The Hard Anodising Ltd 'Ano-lube' process is designed to improve the lubricity and release properties of
conventional hard coats and other anodised surfaces to increase their wear resistance, reduce friction
and repel moisture.
The process consists essentially of the deposition of a very thin layer of PTFE onto the freshly formed unsealed oxide coat. The technique involves little more than flooding the workpiece with an aqueous dispersion of PTFE, allowing it to drain and then drying it at room temperature. It is thus inexpensive and poses little risk of damage or distortion. So long as the coating is applied to the still-wet, freshly anodised work, a good bond to the substrate results.
Comparison of as-anodised specimens with similar pieces Ano-lube coated, using the Taber Abraser, showed a typical weight loss of 0.016g in 10,000 revolutions for the former, and 0.009g (specific weight loss of 0.15) for the latter, using identical wheels and loading. It was noted that the Ano-lube caused 'filling' of the wheel with PTFE, which probably goes a long way to explain the reduced rate of coating removal and might be thought to invalidate the test; however, it may well be that the improvement in performance of actual work pieces in service is explained by this phenomenon, in which case the test may be taken to give good correlation with field use.
Little work has been done to determine the nature of the bond between PTFE and the underlying oxide. It is certainly better than would be expected from simple application of one to the other, e.g. by powder coating. It cannot be related to the porosity of the oxide, since the pore size is many orders of magnitude less than that of the polymer particle size. Electrostatic forces have been suggested, which seems plausible but is yet unproved. The polymer is not 'sintered' to form a discrete coating, since this involves temperatures higher than is safe for the system as a whole.
Excess PTFE may leave a milky sheen on the surface. If unacceptable this can be removed in a number of ways.
Hard Anodising Ltd make no particular claims for the process, but it is known that customers have compared Ano-lube with others and have been unable to detect any difference in performance. Ano-lube must offer an attractive improvement in performance to many users.
DON'T FORGET !
Paint, labels, tape or other adhesives will not take to PTFE.
PTFE coatings can be applied to surfaces other than freshly formed, unsealed films.
Examples include dyed-and-sealed work, parts which have been already anodised and in some cases, non-anodised aluminium and other materials. However, since the anodic film has been sealed, the PTFE coating exists as a thin surface layer and will provide surface lubrication for a limited period only.
