Coatings for polyurethane foam
Q. I need to find a coating that polyurethane foam does not stick to and has a reasonable life.
I am currently using a a teflon impregnated plasma coating on an aluminum mold which then filled with polyurethane foam. It works well for about 1000 shots, but then we must start applying a release agent and eventually must re-coat the molds.
What I have found so far is that the coating must have a coefficient of friction on the order of Teflon and a maximum porosity of .003".
One more catch, the coating must be harder than steel, since it is subjected to a expanded metal screen.
Thank you for your help!Scott Walz
- Bloomington, Minnesota
A. I would try teflon impregnated electroless nickel. It is really smooth with very good release properties, is hard and can stand mold temperatures.
I assume that the teflon over your flame spray is a "painted" film that is a few thousandts thick. There are several different teflon formulations. Maybe a different one would get a little longer life.
Not many companies do teflon filled EN. You have several plating firms in and around Minneapolis so there may be one fairly close.James Watts
- Navarre, Florida
You might look into some of the PVD carbon coatings (diamond-like and diamond) which are very hard and have a low coefficient of friction.
Society of Vacuum Coaters
Albuquerque, New Mexico
Mr. Mattox is
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A. You might try a diamond-like carbon coating. This is usually put down by PVD. It is amorphous carbon, has a low coefficient of friction and has hardnesses above 2000 HV.
Have you tried other hard coatings that are popular these days? (TiN, TiAlN, CrN, etc.) Any success with them?
- Berthoud, Colorado, USA
A. Contact General Magnaplate and request information on their Nedox coating. We have used it as a mold release coating which is very hard and has excellent wearability. They can be found in the list of material suppliers on this web site.Mike Loy
- Stockbridge, Georgia
A. Scott, Diamond-like carbon (DLC) is a good candidate, which has excellent adhesion to Aluminium substrate. The friction coefficient can be less than 0.1 against steel at RH of 50% and the hardness of 20 GPa for a 2-3 um DLC film. There are several companies can provide such coating services, such as Poeton and Son Ltd at UK.xilin Peng
Physics department, University of Wisconsin-Madison
January 26, 2013
Q. I desperately need a good release agent for polyurethane foam that is being formed in a fiberglass mold. I am currently using carnuba wax and pva, but am still having serious sticking issues. I can't seem to get any good advice from the manufacturer's reps. If anyone out there has a proven solution, would you please share.
- Atlantic Beach, Florida, USA
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