Thermal type CTP plate

Thermal-type CTP plates refer to CTP plates that rely mainly on thermal imaging. There are hot-melt type, thermal etching type, photo-etching type, thermal cross-link type, degradation type and other technologies. The thermal type printing plate has both direct imaging and indirect imaging through the mask. The following describes two thermal-type CTP plates.

Hot melt type

Composition: light source, aluminum plate without roughening, ink-receptive layer, PVA layer (in the case of conventional offset printing), silica gel (when waterless offset printing).

Principle: Using a semiconductor laser diode, melt the graphic part to expose the underlying oleophilic layer and remove the residue on the plate to prepare for printing on the machine.

Features: Non-chemical treatment process, from the perspective of environmental protection, especially worthy of promoting the use of thermal-type CTP plate. Second, you can work under the bright room. As far as the Pearl model is concerned, the resistance to India is a bit lower (50,000 impressions), but it has now risen to 100,000 impressions.

Cross-linked type

Composition: Coarse aluminum plate, single layer PS photosensitive layer.

Principle: After a certain temperature is reached by infrared heat instead of spectrum, some of the polymers in the photosensitive layer undergo thermal crosslinking reactions to form latent images; reheating causes the molecular compounds in the graphic part to undergo further cross-linking reflections. It is because the graphic part is not dissolved in the alkaline developer. It is worth mentioning that some reactions occur in the blank part during preheating, so the image of the blank part is removed during development. If the temperature is too high, a hot mist will form on the plate; if the temperature is too low, the graphic part will be weakened or weakened.

Features: There is almost no relationship between exposure time and exposure energy. In other words, below the energy threshold, the external conditions will not affect the quality of the plate; beyond the energy threshold, the size and clarity of the dot will not be affected. Therefore, there is no such thing as underexposure and overexposure; the nature of the graphic part is very stable, and the plate is still usable even six months after exposure; in addition, the thermal crosslinked plate has a low sensitivity to natural light. It is thus possible to work under the light room, and only a conventional plate making apparatus is required for processing.

The earliest manufacturer of thermal-type plates was Kodak. Its direct thermal imaging system has 47 sets worldwide. Polaroid recently joined the market with product models Quantum830 and Quantum1064.

Many businesses that produce CTP plates are considering developing thermal-type plates. DuPont also has related patented products. The company's Horsell Anitee says that it will soon be available on the market. In addition, laser ablation imaging using dry processing is also brewing.