Fire Proofing Composite Post Consumer Plastic HDPE & Rice Hull Fiber 1

[CompositesKid]

Can anyone suggest a chemical additive to HDPE, High Density Poly, and Rice Hull Cellulose Fiber Composites manufactured from recycled post consumer plastics to obtain
a U.L Class A Fire Rating ? The California Fire Marshall is going to require this by code for all Decking Materials
Sold in the State as of January 1st 2008. Hoping Someone could point me in the right direction. Thank You

 

[MikeHalloran]

Here's an additive for making intumescent shingles:

http://www.patentdigi.com/conveyor_skirtboard_apron/intumescable_fire-retardant_products.html

... but shingles are not required to carry a structural load, so the technology might not be such a great idea for decking.



Mike Halloran
Pembroke Pines, FL, USA

 

[Compositepro]

The most common fire retardants are alumina trihydrate (ATH) and magnesium hydroxide. They are used at fairly high loading levels like 30%. They would be the first thing to look at.

 

[MikeHalloran]

I've seen some recycled plastic 'structural' products; deckboards for sale in the lumber yard, and 2x4s in some outdoor benches that were the subject of public recriminations. I put the word in quotes because the stuff is remarkably flexible, hence requires closer support spacing than one would use for wood of similar dimensions. The literature with the deckboards made that clear enough for a technical person, probably not for a civilian. Their dull brown appearance suggests some organic fiber content.

The 2xs are a local product, allegedly adopted by patronage, ugly as sin (coarse, brightly colored chips, some identifiable), and assembled without compensation for the extra flexibility, where they promptly warped. They looked like the aftermath of a food fight even when new.

In an application where the product was expected to retain some structural integrity in the presence of fire, I, personally, would reinforce it with iron, in the form of steel, at loadings approaching 100 pct by volume. ;-)



Mike Halloran
Pembroke Pines, FL, USA