The Process Principle of Offset Printing

"Offset printing" and "lithography" is one meaning. This kind of printing method is through the drum colloid impression touch the glue on the surface of the ink transfer to the paper. Due to the plastic surface is flat, without concave decorative pattern, so the design of printed on paper and decorative pattern is flat, poor stereo feeling, antifalsification is poor. Required for offset printing ink is less, mould manufacturing cost is lower than the gravure.
Also known as Offset printing (Offset), Is a kind of lithography, can restore the original color, contrast and level of the original pattern clearly with high precision, is by far the most common method of paper printing. Applicable to poster, profile, instruction, paper, packaging, books, magazines, calendars, and other relevant color print.

Offset Printing Process Principle
Offset printing is the color theory as the center, using the latest achievements of science and technology, using industrial mass production, copy of the original pattern system engineering. In the process of printing process, From the review of the original pattern, process design to each of the plate making, printing process, process parameters must be determined strictly, directly involved in printing colour information transmission of psychological evaluation and quantitative detection.
Distinguish between "gravure" and "offset", see the colors and stereo feeling of decorative pattern can determine. If the two bill to contrast, the difference is very obvious, it is easy to judge. In addition to a beginner, also can use the following two methods: the first is a "touch". Gravure RMB frontal "The people's bank of China" six words, the feeling of bulging is very obvious, as long as the fingers touched gently from left to right, can clearly feel that every word is raised. The second is "the edge". Gravure printing of text and pattern, line edge will be a spreading of ink caused by tiny "burr", use a magnifying glass can see very clear. And offset printing the line edge is smooth.
The selective adsorption principle of plate
Branches in assaying principle; Indirect printing principle; Principle of oil and water should not be.

Label Printing Plate-making Process

Nowadays label printing mainly adopts letterpress, offset printing, flexo printing and screen printing several ways, from a technical point of view, these come in different printing way, has its inherent advantages and disadvantages, no printing method can replace another way.
Offset printing is a way of printing, widely sheet-fed printing basic is offset printing, this way of printing with high speed, high printing resolution, overprint accurate, printing level full, but shallow, poor durability and ink layer is not suitable for printing bright color label product.
Letterpress copy good graphic definition, printing high speed, high color strength and durability than offset printing, silk screen printing is just slightly worse, but the level and accuracy are better than screen printing and flexo, therefore our country mostly adopts letterpress printing labels in the form of production.

The biggest advantages of silk screen printing is the ink layer is thick, good covering power, but the level of slow and reflect poor, set of low accuracy (this refers to the domestic general level), so the silk screen printing machine can be used to print the administrative levels which is not strong.
Flexible printing quality characteristics is centered, abroad more use this way to print labels, but the technology of anilox roll need high requirement of processing and the technical level of workers, while the machine is simple but the process is quite complex, in the domestic not more adopted labels printing this way.
If you want to printed out one of the most beautiful label, you need all kinds of craft in the printing process effectively together, will integrate the advantages of different printing way, form a greater advantage.

Purpose of combined with the multiple process
1. Effective anti-counterfeiting function: with a label on the product use a variety of printing process effect, especially in some easy to counterfeiting of cosmetics and food packaging label with this way of printing, can let the consumer glance through the label products of true and false, so as to safeguard the interests of product manufacturers and consumers, also won the excellent reputation for printing.
2. Improve the quality of printed matter: technology is the combination of the advantages of various printing process together, so this kind of combination printing mode to ensure maximum printing effect, so as to satisfy people's growing sensory requirements, at the same time improve the quality of printing in the label printing company, and thus more supply of goods for this. Improve production efficiency to reduce costs, combining various processes also contains printing and post-press processes, the combination of products in the production of printing and printing at one time, after the finished products directly, can greatly reduce the cost.

The Basic Principle of Offset Printing

Offset printing this printing method is through the drum impression of glue it in with glue on the surface of the ink transfer to the paper. Due to the plastic surface is flat, without concave, so the design of printed on paper and decorative pattern is flat, no stereo feeling, poor rubber seals. Required for offset printing ink is less, the mould manufacturing cost is lower than gravure.

Fundamental Principles:Oil and water don't mix principle;
The choice of plate adsorption principle;
Branches in assaying principle;
Indirect printing principle.
Overprint or Trapping Trap if misregister, thief easily affect beauty, while overprint easily caused by the ink layer too thick back and smearing, so wet pressure dry printing monochrome machine tend to have overprint, multi-color machine wet wet pressure tend to use trap;
Wet pressing overprint must consider the nature of the ink, first printing ink of the viscosity, adhesion must be greater than after printing ink, otherwise the printing ink will appear after inverse overprint phenomenon. After printing ink must also have high transparency;
On coating of paper printing gold ink, silver ink, the trap of gold ink, silver ink printed on white paper than on other color for color appears more thick, pure;
To print the black, if the black edition only larger area of the field image, adopt the way of trap increase the black version of the ink is printed on white paper than on other field background more thick ink overprint. But small line generally uses overprint way online printing services.
At the top do trap version is at the back of the ink layer covered for guarantee, the stuck print runs are usually based on the alignment precision of the equipment to add 0.03 ~ 0.05 mm. Such as alignment precision is 0.15 mm, then trap part generally larger 0.18 ~ 0.20 mm.
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