Paper Tube For Tooth Powder flexographic ink printing experience sharing

Paper Tube For Tooth Powder flexographic ink printing experience sharing

Printing equipment and printing technology, is the core of the operation, it will reflect the printing equipment, material selection, work and operation level. Correct operation of each process, operators must be the basic requirements.

First, the usual operation sequence is as follows:

Roll feeding → paper feeding → adjustment and correction → reasonable selection of roller roller → plate roll → pressure adjustment → inking → embossing → registration → tension control → drying system → die-cutting → cutting → rewinding

Two, feeding coil

After feeding volume, the center of the material which is printing position, because the post edition correction, die-cutting, section is based on the central shaft for the benchmark, was printed materials shall be in strict accordance with the equipment of paper after the route through the paper guide roller, paper machine to printed material to send to smooth paper, adjust the tension, the printed materials under certain stable tension control, To ensure the accuracy of overprinting, adjustment and correction, so that the material in the printing machine and plate in the middle position, to ensure that the correction action is sensitive and correct.

Three, adjust the pressure

The adjustment of flexographic printing pressure is a key step in product quality, which directly affects the quality of the printing products. The spacing between the plate roller and the embossed roller is the same. The standard feeler with the thickness of 2.08mm(1.7 plate +0.38 double-sided tape) can be selected to make the pulling resistance of the respective feelers at both ends the same. At this point, the spacing is the ideal pressure value for printing (but in actual production, careful fine-tuning by the operator is required, which requires the practical experience of the technician to obtain the best pressure value).

Under the slow running of the machine, from the first color group to start pressing, first check the ink transfer situation of the roller to the plate roller, can be adjusted to the best effect through the pressure system at both ends, the pressure between the two rollers to light is good, is conducive to the normal ink transfer of dot skew, ensure the quality of pictures and images and protect the plate damage. Secondly, the rough adjustment of the pressure of the plate roller and the pressure roller is carried out to observe the transfer situation and the clarity of the printing on the material surface, which is the verification of the correct transfer pressure (note: this key step is adjusted according to the experience of the technical personnel). Must overcome flexo printing pressure is too large, this is the key to the plate.

Four, tension control system

By tension controller to control the printing in the printing process of tension constant, is the key to overprint accurate, so any reel printing machine tension control system is an important organization, it decided to print the overprint accuracy to a great extent, the tension control mechanism mainly in feeding section, printing stations and traction and winding mechanism, material volumes need output resistance, The roll rotation has inertia, and the roll itself also has a certain tension value. In addition to the tension traction of the printing speed, the resistance of various overprints to the printed material in the printing process makes the tension control of the unwinding, printing and winding mechanism particularly important. The tension control should be determined by the thickness of the material and the width of the material. The thicker the printed material, the greater the tension value; Conversely, tension value is smaller, more demanding, such as printing a thin material tension value because of the consideration on printed materials wrinkling problem such as tensile, deformation, generally suitable tension adjustment is multicolor "cross gauge line" all alignment, not back and forth "mobile" as the standard, if a "cross" press overprint is not stable, rolling and the winding tension can be adjusted, So far as the color group "reticle" registration is stable, of course, the tension value is not exactly the same when printing at low speed, medium speed and high speed. It is recommended to fine tune the tension value at the normal speed. The phenomenon of "going" often occurs in the printing process, and people are used to looking for equipment, materials and other reasons. In fact, the impact of overprinting accuracy, often for tension discomfort. If you can carefully adjust the tension, under normal circumstances, overprinting can not be readily solved.

Five, ink PH and viscosity adjustment

Effective control of ink PH and viscosity in the printing process is the main steps to ensure the quality of printing.

The PH value of water-based ink is about 8.5. At this value, the ink is relatively stable. However, in actual production, with the rise of temperature and volatilization of ammonia in ink, the PH value will change, affecting the printability of ink. A small amount of stabilizer can be added to control the PH value. In normal printing, it is usually required to add 5ml stabilizer every half an hour and stir it evenly. Basically, oil black can ensure stable printing adaptability, and stabilizer can not be added at will, otherwise it will backfire and produce various printing defects.

The viscosity of ink is the main factor that determines the transfer performance of ink, printing firmness, permeability and luster. If the ink viscosity is too high, the color will be darker, the ink loss will be large, the drying degree will be slowed down, the color will change if the viscosity is too low, and the dot will be expanded, resulting in the decline of product quality.

Printing level edition and full edition, water - based ink viscosity is different. General level edition ink viscosity should be slightly lower. When printing, the speed of the machine also has an impact on the ink viscosity. Printing speed is high, water-based ink viscosity is low, and printing speed is low ink viscosity is high.

Six, die cutting station

In order to discuss flexographic printing technology in a more comprehensive way, in addition to the above on corrugated box flexographic printing process operation, here also want to talk about the die cutting station of narrow-width flexographic printing press. Narrow soft format printer usually makes up three die cutting station, after printing the attachment to meet the need of creasing and die cutting printed products, can be used for the stickers, forms, cartridge and other finished products processing, die cutting knife USES the circle pressure circle impression roller, exterior knife roller die cutting molding, such as with magnetic tool must first formulate various product specifications of the magnetic roller, composed of series specifications, Can meet most of the different specifications and sizes of the product die cutting processing requirements.

Another kind of die cutting roller, called cutting sheet roll. It is a knife roller INlaid with die cutting blade, according to the need to open one, two, four or more knife slots, mainly used for cutting sheet products, cutting sheet roller and plate roller in general size, or twice the use.

The outer knife roller must be used before the use of the bag knife sea cotton cloth, to ensure the die cutting accuracy and avoid damage to the knife edge, the pressure adjustment to just cut off the printing material is the best pressure.