Coefficient of Friction
Coefficient of friction is a much misunderstood term, and it depends on pressure, speed and temperature. The friction of PolyDyn coatings is relatively constant over a range of increasing pressure from .2 psi to 400,000 psi, and from liquid hydrogen temperatures of -420°F to +550°F. As speed increases the coefficient increases, but it stays well below, meaning better than, the values of other dry film lubricants.
Because of the film transfer of PTFE from the coating to the mating part, frictional values are similar for all mating materials, as long as the surface finish is 50 rms or better.
Frictional oscillation, the stick-slip and chatter you get with other coatings, is virtually non-existent. It is this ability to perform uniformly across a wide range of conditions that separates these coatings from other dry film lubricants.
Published Properties
Every figure on this page is one PolyDyn publishes. Anything not listed here, ask us rather than assume: tell us the application and we will tell you what the coating does in it.
Low friction
As low as 0.02.
Wear resistance
Holds up even under extreme pressure.
Corrosion resistance
In most chemical environments.
Weather resistance
Against sunlight, saltwater and road chemicals.
Temperature range
-420°F to +550°F.
Pressure range
Friction stays relatively constant from .2 psi to 400,000 psi.
Curing schedule
Flexible, from ambient to 550°F.
Overbuild
Engine coatings are applied to leave a .0002″ to .0007″ overbuild on the surface.
Color range
Wide. Color code your product.
Pliability
Bends freely and repeatedly without breaking.
Machineability
Apply multiple coats, most formulations, and mill to specification.
Adhesion
Excellent, to most metals, plastics, ceramics and wood, and to itself.
Fasteners, Pipelines and Petrochemical Equipment
A dramatic example of these coatings in service is the fasteners used on pipelines and related petrochemical equipment. PolyDyn properties improve their function and extend their lifespan.
Fastener nuts do not become frozen onto the stud shafts, and corrosive deterioration is halted. Installation and removal is simplified, because the coating reduces make-up and break-out torque.
PolyDyn coatings differ from traditional fluorocarbon coatings in one important way: they are composite materials. Fluoropolymers with the lowest coefficient of friction known are combined in a matrix with modern high temperature organic polymers. Together these form plastic alloys with properties neither has alone. That is the same matrix described on the industrial coatings page.