Help with plastic selection

[jvo1]

I apologize if this isnt the correct plastic forum, but it was the closet I could find...

I'm in need of a plastic recommendation for a design. For all intents and purposes it can be thought of as a wiper for a wire rope. I need:

-High wear/abrasion resistence
-Some degree of natural lubrication
-Good elasticity properities (flexible)
-Impervious to most factory environment chemicals
-Injection moldable

I have no plastics experience, but my initial thoughts were low density PE, TPRs, or polyurethane. Can anyone give me a better recommendation, something more specific or point me in the right direction? Any info is appreciated.

 

[Demon3]

I would suggest nylon. You can get grades filled with oil, moly disulfide or graphite to reduce friction and help wear. Nylon 6 or 6,6 should both work. Try

http://www.rtpcompany.com/

as a good place to start. They will have such grades. Also check

http://www.matweb.com

for info and links to suppliers.

http://www.specialchem.com

might be of use too.

 

[patprimmer]

Depending on degree of flexibility and on temperature generated by friction in operation, nylon, polyethylene or polyurethane would be my choices. I think from the very limited info provided, polyurethane might be best.

Nylon will be best if high speed or high pressure generates a lot of heat.

Polyethylene will be cheap and has a greasy surface, but has a very low softening temperature.

Polyurethane has good flexibility and abrasion resistance, but the temperature resistance is not as good as nylon and the lubricity is not as good as PE

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[dwightdixon]

Need to know more about what your usage is and what chemical and enviromental conditions might be. If you need the product to be truly flexible (like rubber) then a TPE like urethane is your best bet. How many of these things do you need to make? Call up a number of potential material suppliers and let them give you their pitches. Some salesman will only try to sell you only their materials but the better ones know when to back off and recommend the right material. Recommending a material that does not work makes you an enemy for life.

 

[paulvallee]

Looking for polycarbonate cleaner for automotive headlight lenses, that are turned yellowed Thank You Paul vallee

 

[Demon3]

Paul. Two comments. One is that your issue should be in a new thread. Secondly, yellow polycarbonate suggests the plastic is degraded and cleaner will not help.


There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[patprimmer]

It is normally the scratch resistant coating that yellows. It is quite hard, but can be polished clean with 1000 grit wet rubbing pads or even Scotchbrite pads.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[patprimmer]

The lights tend to last a bit over 10 years here before degrading (at least Honda ones do) but the polish cleaning only lasts about a year, as It would seem their UV stabiliser package has been used up.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Demon3]

Aha, there's a coating on them, I should have guessed. Such scratch resistance coatings are often polyurethane. For example pU is coated onto plastic (PVC) flooring to give wear resistance, control gloss and reduce slip. If the coating is yellow you may be able to apply a new coat. This is commonly done in the case of PU on flooring. Water based coatings are available.


There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[MacGyverS2000]

I've used Brasso and a paper towel successfully to clear yellowed headlights...

Dan - Owner

http://www.Hi-TecDesigns.com