Hi Guys,

Quick question, I have read several times that it is difficult/impossible to infusive unidirectional carbon, especially in a thicker laminate.

I wanted to create a landing gear for a model plane, and I woul make it approx 3mm thick, using BOTH carbon spread tow (about 25mm wide) and a couple of layers of a fabric each side (either a 200gsm canvas, 2x2 twill, or satin harness weave).

Would it be possible to do this in infusion with the fabric on both sides of the "uni directional core"? Or would the resin not flow and/or permeate?

Below is a picture to show a similar finished product, one is pure uni and one is a mix (like i am planning).

I assume they are done in wetlay. Which I suppose would also be possible, but a bit heavier and less stiff.



Cheers People!

Hi,

As long as you can set up to infuse along the fibres in the unidirectional, it could probably work.

The problem with unidir is that the fibres are very tightly packed under vacuum, so there's not a lot of room for "transporting" the resin along.

Adding an outside layer of twill or other weaved CF cloth will certainly help the infusion.

You may have to experiment a bit, make the infusion very slow, using slow hardener and not too warm while infusing, along with clamping the resin line to slow down flow.

As far as I can see these are quite small parts, so it should be possible to infuse them. how much weight reduction and increase in stiffness you'll get compared to a wet layup I would not speculate on..

Not a lot I suspect...

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

A alternative with Uni-directionals is conventional vacuum bagging. Much better consistency than wet lay but the problems with resin flow are eliminated as you are wetting out the layers by hand.

Another technique that works ok is 2 part matched mouldings with the fabric wet laid into the mould then the two sides g clamped together to press out some of the excess resin.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Sorry, I didn't even consider that wet lay up might mean no vac-bagging afterwards....    Some sort of compression mould might work as well ...

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

Thanks guys, I may try both methods, maybe start out with a wet lay. (by wet lay I did mean vacuum bagging it afterwards).

So Mould - Laminate - Perforated release film - breather - vac bag?

Thanks

Yep ... that sounds like a "stack" to me ...    Looking forward to seeing or hearing about your results...   Keep us posted

"Sapere Aude"... Dare to KNOW!

The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind...

103% of all people do not understand statistics...

Do not adjust our mind, theres a fault in reality :-)

Hi people, brand new on here and got a question for those who may know. I have aproject for a new manufacturing idea based on carbon fibre , I use the term loosely What I need to know is.