Offset Printing Using Process-Less Plates…

With the implementation of plate setters in the offset printing plate making process, imaging of the printing plate became more stable and ensured increase of the printing plate quality. But as the chemical processing of the printing plates still highly influences the plate making process and the graphic reproduction workflow, development of printing plates that do not require chemical processing for offset printing technique has been one of the top interests in graphic technology in the last few years. The main reason for that came from the user experience, where majority of the problems with plate making process could be connected with the chemical processing of the printing plate. Furthermore, increased environmental standards lead to reducing of the chemicals used in the industrial processes. Considering these facts, different types of offset printing plates have been introduced to the market today.

Implementation of Computer-to-Plate (CtP) technology has increased the productivity and efficiency in graphic industry by reducing the printing plate-making process and automating the graphic reproduction’s workflow. Printers that had changed their workflow from Computer-to-Film (CtF) technologies to CtP technology have decreased their costs and improved quality of printing plates but the amount of investment in a platesetter device and supporting workflow software could not be disregarded. One should have in mind that the only way of overcoming high demands of the market for shorter production time, reduce of prices and improvement of quality is to invest in new technologies and implement more efficient processes in their workflow. Furthermore, ecology standards are constantly higher and demand usage of different materials and implementation of processes that will diminish bad influence on the environment. One of the examples in the printing plate making process is the change from CtF to CtP technology that completely whipped out usage of the photographic materials and chemicals for its processing. The next logical step in development of the plate making process was to eliminate the developing process.

Processless printing plates

Process free (processless) plates are plates that do not need to go through a plate processor before they are mounted on printing press. The workflow of these plates is almost the same as the regular plates (Figure 1), but one should not neglect that these plates are not printready at the time they are mounted on the printing press.

During the start-up of the press, the absorption of the fountain solution prepares the ink adsorbing coating in the non-image areas to be physically removed by the tack and shear of the ink. This enables a successful transfer of the coating from the plate to the blanket, and the coating is then carried out of the press, in almost all cases within the first several make ready sheets or newspaper copies.