subject: CTP plate of four main types and characteristics of-CTP, sheets - Printing Industry [print this page] CTP plate of four main types and characteristics of-CTP, sheets - Printing Industry
For now, the market dominant CTP plate there are three types: type silver salt, light aggregate type, Thermal Type (thermal imagery). Here we mainly look at the characteristics of these types of plates and their advantages and disadvantages.
CTP plate of the four main types and characteristics of (HC printing network with map)
1. Silver halide type CTP plate
Silver-based CTP plates include silver halide diffusion transfer version and the silver and PS version Two types of composite plates.
Silver diffusion transfer version of the main base from the edition, silver emulsion layers and the physical development of nuclear layers. The transfer by the proliferation of imaging technology, the principle is the exposure of the silver by laser scanning version, containing silver halide solvent Developer solution China, Ag + and silver halide solvent complex spread to the image receiving layer, a catalyst in the physical development of nuclear reduced to metal under the silver deposited on the surfaces of the formation of silver images. Develop after the removal by washing the surface of silver halide emulsion layer, exposing hydrophilic non-image area and image area of sand present in the sense of fat fluid through the fat with long chain thiol selective adsorption of organic molecules in the deposition of silver surface, so that lipophilic image area. Results of silver deposited ink image to start the exclusion of water, rather than the video portion (no silver deposition) are still excluded ink, and then to the computer To plate Purposes.
Silver version with the PS composite plates by the high sensitivity of silver halide emulsion layer and the wide range of PS version of a sense of color composite made of wood. In the coarsening of aluminum with anodized coating followed by a feeling of light on photosensitive polymer layer, adhesive layer and silver halide emulsion layer. The imaging principle is, first of all on the silver layer with a laser light, the resin layer to form graphic images of silver, so that when the second exposure can protect the following photosensitive layer is not photosensitive. First Development, will be non-exposed parts of the emulsion layer dissolved, and then the second exposure, the UV light used to expose the entire page. As the graphic from the shelter effect of the layer on the light, so UV light only non-graphic portion of the light decomposition-type photosensitive resin layer exposed by the second imaging, the second exposure of the resin layer is dissolved, exposing aluminum version of the base Finally, liquid with solid version of the silver image layer can be a sense of lipid processing.
Silver-type characteristics of CTP Plate (1) silver halide type CTP plate has a high sensitivity, up to 1 ~ 3 J/cm2, the use of low output power, can be small, low intensity laser can also achieve high-speed plate output. And silver photosensitive type CTP plate speed is sensitive CTP plate in the fastest plates.
(2) silver halide type CTP plates are wide, red laser, green laser, Violet System can be used, the washing method and the traditional post-process the same way, and different manufacturers CTP plate formula of the chemical solution is compatible.
(3) silver halide type CTP plates with high resolution and wide spectral response and dot reproduction and good, the line screens up to 300 lines / inch, network coverage up to 1% to 99% , plate quality, up to 250,000 anti-Indian forces over India, more suited to seal volume and high-quality printing.
(4) As the silver halide type CTP plate using silver as the raw material is expensive, to a certain extent, increased production costs, and the silver-based CTP plates can not operate in the next room, to the preservation of zone plates to some limitations.
2. Photopolymer CTP plate type
Photopolymerization type CTP plate mainly by sand purpose of the aluminum substrate, photosensitive layer and protective layer composed of three parts, which photosensitive layer forming resin, mainly, by infection materials, photoinitiators, monomers, or gather material, stabilizer and other additives composition. Protective layer is polyvinyl alcohol and oxygen barrier, is mainly used to cut off oxygen to the monomer or oligomer polymerization effect. The imaging principle is the plate through the laser light source scan, see the light part of the photosensitive layer of sensitizing material absorbed photon energy into the first excited state, and then energy transfer to the photoinitiator, photoinitiator decomposition of the formation of free radicals, free lead-based monomer or oligomer polymerization and curing to form a graphic part. No part of light removed by lithography to form a blank portion. It should be noted that, prior to the imaging should be no light part of the first protective layer washed off, and then alkaline developer solution dissolves the high sensitivity of the polymer layer, developing finished, brush thoroughly with clear protective coating. Finally, rinse sections of synthetic resin solution, synthetic resin, can improve not only the hydrophilic part blank, but also enhances the graphic part of the pro-oil, drying can be printed.
