Six technical features of the hottest thermal vers

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Six technical features of thermal version

at present, there are three main digital printing technologies: silver halide technology, high sensitivity technology, and other uses, as well as the latest thermal technology. Silver halide technology includes silver halide diffusion transfer plate and visible light sensitive laser. The light wave is between blue and red. According to this technology, Agfa launched two kinds of aluminum based digital direct printing plates, litiostar plus and silver lithsdb. DuPont hausen introduced a polyester based digital direct printing plate, red sensitive setprint HN ll version

Polaroid light introduced a silver salt composite technology, namely CTX technology, which uses silver halide technology and emulsion to apply to UV sensitive PS plate

Ecker launched a photopolymer offset printing plate, ozasoln90a, which is also a digital direct printing plate, with fast photosensitivity, green and blue sensitivity

recently, a new type of digital offset printing plate has appeared on the market, which is called thermal version. The photosensitive range of the thermal version is 830~1064nm, or even wider. Its plate printing technology includes melting, ablation, transfer, cross-linking, photoelectron decomposition and so on. No matter which of the above technologies is used for imaging, the printing plate will be obtained after development. Due to different plates, some need to be wet processed

1. Chemical insolubility

through laser heat, the polymer in the active layer is crosslinked to produce chemical insolubility and form a negative image. After IR exposure and heating, acid is generated, which catalyzes the chemical crosslinking of the polymer adhesive, so that the exposure area can be selectively crosslinked. The pre heating procedure can obtain a high degree of crosslinking of 10 tested gaskets after the multi-molecular reaction. Therefore, in order to obtain a high printing process, such a version can be obtained by using the traditional wet processing and post baking after the pre heating process. The tolerance of pre heating should be small, and the control of the heating box should be good

2. Physical insoluble

this technology generates physical insoluble substances by heating the active layer. The active layer contains a uniformly dispersed thermoplastic flowing polymer latex particle, which can dissolve rapidly. However, after IR laser exposure, the thermal coalescence of thermoplastic polymer particles inhibits the solubility of the polymer layer, and the dual properties of this particle produce high-quality images. The advantages of this technology are bright room, stable quality, and at the same time, it can drum print the layout inside and outside. Ouyangming informs that the text output imaging is a printing board, which can be baked after wet processing to get a high printing process version. Agfa's rd-9 plate has a photosensitive wavelength range of 830 ~ 1100nm, and has both internal and external drum recording and imaging technology, but it has not been commercialized at present

3. Chemical dissolution type

this technology generates chemical dissolved substances by heating the active layer. Without heating, a positive plate is obtained, which is completely chambered, and then baked after wet processing. The printing process is high. The active layer can be based on acid resin, and the solubility of this layer is improved during thermal imaging. If red line absorption species are added to this layer as dissolution inhibitors, the exposure area will be selectively removed

4. Thermal ultraviolet mask

this technology senses visible light and uses IR rays for imaging exposure, so that the ultraviolet absorption layer is no longer soluble in alkaline developer, thus acting as the ultraviolet mask of the lower layer. The other is to expose and image the ultraviolet photosensitive layer at the bottom through the infrared sensitive ultraviolet absorption layer through thermal etching exposure, but its disadvantage is that the process is complex, and it requires two parts of processing to completely or incompletely remove the ultraviolet mask layer

5. Thermal physical mask

this technology was first developed by Agfa. It is a new type of thermal positive plate, named thermostar. It changes the structure of the physical mask layer by heating it with high-energy laser. After the carbon or IR dye in the protective layer absorbs IR light, the infrared light energy is converted into heat, and the heat energy makes the temperature in the active layer rise sharply to 400 ℃ or higher, so as to complete the exposure. Its specific temperature is determined by the thermal diffusion coefficient of the layer, exposure time, layer thickness and the thermal diffusion coefficient of the adjacent layer. At the same time, the thin active layer can withstand the expansion produced by the light pulse, and the volume and thickness of the layer have increased. The laser used for the same time of exposure can complete the ablation reaction in the layer

due to the high IR light absorption capacity on the protective layer of this version, high temperature can also be generated for relatively low exposure energy levels, causing physical deformation of the protective layer. This physical deformation can not only effectively wet the exposed part of the layout with alkaline developing solution, but also quickly penetrate the protective layer, enter the bottom layer, effectively dissolve the bottom layer, and dissolve faster than the non exposed area. Its protective layer acts as a mask for the alkaline protective film. Obviously, its surface and interfacial tension are important parameters for washing and processing

therefore, it is concluded that this technology uses the different effects of physical developers to image. This unique non ablative process is to image before harmful volatile compounds are formed in the layer, or before some components in the layer are degraded. Because the compound components in the layer will not pollute the environment during treatment. Therefore, by using the above technology, the danger can be reduced, and at the same time, no dust suction equipment can be used, while the fiber points added by laser ablation technology can be black, so it is necessary to equip dust suction facilities in the imaging area

6. Non ablative characteristics of imaging technology

ablation includes the evaporation and decomposition of infrared photosensitive layer. In the meantime, physical and chemical changes have taken place in the layer. When the layer is used as a protective layer, the ablated material evaporates into the air, and in most cases, a part of it is powder and redeposited on the surface of the material. This may further affect the imaging of materials, especially when the ablation degree is too high. When the whole layer is evenly colored, the powder can be easily wiped off, making the layer thinner and the chemical density smaller. This ablative medium can distinguish the quality with eyes, and can also be tested with instruments

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