Wear Parts for Rolling Stock
-
Long
life - No lube - Greatly reduced wear
- Specially formulated
- Excellent replacement for steel
- Maintenance cost savings
Applications
/ Success Stories
Unique formulations
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Hilube 10 and 20
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Vesconite and Vesconite Hilube
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Vescolene Ultrared
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VescoFlex
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VescoPolycap
The information, results and comparisons provided in these railway pages are route specific. Train operational constraints should always be considered when deciding on the suitability of polymers for particular applications.
Comparison - low friction polymers with steel
|
Material |
Coefficient of friction |
|
Manganese Steel |
normally accepted as being twice that of steel on nylon |
|
Polycap |
0.49* |
|
Hilube 10 |
0.11* |
|
Hilube 20 |
0.06* |
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Test results obtained at 4 MPa (580 psi).
-
Results were obtained after a run-in period of 10 000 cycles.
Tests confirm similar static and dynamic coefficients of friction
If a mass is placed on a
surface and a small force is applied to the mass, the mass will not move at all.
The mass seems glued to the surface. This effect is known as static friction. It
takes a certain minimum force (Fstatic)
to get the mass moving.
Once the mass is moving you need a smaller force (Fdynamic) to keep the mass moving. This is known as dynamic friction.
In most situations the static friction is greater than the dynamic friction. This means that the force required to start a body moving is greater than the force required to keep it moving. The difference between the static and dynamic coefficient of friction results in the phenomenon known as stick-slip. The greater the difference between the static and dynamic components the greater the stick-slip and the greater the force required to move the mass initially.
VescoPlastics specialises in polymers that overcome this problem. Our new advanced Vesconite Hilube material has a very low dynamic friction (approaching that of PTFE) and even a lower static friction ! The lower static friction means no stick-slip problems in applications with intermittent motion.
Our Hilube 10 and 20 railway polymers exhibit very similar dynamic and static coefficients of friction.
Nylon and Hilube 10 bogie centre liners were tested in harsh sub-zero temperatures. The high coefficient of friction of Nylon (0.49) resulted in the bogie stiffening up going around corners. The reduced friction of Hilube 10 (0.11) solved the problem, coping with the low temperatures allowing for the smoothest possible movement between the bolster-frame wheel and track when going around corners.
Updated Mar 01 2005
visitors since Feb 28 2005