Overcuring prepreg

[drodrig]

Hi there,

We are making some parts of carbon fiber with prepreg. We are using Sigrapreg E323.

We do a cycle at 80ºC (176ºF) 1,5 hours and then another one at 120ºC (248ºF) another 1,5h.

The timer of the oven didn't work so it cured the second cycle at 120ºC during 18 hours.

Is this a problem? Is there such a thing like "overcuring"?

thanks
regards

 

[ctopher]

When I used to work in that industry, I remember cracks/peeling occurring. Sometimes not caught until I did the testing.
It's been 7 years since I did that.

ctopher, CSWP
SolidWorks '17
ctophers home
SolidWorks Legion

 

[Compositepro]

Did you read the thread just prior to this one?

 

[SWComposites]

The oven was left unattended for 18hrs? Really?

Yes, could be a problem. You will need test data to determine the effect. Or just scrap it and start over.

 

[drodrig]

Yes, 18 nonstop hours.

More light has been shed on the case: the person setting the oven selected the timer to "on" and not "off" since we have additional heaters the oven was showing a high temperature and the timer clock ticking. The day after the oven was working normally.

We will dispose the part.

The previous post was more about higher temperature and not time.

Thanks for the answers!

Regards