Analysis on the Influencing Factors of Flexi Dot Extension in Corrugated Boxes (II)

equipment

â–  Anilox roller

The anilox roller is the heart of the printing machine. At present, there are mainly two kinds of metal anilox roller and ceramic anilox roller. From the perspective of using effect, there is not much difference between the metal anilox roller and the ceramic anilox roller. The main difference between them is that the number of ceramic anilox rollers with the same number of lines is greater than that of metal anilox rollers; ceramic anilox rollers are relatively prone to network blockage; ceramic anilox rollers have better durability.

In general, when the number of lines of the anilox roller is at least 5 times the number of lines required for printing, no stencil phenomenon occurs. The anilox roller needs regular cleaning to ensure its ink loading. In the dot printing, the ink volume control should be as small as possible to ensure the dot clear, and the ink volume is opposite.

â–  Scraper and rubber roller

The difference between a doctor blade and a rubber roller is that when the doctor blade is used, the amount of ink carried by the anilox roller is independent of the speed of the printer. When using a rubber roller, the ink loading of the anilox roller increases as the speed of the printing press increases. It is best to use a squeegee in dot printing to ensure consistent ink levels. When using a rubber roller, it is important to control the speed of the vehicle, and it is very important to maintain the consistency of the ink when it is repeated.

â– Printing machine

Some of the corrugated box printers have the function of infrared drying and blow drying, which can accelerate the drying of ink and avoid the proliferation of dots due to insufficient drying of the underlying ink.

â– R/BAK pad

The role of the R/BAK pad is to reduce the deformation of the plate by suitable deformation in the corrugated box printing. In actual production, the dot diffusion at the peak can be reduced.

Polishing

At present, customers have more and more requirements for corrugated boxes, such as ink abrasion resistance and waterproofness. In order to meet the requirements of customers, many corrugated cartons have been increased in the production of this process. There are many types of varnishes and their uses are different. When using varnishes, it is best to choose products that have poor re-solubility with inks. If they do not achieve the desired results, they can only choose the method of glazing after printing first.

operator

The operating level of the printing press operator is a key factor in the production. It is crucial to master the gap between the rubber roller (scraper), the anilox roller, the printing roller, and the embossing roller in actual production. The flexographic plate hardness is not high and it is easily deformed, so the clearance between the anilox roller, the printing roller, and the embossing roller should be just right.

Rubber roller (squeegee) and anilox roller gap can control the amount of ink, too much ink will be fuzzy dot network, ink is too small, the color is not full; anilox roller and printing roller gap can control plate and anilox roller The pressure, if the gap is too large, the printing plate can not evenly ink, the gap is too small will cause deformation of the upper plate, resulting in ink between the dots, there will be dot adhesion after printing; the gap between the printing roller and the embossing roller is It is to control the pressure of the printing plate and the corrugated board. Too much pressure will deform the lower plate of the printing plate. The dots will spread badly on the peak, and the corrugation marks will be obvious. The pressure will be too small to make the plate and the cardboard unable to fully contact, and there will be no ink in some positions.

In addition, the surface of the printing roller and the embossing roller should be clean and free of ink and other dirty things. The feed roller gap in the feed section must be just right, neither can crush the corrugated board, but must also be able to accurately feed the corrugated board into the machine.

In the long-term production, there will be remnants of the ink on the plate, which will cause the dot to be blurred, and the plate needs to be cleaned in time. During the production, we must also pay attention to maintaining the viscosity of the ink and the consistency of the PH value. If necessary, add water or additives. Finally, in order to avoid abnormalities, frequent convulsions are also very important.

Source: Shenzhen self-adhesive web