What are the types of CTP plates

I. Silver salt diffusion transfer type

Such plates due to the use of diffusion transfer imaging technology, adapted to a variety of lasers, such as argon ion blue lasers, yttrium aluminum garnet lasers, ruby lasers and so on.

Principle: when the blank part of the light, the color development of the light part of the light is dissolved by the developer, the image part of the light is not seen in the core layer to form a bond, the blank part of the residual part of the blank part of the warm water to clean, and then use the image part of the oil part of the treatment. .

Characteristics: similar to silver halide film, good sensitivity, fast exposure, moderate contrast, the light source is a low-intensity, low-energy laser, different manufacturers of CTP plates compatible with the chemical solution formula.

Second, polymer compound type

Polymer compound type CTP plate has similar printing suitability with traditional PS plate.

Composition: Roughened aluminum plate, polymer compound layer, PVA layer. The polymer compound layer contains sensitizer, polymerization monomer, polymerization initiator, adhesive and so on.

Principle: During exposure, the sensitizer absorbs laser energy and produces polymerization groups together with the initiator. Before developing, the unexposed portion of the PVA layer is washed away and the highly sensitive polymer layer is dissolved with an alkaline developer. After development is completed, the PVA is completely eliminated by brushing. * The plates were washed with a synthetic resin solution. The synthetic resin not only improves the hydrophilicity of the blank portion, but also enhances the lipophilicity of the graphic portion, which is ready for printing after drying. It is worth noting that the polymerization reaction continues for several hours after the end of exposure. This is generally stabilized by infrared rays, and defects in the sheet can be removed by the aging effect of infrared rays.

Features: good printing suitability, the process is relatively clean, after printing, printing durability is quite impressive, the printing plate is not scratched and drawn.

Third, silver salt emulsion and polymer compounds composite type

Composite type (referred to as) takes into account the advantages of the first two types of printing plates.

Composition: roughened aluminum plate, PS photographic layer, adhesive layer, silver salt emulsion layer.

Principle: One exposure to form a silver salt latent image, develop, develop and make a protective film. Then the second exposure, see the polymer layer, wash off the mask with a brush, develop the polymer layer with an aqueous solution, and then rinse with water. To be dry and dry can be printed on the machine.

Features: complex processing, increased chemical pollution, but the advantages are also obvious; light source energy than a single polymer type low, improve the latent image stability, printing suitability is good, print resistance after printing.

Fourth, spray mask type

The fourth CTP plate using spray or spray technology.

Component: traditional PS plate with a thin soluble layer or wax layer.