Control of the most popular printing light source

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Control of printing light source and printing time

1 Requirements for photosensitive materials of silk plate: good plate making performance, easy coating, appropriate photosensitive spectrum range, generally in M, photosensitive wavelength, strict darkroom conditions for plate making operation and plate storage; If the wavelength is too short, the selection of light source and personnel protection will become more difficult; High sensitivity, which can achieve the purpose of energy saving and rapid plate making; Good development performance, high resolution, good stability, easy storage, less waste

2. Requirements of silk printing on photosensitive materials: the plate film formed by photosensitive materials should meet the performance requirements of different types of inks, have considerable printing resistance, and can withstand the scraping pressure of a considerable number of times of scraping; The combination ability with silk is good, and there is no film failure during printing; Easy to peel, not easy to produce ghost, conducive to the regeneration of silk plate. For non drying inks, the photosensitive film is required to reach a certain thickness of 10~40 m on the printing surface, which is about the thickness of 1~2 pieces of 80g copy paper

printing light source and equipment

I. selection of printing light source

in the photosensitive silk plate making process, printing is a very important process. If you choose and use the printing light source correctly, it is of great significance to improve the quality of silk screen printing plate, effectively save energy, simplify operation, structural principle: nj-s series change experimental machine adopts servo control system to maintain the health of operators and reduce costs. Due to the different types of photosensitive resin photosensitive materials, we should choose to use light sources that meet the needs of various photosensitive materials

at present, the color sensitivity of various silk photosensitive materials we use is mostly distributed between M. Therefore, theoretically, any light source with a peak wavelength of m on the emission curve of luminous spectral energy can be used for silk printing. In addition, when printing, we should fully study the size of the version, the output power of the light source, the distance between the version and the light source, and pay special attention to the role of the light reflector

II. Precautions when selecting light source

1 The emission spectrum of the light source should match the absorption characteristics and color sensitivity of the photosensitive material. The energy of light varies with the frequency of the wavelength. The shorter the wavelength, the higher the frequency from import to production, and the greater the photon energy. When light is absorbed by substances in the process of radiation, because photons have certain energy, it will cause physical and chemical changes in substances. The chemical reaction caused by light energy is called photochemical reaction. Photochemical matching means that the spectral output distribution of the selected light source should match the spectral color sensitivity of the photosensitive material. That is, the wavelength range of the photochemical reaction generated by the light-sensitive material absorbing light is exactly the output range of the light-emitting spectrum of the light source, and the maximum absorption peak of the photosensitive material is just at the output peak of the light source. In this way, the light of the light source can be absorbed by the photosensitive material to the greatest extent and produce photochemical reaction

2. High luminous efficiency and intensity. With other conditions unchanged, the greater the power and luminous efficiency of the light source, the greater the luminous intensity or brightness, the illumination of the exposed surface will also increase, and the shorter the time required for the photosensitive material to obtain the same exposure

3. The thermal radiation of the light source is small. On the premise of ensuring that the light source has sufficient luminous intensity or brightness, the thermal radiation of the light source should be as small as possible. When using high-power and strong light source, forced cooling (air cooling, water cooling) and other measures must be taken for the lamp tube to control the exposure temperature of photosensitive materials below 32 ℃

4. According to the calculated displacement, the luminescence determines whether the displacement control accuracy of the actuator is suitable for uniform intensity. The luminous intensity of the illuminating surface of the light source should be as uniform as possible. The design of the exposure device should ensure that the illumination difference of each point on the exposure surface of the photosensitive material does not exceed 15%. The light source has strong adaptability to the environment. The light source shall have strong adaptability to the environment, and can work normally under various temperature, air flow and voltage changes. Of course, in actual production, it is unrealistic to choose a light source that can fully meet the above requirements. The purpose of the above selection principle is only to hope that the plate making operators should consider the influence of the light source on the exposure quality of photosensitive materials when choosing to use the plate making light source, so as to achieve a targeted goal

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