Why does the CTcP plate making technique prefer the negative plate material?

The UV-setter series platesetter has the following major features:

1. The use of ordinary high-pressure mercury lamp as a light source, cheap and easy to be easy to maintain and replace, its output wavelength and the traditional PS version of the spectral sensitivity range more consistent, easy to fully utilize the output of the UV light quantum efficiency.

2. Use a digital screen imaging device (DMD) that contains 1.3 million microlenses within 20 cm2. The DMD is connected with the output end of the computer workflow, and drives the deflection angle of the micro lens according to the requirements of the graphic file stored in the computer, so that the light reflected by the micro lens falls on the PS plate or reflects to other places, so that the PS plate is The purpose of imaging exposure. Since each micro-lens is a square pixel, in the case of the same DPI number, the imaging resolution is higher than that of a circular pixel, so that the produced printing plate dots have high reproducibility and good image quality.

3. Exposure imaging is a step-by-step exposure method. Exposure to 2cm2 followed by exposure to 2cm2, exposure of one line and then exposure of one line, until the entire layout of the image part of the exposure. Due to the step-wise exposure, the mechanical movement accuracy of the plate-making machine is required to be high, so as to ensure that the accuracy of the front 2 cm2 and the rear 2 cm2 exposure area is within 3 μm. Still due to the step-by-step exposure, the ratio of step-moving time to exposure-retardation time, with the increase in sensitivity of the PS version and the requirement for a shorter and shorter exposure time, this ratio is also increasing, resulting in the sensitivity of the PS version. The problem of reciprocity rate failure occurs between platemaking speeds, and it is impossible to reach the result that the platemaking speed is proportional to the sensitivity. For example, a sensitivity of 20mJ/cm2 can produce 30 split sheets per hour, a sensitivity of 10mJ/cm2 cannot produce 60 split sheets per hour, and only 30-40 blank prints are produced because most The time is spent on the DMD's movement time, which brings great restrictions to the CTcP high-speed plate making mechanism version.

4. In addition to the advantages of convenient operation, the fixed version of the platform is not as stringent as the requirements of other CTP plates. In addition, the thickness of the plate ranges from 0.1mm to several millimeters, and can be imaged by auto-focusing after exposure. The adjustment speed is very fast. This aspect cannot be compared with other CTP plate making technologies.

5. The most important feature of CTcP plate making technology is the use of inexpensive and readily available traditional PS plates and traditional PS plates. The total cost of plate-making consumables is not only lower than the total cost of other CTP technology-making consumables, but it may also be lower than the total cost of consumables for traditional PS plates and traditional exposure plates. For printing manufacturers, making plates with this technique can bring attractive economic benefits.

In addition to the above five advantages, the UV-setter CTcP platemaking machine is compatible with the negative PS plate. In the platemaking process, only the graphic part needs to be exposed, and the edge and the middle blank of the plate need not be exposed at all, thereby saving A great deal of time, especially for trademark printing and packaging printing, which has a large percentage of blanks, has become even more prominent. Even if the full version is a graphic newspaper, the use of negative edition can still save 20% to 30% of the time. This is why the CTcP technology is more inclined to use the negative version.

Source: Guangdong Printing