What are the common types of presses?

2019-10-25

Flat press printing machine


The structural feature of the flat press type printing machine is that the plate loading mechanism and the stamping mechanism are both planar.


During printing, the imprint lithography reciprocates around the main axis to complete the paper feeding and imprinting. Since the ink and the imprinted lithographic plate of the printing plate are all in contact at the same time, the embossing time is long, and the pressure applied to the substrate is large, so the ink color of the printed matter is heavy, and the lines and strokes are full.


Flat-press flat printing machine, small size, slow printing speed, low production efficiency, suitable for printing small prints, such as: greeting cards, invitations, book covers, envelopes, labels, etc. This type of printing machine has a movable type machine, a copper-zinc plate proofing machine and a disc machine.




2. Round press printing machine


Also known as a rotary printing press, its structural feature is that the loading mechanism and the embossing mechanism are cylindrical rollers, and a cylindrical plate-loading mechanism, commonly known as a plate cylinder.


At the time of printing, the impression cylinder carries the substrate and is embossed while rotating in the opposite direction with respect to the plate cylinder. Since the impression cylinder and the plate cylinder are in contact for a short period of time, the pressure applied to the substrate is smaller than that of the circular flattening printer.


The circular press type printing machine uses the imprinting roller and the plate cylinder to contact and imprint without stopping, and the movement is stable, the structure is simple, and the printing speed is fast. If the printing devices are combined and designed as a satellite or unit type printing machine, double-sided and multi-color printing can also be performed, and the production efficiency is high. These types of printing presses are currently used the most, including lithographic printing presses, gravure printing presses, flexographic printing presses, and high-speed web presses for printing books and newspapers.




3. Round flat printing machine


Also known as the platform printing machine, its structural feature is that the loading mechanism is in a flat shape, and the embossing mechanism is a circular roller, commonly known as an impression cylinder.


During printing, the printing plate moves along with the plate loading platform with respect to the impression cylinder. The impression cylinder is generally in a fixed position, and the substrate is embossed while rotating with the substrate, and the pressure ratio of the impression cylinder to the substrate is applied. The flat press type printing machine is greatly improved, but due to the reciprocating motion of the plate table, the printing speed is limited and the production efficiency is not high. The main body of the printed book. Such printing machines include: a rotary letterpress printing machine, a two-slewing letterpress printing machine, a stop-and-turn letterpress printing machine, a lithographic proofing machine, and the like.




4. Lithographic printing machine


The graphic portion of the lithographic printing plate surface is almost in the same plane as the blank portion. It utilizes the principle of water and oil repelling, so that the graphic part is resistant to water and oil, and the blank part is resistant to oil and hydrophilic without ink, and the ink of the inked part is transferred to the surface of the printed matter under pressure to complete the printing process.


After the indirect printing method, the lithographic printing machine has developed rapidly and has many varieties. Among them, monochrome offset presses and web offset presses are representative. The lithographic printing press has widely adopted electronic computer control devices, and the technology is becoming more and more advanced. Plate-making equipment has also been developed to use electronic color separation machines, and pre-coated photosensitive plates are widely used.




5. Gravure printing machine


The main feature of the gravure printing machine is that the graphic part on the printing plate is concave and the blank portion is convex, which is opposite to the layout structure of the letterpress printing machine. When the machine is printing a single color, the plate is first immersed in the ink tank to roll, and the entire surface of the printing plate is coated with the ink layer. Then, the ink layer on the surface of the printing plate which is a blank portion is scraped off, the convex portion is formed into a blank, and the concave portion is filled with the ink, and the deeper the recess is, the thicker the ink layer is. The machine transfers the ink of the recessed portion to the printed matter by pressure to obtain a printed matter.




6. Letterpress printing machine


The letterpress printing machine is the oldest printing machine, and the graphic part of the surface of the printing plate is convex, and the blank portion is concave. When the machine is working, the rubber roller coated with ink rolls over the surface of the printing plate, and the raised image portion is covered with a uniform ink layer, while the concave blank portion is not stained with ink. The pressure mechanism transfers the ink to the surface of the print to obtain a clear print that replicates the desired print.




7. Screen printing machine


Screen printing machine is a representative printing equipment in stencil printing machine. Its printing plate is a criss-crossing, warp and latitude wire mesh woven from materials such as silk. A variety of screen printing machines, such as planes, curved surfaces, forming, printing and dyeing, printed circuits and new types of rotary printing, have been produced. Among them, the new rotary screen printing machine has a relatively high speed and productivity. It is characterized in that the screen is mounted on the drum and the ink is poured into the drum. The drum rotates while the machine is working, and the squeegee prints the pattern quickly onto the print.


Screen printing was originally hand-operated, with only one plate, one screen and one plate. In the 1950s, screen printing was mechanized and automated. The drum screen printing machine prints a large amount of ink, suitable for printing thick ink layers. It can be used in a variety of inks, including conductive metal inks, which can be used in various paper, glass, wood, metal, ceramic, plastic or Printed on the cloth.