Similar (less expensive) materials to UHMW plastic

[barwick11]

We use some 18" diameter x 1/2" width UHMW plastic plates as lightweight training plates for weightlifting. They're insanely strong, but the ones we got aren't available anymore. We'd like to have some new ones made, but need something strong, yet not quite as expensive as UHMW.

Any suggestions as to what we should be looking at? We were quoted almost $100 per plate, which isn't going to happen, we were thinking on the order of $25 would be ideal, cheaper if possible and bought in bulk.

 

[MikeHalloran]

Ask for 'polyethylene' or 'polypropylene', which are similar plastics of lower molecular weight and likely lower price.

OR, call your local plastic supplier, and ask him to suggest a material that would be cheap in 1/2" plate form.

OR, with a modest tooling charge, you could get the plates cast from polyurethane. This also presents an opportunity, in that the plates can be cast to finished size, and can have markings, e.g. "Property of ____" cast in.





Mike Halloran
Pembroke Pines, FL, USA

 

[barwick11]

I may be showing my ignorance on the topic here, but wouldn't polyurethane flex relatively easily under even light weight?

I got a quote for around $47 for UHMW and $38 for HDPE. The info on broad general types of plastics I just can't find anywhere easily accessible.

 

[MikeHalloran]

Polyurethane has two precursors; their relative proportion governs whether it's rubbery or hard. Some is compounded with fillers and sold as tool/fixture material.




Mike Halloran
Pembroke Pines, FL, USA

 

[dgowans]

If you're willing / able to make your own donuts, here's a link to a 36" square, 1/2" thick UHMW plate for about $100:

http://www.mcmaster.com/#8752k135/=5yjdo1

Yes, your plate will end up slightly under 18" diameter when you turn a plate of this size into four smaller ones. That may not matter to you, or it may be a deal breaker.

McMaster-Carr is probably not going to be your lowest cost option for material so you should be able to find a better price elsewhere.

 

[barwick11]

That's a pretty good deal, we might just do that, we've got a place that can do the labor for us for probably fairly inexpensive. $25/plate is pretty good. One of the other owners used a plastic pizza serving dish (I think), just cut off the handles and drilled a hole, might try that too, but I like the 36x36 square price.

 

[Demon3]

You could buy a sheet of PE from a company that makes synthetic ice. It's sheets of PE that slot together so you can ice skate on the plastic floor you make. They are big square sheets of PE 1/4, 3/8 or 1/2 inch thick.

Look here for an example:

http://www.kwikrink.com/

Not sure if they'll sell a single sheet but worth a try.

Chris DeArmitt PhD FRSC CChem

http://www.phantomplastics.com

Consultant to the plastics industry

 

[Demon3]

Here's another place that does HDPE sheets in custom sizes:

http://thecuttingboardfactory.com/two.html

Chris DeArmitt PhD FRSC CChem

http://www.phantomplastics.com

Consultant to the plastics industry

 

[unclesyd]

Do little searching on reprocessed UHMW for sites like the link below. For your purpose this material should be adequate and cheaper than virgin material. We use a lot of this material around the fish house and docks. We use it for fenders and rub rails and guides on the conveyors and sorters.

http://www.redwoodplastics.com/index.php?content=redco_reprocessed_uhmw

 

[Demon3]

That Cutting Board Factory link includes recycled UHMWPE as well as PE and PP.

Chris DeArmitt PhD FRSC CChem

http://www.phantomplastics.com

Consultant to the plastics industry

 

[barwick11]

Thanks, I've got an eMail into them last night, I'll call them now that they're open this morning.

 

[Demon3]

I am now working with a company specialised in making such plates. I will put you in contact if you like.

Chris DeArmitt PhD FRSC CChem

http://www.phantomplastics.com

Consultant to the plastics industry