Flamability ratings for plastic caster 1

[GlennA]

Recently, a polypropelene caster on a cart in my shop caught fire after several minutes of contact with a hot piece of metal from a plasma cutter. We need to replace the caster with a non-flamable material. What material, typically used in casters, is flame-resistant? Also, can anyone recommend any company that sells fire-resistant caster?

 

[patprimmer]

Cast iron is pretty well fire resistant.

Regards

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[GlennA]

Well sure, but how about something that rolls a little better on a gritty concrete floor? I'm not looking for fireproof, just more resistent than the polypropylene is.

 

[Pud]

Natural rubber is less flammable, but by how much is difficult to say......


Cheers

Harry

 

[patprimmer]

Castors are typically made of PP, PA, PET, Acetal and may or may not have a thermoplastic rubber tyre moulded over them.

They will all melt on contact with red hot metal, and most will ignite and burn for a short time at least.

Regards

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Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Demon3]

All of those caster materials are available in flame retardant versions, see

http://www.matweb.com

for materials and contacts to suppliers.

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

 

[patprimmer]

Molten iron drops (you don't actually specify the metal or the temperature of the drops) will still ignite flame retardant plastics, but the fire will quickly self extinguish. The wheel will still be damaged a little each time and pieces of metal will get stuck in the rolling surface making it difficult to roll.

I still stick by the cast iron recommendation, or possibly aluminium. Either metal with a replaceable FR rubber tyre might work. I am not up on FR rubber, but I am sure there will be good knowledge available on the DuPont web site, or whatever Bayer's rubber division is now called.

If it has to be plastic, FR nylon, once again, possibly with a replaceable rubber tyre. Wether or not you can buy FR nylon castors is another story. Although you don't say, I am presuming you do not require enough to warrant setting up a production run in a special grade.

The flame retardant spec most relevant to your application should be the glow wire test.

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.

 

[MikeHalloran]

I think you can still get reinforced phenolic caster wheels.

Phenolic doesn't melt; it chars, and doesn't lose much strength when it does.

It's not as strong as cast iron.



Mike Halloran
Pembroke Pines, FL, USA

 

[Pud]

Here are some castors that are good for up to 250C.

http://rs

http://www.com/cgi-bin/bv/rswww/sea...mejiegdicefeceeldgondhgg.0&cacheID=uknetscape

Cheers


Harry