Introduction to the classification of printing machinery

There are many types of presses that can be classified in the following five aspects:

First, according to the layout type is divided into: letterpress printing presses, lithographic printing presses, gravure printing presses, aperture printing presses;

Second, according to the size of the paper is divided into: lithographic or sheetfed printing presses, web printing presses;

Third, according to the number of printing color is divided into: monochrome printing presses, two-color printing presses, multi-color printing presses;

Fourth, according to the printing format is divided into "eight open printing presses, four open printing presses, off printing presses, full sheet printing presses, super-wide sheet printing presses;

5. Although there are many methods for classifying printing presses, the core part of the printing press is the imprinting mechanism of the printing apparatus. Therefore, depending on the way in which the pressure is applied, the printing press is generally classified into flat, flat, circular, and circular. Three kinds of pressure round.

Flat Presses

The structural features of the flat-press type printing press are that the plate-attaching mechanism and the imprinting mechanism are flat.

During printing, the imprint lithographic plate swings back and forth around the spindle to complete the paper feeding and imprinting. Since the ink and the imprint lithography of the printing plate graphic portion are all in contact at the same time, the imprinting time is longer and the pressure exerted on the substrate is greater, so the ink color of the printed matter is heavy and the lines and strokes are full.

Flat-press type printing machine, small volume, slow printing speed, low production efficiency, suitable for printing materials with small format, such as: greeting cards, invitations, books and magazine covers, envelopes, labels and so on. This type of printing press has movable type machine, copper and zinc proofer and disc machine.

Round flat printing press

Also known as the platform printing machine, its structural features are that the plate loading mechanism is planar and the embossing mechanism is a circular cylinder, commonly known as an impression cylinder.

During printing, the plate moves with the platen relative to the platen, and the platen is generally in a fixed position. The substrate is imprinted with the substrate while being rotated, and the pressure applied by the platen to the substrate is greater than that of the platen. Flat presses have been greatly improved, but due to the reciprocating movement of the table, the printing speed is limited and the production efficiency is not high. The main text of the printed book. Such printers include: a rotary letterpress printer, a two-rotation letterpress printer, a rotary rotary letterpress printer, and a lithographic proofer.

Round press printing machine

Also known as a rotary printing press, its structural features are that the plate loading mechanism and the embossing mechanism are all cylinder-shaped cylinders, cylindrical printing machinery plate-making mechanisms, commonly known as plate cylinders.

During printing, the impression cylinder bears the substrate and is imprinted against the plate cylinder while rotating in the opposite direction. Due to the shorter contact time between the impression cylinder and the plate cylinder, the pressure exerted on the substrate is less than that of the round-enamelling press.

The round press type circular printing press makes use of the contact between the impression cylinder and the printing plate cylinder and imprinting. The movement is stable, the structure is simple, and the printing speed is fast. If the printing devices are combined together and designed as a satellite-type or group-type printing machine, double-sided and multi-color printing can also be performed, resulting in high production efficiency. This type of printing press, which is currently used most, has lithographic printing presses, gravure printing presses, flexographic printing presses, and high-speed web-fed printing presses for printed books and newspapers.

According to the layout type is divided into: letterpress printing presses, lithographic printing presses, gravure printing presses, stencil printing presses.

Letterpress Printing Machine

The letterpress printing press is the oldest printing press. Its graphic part of the printing plate is convex and the blank part is concave. When the machine is working, the roller coated with ink rolls over the surface of the printing plate. The raised graphic part is covered with a uniform layer of ink, while the concave blank part is free of ink. The pressure mechanism transfers ink to the surface of the print to obtain a clear print and reproduce the desired print.

There are three types of letterpress printing presses: flat press, round press and round press. Flat Press Digital press flat letterpress press, also known as flat press. The plate table and the imprinting mechanism of the device printing plate are all in a planar shape. When the working plate is in full contact with the platen, the total pressure of the machine at one time is relatively large, and the relative imprinting time is longer. This type of printing press requires that the printing plate and the imprinting plate be flat and the printing format is not large. The round-pressing letterpress printing machine is also called a platen printing press. It has a plate-shaped printing plate, and the embossing mechanism is a circular roller. . When the machine is working, the platen moves back and forth, and the printing speed is subject to certain restrictions, so the output is not high. The rotary press is also called a rotary printing press, and the printing plate and printing mechanism are circular rollers. When the machine is in operation, the impression cylinder moves with the print and comes into contact with the plate cylinder. The impression cylinder and plate cylinder continuously rotate at high speed, so the productivity is high.

Lithographic printing machine

The graphic part and the blank part of the plate surface of the lithographic printing plate are almost on the same plane. It uses the principle of water and oil repulsion to make the graphic part resistant to water and oleophilic. The blank part is resistant to oil and water and does not touch the ink. Under the effect of pressure, the ink in the ink part is transferred to the surface of the printed material, thus completing the printing process.

After the indirect printing method, the lithographic printing press has developed rapidly, with many varieties, such as office-use micro-offset printing presses, large-scale, multi-colored, high-speed newspapers and magazines offset printing transfer machines, for flat sheet or web, Single-sided or double-sided lithographic printing presses. Among them, monochrome offset presses and web offset presses are representative. Lithographic printing presses have been widely used electronic computer control devices, the technology is increasingly advanced. Platemaking equipment has also been developed to use electronic color separation machines and widely used pre-coated printing plates.

Gravure printing machine

The main feature of the gravure printing machine is that the graphic part of the printing plate is concave and the blank part is convex, which is exactly the opposite of the layout structure of the letterpress printing machine. When the machine prints a single color, the printing plate is first immersed in the ink tank and the entire surface of the printing plate is covered with an ink layer. Then, the ink layer on the surface of the printing plate which is a blank portion is scraped off, the convex portion forms a blank, and the concave portion is filled with ink, and the deeper the concave portion, the thicker the ink layer. The machine transfers the ink of the recessed portion to the print by pressure to obtain the print.

For multi-color printing, overprinting method or indirect local ink painting method is used to make the inks of various colors distributed on the relevant parts of the printing plate surface according to requirements. The basic printing principle of multi-color printing is the same as the printing monochrome. There are mainly two kinds of printing plates used in gravure printing machines, one is a photogravure, which is a shadow edition; the other is an engraving version. Engraving engraving includes manual engraving, mechanical engraving, and electronic engraving.

Screen printing machine

The screen printing machine is a representative printing device in a stencil printing machine. Its printing plate is a screen with criss-crossing and longitude and weft woven by silk and other materials. Has been produced in plane, curved surface, forming, printing and dyeing, printed circuit and a new type of rotating screen printing machine. Among them, the speed and productivity of the new rotary screen printing machine are relatively high. Its characteristic is that the screen is installed on the drum, and the ink is poured in the drum. The drum rotates while the machine is working, and the squeegee quickly prints the pattern on the print.

In addition to silk, the material used to make screens can also be nylon, copper, steel or stainless steel. The principle of stencil printing for screen printing applications originated from ancient stencil printing. The stencil printing has a variety of forms, such as stencil printing, stencil printing, and screen printing.

Screen printing was initially manual, when there was only one plate, a screen plate, and a stencil. By the 1950s, screen printing was only mechanized and automated. Roller screen printers have a large amount of ink when printing, suitable for printing thick printed materials, and can be printed on a variety of paper, glass, wood, metal, ceramic, plastic or cloth, and can be used in a variety of inks, including conductive Metallic ink.