Mesh test piece
Screen test piece is one of the common test tools for screen printing workers. It can accurately measure the mesh number of the selected screen. The usage is to close the mesh test piece to the silk screen, look at the light, and rotate the mesh test piece. This is to see that diamond-shaped interference fringes are generated on the mesh test piece. The readings indicated by the upper and lower corners of the diamond are silk. The mesh number of the net. Application of mesh test piece plays an important role in correct selection and purchase of wire mesh. At the same time, it can also accurately measure the number of screen lines of screen-printed products. The method of use is the same as above.
Exposure test piece
Exposure test piece is one of the commonly used test tools for screen printing workers. It can accurately test the correct exposure time that should be selected under the conditions of different types of photosensitive adhesive, different light sources, different colors of silk screen, and different thickness of photosensitive adhesive film. The exposure test piece generally has 5 gray density test sections, each section has an exposure coefficient, generally 1, 0.7, 0.5, 0.35, 0.25. After printing, observe the clarity of the five gray gradient lines on the screen, and multiply the exposure coefficient of the clearest section by the actual exposure time to calculate the optimal exposure time. For example: the printing time is 10min, and the line of the 0.7 step after the printing is the clearest, that is, 7min obtained with 10minX0.7 is the best exposure time of this screen. At the same time, the general exposure test film is also equipped with halftone test strips with different levels from 1% to 97%. Exposure test piece plays an important role in improving the yield of plate making.
Resolution test piece
The resolution test piece is one of the testing tools for the plate making process. It can accurately test the resolution of the photoresist used. The test piece lists 15 gradient lines from 0.025-0.375mm and 8 gradient and yin-yang dots from 0.5-4mm. Observe the lines and dots on the screen printed at the correct time to analyze the resolution of the photoresist you use. At the same time, it can also reflect the quality of the jaggedness of lines with different angles on the screen.
Screening angle test piece
The screen angle test piece is a special tool for testing the screen angle during the screen printing process. It can measure the screen angles of four screens of single screen and four screens: yellow, magenta, cyan, and black, or the finished screen print of single screen. The method of use is to stick the test piece on the negative film or the monochrome print and rotate the test piece. At this time, you can see that the test piece produces circular or diamond-shaped interference fringes. The angle of the interference fringe center is the screening angle.
Tonometer
Tensiometer is a commonly used tool in screen printing process. At present, the tensiometers commonly used in China are divided into Newton tensiometer (N / cm) and millimeter tensiometer. They all use the self-weight pressure to measure the mesh tension. Newton tension meter can directly read the tension value. When stretching the net, according to the requirements of different printed parts, the tension is generally controlled between 8-25N / cm. The head of the millimeter tensiometer is a dial indicator. When you use it, you need to put the tensiometer on the reference glass to zero, and then put it on the stretched wire mesh. The large hand rotates counterclockwise and the small dial rotates clockwise. The tension of the stretched net can be obtained by reading back the reading. The tension of the stretched net has a direct impact on the registration and the printing durability of the printed matter in screen printing.
Thickness meter
The film thickness gauge is a test tool used in the plate making process. It can accurately measure the coating thickness of photosensitive adhesive on the silk screen. It is mainly used for the determination of screen printing plates in printed circuit boards, glass decoration, ceramic decoration, transfer printing paper for porcelain and special printing.
Surface roughness meter
Surface roughness meter is a special instrument for measuring the flatness of screen surface. The flatness of the screen surface plays an important role in printing high-quality screen prints. If the photoresist coating on the screen is too thin, the printed product is prone to burrs and jaggies, affecting the quality of the print. The roughness of the screen surface is generally expressed by the Rz value. The Rz value should be below 10 μm, if more than 25 μm printed matter will be affected.
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