Wire galvanising wiping pad material?
A discussion started in 2012 but continuing through 2020April 25, 2012
I am an engineer and my company is implementing continuous wire galvanising process. We have fully designed and manufactured the whole galvanising line. Everything works fine except for the wipes.
The wire exits the zinc bath at 45 degrees angle and immediately passes through two wiping pads, which are 50 mm long and 25 mm wide. Right after wiping, the wire enters the quench tube were cold water circulates and cools the wire. As a wiping material I am using Palmetto Brite wire wipes.
The wire is clamped in between the pads with a clamping screw and the finish is good but after running for 2-3 minutes the coating gets thicker and rougher. The problem can be solved by applying a bit more force to the pads. The finish is smooth again for 2-3 minutes and then the same problem comes up. The same procedure is repeated until the physical limit of clamping is reached and wiping pad needs to be replaced.
Is there anything I might be doing wrong, or alternatively should be doing. Maybe I should try different wiping materials? What materials are you using for wiping galvanised wire.
Wire traveling speed 40 m/min
zinc tank length 2 m
zinc temperature 520 °C.
Any ideas would be highly appreciated.
engineer - Latvia
April 27, 2012
Zinc temperature is very high. If the kettle is iron, it will not last long.
Galvanizing Consultant - Hot Springs, South Dakota, USA
July 10, 2012
Q. We have a continuous galvanizing line for steel wires here in Kampala. We are using Palmetto Brite Wipes pads. Yes, they work well but padding is not automatic and is done by operators; the coating weight varies with operators and is sometimes less than what is required! My question is: Is there any cheaper alternative to pad wiping apart from nitrogen wiping or if there any way we can make pad wiping automatic (as in set it so as to achieve the coating we want automatically)?Collins Wasswa
- Kampala, Uganda
May 25, 2017
A. Hi. I'm a production coordinater on a 24-wires galvanizing line.
Here our pads (from Robco) are made from teflon.
When all parameters are good (lead, charcoal, HCl, flux), pads can last a day or more depending on zinc level and welding quality.
I've talked to some people in Bissen Luxembourg and they said that their pads can last more than a week.
- Montreal Canada
Ed. note-- Readers: to the extent possible, try to keep any suggestions generic, suggesting operational procedures, pad materials and types, etc. But no testimonials to brand names please.
September 14, 2017
How is it possible to achieve zinc coating of above 50 g/m2 especially for wires of diameters below 1.90 mm using the pad wiping method?
Bath length is 2 m.
Bath temp is 450 - 460.
Line speed is 60 m/min.
April 5, 2018
A. We are currently supplying wiping pads for a steel company in India. The Pads are lasting around 10-12 hrs for smaller sizes at high speeds and 24 hrs for bigger sizes at lesser speeds. The pads give better performance if the scaling is removed by pickling. If Mechanical scaling is used then life is reduced.Amol Tanawade
- Mumbai, Maharashtra, India
February 4, 2020
Q. CONTINUOUSLY NITROGEN WIPING NOT GOOD
... BUT N2 PURITY IS 0.01, NO ROUGHNESS BUT SURFACE LOOKS LIKE LITTLE BIT LUMPS.
ALREADY WE DID NITROGEN TANK EMPTY-OUT 3 TIMES. ZINC BATH TEMP ALSO UP TO 460. WE TRIED ACID CONC 12, FLUX 5.0 PH, SP.GRAVITY 1.06, AND NITROGEN PRESSURE ALSO GOOD. MAY I KNOW THE PROBLEMS?
KHALEEJ STEEL - UNITED ARAB EMIRATES