Made in china satellite type 620*450mm paper offset printing machine a3

Technical Features:

      Two-color satellite color offset press is in any one color, monochrome coding machine to install two-color head, in addition to his monochrome, all the advantages of single-color coding machine, the two-color head along the mainframe parts and free link link Separation, simple and convenient. The effective realization of the two-color paper sets of red, playing yards, indentation time to complete and improve work efficiency.

Technical Parameters:

Offset printing is a commonly used printing technique in which the inked image is transferred (or “offset”) from a plate to a rubber blanket, then to the printing surface. When used in combination with the lithographic process, which is based on the repulsion of oil and water, the offset technique employs a flat (planographic) image carrier on which the image to be printed obtains ink from ink rollers, while the non-printing area attracts a water-based film (called “fountain solution”), keeping the non-printing areas ink-free. The modern “web” process feeds a large reel of paper through a large press machine in several parts, typically for several metres, which then prints continuously as the paper is fed through.

Development of the offset press came in two versions: in 1875 by Robert Barclay of England for printing on tin, and in 1904 by Ira Washington Rubel of the United States for printing on paper.

Offset printing process
The most common kind of offset printing is derived from the photo offset process,Made in china satellite type 620*450mm paper offset printing machine a3, which involves using light-sensitive chemicals and photographic techniques to transfer images and type from original materials to printing plates. In current use, original materials may be an actual photographic print and typeset text. However, it is more common—with the prevalence of computers and digital images—that the source material exists only as data in a digital publishing system.

Offset printing process consists of several parts:
the inking system (ink fountain and ink rollers);
the dampening system (water fountain and water rollers);
the plate cylinder;
the offset cylinder (or blanket cylinder);
the impression cylinder.

In this process, ink is transferred from the ink fountain to the paper in several steps:
The inking and dampening systems deliver ink and water onto the offset plate covering the plate cylinder.
The plate cylinder transfers the ink onto the blanket covering the offset cylinder.
The paper is then pressed against the offset cylinder by the impression cylinder, transferring the ink onto the paper to form the printed image.

Web-fed refers to the use of rolls (or “webs”) of paper supplied to the printing press. Made in china satellite type 620*450mm paper offset printing machine a3,Offset web printing is generally used for runs in excess of five or ten thousand impressions. Typical examples of web printing include newspapers, newspaper inserts or ads, magazines, direct mail, catalogs, and books. Web-fed presses are divided into two general classes: coldset (or non-heatset), and heatset offset web presses; the difference being how the inks that are used dry. Cold web offset printing dries through absorption into the paper, while heatset utilizes drying lamps or heaters to cure or “set” the inks. Heatset presses can print on both coated (slick) and uncoated papers, while coldset presses are restricted to uncoated paper stock, such as newsprint. Some coldset web presses can be fitted with heat dryers, or ultraviolet lamps (for use with UV-curing inks). Made in china satellite type 620*450mm paper offset printing machine a3,This can enable a newspaper press to print color pages heatset and black & white pages coldset.

Web offset presses are beneficial in long run printing jobs, typically press runs that exceed ten or twenty thousand impressions. Speed is a determining factor when considering the completion time for press production; some web presses print at speeds of 3,000 feet per minute or faster. In addition to the benefits of speed and quick completion, some web presses have the inline ability to cut, perforate, and fold.

Heatset web offset
This subset of web offset printing uses inks which dry by evaporation in a dryer typically positioned just after the printing units. This is typically done on coated papers, where the ink stays largely on the surface, and gives a glossy high contrast print image after the drying. As the paper leaves the dryer too hot for the folding and cutting that are typically downstream procedures, a set of “chill rolls” positioned after the dryer lowers the paper temperature and sets the ink. The speed at which the ink dries is a function of dryer temperature and length of time the paper is exposed to this temperature. This type of printing is typically used for magazines,Made in china satellite type 620*450mm paper offset printing machine a3, catalogs, inserts and other medium-to-high volume, medium-to-high quality production runs.

Coldset web offset
This is also a subset of web offset printing, typically used for lower quality print output. It is typical of newspaper production. In this process, the ink dries by absorption into the underlying paper. A typical coldset configuration is often a series of vertically arranged print units and peripherals. As newspapers seek new markets, which often imply higher quality (more gloss, more contrast), they may add a heatset tower (with a dryer) or use UV (ultraviolet) based inks which “cure” on the surface by polymerisation rather than by evaporation or absorption.

Sheet-fed offset
Sheet-fed refers to individual sheets of paper or rolls being fed into a press via a suction bar that lifts and drops each sheet onto place. A lithographic (“litho” for short) press uses principles of lithography to apply ink to a printing plate, Made in china satellite type 620*450mm paper offset printing machine a3,as explained previously. Sheet-fed litho is commonly used for printing of short-run magazines, brochures, letter headings, and general commercial (jobbing) printing. In sheet-fed offset, “the printing is carried out on single sheets of paper as they are fed to the press one at a time”. Sheet-fed presses use mechanical registration to relate each sheet to one another to ensure that they are reproduced with the same imagery in the same position on every sheet running through the press.