Add a low friction bearing surface to a PP component

[bigdave285]

Hi

I have an application with a polypropylene wheel running on another PP component. To make the wheel rotate as freely I have added cylindrical ribs on the running surface for the wheel to run on and this works but I am concerned about wear to the wheel.

1. Can anyone suggest a suitable grade of PP or filler for the wheel to reduce friction/wear?
2. Alternatively what do you think of a twin shot moulding with another more suitable material for the bearing surface of the wheel.

 

[Demon3]

Just add some ultrahigh molecular weight silicone to the PP. That's available from Wacker as Genioplast S or from Dow Corning (go to

http://www.multibase.com

and select silicone masterbatches). It's great for reducing friction, I've used it. Its advantage over regular silicone is that it doesn't migrate and cause the problems that entails.

Chris DeArmitt
Plastic Training Webinars since 2003
visit:

http://www.plastictraining.com

 

[btrueblood]

"2. Alternatively what do you think of a twin shot moulding with another more suitable material for the bearing surface of the wheel."

Personally, I like this approach better. The alternative material in my mind would be a suitably sized rolling element (e.g. ball) bearing.

 

[bigdave285]

Thanks btrueblood, but I forgot to mention that in the centre of the wheel is hubless. we have a removeable filter elements mounted inside the wheel. A ball bearing will not work. thanks anyway.

 

[HDS]

It all depends on loads and speeds.

You could press fit a UHMWPE "tire" on your wheel and save the trouble of two shot molding.

 

[dwightdixon]

If the wheel rotates on a steel or metal shaft, I would suggest a nylatron insert that contains TFE is a nylon matrix. It will give lower friction and superior wear than just using PP.