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Tin plated copper wire 'dusts' when drawn

December 22, 2011

Q. Dear Sir,

We are doing Electroplating on Copper wire and drawing the same to further fine sizes using natural diamond dies.

But we observe the tin dust when we use this fine drawn wire in bunching / Braiding process.
We observed this dust on lay plate and on eyelet of braiding machine. Our customer wants no dust to be generated while running the tin plated copper in their machine.

What could be reasons of this dust generation?
How can we get rid of this problem?

Please suggest.

Hitendra Mahajan
- REWA, MP, INDIA

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December 24, 2011

Tin is much softer than copper, so it is easy to damage the tin plating. However, there are millions of feet of tin plated copper drawn and bunched or stranded every day.

Possible causes of your problem are -

Excessive tin thickness.

Large grain size of the tin plating.

Poorly shaped drawing dies.

Poor lubrication during drawing.

Excessive pressure over guides.

Rough guides and other mechanical damage.

Jeffrey Holmes, CEF
Spartanburg, South Carolina

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December 27, 2011

Hi Hitendra,
Softer metals like tin have a nasty habit of building up on your wire dies. Check your dies with a 20X loop for tin build up on the dies. The Tin build up on the dies could cause dusting, heating, chattering or breakage of the wire. Periodic cleaning of the diamond dies is very helpful. For larger dies, put the die in a lathe and use a pointed wooden dowel dipped in wax and fine emery powder to clean the spinning dies. On small diameter dies use a string dipped in wax and coated with fine emery powder, spin the die and pull the string back and forth to clean the die. This will keep your dies clean by removing the tin build up.

Good Luck & Best regards,

Jim Sivertsen
Refining & Alloys - Alden, New York, USA