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

Fillet welding, Strength of member when fillet welded

Strength of member when fillet welded

Delay of bituminous laying on top of sub-base, Question In case if ther...

Question In case if there is a delay of bituminous laying on top of sub-base, have to tack coat be applied on the top surface of sub-base? Answer When there is a d

Determine the cost of compensation, The soil in a borrow pit has a void rat...

The soil in a borrow pit has a void ratio of 0.90. A fill-in-place volume of 20,000 m 3 is to be constructed with an in-place dry density of 18.84 kN/m 3 . If the owner of borr

Joints in concrete carriageway, Question Is it necessary joints of conc...

Question Is it necessary joints of concrete kerbs be in line with joints in concrete carriageway ? Answer In regular practice, joints are provided in road kerbs to ca

Significance of tailwater level in culverts, Significance of tailwater leve...

Significance of tailwater level in culverts Headwater level and tailwater level of culverts are significant parameters in hydraulic design. Headwater level can't be set too la

Docks, DOCKS: Types of Docks Docks are artificial enclosures ...

DOCKS: Types of Docks Docks are artificial enclosures for the reception of ships. Three types of docks are found : (a)        Harbour Docks, or Wet Docks, which ar

Digit of cells for concrete box girder bridges, Question How does an engine...

Question How does an engineer determine digit of cells for concrete box girder bridges ? Answer If depth of a box girder bridge exceeds 1/6 or 1/5 of bridge width, then it is o

Most aggregate size advantage structures, Question Design of concrete struc...

Question Design of concrete structures, normally most aggregate sizes are adopted with scopes from 10mm to 20mm. Does an increase of most aggregate size advantage structures ?

Chemistry, discuss various chemical reactions involved in lime soda process...

discuss various chemical reactions involved in lime soda process ?

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