Science and technology
Screen printing static electricity fault how to exclude?
Electrostatic current is generally small, the potential difference is very large, and there can be attractive, repellent, conductive, discharge and so on. These phenomena can lead to product degradation, performance degradation, fire and other harmful consequences.
Adverse effects on screen printing The screen at the time of printing is charged with the rubber portion and the screen due to the squeezing movement of the squeegee. Screen itself charged, will affect the normal inking, blocking version of the fault occurs, the output of the substrate will be the moment the screen sucked.
a. Synthetic resin-based ink easily charged.
b. Even if the substrate is as absorbent as paper, static electricity is generated when the air is dry. Plastic substrates insulation, not temperature, but also easy to produce static electricity.
c. printing area, the greater the charge, easy to produce undesirable effects.
d. Use caution when using flammable solvents because spark discharges can cause flames.
e. An electrocution of the human body caused by static electricity is caused by contact with a charged object, or spark discharge when static electricity is grounded before storage. Although the current generated by the electric shock is small and will not be dangerous, frequent electric shocks will adversely affect the psychology of operators.
Methods to prevent static electricity Static electricity generation methods are: adjust the ambient temperature, increase the air humidity, the appropriate temperature is generally about 20 ℃, the relative temperature of about 60%; a small amount of anti-static agent into the alcohol for printing materials; reduce Friction pressure and speed; Minimize the substrate friction, pressure, impact; Install a general grounding device; The use of flame, infrared, ultraviolet ionization; The use of high-voltage current corona discharge ionization.