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

Preloading - control of settlements, Q. Preloading - Control of settlements...

Q. Preloading - Control of settlements? This method consists of loading the soil strata by a load intensity which will be equal to or higher than the expected load intensity. T

Leveling, cooke''s reversable level

cooke''s reversable level

Doors and windows, important considerations in case doors and windows

important considerations in case doors and windows

Consolidation settlement, The integration of strain over the depth is settl...

The integration of strain over the depth is settlement. The method of producing the settlement is non-recoverable when the intensity of stress is removed. Hence, a permanent reduc

Draw the shape of the pressure line, Draw the shape of the Pressure line. ...

Draw the shape of the Pressure line. Solution The locations of resultant force at sections A-A, B-B  and C-C have already been determined. Joining these locations, we can dr

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

Compute the stresses at top and bottom fibres, Compute the stresses at top ...

Compute the stresses at top and bottom fibres in a simply supported pre-stressed concrete beam with a rectangular cross section, 200 mm wide and 400 mm deep at sections A-A, B-B an

Contours, how can you draw contours of a non square grid?

how can you draw contours of a non square grid?

Define recommendations for ptfe, Define Recommendations for PTFE? (a) I...

Define Recommendations for PTFE? (a) It can be either of the two forms given below: (i) Dimpled large sheet It may be circular or rectangular divided maximum into four pa

Functions of water stops in joints of box culverts, Question What will func...

Question What will functions of water stops in joints of box culverts and drainage channels ? Answer Principal function of water stops is to stop liquids, water-borne materials

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