What additive can increase the hardness of Polyurethane?

[danial1987]

I want to increase the hardness of polyurethane for making parts via injection molding. The material I have is one-component polyester urethane based on an aromatic diisocyanate in granule form. It's hardness is 80 Shore A.
What additive can i mix with the granules to get a harder product after injection molding?
Is there any additive/material that I can use with my granules to harden them by twin screw extrusion/compounding?

 

[btrueblood]

Carbon black?

Seriously, why not source a harder durometer material?

 

[Demon3]

Anything with higher hardness than the PU which means just about anything.

Calcium carbonate, talc, mica, wollastonite, silica, barium sulfate etc. etc.

Contact a mineral filler supplier.

Chris

Chris DeArmitt - PhD FRSC CChem
Plastic & Additives Webinars
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[Pud]

You could compound it with a 60 Shore D material (about the stiffest grade). You would get some intermediate hardness depending on mix ratio.

H

http://www.tynevalleyplastics.co.uk

Why be happy when you can be normal?

 

[patprimmer]

Urethane PBT copolymers are harder and are available as Arnitel and Hytrel. There are others, but you can look them up as easily as I can.

Regards
Pat
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