Hello Rogerio,
I've seen this static issue give big electric shocks (very uncomfortable) and discharges even to the point of melting the powder hose itself!
So far what has been helpful with this is to use a Nylon or PTFE Anti-static hose. As Bob said, this has carbon black as an additive to allow the tubing to disperse the static electricity. You can supplement this with a metal (steel or copper) braided sheath that goes over the outside of the powder hose. This sheath should be earthed at the powder feeder end of the line. Any metal transitions in the powder hose should also be earthed to allow any static to dissipate.
Sometimes the powder hopper in the feed system isn't correctly earthed either so this should be checked.
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Nicholas Curry
Consultant
Thermal Spray Innovations
Bruck an der Großglocknerstraße
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Original Message:
Sent: 01-10-2023 16:25
From: Rogerio Lima
Subject: Static electricity in powder feed hose
Dear Thermal Spray Community,
I am sure that many of you have already experienced a problem with static electricity being generated by a polymer powder feed hose. When one disconnects the hose and empties the powder feeder, one receives an electrical shock (static). Typically by earthing the powder feed hose by wrapping it in a copper wire around part of the tube and attaching the said wire to a big metallic component will solve the problem.
But do you know if there are other approaches to address this issue?
Cheers!
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Rogerio Lima, PhD
Senior Research Officer
National Research Council of Canada
President of Thermal Spray Society (TSS)
e-mail: rogerio.lima@nrc-cnrc.gc.ca
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