How to distinguish between gravure printing and dragging in gravure printing

Gravure printing often encounters scumming and dragging faults. These two types of failures exhibit different phenomena, causes, and solutions. However, there are many people, including some printing specialties and old ones.   饬 饬 饬 饬 饬 饬 饬 饬 饬 娜 娜 娜 娜> The phenomenon is different

Drag and drop is a gradual change from a certain part of the image and gradually disappears. It is shaped like an animal and is often called trailing.

The affixed version is different, it is in the graphics and text edge overflow and graphics width is basically the same, the ink is lighter than the image, shape indefinite graphics.

2. The reason is different

The cause of dragging is that there is an impurity between the doctor blade and the plate, and it extends to the back of the blade. When the scraper blows through the graphic part on the printing plate, impurities and the ink come into contact with each other. When the scraper scrapes out the force producing part, the impurities lag behind the blade and come into contact with the printing plate, which will drag the graphic.

Paste is mainly due to the scraper and the printing plate arc contact, that is to say the knife is very tight, the pressure is also large, the scraper scrapes through the printing plate graphic part, the long-pressed blade has a tendency to straighten, this is in the elastic range Within is allowed. When the scraper moves out of the graphic part, the blade touches the shoulder of the net and it will bounce like the ball hits the wall. When the blade is moving out of the plate graphic part, the scraper that is in contact with the graphic will sideways and cannot The plate is scraped clean, under the pressure of printing, the ink will overflow the graphic part, resulting in paste plate.

3. Different solutions

In the production, you will encounter the troubles of graphic dragging. Generally, you only need to use bamboo chopsticks to gently scrape it.

Encountered stencil problems need to be solved by loose knives and reducing air pressure.

4. Common to both faults

When the viscosity of the ink is relatively low, both dragging and stencil failures are prone to occur. Therefore, properly increasing the ink viscosity plays an important role in preventing the occurrence of the above two kinds of failures.

Rotary sudden printing press to change the die-cutting machine

A rotary printing machine in the printing factory can be converted into a die-cutting machine. The die-cutting machine converted into a die-cutting machine is accurate, the pressure is uniform, the die-cutting speed is fast, the operation is simple, and the labor intensity is low. It can be used for die-cutting below 450g/m2. Prints. The machine can also be used to emboss pits. It also has the advantages of accurate overprinting, high pressure, and high speed.

The specific modification steps are as follows:

First, remove the entire ink fountain assembly. In order to ensure the safety of the modified equipment, a glass cover can be added to cover the platen. The shroud should be designed to be open to facilitate loading and other operations.

Then, the impression cylinder was lining removed and wrapped with a stainless steel skin approximately 0.50 mm thick. Depending on the thickness of the print, the PS plate, polyester plate, or paper may be placed under the steel skin to ensure that the total thickness of the press plate itself does not exceed 1.20 mm.

Then, a die-cut version was installed, and a round flat die-cutting machine was successfully converted.

Corrugated box indentation and molding quality

In the production of corrugated cartons, in addition to some of the relatively high requirements on the molding quality, the cartons on the high-speed automatic packaging line, are basically and cut, indentation, opening angle, forming, nail box process route. The indentation plays a key role in the forming quality of corrugated boxes.

The effect of the indentation is to enable the corrugated board to be folded into boxes as designed. Due to the different structure of corrugated cardboard than ordinary cardboard, in order to ensure that the mark lines are clear after indentation and do not damage the cardboard, it is easy to fold and shape, the edges and corners are clear after folding, and the straight lines and box bodies are regular, no matter in the indentation knife. The location of the line, or the selection of indentation lines, are very particular about. Especially for thicker corrugated board, indentation quality, box size and indentation location have a great relationship.

For vertical and press makeup, when the indentation line falls on the peak or valley of the corrugated medium, the quality of the indentation is generally better, and the forming size of the carton is also easily ensured. However, if the indentation line falls between the peak and the valley, which is half the waist, the indentation quality is difficult to guarantee, and the molding size of the carton tends to be deviated.