Common test tools in screen printing

China's screen printing is in a period of rapid development, how to reproduce a beautiful and realistic print, based on the industry is the goal of every business. At present, many small and medium-sized enterprises still follow the hands-on test methods based on experience and hand testing, which hinders the improvement of screen printing quality. How to realize the dataization and standardization of screen printing is a problem faced by every enterprise. The application of commonly used screen printing tools is the key to solving this problem. The following introduces several test tools commonly used in screen printing.
Mesh test piece

Mesh test strips are one of the test tools that are routinely reserved for screen printers. It can accurately measure the mesh number of the selected screen. The usage is to close the mesh test piece on the wire mesh, look at the light, and rotate the mesh test piece. This is to be able to see the rhombohedral interference fringes produced on the mesh test piece. The reading indicated by the upper and lower corners of the rhombus is the wire. The number of meshes. The application of mesh test strips plays an important role in the correct choice and purchase of silk screens. At the same time, it can accurately measure the number of screening lines for screen printed products. Use the same method as above.

Exposure test piece

The exposure test strip is one of the commonly used testing tools for screen printing workers. It can accurately measure the correct exposure time for different types of photosensitive adhesives, different light sources, different color screens, and different photo-resist film thickness conditions. Exposure test strips generally have five gray density test sections, each with an exposure coefficient, typically 1, 0.7, 0.5, 0.35, 0.25. After the printing, observe the sharpness of the line on the five gray gradients on the screen, and multiply the exposure time by the clearest exposure factor to calculate the optimal exposure time. For example, the printing time is 10 minutes, and the 0.7 line of the bench after printing is the clearest, that is, the 7min obtained with 10 minX0.7 is the best exposure time of this screen. At the same time, general exposure test strips are also equipped with dot test strips ranging from 1% to 97%. Exposure test strips have an important auxiliary role in improving plate yields.

Resolution test piece

The resolution test strip is one of the testing tools of the plate making process. It can accurately test the resolution of the photosensitive adhesive used. The test piece lists 15 gradient lines from 0.025 to 0.375 mm and 8 gradients of yin and yang from 0.5 to 4 mm. Observe the resolution and resolution of the photoresist you are using through the lines and dots on the screen that have been exposed to the correct amount of time. At the same time, it can also reflect the quality of saw-tooth jaggies generated by screens with different angles.

Screen angle test piece

The screening angle test screen is a special tool for testing screening angle during screen printing. It can measure the screening angles of yellow, white, blue and black in the single-color screening and four-color screening, or the screen printing of monochrome screening products. The method of use is to tightly attach the test piece to the film or monochrome print and rotate the test piece. At this time, it can be seen that round or diamond-shaped interference fringes are produced on the test piece. The angle of the center of the interference fringe is the angle of the screen.

Tonometer

Tensiometers are commonly used tools in the process of screen printing. Tension meters commonly used in China are classified into Newton Tensiometers (N/cm) and millimeter tensiometers. They are all using the pressure of their own weight to measure the screen tension. The Newton tensiometer can read the tension value directly. Stretching the net can be based on the requirements of different prints, the tension is generally controlled between 8-25N/cm. The head of the millimeter tension meter is a dial indicator. When it is used, the tension meter needs to be placed on the reference glass to zero, and then placed on the stretched screen. The counter is rotated counterclockwise and the small dial is rotated clockwise. Reading the readings backwards will give you the stretching tension. The tension of the stretch net has a direct impact on the registerability and the print durability of the print in the screen printing.

Thickness meter

The thickness meter is a test tool used in the plate making process. It can accurately measure the coating thickness of photoresist on the screen. It is mainly used for screen printing plate, glass decoration, ceramic decoration, porcelain transfer printing paper and special printing industry screen printing plate determination.

Surface roughness meter

The surface roughness meter is a special instrument for measuring the flatness of the screen surface. The flatness of the screen surface plays an important role in printing high quality screen printing products. If the surface of the screen printing paste is too thin, the finished product will be prone to produce burrs and serrations, which will affect the quality of the printed product. The roughness of the screen surface is generally expressed by the old Rz value. The Rz value should be below 10 μm, and if it exceeds 25 μm, the print will be affected.