There're many different types of Polyurethane,the four basic types are:

 

A. POLYETHER /TDI

B. POLYESTER/TDI

C. POLYETHER /MDI

D. POLYESTER/MDI

 

 

As a general guide, Polyethers are recommended for applications were parts undergo dynamic stress, ie, they incur lower heat build-up. They also

have advantagesin resilience, low temperature performance and resistance to water attack (hydrolysis).Polyethers also have lower viscosity and

specific gravity.

 

Polyester base urethanes have superior cut, tear, abrasion, oil and solvent resistance.

 

MDI based products have lower isocyanate odour than similar

 

TDI types and have superior hydrolysis resistance and higher resilience. TDI based products are less sensitive to moisture, have shorter demould

timeand lowercure temperature requirements compared to MDI types.

 

Pu applications:

 

Polyurethane is used widely in many industrial fields; some applications are shown as follows.

 

Industry	Application
Automotive	Grommets, bearings, bushes, flexible couplings.
Building and Constructions	Moulds for concrete , gate seals, concrete pump ports
Coated fabrics	Conveyor belts, fuel storage tanks, power transmission belts
Electrical	Encapsulation, insulation, potting, cable joining.
Engineered components	Gears, sprockets, wire guides, rail draft gear, stripper plates, press brake pads, textile yarn guides, cutting boards, business machine Belts, couplings.
Food	Chute lining, grain buckets
Mining	Bucker liners, conveyor rollers, scraper blades, floatation cell impellers, pump linings, grading screens, lined pipes, cross-over pads.
Oil, Chemical and Marine	Bushings, bearings, hydrocyclones, buoys, pipeline pigs and scrapers, fenders, valve seats.
Rollers	Board rollers, nip rollers, metal forming, printing, conveyor, can coating, paper mill.
Wheel and tyres	Fork-lift tyres, heavy duty caster wheels, escalator wheels, roller skate wheels, roller blade wheels.
Shoe Industry	Shoe soles, bottom-moulding diaphragms, wear plates, energy absorbing insoles.
Seals and gaskets	Pneumatic and oil seals, diaphragms