A study of gravure cell structure generated by the Hell Chromagraph 399 ER laser scanner onto a photopolymer plastic gravure printing surface

It is known that the gravure process provides the best quality printed materials and the fastest production speed. The gravure process, as a matter of fact, is the only process which can utilize fully digital imaging technology. For instance, the Helio-Klischograph Model K201 and K202 incorporated with the Hell Chromacom System can engrave gravure cylinders directly without using any halftone films or bromides. Hell Co., Ltd., moreover, has been developing the electron beam engraving technique which employs digital imaging technology to engrave gravure cylinders. On the other hand, Crosfield Electronics Co., Ltd. introduced the Lasergravure process which also utilizes digital imaging technology to engrave gravure cylinders. However, these techniques represent very high costs for gravure printers. Only large companies can afford such investments. The gravure process, generally speaking, is the most expensive process, mainly due to the costs of printing cylinder preparation. To compensate for costly prepress, it is therefore used for high production runs. This constraint is the main disadvantage of the gravure process and has caused the gravure market to become smaller than its competitors web offset and flexography. Research in web offset and flexo has been successful in developing higher print quality, faster production speed and lower costs. Therefore, there are some companies which have been developing a method of making photopolymer-coated cylinders for gravure to reduce, not only the costs of the metal cylinders and the sophisticated equipment, but also the production time. The company that provided photopolymer material for this thesis claimed that its products can be commercially made as gravure cylinders. This photopolymer can be imaged by a conventional ultraviolet fluorescent lamp. Both the company and the author agreed that it might be feasible to utilize digital imaging technology to image this photopolymer. The author selected the Hell Chromagraph 399 ER Laser Scanner as a digital imaging source to image onto this photopolymer. After enormous efforts in the experiments, the argon ion laser on the Hell 399 ER was not able to image onto this photopolymer regardless of the laser intensity and the length of the exposure time because the spectral sensitivity of this photopolymer did not match the argon ion laser. The author, however, conducted further experiments to prove that this photopolymer can be imaged by a high-power UV-argon ion laser, but it is, at present, impractical for gravure printers. Some recommendations for further studies in this area are suggested