Sorry for a second post but I have a few questions that I need fast answers to.
We have 350degree cure prepreg and our foam starts to outgas at 300dergees.
Is there any way we can use the foam we have for our female mould AND used the prepreg we have?
I am trying to find someone to trade our higher temp prepreg for a lower temp cure. Im willing to give extra material in the trade for the lower temp. stuff
a lot of prepregs can be cooked for a longer period of time at a lower temperature. I have used prepreg that should be cooked a 275 for 2 hours, but you can do 200 for 5 hours. best thing to do is either test or call the manufacturer for different cure cycles
350 is 350. The prepreg will not cure properly otherwise.
In my former classroom I would have some students use CE PUR foam, wrap single layer of CF PP, bag it in a Bondline bagging system and cook it in our oven for 1 hour and then came out great!
They couldn’t break those skateboards decks…
And the CF PP was more than 2 year old but was frozen all the time.
definatly call the manufacture of the prepreg. We have done lower temp cures on various prepregs. But remember, it will take forever. Look at costs to run the oven that long, vs. new foam/prepreg.
Please, show us the aftermath of the out gas foam…? What does it do to the part?
Would I be right in thinking it would take the heat a bit of time to reach the foam core vs much faster absorption by the carbon? What if it went in for, say, 10-15 minutes at full temp, then was removed for an hour…then back in…then back out…ad nauseum, until it reaches full strength?
This weekend I will have access to an over and will be experimenting with some cure cycles.
The foam out gassing would create exactly what you think. Air pockets between the part and the tool(foam)
The foam would also expand too far out of tolerance at that temp.
I talked to the manufacturer, Cytev Engineered Materials (coolest guys ever!). They said there was no way without sacrificing major strength.
We are now looking into different materials to machine our female molds from. $$$$ big time!
What did they say about the lower temp cure? Yeah, Cytec guys are great…even though they wouldn’t explain why the same resin in different fabric was 3 EXTRA hours of cure time!!! I don’t like bagging and cooking, and then stayin late to shut down our clave!
They that the type of prepreg we have, their BMI model. must cure at the temp with the autoclave press. Stupid aerospace crap!
We sent some smaple panels to an oven to cure at 350 to see if it works out with no pressure. We have some back up prepreg but it would be a very very close in regards to having enough material.
ah, yeah BMI might be hard to get cured at a lower temp.
good luck with your endeavors!