CF prepreg frame proces (China)

[riff42]

Im not sure if its a wax. It looks like wax. It should be other material, but it has to be removable (meltable or washable)

hmm…amazing process. never saw manufactures pictures like that before. And I LOOOOOVE that UD crossply look. Should have thought of that before I left my wonderful UD prepreg at my last job.
Hmm…maybe there is some laying around here…

Anyway, yeah, that could be a very hard machineable wax. It would make sense, I’m sure whatever molding and epoxy is used, the wax will melt at a lower temp.
However… if you melt the wax in an uncured part, then the pre-preg/epoxy will not bond to itself. So it very well might be plastic that they pull out of the rough form, and then bladder mold it in the frame mold.
Or something…

ROAD TRIP!

[CarbonMike]

However… if you melt the wax in an uncured part, then the pre-preg/epoxy will not bond to itself.

Yes, I was also thinking this way. Maybe its made all different way. Maybe they dont use that core on picture No.7. In pic. No.3 that material is definetly som kind of wax. You can see that its also transparent littlebit. But whats more amaizing, I was looking carefully to all pictures and found differences. Mould on picture No.6 match frame layup at pic. No.5 but at pic. No.7 there is differen frame! Also on picture No.8 the frame is different from those above.

And what do you mean by: ,Road trip,?

[TET]

Is that a filament winder in the background of the first or second photo?

If you’re talking about the green thing in the right of the second pic, that’s definitely not a filament winder. That shop’s a bit too low tech for that! It’s just a cutting or stamping tool.
This is a low end filament winder:

[JRL]

No.3 that material is definetly som kind of wax. You can see that its also transparent littlebit.

Pure teflon looks exactly like that. White and slightly transparent (up to a certain thickness). Obviously nothing will stick to it.

We used it as a brace in some of our B52 parts.

[CarbonMike]

Pure teflon looks exactly like that. White and slightly transparent (up to a certain thickness). Obviously nothing will stick to it.

We used it as a brace in some of our B52 parts.

So it should by also teflon. Hmm. Interesting. What is melting point of teflon?

[JRL]

So it should by also teflon. Hmm. Interesting. What is melting point of teflon?

Not sure. Definitely not cost effective to melt teflon. Its super expensive in a machined form. And most epoxys will melt long before teflon does.

For the purpose you mentioned it makes sense cost wise to use wax. An diluted acitic acid bath will take care of cleaning the part for secondary bonding.

If its a solid re-usable mandrel I would guess polyethylene. As its a release agent for epoxy, but also a hard plastic (and cheap). Or teflon.

[riff42]

So it should by also teflon. Hmm. Interesting. What is melting point of teflon?

I don’t think it melts, more than chars, but either way, above, 315c.

[riff42]

Yes, I was also thinking this way. Maybe its made all different way. Maybe they dont use that core on picture No.7. In pic. No.3 that material is definetly som kind of wax. You can see that its also transparent littlebit. But whats more amaizing, I was looking carefully to all pictures and found differences. Mould on picture No.6 match frame layup at pic. No.5 but at pic. No.7 there is differen frame! Also on picture No.8 the frame is different from those above.

And what do you mean by: ,Road trip,?

I’m sure they have several bike lines, and styles of layups. The pictures can be out of order, and very random. Who took them?

Roadtrip to the factory and get our OWN pictures!!!

[riff42]

This is a low end filament winder:

haa!! It’s more high-end then ours, THAT is for sure!!!