Reusing Expired Pre-Preg

[Micalessio]

Hello all!

We currently have 2 rolls of old expired PrePreg Carbon Fibre and would like to know the viability of using it in non structural parts.

I've been thinking about chopping it up and using it as chopped tow in forged carbon parts that are mostly esthetic, or try and re-laminate those in small plates using epoxy resin,just like if it was normal carbon fibre, probably using a press and steel plates so that it would maintain its shape while the resin cures.

The parts made out of this wouldnt be at any, stress, such as clipboards and maybe some small brackets, trying to find an use for this old (and fairly expensive) material, instead of using aluminuim plates

Anyone has any experience trying to reuse prepreg?

Thanks!

 

[SWComposites]

Assuming it has been stored properly, it is likely to cure just fine, maybe with slightly elevated porosity level.

How long expired?
What is the specific resin system?

You could run a flow test and compare to the specification requirements.

 

[Micalessio]

Hey SwComposites, thanks for the answer!

I dont actually know how long its been expired for, nor the conditions it was stored, feels kind of hard already, probably the resin already cured (never used prepreg before, im used to wet plying), we got these rolls for free while buying some things from a warehouse that closed down, they were not stored in afreezer when we got it, they were just left in a corner in storage and the guy handling didnt know how long they've been there.

Going to try wet plying a few pieces just to see what happens. Is it going to be great? Probably not, but yeah these were going to be landfill so if they become barely useful its better than nothing

 

[SWComposites]

hmmm, well, how do you know what the cure temperature needs to be?
most prepregs need to be freezer stored, so this stuff might not be that useful.
what do you mean "wet plying" a prepreg material?

 

[WKTaylor]

M...

NO certs no-nothing... in aerospace... that carbon-fiber pre-preg is considered 'trash'.

IF VERY interested... contact the material OEM to discuss it. It should be bagged/tagged... info available. THEY MAY have suggestions.

Regards, Wil Taylor
o Trust - But Verify!
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation, Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov