Screen Production Foundation - Selection, Application (on)

Preparing a screen is the first and important step in the screen printing process. If the screen is not properly selected, good printing results cannot be made. Silkscreen workers must choose the right screen system and equipment to reproduce the original character. Silk screen is widely used to meet different quality requirements. Modern screen systems can produce a variety of different drawings, but must choose the right one. If it cannot be used and operated correctly, even the best screen system will be unsuccessful. This article covers the introduction of most modern screen materials and how to use them correctly.
1. Screen Requirements: Regardless of the printed material, you must confirm the screen requirements before selecting the screen. These requirements include:
(1) Resistant to ink and other chemical materials that need to be used (2) Mechanical resistance (3) Edge resolution (4) Screen bridging (5) Resolution The production of raw materials and production technology determines the quality of screen printing products. In the application process, the best printing quality depends on the method of operation and the exposure and development equipment.
2. Chemical resistance: Chemical resistance is the basis for the ability to use different inks and cleaning chemicals. According to the screen system and its own chemical properties, each system has a certain degree of chemical resistance. Different products have different degrees of chemical resistance and can be determined based on the chemical composition of the product. The screen system is based on the requirements of the ink.
3. Mechanical: By selecting the appropriate raw materials, the hardness and elasticity of the material can be balanced and the screen can be mechanically resistant. The factors that affect the mechanical resistance are: screen tension and mechanical strength. Mechanical strength can include the number of prints. To achieve maximum tension, correct operation.
4. Edge definition: High-quality photosensitive particles are small and smooth. The edge of the screen image with poor quality is not flat, and the reason that the edge cannot be clearly displayed is: overexposure or underexposure. The poor resolution of the edge will affect the penetration and resolution of the ink on the screen, and the image cannot be fully displayed. Edge sharpness can be observed with a microscope of 5060 times.
5. The bridging property of photosensitive materials: The screen system of photosensitive materials has a good screen system, and the straight line made is very straight; while the printed materials of poorly bridged photosensitive materials are curved or serrated. Photographic material bridging can be viewed with a 50x or 60x magnifier. The best effect is to pass the thread through the thread at a small angle. In printing, any deviation from the original can be found in the bridging property of the photosensitive material. The thinness of the screen, underexposure, and overexposure are all related to the bridging of photosensitive materials.
6. Resolving power: Good resolution means that the screen can accurately display the fine lines of the original, so the requirements for the screen materials are very high. The resolution of the screen is influenced by the thickness of the screen (including the screen), the screen color, and the quality of the exposure lamp. Exposure and overexposure are other reasons. Similarly, the resolution is also affected by the grain size, edge definition, and mesh shape of the photosensitive material.
The above six requirements determine the print quality. The screen materials are different, with advantages and disadvantages; to choose the right material must be selected according to the requirements.
Screen system and features:
There are many ways to produce printed screens. Today, there are hand-entry stencils or drawings directly on sealed webs. These methods can achieve certain results, but in industrial printing, modern screen printing systems can achieve good results.
Early screen system: hand-entry template film colloid direct/indirect (slurry + unsensitized film) diazo capillary film dichromate sensitized paste synthesis direct film diazo sensitized paste modern screen system : Direct, direct/indirect sensitometric system for diazo photopolymerization paste (to be continued)