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Take the Zap Out

(January 2012) posted on Wed Jan 25, 2012

What do you do to eliminate static in your printing operation?


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By Gail Flower

Now that it’s winter and the air is dry, we all get zapped by static electricity. Any time you rub two materials together, that sliding friction stirs up static electricity, and ZAP, electrostatic discharge (ESD) gives you a little wake-up charge.

Some industries are hit more than others. ESD really can hurt components in the electronics contract assembly industry where damage can occur from as little as 15 to 30 V. The effect of ESD on electronic devices in that industry can cause latent failures as components become unstable with latent failures or it can cause catastrophic failure with components not working at all. Materials that transfer electric charges are those with low surface resistivity and these conductors (metals, water, carbon, and people) can transfer a charge to the earth’s ground.

What’s required? Insulating materials, like plastic and glass, can hold an electric charge, but not transfer it easily. It takes dissipative materials, or those that cause charges to leave the insulating materials just a fraction faster than the charge can be created from friction to get rid of the effects of static electricity.
Just walk through any reputable electronics assembly plant and you will see dissipative materials everywhere: workbench mats, carbon content storage boxes, ankle straps, wrist straps, floor mats, earthed workstations with bonding points, no nylon clothing or uncoated paper. There are ESD bags holding components, ionizer power supplies, anti-static bars, ionizing air blowers, and signage everywhere.

What do printers in the digital and screen printing do to eliminate the problems associated with static electricity? In our industry the problems related to static are dust attraction, printing defects, and shocks to operators. When a printer takes plastic substrates from a stack, lifting the sheet transfers a static charge into the conductive person. Next the substrate is fed into a piece of metal equipment where it is discharged. Result? The effect of a static field on a surface can result in ghost tracks, overspray and fogging. Dust can block printheads as well.

What do you do to eliminate static in your printing operation? Do you use antistatic sprays, grounding devices, humidity controls, ionizing tapes, ionizing wands, ionizing gloves, or other devices? Let us know what you do control a common industry problem and we will share your information in print! Drop me a line with your solution: gail.flower@stmediagroup.com.
 


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