Photoengraving is the main way of modern printing plate. It is through the photographic equipment, to copy the text, design according to the request, shooting in the GanGuangPian screen printing plate making, which get the Yang figure DeBan with. Because of photographic technology is applied in the printing plate making, in order to expand the screen printing plate making and application scope. Photographic production DeBan, not only can provide very fine line, text DeBan, still can copy colour, order the complex design, produce conform to the requirements of the screen printing plate making DeBan color separation. Therefore, photoengraving on the printing plate making occupies an important position in the process.
Silk screen photoengraving process can be divided into line, from photography; The picture, color the mesh of monochromatic color photography three categories of the mesh.
The following simple introduction of each process photoengraving the specific contents of the:
(1) the whole draft. Finishing the original, determine the proportion, and determining the spring style rules line.
(2) camera. Use photographic equipment, equipment, the shooting of the original manuscript of the monochrome or color piece.
(3) the enhancement. After the exposure of the film into developer of enhancement. Photographic emulsions after exposure, the silver layer halogenating by light QianYing role in the formation, the developer of the chemical treatment, QianYing namely become visible clearer images. Commonly used by contrast extravasation meters, vomit developer (also named in Aaron), a few slave mani (and name to the sea's scientific name, hydroquinone); Sodium sulfite protectants; Promote agent sodium carbonate; XiuHuaJia inhibitors etc.
(4) the fuser. Fuser is in order to make the developed silver like long remain unchanged, its principle is not photographic film photosensitive residual halogenating silver dissolved out, and get a fixed imaging. Fixer general for sulfur and sodium (DaSuDa) solution. In order to prevent photographic films in the fixer happened in reaction can be developed in ordinary fixer in a certain amount of weak acid made into acid fixer, acidic fixer pH value should be held in 4 ~ 6 between. In order to strengthen the photosensitive plastic mechanical strength, can be in acidic fixer with a certain amount of k, chromium, etc are are established, Kennedy made capf conforms to the membrane fixer.
(5) washing. Water is divided into water and water eventually among. Water in the developed, middle finger, can rise to stop before the show and protect the fixer role; Finally, after washing in fixed his role is to wash away fuser process in photographic form soluble FuYan. Washing water to flow water for good, water temperature should be held in 16 ~ 24 ℃. With photographing method DeBan obtained, simple operation, and speed. In recent years, automatic enhancement machine and automatic fuser machine has made photoengraving process gradually mechanization and standardization.
