Straight Talk

Polyurethane

 

Chemical Name: Polyurethane – elastomer
   
Abbreviation: PUR
   
Common/ Trade Names: Austane®, Urethane®, Lurathane®
   
Properties:  

*Colour

Typically colour determines the hardness however uncoloured PUR typically is creamy in colour. This is also highly dependent on the isocyonate makeup of the urethane; either TDI, MDI, NDI or PPDI.

Typical colours range from Black, red, greens, yellows and Blues to name a few. Colours will determine a hardness grade with most manufacturers

*Form

Rod, Tube, Sheet and Special purpose castings
   
Applications: Drive Rollers, Drive and idler wheels

Sheave linings, Piston cups and seals

Gaskets, Vibration Bushings

Vibration isolation Wear pads

Scraper Blades, Pump liners

Impellors, Conveyor rollers

   
Machining: Can be difficult to machine. Hardnesses above 80 Duro are more readily machined; below this hardness parts are usually cast to shape or rough machined. Closer tolerances are achieved by grinding.
   
Types: Polyester base Urethanes mostly for dyamic applications and Polyether base Urethanes for moist environments. Hardness range from 40 Duro’A’ to 75 Duro ‘D’

Cellular foam

   
Advantages: Can be cast with low cost moulds, Good abrasion resistance, Good tear resistance, High impact resistance. Polyurethane is resilient like rubber but the abrasion resistance and load-bearing capacity is better than rubber resulting in longer life.
   
Disadvantages: Limited operating temperature range,

Hydrolysis & Hysteresis failures

   
Chemical Resistance: Resists water, oils, chemicals and solvents

 

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