The scope and characteristics of several different rollers　Printing press printing form is divided into letterpress, offset, gravure and stencil printing machine; according to the version and embossed structure is divided into flat type, flat type and rotary type printing machine.

　　Letterpress printing machine printing machine is the oldest, the printing plate surface graphics and text part of the convex, concave blank part. When the machine works, the surface coated with ink rollers roll over the plate surface, and part of the convex is stained with ink layer is a layer of uniform, but the blank part of concave is not stained with ink. The pressure mechanism of the ink transferred to the printing surface, thereby to obtain a clear print, copy print required.

　Letterpress printing machine has a flat, circular applanation and rotary three types. Flat letterpress printing machine, also called platen press. The version table and nano imprint lithography mechanism of the device are flat plates, work, printing and embossing plate full contact, total pressure machine a bear is relatively large, relatively long time stamping. This printing machine for the printing and embossing plate leveling, printing format not; circular applanation relief printing machine is also called platform printing machine, the version table it device for flat plate, and the imprint mechanism for circular cylinder. When the machine works, the reciprocating motion of the version table, printing speed is limited, therefore, yield is not high; rotary letterpress printing machine, also known as rotary printing machine, version and imprinting mechanism which device plate are circular cylinder. When the machine works, nano imprint lithography drum with printed matter movement, and contact with each other and a printing plate cylinder. Nano imprint lithography drum and a printing plate cylinder continuously rapid rotation, so the higher productivity.

　The text part and the blank part of lithographic printing plate printing machine surface is nearly in the same plane. It uses the principle of water, oil repellent, make the graphic part of anti water dear oil, anti oil blank part of hydrophilic and not touch the ink, under pressure to make the ink part transfer of ink to print surface, thus completing the printing process.

　　After the use of indirect printing, offset printing machine is developing rapidly, more varieties, such as micro press office, large-scale, high-speed multi-color, books and newspapers in the offsctdruckereien for lithographic printing machine, single-sided or double-sided printing of sheets or webs. The single color offset printing machine and web offset press representative. Lithographic printing machines have been widely used computer control device, the technology is advanced. Plate making equipment is developed to use electronic scanner, and extensive use of precoated photosensitive plate.

　The main characteristics of gravure printing machine is a plate of concave convex part, blank section, and page structure letterpress printing machine on the contrary. The machine printed in monochrome, put the plate immersion rolling in the ink tank, the entire surface of the plate was covered in ink layer. Then, the ink layer surface belongs to scrape the plate blank portion, a protruding portion is formed blank, and the concave part is filled with ink, the ink layer of local concave deeper more thick. The machine to transfer the concave part of ink to print by the action of pressure, thus obtaining pOverprinting by topical ink overprint method or indirect, the various color ink according to need, distributed in the relevant parts of the plate surface, printing multicolor printing and printing monochrome same basic principle. There are two main types of the gravure printing machine printing plate, a gravure, namely photogravure; another is the carving version. An engraved plate engraved with hand carving, engraving machinery and electronic engraving method.

　　Printing machinery modern is further toward high speed, high efficiency, high quality and direction of development. Large, multi-color, multi function, and automation, linkage, a series of models and models, but also grow with each passing day.

For example: on the basis of the original main types, the same type units together, can make single-sided, monochrome printing into single-sided, double-sided multi-color printing, also can make, monochrome printing into a single, double color printing; the different types of units together, can be re combined into offset, gravure and the convex printing various joint printing machine etc..