Thickness of a PTFE plate against bearing 5

[IJR]

I was just curious how one determines the size of a teflon (PTFE) plate to be designed as a sliding support but has to bear serious vertical load.

Any basic info will do. Do these plates crack? Do they crush?

respects
IJR

 

[RiBeneke]

The ptfe bearing manufacturesr may be able to give you a guideline pressure.
Normally the ptfe is only a thin layer and is bonded onto a steel or other structural backing plate. The ptfe then carries direct compression for static loads and then also shear in itself and at the bond interface when sliding movement occurs.

 

[Qshake]

IJR,

What type of load are you looking at? Most PTFE bearings I've seen have a 1/16" plate bonded to a steel plate. The steel plate is then attached to a larger steel plate to form the upper assembly of the bearing. The bearings I've seen are for bridges where the loads are quite high.

 

[Qshake]

IJR, I forgot to mention that AASHTO is probably the best source of information on this.

 

[Taro]

Besides manufacturer literature and AASHTO, another good reference for bearing design is the American Iron and Steel Institute/National Steel Bridge Alliance publication "Steel Bridge Bearing Selection and Design Guide", 1996.

 

[flamby]

Strength of PTFE in compression goes manifold high when it is confined by lateral boundaries. Thats why you will observe that the bridge bearings taking very high loads are resting on "pot" type of PTFE bearings. The PTFE is inside a closed pot and applied load from top. It is something similar to a well founadtion on a different scale.