The principle of rapid printing

The rapid printing technology that is the rapid printing technology is a new type of light printing technology developed on the basis of traditional mimeograph technology. According to the usual printing theory, light printing technology refers to the printing technology that is formed by the use of electronic typography, electrostatic plate making, small offset printing and other comprehensive means. According to this theory, the rapid mimeograph technology cannot be included in the light printing technology category. Therefore, this technology and its speed printing equipment have not attracted enough attention in the theoretical community. However, among the modern office equipment, the use of the speed printing mechanism far exceeds that of other printing equipment. It can be said that the general enterprises, institutions, and schools use it as an important office equipment. With the development of science and technology, the printing quality, automation, and ease of operation of the printers are constantly improving. The speed-printing equipment for mechanical driving and control has become very popular. Computer-controlled, optical-mechanical one-shot printing machines And the integration of plate-making and printing machines has begun to promote the integration, and the new digital printing machine can meet the direct printing with the computer, truly network version, direct plate-making, direct printing.

First, speed printing plate, plate base and plate making

Wax version

The wax version used for speed printing is generally a wax paper version. Currently, there are mainly the following types: computer-printed wax prints, hand-printed wax prints, and heat-sensitive wax prints. The waxed paper plate is made by applying pressure and drying after coating the desired waxy material on both sides of the thin tissue paper. After the wax paper version is made, it is necessary to lining the outside with a protective paper. The wax pattern head must also be punched out as required. With the development of new technologies, we believe that there will be better production of printing plates.

2. Edition base

The plate base can play two roles: 1 With the rotation of the connected roller, it plays a role of uniform ink; 2 The wax paper version plays a supporting role.

The plates currently used are mostly nylon or polyester meshes. With the advent of single-drum speed printers and all-in-one machines, stainless steel, copper, nickel or other wire braided meshes have been widely used. This mesh base not only has the function of a plate base, but also is fastened to a metal frame. Replaced the original version of the drum.

3. Plate making

Different stencils use different platemaking methods.

The hand-waxed version is to lay the wax plate on the steel plate, and the artificial stylus is used to depict the graphic on the wax plate.

The current widespread use of computer-generated wax prints is the use of computer input text and editing, and then use the dot matrix strike printer output on the wax version.
The new type of special-purpose plate-speed platemaking machine uses optical scanning and photoelectric conversion to convert the graphic and text information into strong light, and then uses a thermal wax plate to directly produce a wax plate on the plate-making machine according to the principle that the wax is heated and melted through the ink.

One-speed printing machine integrates the plate-making machine and the quick-printing machine organically into one, that is, plate making, printing, unloading and printing are completed automatically and continuously.

Digital plate printer platemaking system uses advanced CCD image sensors and ultra-fine thermal scanning plate making technology, the use of ultra-fine heat pipe breakdown of thermal wax paper, its scanning accuracy of up to 400 lines. The plate making system has the functions of zooming in, zooming out, and removing shadows. Through its computer interface, the digital signal transmission between the computer and the printer and the conversion between the digital signal and the optical signal and the electrical signal are realized, so that the printer becomes a printing terminal of the computer. Can become a perfect print. If you use a computer network to print long distances and multiple users on the same file, "thinking and printing" becomes a reality.

Second, speed printing ink

Speed ​​printing ink is a homogeneous mixed colloidal dispersion system composed of pigments, binders, auxiliaries and the like. Color, rheological properties and dryness are its three important physical properties.

1. colour

Speed ​​printing inks are mostly black, occasionally blue, red and so on.

2. Rheological properties

Speed ​​printing ink is a pseudoplastic system containing solid suspended matter. It is determined by its printing characteristics. The speed of printing ink is not large, the viscosity is small, and the thinness is moderate. It is generally soft and thixotropy. Not sticky, quite weak."

3. Drying performance

Seen from the drying classification, the printing ink is an osmotic drying ink. After printing on the paper, mineral oil and some of the resin quickly penetrates into the pores of the paper and quickly dries through an imbalance-to-equilibrium process. Because its outer phase is a water-in-oil type that uses a non-drying oil as a linking material, the quick-printing ink can maintain a long time without drying on the drum and the ink roller. To sum up, it is “long time for quit, fast dry after printing”.

Third, speed printing equipment

It can be said that it is the widespread use of speed printing equipment that will enable this old technology of mimeograph to rejuvenate its new vitality. In terms of quantity alone, the current production and use of printers far exceeds any other type of printing equipment.

1. Printing features

Table 1 compares the printing characteristics of the three most widely used desktop printing equipments, namely the offset printer, the desktop offset press, and the copying machine.
Equipment Name Performance Features Speed ​​Printing Machine Desktop Offset Copier

Printing plate stencil version zinc oxide plate without plate

On the version of the automatic, manual manual without maximum printing capacity of 2,000 sheets per sheet can not be used for a large number of printing and printing format generally eight open below the following general eight open general eight open following paper range 45-200 (g/m2) 30-120 (g/m2) Copy paper printing speed 40-130 sheets/minute 40-120 sheets/minute 20 sheets/minute (approx.)
The printing quality is generally slightly better, the printing cost is very low, the highest, the average price per unit (approx.) 6000 yuan, 15,000 yuan, 25,000 yuan.

From Table 1, we can see that the characteristics of the speed printing equipment are: the low price of the machine, the low printing cost, the wide range of paper, and the convenience of the upper edition. For the small print, time-critical text and simple graphic monochrome manuscripts Is the ideal printing equipment, its disadvantage is that it can not achieve multi-color overprint.

2. Structure and working principle of common quick printing equipment

At present, commonly used speed printers are mostly double drum structures (see Figure 2). The upper roller is floating, and the drive belt rotates in the same direction as the lower roller rotates in the same direction, and starts to evenly ink and support the tension plate base (nylon mesh). The ink is pumped onto the distribution plate by the ink pump, and then evenly distributed through the two rollers and the two ink rollers, and the printing base and the printing plate are then infiltrated. The paper is in contact with the printing plate under the action of the embossing roller, and after receiving the ink, it is transmitted to form a power source of the printing machine as an AC servo motor. The purpose is to be able to adjust the machine forward and backward and change the printing speed. Power is transmitted to the main gear via pulleys and then distributed to the drum and rollers via the respective pinion distribution. The timing rollers and the timing of the transfer roller are formed by the reciprocal movement of the two sector gears. The reciprocating motion of the embossing roller and the transfer roller is formed by the cam.

The more advanced speed printing equipment uses a single drum structure. The single drum is made of nickel alloy mesh on the metal frame and has a certain hardness. The output and uniform distribution of the ink is completed in the drum. Nickel screen not only plays the role of the plate base, but also can come into contact with the embossing roller to generate pressure. The single drum structure is a qualitative leap in the history of the rapid printing equipment. It brings space and structural possibilities for automatic printing and automatic unloading. Modern plate-making and printing integrated printing machines are all based on the single-drum printing machine. As long as the manuscript is placed in such a machine, the printed sheets can be output as required, and the performance of the copying machine is better than that of a copying machine.

Digitization, networking, and automation are the inevitable trends in the development of the printing industry. We believe that with the continuous production of new technologies and new materials and their integration with various printing technologies, the speed printing technology will show itself in the field of rapid printing. (Text / Li Shuangzhi)