Printing technology
In screen printing, the mesh screen, wire diameter and mesh textile methods and the choice of materials directly affect the size of the tension Stretching, Stretching, is based on these parameters to measure the tension of the screen, When measuring the tension, the tension point is detected from the network side of the box should be 10 cm, otherwise the measured tension is inaccurate. Zhang maximum value of each mesh SEFEN PET 1000 can be achieved in the table below. The maximum tension value indicated in the table is given the intensity of the display screen, the various heads of different wire diameter and can withstand the maximum tension value rebound, if it exceeds the table given tension, mesh will It loses its elasticity, becomes plastic deformation, which should pay attention to the stretching of. Tension unit: N / cm (N / CM), available Newton tension measured. The tension meter can measure the tension of the warp and weft. The so-called mesh warp tension is tension on the winding direction of the entire volume of the screen, that tension edge typing direction; zonal mesh tension is tension screen width direction. Tension can be seen from the table, the same kind of material to create a different wire diameter, different mesh screen, the tension is different, that is, the same mesh screen, the tension is different, that is the same purpose the number of mesh, mesh wire diameter is different, the tension is different, because the tensile tonicity with mesh diameter is proportional. For example: A is twice the radius of the wire B, then A wire tensile strength is four times B wire. Tension values in the table on the side length of about one meter below the high strength of the frame effectively, when the edge length of up to 2 meters of the screen frame, the tension value should be reduced by 15% -20%, if the frame edge up to 3 meters When the left and right, Stretching, according to the table given 20-25% reduction in tension. In order to ensure danger during handling and printing, screen is not torn, so when stretching, the tension should be higher than the table given that it is necessary to lower the tension.
Second, the tension requirements
1, the network uses a different template sizes tension requirements are different. For example: color network printing, in order to ensure the accuracy and reducing tonal values of good, requiring tension 20-30N / CM. Fine print, dial scale, etc., tension 12-18N / CM. General graphics printing, tension 8-12N / CM. Hand-printed, rough prints, or accuracy, size, etc. No person, tension> 6N / CM, is worth noting that when the overlay of colored blocks, in order to accurately overlay position requires not only screen tension should be greater than 10N / CM, And a few template overlay must reach consensus tension is more important for network printing, otherwise it will cause deviations moire and hue, etc.
2. Why network printing templates require a higher tension network? This is because A, high tension network stencil obtain lower net distance, when the net from doubling, tripling make printing graphic distortion, therefore, when the lower net stencil tension of ink is not uniform and dot gain deformation, affecting hue. B, low net distance, you can use a smaller screen of pressure, so that the net reduction in net stencil stencil wear longer life. C, small scratch pressure, helps to avoid network perimeter of the ink, deformation and improve the sharpness of the edge of the network, to ensure the printing effect.
