Is there a need for peel ply fabrics when infusing?

[system]

If this part has 20-30 layers of carbon, then its sure going to be expensive and heavy!

Exactly what i’m thinking. 20-30 layers of carbon will be thicker than the steel you will be replacing. In my tests, 6 layers of ~5.7oz cloth infused nets approximately 1mm thickness. 30 plies can be 5mm thick! Thats nearly 1/4". The shape of the structure, type of reinforcement, and fabric orentation will determine the amount of layers you need. I would venture to guess no more than 10 would be required. Possibly no more than 6. Here is a photo for thickness comparison. This is a 6 ply sample plate ((2) 3 ply pieces bonded together) next to a nickel.

[20_rc51_00]

Thanks for you questions and replys.

I am planning on (once I feel profecient enough) making a Carbon subframe for my bike to replace the larger , much heavier aluminum subframe. I got my inspiration and idea from this guy, he makes all his oun stuff very nice! http://www.honda-rc51.de/ he also made a subframe and used 25 plys, therefore I am guessing on 20-30 plys for my application, since he has had positive results with his. The difference between mine will be that it will still allow for mostly stock setup. but still benefit from the weight savings, even if the projected CF subframe is at a weight of lLb as a rough and generous estimation.

I plan on using twill weave. Right now I am considering using 3k ~6 oz fabric, but I am looking into the benefits of going with heavier cloth for faster buildup and strength, while maintaining a reasonable level of formability and ease of handling. I have also considered using Carbon and Kevlar in an alternating fashion, also I plan to pile that fabrics at 45 degrees to one-another.

Any insight into the use of heavier fabrics with regard to strength and workability would be appreciated aswell as cloth orientation.

Also, could you please elaborate more about the interlaminar flow materials? how do they work, do they take away from the structural integrity of the part or add to it?

Bear in mind that the subframe would need to be rigid and strong enough to support my ass, road bumps and all:D .
Thanks.

[system]

Edit: I see, after looking at the authors website, it states that the mounting areas and center of stress compose of 25 plies of carbon. Not the entire subframe.

I can’t imagine a subframe needing that many plies of material. This item, for example, is made using 45 plies of carbon. It measures 8mm thick. It follows that 30 plies will be 5-6mm in thickness. That has got to be overkill for a subframe. Unless, of course, by “subframe”, you mean flat plate.

(from http://compositeforum.werksberg.com/showthread.php?t=1207)

Regarding interlaminar flow media, it is used inbetween plies to aid in wetout whereas regular flow media is used on the surface. Enkafusion is one brand along with a core material called Divinymat. Speaking of core material, have you looked into sandwich construction?

Is the pictured item what you are looking to build? Based on that angle, that looks no where near 25 plies.

Also, look into unidirectional fabrics.

[20_rc51_00]

What benefit do unidirectionaly fabrics have?

I will check out the Enkafusion for sure. Does is also add structural stability or take a bit away? How many layers do you put it between (or is it just one of those things that requires experimenting)?

I am not familiar with sandwich construction but from the sound of it, it must be tasty!, no but seriously, is that where you put a structural material in as a core( such as honeycomb aluminum or something)?

your part there looks pretty think! did you use some sort of inerlaminar flow material? In your original thread you said you shaped the part with 2 molds?.

[system]

I wonder what point there is in making something that is likely to cost a great deal of money, and which will probably be heavier than the part it replaces?

Also with a part like a subframe, failure could have very serious consequences, so surely it might be better to start with something far simpler, to get the feel of the materials, and the processes used?

[20_rc51_00]

I wonder what point there is in making something that is likely to cost a great deal of money, and which will probably be heavier than the part it replaces?

Also with a part like a subframe, failure could have very serious consequences, so surely it might be better to start with something far simpler, to get the feel of the materials, and the processes used?

There is no way that it would be heavier, please read the previous posts so you get an idea about what my intentions are before giving anecdotal information. Not trying to be rude but…

[system]

What benefit do unidirectionaly fabrics have?

I will check out the Enkafusion for sure. Does is also add structural stability or take a bit away? How many layers do you put it between (or is it just one of those things that requires experimenting)?

I am not familiar with sandwich construction but from the sound of it, it must be tasty!, no but seriously, is that where you put a structural material in as a core( such as honeycomb aluminum or something)?

your part there looks pretty think! did you use some sort of inerlaminar flow material? In your original thread you said you shaped the part with 2 molds?.

Unidirectional fabrics allow you to increase strength along a single axis.

I don’t have any direct experience with the interlaminar flow media. I think Kyankton uses it if he is still around. The usage will depend heavily on the type of reinforcement and the resin matrix used.

Correct on sandwich core.

The part pictured isn’t mine. I was just using as reference to the type of thickness you would be seeing using 30 plies.