Silk plate technology applied to the camera

Photolithography is the main method of silkscreening organic glass. It is through the camera equipment, the text, pattern to be copied in accordance with the requirements on the photosensitive film, in order to obtain a positive version of the silk screen plate.

As the photographic technology is applied to silk screen printing, the application scope of screen printing and screen printing is expanded. Photographing the bottom plate can not only provide very fine lines, text bottom plates, but also can reproduce colors and gradations of complex patterns to produce a color separation bottom plate that meets the requirements of silk screen printing. Therefore, photolithography plays an important role in the organic glass screen printing process.

The plexiglass screen printing photographic platemaking process can be divided into lines, text draft photography; monochrome mesh tone photography, color mesh color separation photography three categories.

The following is a brief introduction of the specific contents of each process link in photolithography:

1 full text. Organize the originals, determine the proportion of spring style, and determine the rules.

2 photos. Using a photographic device, equipment, take a monochrome or color separation of the original.

3 development. The exposed film is placed in developer and developed. After exposing the photographic film, the silver halide of the emulsion layer is exposed to light to form a latent image. After the chemical treatment of the developer, the latent image becomes a visible and clear image. The commonly used developer consists of the developer Mituol (also known as Irun), Nuonanni (also known as Hydra, scientific name hydroquinone), the protective agent sodium sulfite, the accelerator sodium carbonate, and the inhibitor potassium bromide.

4Fixing. Fixing is to keep the developed silver image unchanged for a long time. The principle is to dissolve and remove the unsensitized residual silver halide on the photographic film to obtain a fixed image. The fixing solution is generally sodium thiosulfate (soda soda) solution. In order to prevent the development reaction of the photosensitive film in the fixing solution, a certain amount of weak acid may be added to the ordinary fixing solution to make the acidic fixing solution. The pH value of the acid fixing solution should be maintained between 4 and 6. In order to strengthen the mechanical strength of the photo-resist, a certain amount of potassium rhenium, chrome tanning, and other hardeners can be added to the acid fixative to make a firm fixing solution.

5 washed. Washing is divided into intermediate washing and final washing. The intermediate water washing is performed after the development and before the fixing, and can play a role of stopping and protecting the fixing liquid; the final water washing is performed after the fixing, and the function thereof is to wash away the soluble double salt formed on the photosensitive film during the fixing process. Washing water is better with running water. The water temperature should be maintained at 16~24°C.

Photographic preparation of the bottom plate is easy and fast. In recent years, with the advent of automatic developing machines and automatic fixing machines, the photoengraving process has gradually become mechanized and standardized.