CTP Digital Printing Requirements on Plate Base

As we all know, the CTP digital printing has brought many benefits to printing: excellent image quality, near perfect calibration, and fast production turnaround. However, its various advantages are not only attributed to the imaging equipment, but also depend on the quality and performance of the CTP plate.

Now in the CTP market, the three CTP technologies with the largest sales volume are silver salt, thermal and violet laser. The printing plates produced by these technologies are silver salt, thermal and violet CTP plates.

The CTP plate consists of a plate base and a photosensitive layer. The plate base treatment generally includes the following processes: degreasing, electrolysis, ash removal, oxidation, sealing, etc. Among them, the sealing has a crucial influence on the performance of the CTP plate.

Sealing directly affects the sensitivity of the CTP plate, the printing durability and the balance of ink and water in the printing process. And the degree of sealing is not easy to control, if it is too high, the printing durability will be low, and if it is too low, the sensitivity will decrease.

In the requirements of the PS plate, the surface roughness Ra value is 0.3 μm, which is not enough for the CTP plate, because the Ra value of the grain roughness of the CTP plate is only 0.5 μm to 0.6 μm. The Ra value of the surface of the aluminum plate base for the manufacture of CTP plates is preferably around 0.2 μm.

The thickness of the aluminum plate base for CTP plates is generally 0.280mm, which is slightly thicker than the PS plate currently produced (the thickness of the PS plate base is 0.270mm±0.005mm). Some foreign companies also use 0.275mm thick aluminum plate base, and the thickness tolerance is ±0.005mm. The thicker the aluminum plate, the better the stiffness of the plate.

Aluminum plate for making CTP plate should be clean and smooth. It can’t have cracks, corrosion, vent holes, severe abrasions, scratches, marks, peeling, oil marks,etc. Defects such as non-metallic pressing, slight color difference, bright stripes and other problems are not allowed.

Haomei Aluminum has different types of printing plates including PS plate, CTP plate and CTCP plate. Our thermal ctp plate is very favored by the global customers. Welcome to inquire thermal CTP plate price.