Talk Composites - The Forum for Advanced Composites

Can prepreg parts be cured again?

http://www.talkcomposites.com/Topic19970.aspx

By valerio.polenta - 12/9/2015 12:36:15 PM

Hello,

I'm building some pregreg components as part of a university project. For brevity, I will skip details, I just tell you that so far I've built some "pipes" with a kind of D-section (and a taper angle to facilitate mould extraction). The picture shows the mould, the prepreg shapes and the final part.

http://www.talkcomposites.com/Uploads/Images/f71904e5-dc01-4790-a690-d3af.png


Now, what I want to do is to attach 2 of those pipes together by placing them adjacent along the flat part and adding an outer layer of prepreg, like in this sketch:

http://www.talkcomposites.com/Uploads/Images/1bc8779f-a185-4ff3-a3f1-ed6a.jpg


My question is: can the two inner pipes go into the oven again? They already underwent a cycle of 4 hours ( 1hr @ 50'C, 1hr @ 60'C, 1hr @ 70'C, 1hr @ 120'C). I'm using Easy-Preg 240g 3K Surfacing Prepreg and Vari-Preg 400g 12K.Backing Ply. I wonder if the mechanical properties deteriorate after a second cycle like that.

Thanks,
Valerio
By fgayford - 4/17/2017 2:18:58 PM

I once had left out two layers of prepreg in an autoclaved piece. I ground the surface with 36 grit placed two layers of prepreg on it and then put it back in the autoclave for a cure. It became one with no issues.
Fred