Poly tetra fluoro ethylene, Civil Engineering

Assignment Help:

Question
Why Poly tetra fluoro ethylene (PTFE) is usually used in sliding bearings?

Answer
The choice of sliding surface of bearings is of very important importance since sliding surfaces generate frictional forces that are exerted on bearings and substructure of bridge. For example, PTFE and lubricated bronze are usually choices of sliding surfaces for bearings. PTFE is fluro carbon polymer which possesses high-quality chemical resistance and be able to function in wide range of temperature. On whole significant characteristic of this material is its low coefficient of friction. PTFE has slightest possible coefficients of static and dynamic friction of any solid with absence of stick-slip movement by David J. Lee. The coefficient of friction is established to decrease with add to in compressive stress. However, PTFE contain some demerits like high thermal development and low compressive strength.

In designing complementary contact plate with PTFE sliding surface, stainless steel plates are in general selected where plates have to be larger than PTFE surface to let movement without exposing PTFE. Moreover, it is recommended that stainless steel surface be located on top of PTFE surface to avoid contamination of dirt and rubbish. Lubricants are now and then introduced to decrease friction between PTFE surface and upper stainless steel plate. Hence, PTFE might be designed with dimples to keep away from lubricant from squeezing out under repeated conversion movements.


Related Discussions:- Poly tetra fluoro ethylene

Centroid, use of centroid in civil engineering

use of centroid in civil engineering

Defects of timber, what are defects in timber occur due to natural causes?

what are defects in timber occur due to natural causes?

Sewerage, what is the manhole to manhole joining preferences? why it is joi...

what is the manhole to manhole joining preferences? why it is joined crown to cron, not crown to invert?

What is the unit weight of water, In a pipette analysis, 0.5 N of dry soil ...

In a pipette analysis, 0.5 N of dry soil (fine fraction) of specific gravity 2.72 were mixed in water to form half a litre of uniform suspension. A pipette of 10 ml capacity was

Define fixed instrumentation - sounding or sensing devices, Define Fixed in...

Define Fixed instrumentation - Sounding or Sensing Devices? It is possible to monitor local scour at pier or abutment using fixed instrumentation as an alternative to the sound

Arches, what is arches ? what are the classification of arches

what is arches ? what are the classification of arches

Bending moment , The internal forces in any cross-section of a symmetric me...

The internal forces in any cross-section of a symmetric member in pure bending are equivalent toa couple M The moment of the couple is referred to as the bending moment in the s

What is shock transmission unit in bridges, Q. What is Shock transmission u...

Q. What is Shock transmission unit in bridges? Shock transmission unit is fundamentally a device connecting separate structural units. It's characterized by its ability to tran

Water tretement, define scale and sludge and mention the scale and sludge f...

define scale and sludge and mention the scale and sludge forming substance and explain the prevention methods

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd