No matter using the traditional direct method, indirect method, direct question mixed method, or using the digital platemaking method.Photosensitive materials are used in the platemaking process.The photosensitive materials for screen printing plate-making are divided into photosensitive glue and film (also known as film film and film paper) according to their existing forms, and according to the properties of the materials they consist of, they are divided into dichrochrome series, heavy ammonia series and iron series, etc.According to its use to distinguish water resistance, solvent resistance.
The basic properties and requirements of photosensitive materials
1. Requirements for photosensitive materials for screen printing plate making
Screen printing plate making to the substrate material, the plate making, such as easy to coating: appropriate photographic spectral range, general appropriate in 340 ~ 440 m. sensitive wavelength range is too long, plate and plate storage become relatively difficult operation, short wavelength, the selection of light source, the personnel protection will become more difficult: high sensitivity, can achieve the goal of energy saving, rapid reproduction;Good development performance, high resolution;Good stability, easy to store, reduce waste;Economy, health, non – toxic, non – pollution.
2. Requirements for photosensitive materials for screen printing
Screen printing process, to use a variety of types of ink and solvents.The requirements of screen printing on photosensitive materials are that the plate film formed by photosensitive materials should adapt to the performance requirements of different types of inks. At the same time, in the process of screen printing, we need to use different organic solvents to wipe the screen and other work, the requirements of photosensitive materials to adapt to the performance requirements of different solvents;Due to the different size of the printing quantity, it is required to have a considerable resistance to printing, can withstand the scraping plate repeatedly squeezingpressure: at the same time, the photosensitive material must be able to combine with the screen well, no debonding fault occurs when printing;Of course, after the completion of the printing needs to do easy peeling, so that the screen plate for recycling.
Development of photosensitive adhesives for screen printing
Photosensitive glue is generally divided into single liquid type and double liquid type.Single – liquid photosensitive adhesive in the production of the photosensitive agent into the latex, the use of no preparation, that is, directly coated.Before using the two-liquid photosensitive adhesive, the photosensitizer should be dissolved in water according to the formula, and then mixed and dissolved in the latex to be fully stirred, placed and used only after the bubble disappears.
Screen printing plate with photosensitive materials, according to its use, there are screen photosensitive adhesive, screen photosensitive film, screen sealant, film hardening agent, film stripping agent, developer, etc.
(3) Main components of screen printing photosensitive adhesive
The main components of silk screen photosensitive adhesive are film forming agent, photosensitive agent and auxiliary agent.