Rotogravure printing machine engraving gravure is a gravure made by manual or mechanical engraving, and it is the earliest plate-making process in Rotogravure printing machine printing. At present, the traditional Rotogravure printing machine engraving gravure is rarely used, and the electronic engraving gravure is the most widely used printing plate in the field of gravure printing. Next, let’s take a look at the gravure plate-making method of the Rotogravure printing machine with JINYI
1. Rotogravure printing machineGravure platemakingHand engraving
Rotogravure printing machine Gravure plate-making manual engraving method can be divided into two types: engraving method and etching method. In the Rotogravure printing machine engraving method, the direct engraving gravure is hand-carved with an engraving knife, and the original plate of the image gravure is directly made; Rotogravure printing machine engraving method is a method of directly making a gravure plate by rolling on a plate with an engraving tool such as an embossing shovel and forming a uniform fine concave and convex grit on the plate surface to make a shading plate use. The etched intaglio plate in the Rotogravure printing machine etching method is to coat a layer of anti-corrosion film on the metal plate, manually engrave it with an etching needle, etch the anti-corrosion film, and obtain the graphic and text by chemical etching method. Line gravure, which can print softer tones; Rotogravure printing machine etching method is a kind of etching gravure, on the ground plate, by mechanical and manual methods, sprinkle resin or asphalt powder, and heat to fix the powder On the plate, the negative image is then engraved with the resist, and the image gravure is made by the etching method.
Negative image, image gravure made by etching method.
2. Rotogravure printing machine Electronic engraving plate making
Rotogravure printing machine Electromechanical engraving techniques is a process of converting optical or digital signals into mechanical motion through photoelectric conversion (digital-to-analog conversion) and electromagnetic conversion. A frequency generator is used to generate oscillation with a certain frequency (4-8kHz) and an appropriate amplitude. After the digital signal of the image memory is converted into an analog signal by a digital-to-analog converter, it is combined with the amplitude of the previous item to control the engraving knife to rotate at a constant speed. The surface of the plate-making copper layer of the plate roller is engraved with cells of different sizes and depths. Rotogravure printing machine The principle of electronic engraving gravure plate making is that the electronic engraving machine can correctly control the required number of screen lines and screen angle by controlling the rotation speed of the drum and the lateral feed speed of the engraving head to match the engraving frequency.
Electronic engraving plate making is when the Rotogravure printing machine electronic engraving machine directly engraves the plate making on the drum according to the digital information generated by the color desktop publishing system. The working principle of the digital mechanical electronic engraving machine in the filmless electronic engraving system: Rotogravure printing machine filmless electronic engraving plate making is the first to fully realize CTP technology in all printing plate making processes. Rotogravure printing machine filmless electronic engraving plate making process: digital page layout → parameter setting → trial engraving → formal engraving.
Imposition: At the imposition workstation, according to the requirements of Rotogravure printing machine gravure printing, the pre-pressed unit pages are assembled into large-format files for engraving according to the layout, and at the same time, the control for post-process control is placed on the assembled layout. mark. The control marks mainly include registration marks for controlling accurate overprinting, slitting marks for controlling the cutting of the Rotogravure printing machine, etc.
Parameter setting: Set the engraving level curve, mesh line, mesh angle, etc. in the Rotogravure printing machine electric engraving control workstation.
Trial engraving: The purpose is to adjust the engraving current of the Rotogravure printing machine (set the amplitude, high light current and dark adjustment current), so that the engraved dark tone, high light, and communication meet the process requirements.
Formal engraving: After the engraving current is adjusted to a suitable value after the Rotogravure printing machine trial engraving, the engraving starting position can be set and the official engraving can be started.
3. Rotogravure printing machine Ultra-fine electronic engraving technology
In addition to the two Rotogravure printing machine electro-engraving techniques described above, a new Rotogravure printing machine electronic engraving technique has been discovered: XT (Xtreme Engraving) ultra-fine electronic engraving technique. XT Ultra Fine Electronic Engraving technology uses high-resolution engraving for text and fine graphic elements. Rotogravure printing machine adopts XT ultra-fine electronic engraving technology. On the premise that the engraving head remains unchanged, the engraving resolution of conventional electronic engraving machines is increased to 200 lines/cm; and for electronic engraving machines used in the field of security, special development can be adopted. The engraving head increases its engraving resolution to 2000 lines/cm. Rotogravure printing machine The ultra-fine electronic engraving technology requires a screen controller, which is placed in the XT engraving head, and the screen is engraved at the same time. One cell of the engraving is composed of multiple lines of engraving. The number of lines of the engraving cell is the same as The engraving resolution can be different. The high-resolution engraving signal of each line must be responsible for forming the inner concave contour. The shape of the cell opening formed by the combination of multiple lines of engraving also needs to be determined by the engraving data. Under the control of the processed grayscale data, cells with different screen angles and opening shapes can be generated more freely, and even frequency modulation screening can be performed because the cell shape and angle are freed from the constraints of the “one cell at a time” method. processing, and finally realize FM screen gravure reproduction.
The above is the whole content of the Rotogravure printing machine’s gravure plate-making method brought to you today by JINYI. I believe that after reading the whole text, everyone has some understanding of gravure plate making manual engraving method, electronic engraving plate making method and ultra-fine electronic engraving technology, and more More information is continuously updated, see you in the next issue.
Post time: Aug-01-2022