Offset production process overview

India rubber production characteristics

1. Using the advanced methods of modern graphic and text information processing, the tone and color of the manuscript are expressed in halftone, and the reproduction tone and color reproducibility are good.

2. Utilizing the basic principle of oil-water incompatibility, the first water and the second ink are used on the same plane of the printing plate to achieve the ink-water balance, so that the graphic ink will be transferred and the graphic and text will be clear and complete.

3, blankets for the media, the substrate from the blanket to obtain the text, so that the full transfer of ink, color reproduction effect is good, and to maintain the printing plate resistance to force.

4, the use of metal aluminum plate, a wide range of resources, especially the use of PS version (presensitized plate Presensitized Plate), plate speed, good quality, high resistance to India.

5. Lithographic offset printing is currently developing towards multi-color printing, with high printing speed, high degree of automation control, short printing cycle, and good quality of printed products.

Offset production process

Offset production is the process of copying colored originals. It includes three major processes of plate making, printing and post-press processing.

(1) Plate making: This is the process of copying an original into a plate. The process flow is shown in Figure 2.1.

1, image platemaking and text typesetting classification processing, and then the text map one, copy into the original printing version (negative film).

(1) Image-making: The general term for copying image originals using a manual, photographing, electronic, or other plate making method. The process is:

1 Separation: The process of decomposing a color document into a single color version. The traditional photochromic separation method is currently phasing out, and most of them use electronic color separation to decompose color originals into various monochrome versions by electronic scanning.

2 copies: the process of copying images by exposure and contact with a photosensitive material in a copying technique. The commonly used equipment has a drying machine, a copy machine and so on.

3 to fight the big version: the text, graphics, images and other negatives according to the printing conditions and format arrangements spelled into the original version of the print.

4 Shaiban: The process of copying the graphic on the printing plate to the printing plate by means of contact exposure through a printing machine. Plates generally use the PS version.

5 Proofing: The process of copying the proofs from the grouping of graphic information. Proofing proofs are divided into three types: monochromatic samples, stacked samples, and full-color samples. Proofing can be done on the proofer or on an offset press.

(2) Text typesetting: The text manuscripts are organized according to the design requirements in a prescribed layout process. The main use of computer typesetting process. The process is as follows:

1 First use the computer terminal to enter, organize, and print the text.

2 After proofreading, use the laser photosetter to output negatives.

3 Photographic plates can be directly printed on the plate or according to the requirements of the layout design, the film will be imposition, copy, and then printing plates for proofing and printing.

2, DTP (Desktop Publishing System) color desktop publishing system: the image, text input into the computer, the use of computers for image processing and processing, graphics, and then graphics, images, text, spelling the entire page layout , The use of laser phototypesetting machine to output the electronic layout, to become the original version.

3, CTP (Computer To Plate) computer direct plate making: The further development of the printing technology, not only can make the plate directly by the manuscript, but also realized the computer publishing system and the printing press direct connection, completes from the manuscript to the printing step.

(2) Printing: A process in which a plate is used to transfer graphic information on an original onto a substrate. It is from the time when the printed plate is received until the finished product is printed. This process can be divided into four parts: prepress preparation, test printing, formal printing, and printing.

1, prepress preparation: including familiar with the production and construction orders, check the printing plate, the preparation of printed materials, machine pre-conditioning work.

2. Test printing: Including the surface treatment of the printing plate, the correction position, the adjustment of the ink, etc., until the test printing of the printed sheet can meet the sample request.

3, the official printing: including normal printing when the sampling inspection, wetting fluid and ink supplement and ink balance control, inspection of machine operation status, exclusion of printing failures.

4, the end of printing work: including the preservation of semi-finished products and finished products, offset press cleaning and maintenance, printing plate and blanket maintenance.

Postpress

The production process that enables the printed product to achieve the desired shape and performance. Such as books and products to be bound, quality inspection, packaging process. A variety of packaging products according to different requirements for different post-press processing, such as die-cutting, hot stamping, plastic, box and so on.

Offset machine basic knowledge

(1) Origin, Status Quo and Development Trend of Offset Press

Offset presses are the main equipment for lithographic offset printing. It was first invented by the American W. Rubel. Afterwards, German American Caspar. From 1906 to 1907, Caspor Hermonn made offset presses for the first three cylinders (plate cylinders, blanket cylinders and impression cylinders) in Germany. Today, the basic structure of an offset press is still three rollers. Although the printing presses produced by various printing press manufacturers have their own characteristics, the general structure, operation method, operation procedure, and paper direction of the printing presses are basically the same.

At present, there are many companies that produce sheetfed offset presses in China, among which the Beijing People's Machine Factory has many types of products with relatively stable quality, such as the J2108 type, J2205 type, and PZ4880 four-color offset printing machines. Speed ​​up to 11000 / hour. Imported offset presses are the most representative of offset presses in Heidelberg, Germany. Others include Roland from Germany, Komori from Japan and Mitsubishi offset presses.

The level of imported sheet-fed offset presses has taken a big step forward in the 1990s. mainly reflects in:

1, the printing speed increased to 15,000 / hour.

2. As the level of automatic control increases, the pre-adjustment time before printing is greatly shortened.

The original pre-adjustment time is generally about 2 hours, but now can be reduced to 15 minutes;

3. The degree of automation is greatly improved, and the entire printing press operation and operating system can be fully automated from paper handling to printing.

The future development trend of printing presses is still the integration of machine, electricity, light and sound, and ultimately achieve full automation.

2.2.2 Classification of Sheetfed Offset Press

1, according to purpose classification. Can be divided into offset printing press paper, proofing offset printing press, offset printing press and so on.

2, according to the number of printing color classification. Can be divided into monochrome, two-color, four-color, five-color offset press and so on.

3, according to the size of paper size. Can be divided into souvenir sheets, full sheets, open, four open, eight open offset press and so on.

4, according to the situation of printing the printing surface classification. Can be divided into single-sided printing and double-sided printing offset press.

Source: Printing Technology