mm) and inflatable cylinder core structure can be used. During the printing of the previous order, the printing plate of the latter order has been pasted onto the sleeve. When replacing, the time required for each color plate is only twoorthree minutes. This new technology of rapid plate replacement is particularly convenient for printing pieces (cigarette packets and beer labels) with fixed size and changing patterns

the rapid replacement of the embossing cylinder technology is to increase the printing range of the flexographic press, which can not only introduce film, but also print paper and thick cardboard. In the past, replacing a set of imprinting rollers was quite a hassle. With the rapid replacement technology, only a few screws can be removed to remove an imprinting roller. It only took half an hour to replace a complete set of imprinting rollers

in terms of rapid replacement of die-cutting tools, it is said that chromas has adopted the on-line laser die-cutting technology, which can call out the data entered in advance for execution, and then complete the replacement work conveniently and quickly. At present, this technology has been successfully applied to the processing of self-adhesive labels

III: shaftless drive and servo drive technology

for the unit type flexographic press, perhaps everyone is familiar with the fact that there is a long, segmented main drive shaft behind the machine. When the number of printing units is increasing or the width is increasing a lot, the main drive shaft is bound to produce large distortion due to the increase of load, which will seriously affect the accuracy of multi-color overprint

with the rapid development of motor and control technology, shaftless drive and servo drive have become possible. The independent printing unit is driven by a separate motor to ensure that the relative position of the plate cylinder of each unit is accurate and that the tension of the whole machine is stable. So as to improve the overprint accuracy of multi-color printing and avoid the phenomenon of "ink bar" caused by vibration. In addition, the printing range of each machine will be further expanded, from film to thick cardboard. The servo drive technology can also expand the application range of flexographic press. For example, the first unit can print the first 450mm of the required repeat length of 900mm, while the second unit can print the remaining 450mm

IV: PLC control and remote diagnosis service system

convenient man-machine interface and menu command make the control faster and more efficient. Once the machine breaks down, the system will display the error information in time to guide the operator or maintenance personnel to find the fault point as soon as possible, so as to eliminate the fault as quickly as possible and reduce the downtime. For serious faults, the operator can also use the means of remote diagnosis service to consult the machine manufacturer, so that they can provide services in time

V: other technologies

in addition to the above new technologies, many other new technologies are used on different flexo printing machines by pressing the power button respectively. They are: sleeve technology (quick and convenient replacement and simple operation), sleeve technology is widely used in corrugated roller and laser engraving seamless rubber roller; Online digital printing technology (digital printing technology is applied to flexographic press, which can be used for point printing or monochrome text and pattern printing); On line lamination (including cold lamination, hot lamination, UV glue lamination), on-line cold stamping, inkjet, etc. In the satellite flexo printing machine, a more efficient drying system is used to improve the effect of color drying and final drying, and an automatic ink washing system is used to save manpower

from the introduction of the above new technologies, we can see that the major equipment manufacturers are racking their brains to continuously introduce various new technologies and processes. Their ultimate goal is nothing more than to reduce costs, improve flexo printing quality, reduce downtime and 3. Production efficiency during installation, reduce unnecessary waste, etc. only in this way can the equipment manufacturers remain invincible in the fierce competition Only in this way can flexo printers get products with better quality and lower cost, and the entire flexo printing industry can continue to develop. It can be said that technological progress has made our dreams come true

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