One of the cruelest pranks I’ve ever been party to happened during my time in the United States Navy. All it took was:
- A cigar box
- A rubber band
- The scrap “dots” from every 3-hole punch we could find
We cut the lid off the cigar box, filled it with the “dots,” used the lid and the rubber band to make a wind-up flapper that we stretched across the open top of the box, and carefully placed it in our Leading Petty Officer’s (LPO’s) desk drawer. Then we waited for hilarity to ensue the next time he opened that drawer.
Unbeknownst to us, he was going to a pretty important meeting that morning, so he was wearing his Service Dress Blues (also known as “crackerjacks” – the dark wool one; not the white one on the popular snack mix box). When he opened his desk drawer, the rubber band-powered flapper flung those little white paper dots all over him. It was wintertime, in an office space with electric baseboard heat, so the static cling was heinous. It took several of us with makeshift lint brushes fashioned from duct tape to get his uniform “shipshape” and presentable for the meeting.
I was reminded of this incident recently when I had the pleasure of helping a caller from a paper recycling plant, who was having a static problem in a baler, with, basically, large confetti-like pieces of shredded paper. These shreds are pneumatically conveyed through a long 8-inch duct, where they picked up enough static to cling to the inside of the baler chute, and built up to a point where they covered the sensors that opened the chute. This caused the chute doors to cycle without the chute being full, which triggered the baler to activate with nothing there. The result from the operators was a lot of slamming, frustration, and cursing…which further reminded me of my LPO’s reaction to getting covered in paper dots.
While lint brushes (and duct tape, in a pinch) work just fine for removing statically charged debris from one’s clothing, the baler required a different solution…in the form of a pair of EXAIR Gen4 Ion Air Cannons. These were installed to blow into the baler, from opposite walls just above the chute, and aimed slightly down towards the sensors. This keeps the sensors clear until paper shred actually DOES fill the chute, allowing it to dump a whole bale’s worth of scrap, keeping the baler (and the operators) happy.
Many industrial static charge problems have similarities to “real world” experiences that most of us are familiar with. If you want to talk about static control, give me a call.