Offset Thermal Plates

Offset thermal plates is a new type of digital offset printing plate has appeared on the market, which is called thermal plate. The photosensitive range of offset printing thermal plates is 830nm-1064nm, even wider. Its printing plate technologies include melting, ablation, transfer, cross-linking, photoelectron decomposition, etc. Regardless of which of the above-mentioned techniques is used for imaging, a printing plate is obtained after development. Due to the different plates, some require wet processing.

The technical performance of offset thermal plates are:

1. Chemical insolubility

Through laser heat, the polymer in the active layer is cross-linked to produce chemical insolubility and form a negative image. After IR exposure and heat, an acid is generated to catalyze the chemical cross-linking of the polymer binder, so that the exposed area is selectively cross-linked. A preheating procedure enables a sufficiently high degree of crosslinking to be obtained after the multimolecular reaction. Therefore, such a offset printing plate can be obtained by using traditional wet processing and post-baking plate after the preheating process to obtain a high printing process. The latitude of preheating is small, and the controllability of the heating box is better.

2. Physical insolubility

This technology generates physically insoluble substances by heating the active layer. The active layer contains a uniform dispersion of thermoplastic flow polymer latex particles, which can be quickly dissolved, but after IR-laser exposure, the thermal coalescence of thermoplastic polymer particles inhibits the solubility of the polymer layer. The dual properties of this particle produce High quality images. The advantage of this technology is bright room, stable quality, and at the same time, it can output images of graphics and texts inside and outside the printing plate. Offset printing plate has a photosensitive wavelength range of 830nm to 1100nm, and has both internal and external drum recording and imaging technologies, but it has not yet been commercialized.

3. Chemically soluble

This technology produces chemically dissolved substances through the heating of the active layer, without heating, to obtain a positive offset thermal plates, completely bright room, and then bake the plate after wet processing, with a high printing process. The active layer can be based on acid resin, and the solubility of this layer is improved during thermal imaging. If a red line-absorbing species is added to this layer as a dissolution inhibitor, the exposed areas will be selectively removed.