Bending and reshaping carbon fiber

General Composites Discussions Composites Talk
#1

Hello. New here. Anyone have experience in bending or reshaping carbon fiber that’s already cured, I know if you heat it you can bend it. But do you have to recurr it, will it lose its strength? How’s it done

#2

The whole concept of making a part from composites is you mold it into the final shape while you make it in the first place , that’s how its done.

#3

The only way you can change the shape of a composite after the resins have cured is to exceed the TG temperature of the resin system. This will soften the resin to some degree and allow you to reshape it. Now whether it will have usable properties after you do this is another question. But I have had some room temperature resins that I have successfully warmed to where they are somewhat pliable and slightly changed their shapes. You aren’t going to move them much.

#4

There is a company in the UK called Cecence who do (or did) remoldable carbon fiber. It wasn’t cheap when I enquired, but can’t remember the exact price.

Here is a video link to it in action - https://www.youtube.com/watch?v=g39mLeexpyo

#5

Just yesterday I made one of my usual mudguards for bicycle, and one of them has been just a bit bended by the heating, because I put the whole bag into a sort of oven during the process of vacuum, and the piece and the mould have been just a bit smashed. So, reading this post, I’m thinking to give a layer of resin, heating it with the gun, and trying to put the mudguard under a weight. Do you think could be enough to bring the mudguard to the original shape?

#6

I wouldn’t add any more resin.

#7

So, do you think I could bring the mudguard to its original shape only heating it? Not also adding resin?

#8

It’s certainly possible if it was room temperature epoxy and you can gently get it warm enough without going too far.

#9

you are looking at thermoplastic composites if you wish to heat and reform the laminate, most of the thermoplastics such as PEI and PPS mould at temps of 320-340 degrees and PEEK is even higher.

#10

We’ve used a thermoplastic infusion resin on some parts in the past. Neat stuff, after its fully cured which was quite short you could heat it back up and re-shape it sort of speak. Its useful if you have a part that has a lot of secondary bonding like clips.

#11

Thank you for ypur advice, I will try