Dotline new violet laser platemaking machine

CTP (computer-to-plate) technology has become widespread in developed countries and is used in commercial and newspaper printing. Judging from the plates and CTP platesetters, they are mainly divided into thermal and violet laser technologies and equipment.

Violet laser plate making technology has developed rapidly in recent years and has formed a fierce competition with the thermal technology in the market.
The three major suppliers of CTP plates and plate-making equipment in the world, such as Agfa, Kodak and Fujifilm, dominate the market. Most other small companies were mostly merged or closed down.

In 2005, a new company called Dotline was founded in Germany and launched the first internal drum exposure machine (platemaking machine) using a prism for commercial printing CTP plate making. The high quality requirements for commercial printing are the ideal test standards for research and development newspapers and platesetters, so the platesetters are designed according to the same requirements. In June 2006, Dotline provided Rheinland Group with its first fully automatic CTP platesetter.

Rheinland Publishing Group publishes 21 different newspapers and prints 228,000 copies a day. The Dotline platesetter is installed at the Rheinische Press Center. The machine is a CTP platemaking system using a violet laser plate. The model is the Dotline® NA55V2, which is divided into three different platemaking speeds, manual, semi-automatic or fully automatic.

The manual type is to place the plate manually, and put it into the developing machine manually after exposing the plate. This situation is only possible when dealing with violet laser printing plates under yellow light, but for newspaper printing, this manual type can only be used as a back-up program or used in low-wage countries. It is best to use the automatic transfer plate on the developing machine and continue printing plates only under the yellow light.

The Rheinland Group uses a fully automatic platemaking machine that accommodates two stacks of 334 x 530 mm plates, each stack can hold 500 Agfa Lithostar LAP-V plates, and eliminates the need for isolation between plates. paper.

At the time of plate making, the plate is automatically taken out of the two cartridges in the longitudinal direction and fed into the exposure cell for exposure. The plate is quickly and accurately fed into the platesetter through a 60o exposure slot and positioned with a platen, held in place by a jig, and a linear motor is used to transfer the plate to the laser beam at an exposure speed. Through the inner drum principle, the laser beam maintains the same focus throughout the entire 60o circle, thus achieving high-resolution exposure quality that meets commercial printing. When the plate is exposed to its fixed-mounted optical system with its width, it reaches the output and continues to the developer.

The DotlineNA55V2 is capable of producing 170 plates per hour, low-speed models producing about 110 plates per hour, and high-speed models exceeding 200 plates per hour. This speed is only possible at the same time as loading, exposure and plate output. Although the platesetter can only expose one plate, there are always three plates running in the machine. The maximum size of plates used for all models is 635x845mm and the minimum is 250350mm. The machine's basic model uses 405nm and 60mW violet laser diodes and its resolution is fixed. Rheinland Group chose 1270dpi resolution. It is said that a variable resolution of up to 2540 dpi can be selected, which reads the TIFF file mark information to be exposed in one dpi step and focuses the laser beam to 10 nm at the highest resolution.

The reason why the newspaper printing center chose this platemaking machine is that the price of the violet laser diode is cheap. Agfa offers violet laser plates. Its resistance to India can reach 140,000 prints. Isolate paper removed between plates.

Since June 2006, the Dotline platesetter has used the PPI workflow as the main equipment, and the editorial department has used the server to obtain the l-bit-TIFF file for exposure of the plate. The machine produces 170 plates per hour, which is equivalent to the combined workload of three old platesetters. Only the assault time from 21:00 to 23:00 every day uses one of the 3 old machines to complete the extra needed plates.

The newspaper printing center produces more than 8,000 plates per week, of which 70% is done by the Doté„„line platesetter. The machine is compact, stable and reliable, and its cost performance is also satisfactory, because the price of 159,000 euros is attractive for this high-efficiency platesetter.

Reprinted from: China News Publishing Network