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Teflon coating of stainless steel
Q. I work in a watch company and we are having a problem with one of our straps. The strap is made of 316L stainless steel and is sandblasted with a special blend of coloured sand to achieve a matte and grayish finish. The sandblasted pieces were coated with a very thin layer of PU (polyurethane) coating.
The problem with this finish is scratches show up very easily, which our customers don't like. One solution from our vendor is to coating the pieces with a thicker PU coating but the straps are shinier than before. I'm not sure whether the coating really helps to reduce scratches, or the scratches are just less obvious on such finish. What are the advantages and disadvantages in such an application?WY Wong
- Hong Kong
A. You can put a water based Teflon coating instead of a thick PU coating for your application. Water based Teflon coating is very easy to use. It produces a very thin layer of coating that has good wear resistance, non-scratchable, good chemical resistance and heat resistance.S. Y. Yuen
- Hong Kong, China
Q. I work in a portable measuring instruments company, and we need to put PU coating on stainless steel, is there some special requirements for the part surface, and how about the process of PU coating and equipment? Thanks in advance!Fei Peng
- Shenzhen, Guangdong, China
Q. I'd like to manufacture a product in SS306 and I want to coat it with Teflon coating.
My condition is: The SS tube with OD 4.6 mm and length 310 mm. I'd like to coat Teflon coating thickness of 20 microns on OD throughout length.
Purpose: Anti corrosion, non conductivity of heat and non conductivity of electric current.
Area of application: Pharmaceutical / Surgical.
1. Please let me know the best method of Teflon coating considering my area of application.?
2. Is there any specification for Teflon coating, surface finish, hardness, etc.? If so, what purpose it will be used?
With regards,M. Mahendran
- Coimbatore, Tamil Nadu, INDIA
A. Coating the OD is absolutely no problem. Typical two coat Teflon coating is 35 microns +/- 10 microns. Lower thickness can be archived with good coating practices.
It will serve the purpose of anti-corrosion, heat transfer and electrical insulation (to some extent only).
However, if the application is surgical, then Dupont specifically restricts use of Teflon®. Prior clearance will be necessary from Dupont on selection of grades and the application process.
Hope this helps you.
Mohali, Punjab, India
June 18, 2008
I need to coat a SS-316 rod (currently coated with epoxy powder coating) of 60 cm length & 6 mm dia with Teflon, over the powder coating.
I need to use it for a prototype design.
It should meet the following demands
- Environment of application is oil & salt water
- Need to get electrical insulation
- Need to know how long it will last, if it is used in a water flow region?
- What should be the coating thickness to withstand such a rough condition?
student - India
November 10, 2009
A. Try PEEK Coating instead.William Maghen
- Bayan Lepas, Penang, Malaysia
June 27, 2010
Thanks William, but we don't know whether you are suggesting that PEEK (Polyether ether ketone) coatings would be better than Teflon for Wong's watches ... or better than PU for Fey's portable measuring instruments ... or for Mahendran's pharmaceutical/surgical application ... or better than Teflon over the epoxy on Isaac's rods :-( And in what ways would they be better? Thanks.
Ted Mooney, P.E. RET
Pine Beach, New Jersey
June 1, 2012
Q. I am interested in a thin coating of a low coefficient of friction material for stainless steel sheet metal, to prevent metal to metal contact and act as a smooth surface when components are slid against each other.
Minimal load bearing on the surface.
- West Berlin, New Jersey
June 25, 2012
A. Depending if it has to be permanent and very long lasting or is only for occasional contact and short periods the possibilities are so vast and range from the cheapest special greases to mid-cost treatments like Teflon spray, to more expensive platings to the most expensive and exotic composites deposited by PVD, CVD, Thermospray, Plasma, etc.
G. Marrufo - Mexico
Monterrey, NL, Mexico
A. Teflon adhesion to stainless steel is a problem. However, it was sorted out when Gillette introduced their Teflon coated razor blades and put down an interlayer of Pt-Cr onto their stainless steel blades. This is well patented and documented, but in essence, the process involved vacuum deposition of the Pt-Cr followed by spray coating and sinter polymerisation of PTFE. The adhesion mechanism is believed to go through a Cr-F complex structure, although I am not sure of its details.
R&D practical scientist
Chesham, Bucks, UK
January 31, 2013
Q. Can we coat Teflon coating of 70 microns on SS304 material? If so what is temperature that needs to be maintained for curing.R.Ramakrishnan
Thin Opaque Dip-able coating for stainless steelMarch 3, 2014
Q. A handful of years ago I was shown a thin, dip-able coating applied to a stainless steel bicycle spoke which was opaque, had very good color, and was so thin that cleanly coated the fine threads of the spoke allowing the nipple to thread on without issue. Even white was very bright with no stainless showing through, on a coating that seemed to be microns thick. We chose to go another direction and I've not thought about it again until recently as I need a thin disable coating for a part with threads.
Supposedly the finish was 'sol-gel' and was being performed in Taiwan and was commonly used in manufacturing electronics, that is really all I remember about it.
Now, I've been involved in composites manufacture for a long time and am familiar with sol-gel processing for aluminum (Boegel, AC-130), but this is clearly something completely different.
Essentially, I need a very thin, dip-able cosmetic coating and can't for the life of me seem to figure out what what I'm actually looking for!
Many thanks in advance for your help
Product Engineer - Indianapolis, Indiana
A. Hi Josh. My understanding is that sol-gel coatings were most used for thin films on electronics in the beginning, but that they are now applied to glass, plastics, and metal as functional coatings. Although I have no real experience with them, it would not surprise me if you had seen TiO2 sol-gel coatings, as I'd expect them to be both white, and useful as a metal protector.
Although they are dip-able, I don't think I'd categorize them as low technology . . . by which I suggest that competitive thin coatings that are not "simple dip coatings", like electrophoretic lacquering, PVD coatings, or anodizing may sound more complex but may actually be just as "simple" and inexpensive, or more so :-)
Ted Mooney, P.E. RET
Pine Beach, New Jersey
April 28, 2015
Q. I would like to know how to give a teflon coating of 2-3 mm thickness outside a 40NB schedule 40 ss pipe, flanged at one end. Kindly advice if any enterprise is supplying the same for service as dip pipe for feeding 98% H2SO4 to treatment tank (many other chemicals are being added to tank, pH variation till 9 will occur during the process (maximum operating temperature 90 °C ).
I would have used just teflon, but there is a high speed agitator in the tank and I assume using just teflon pipe won't survive that turbulence for so long.
Thanks in advance
chemical industry - kerala,india
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July 23, 2015
Q. I work in a Gas control system company, and I need to put teflon coating on stainless steel 430F material , for avoiding corrosion as the part/assembly has to work on open environment and also it faces more than 250 °C temperature, hence the part gets easily corroded. and is there any alternate way to avoid corrosion please suggest if possible.
1)should avoid corrosion
2)coating thickness should be 5-10 micron(as part is too small)
GAS CONTROL SYSTEMS - PUNE,MAHARASHTRA,INDIA
Teflon coatings on formed metal stripsApril 27, 2016
Q. Hi All,
I want to add a teflon coating to a formed metal strip for a medical device, the strip comes in contact with the body. Can the teflon be added
after^before the strip is formed? or will it crack?
Thank you in advance.
Engineer - Manchester, UK
June 21, 2016
A. It would be best to coat this after forming masking can be used. Also you need to be more specific than Teflon this is just a trade name for a range of products but i suspect you will be wanting the P.F.A powder over a primer.Paul Rennison
Surface technology - Leeds, Yorkshire, United kingdom