PS version 4 in the hottest digitalization process

PS version in the process of digitization (4)

UV setter-710hs uses two UV light sources to scan and expose the PS version at the same time through the digital LCD, and the scanning speed has been greatly improved. The working principle of this system is similar to that of the traditional continuous drying machine, except that the pattern of the digital coated plate is sealed by the computer digital signal control 122 silicone structure for construction, so as to realize the digital scanning and modulation of the UV light source, and make the traditional PS plate a reality in the original application of CTP. However, the scanning resolution of this system is directly affected by the small electrode size (electrode integration) of the liquid crystal panel. Moreover, it requires a high scanning operator, who should learn to find problems and eliminate the accuracy of scanning control

inkjet printing relies on mechanical force to transfer ink from a small nozzle (generally with a diameter of μ m) The ink drops are sprayed out to form ink drops, which can form an imprint after reaching the receiving medium. It is a color print that can be obtained by using inks of different hues (yellow pinkish green black) to spray on the same receiving medium. The ink droplet ejection state/printing state (on, off) of inkjet printing is completely controlled by computer instructions. It is a typical non-compact printing and plate less printing mode. Therefore, the digital printer working according to this principle has the characteristics of non-contact and plate free, and can print on the substrate with different thickness and different shape (plane or curved surface). The ink drop generation speed of inkjet printing is generally 10-10 drops/s, which is a way to achieve high-speed printing. The quality of inkjet printing depends not only on the inkjet printing equipment and the performance of the ink used, that is, it requires the use of special substrates. For a long time, the low resolution of inkjet printing system, the nozzle easily blocked and unable to print on ordinary substrate have been obstacles to the wide application of inkjet printing technology. At present, these problems have been preliminarily solved, and an inkjet printing system with a resolution of hundreds or even more than 1000 DPI has emerged, which can print on ordinary substrates. These technological advances have expanded the application scope of inkjet printing technology and laid the foundation for its application in digital printing

the direct plate making system based on ink-jet printing uses the principle of ink-jet printing to directly spray ink drops on the surface of hydrophilic base plate (such as aluminum base plate whose surface has been sanded and anodized) to form lipophilic printing area (area with ink drop image) and hydrophilic non printing area (base plate surface without ink drop image). The characteristic of this system is that the system structure is simple, the operation performance is excellent with the installation of these main equipment, and there is no need for post-processing: the disadvantage is that the resolution is directly limited by the size of the ink nozzle, so it can not be made high at present. Ctplate technology using inkjet printing is not a new invention. Polychrome exhibited a similar CTP system at drupa exhibition in Germany in 1995. The system on display at that time used the conventional inkjet printing method to print the ink drop image on the positive PS plate of the system, and then fully expose the PS plate with the ink drop image to ultraviolet light. The PS photosensitive layer with ink drop image protection on the layout is not exposed to ultraviolet light, which is still impermissible, but the PS photosensitive layer without ink drop image protection becomes soluble under the action of ultraviolet light. Finally, regular PS plate development processing can obtain the same printing plate as the conventional plate making method. However, the system on display adopts solid inkjet technology, which can image directly on a hydrophilic substrate. After imaging, it can be printed immediately without any post-processing. Solid inkjet technology adopts a solvent-free ink that is solid at room temperature and liquid at the sprayed working temperature (such as 100 ℃), which is made of the following components: recycled broken pieces of cross-linked PE cable. Such ink can become a solid due to the change of temperature when it is in contact with the surface of the base plate (high temperature), which is firmly attached to the surface of the base plate and becomes the graphic area of the printing plate. The current problem is how to improve the resolution of this way to meet the needs of commercial printing. It should be said that this imaging method without any post-processing is more suitable for the application of ctpress

purple laser CTP technology

purple laser CTP technology is composed of a purple laser CTP plate making system and CTP plates that can be used for purple laser. As far as the plate making system is concerned, the core is the laser diode that can generate nm purple laser

people love purple laser for the following reasons:

1 Economy

because its wavelength is relatively short (around 405nm) and it is relatively easy to avoid light divergence compared with the current universal 830nm wavelength, it can realize long-distance transmission in a compact structure, that is, the inexpensive semiconductor laser can be used as the inner drum CTP direct plate making machine, which reduces the manufacturing cost of the CTP direct plate making machine and conveniently corresponds to the output of plates of different sizes and weights; In addition, because its rotating mirror is very small and light, it can realize high-speed scanning and improve the production efficiency of CTP plate making machine

2. Close to open room operation

3 The design of plate becomes easy

the current situation is that the power of UV diode is low, generally 5MW, so it is required that the sensitivity of plate is higher, that is, it should be ≤ 20 μ J/cm2, currently only silver salt diffusion plate and photosensitive macrocompound plate are applicable

the real potential of UV laser is that when the power increases (such as MW), and the wavelength moves to the short wave direction (such as nm), the diode appears. That will threaten all forms of CTP technology at present. Of course, it is also the biggest opportunity for plate manufacturers

in order to visually understand the requirements of laser on the sensitivity of plates, the sensitivity of commonly used photosensitive materials for printing is listed as follows:

① silver halide film μ J/cm2

② silver plate (silver salt diffusion, composite plate) μ J/cm2

* ③ purple laser version lv-2 (Mitsubishi) 10 μ J/cm2

* ④ purple laser Version (Fuji) 60 μ J/cm2

⑤ high sensitivity and photosensitive resin version μ J/cm2

⑥ thermal version 150mj/cm2

⑦ regular PS version mj/cm2

* those with asterisks are purple laser CTP plates launched at this drupa exhibition. (to be continued)