The angle of the bandage is the angle between the warp of the silk screen, the weft line (silk) and the edge of the screen frame. There are two forms of the bandage screen, one is a normal bandage screen,the other is a skew bandage screen. The following two methods of the bandage are described respectively.
Is stretching, is the screen of the warp and weft are parallel and perpendicular to the four edges of the screen frame. That is, the meridian, the weft line and the net frame are 90 degrees.
Skew the tension and the network refers to the screen of the warp and weft are screen frame with four was a certain angle. It is convenient to use the normal bandage silk screen form, and it is convenient to operate. Because of the ability to make full use of silk screen, it can save the corner material of silk screen and reduce the waste of silk screen. But, in the sleeve
Printing using this form of stretching plate prone moire, so color printing is generally not used is stretching. The use of oblique cross bandage net is beneficial to improve the printing quality, and it also has some effect on increasing the amount of ink leakage. The shortage is that the silk screen is wasteful. In high precision printing and color printing, stretching angle has a direct influence on the printing quality, stretching angle is not suitable, there will be a moire. So, general copy printing, often with stretching angle is 20 degrees to 35 degrees, in the printed circuit board with high resolution, due to the use of the screen mesh is higher, so the stretching angle 45 degrees more appropriate. In the actual bandage network, in order to reduce the waste of silk screen, the general copy of print is usually used as a normal bandage.
The precision screen printing and screen printing precision, while the screen tension is one of the important factors influencing the quality of screen printing. Material and strength, silk screen tension and net frame of the prime, temperature and humidity, stretching method and so on. Usually in the manual stretching and no tension tester under tension to determine the main experience and decide, the tension and the network side of the screen, while stretching fingers press the screen, the general finger pressure screen, feel the screen has certain elasticity can be. In the use of the bandage machine and the large net frame bandage net, the tension instrument is generally used to test the wire mesh tension.
In the use of the tension and the machine tension and the network, the mobile screen chuck (elastic debugging) by pressure meter to control the realization, so different screen, the screen of the pressure value of different. Usually a stretch mesh pressure value is 7-9kg/cm2; the nylon mesh stretching pressure value is 8--10kg/cm2; polyester mesh stretch mesh pressure value is 8--10kg/cm2; stainless steel wire mesh stretching pressure value is 10--13kg/cm2.