Lessons in carbon fiber laying: Boeing 787

[Conceptual]

I had a meeting with my community rehabilitation foundation, and their main focus currently is getting the closed factories in my area up and running again. The major ones are a Weaving factory and a Knitting factory, both still have all machines still in them, and apparently they have been given over to the borough.

Anyways, what is so hard about making Carbon Fibre cloth? From the project airplane catalog that I have from 1997, it shows the weaves available from Rutan, and none of it seems very complex.

So, the question here is: Can conventional weaving machines be used to weave CF cloth, and is it the cloth or the thread that is in shortage?

ALSO:

After reading alot about how CF molds are done, and the autoclave process for curing, I was struck by the thought of "Why aren't the UV curing resins used?" For $5000, you can build a 3 axis cnc machine that will handle blocks of polycarbonate at 4'x4'x8'. Since the mold would be carved out of clear plastic, is it reasonable to assume that molds like that could be used with UV curing resins to reduce cure time from hours to seconds?

Thanks, I know it is alot of rambling, but it is a very exciting proposition to my local community!

[Carlos]

Sort of OT but I have a few spare minutes in front of the monitor.

Been a C-Fiber shortage since '05 - See:
http://www.shopmaninc.com/carbonpage.html
Not just the cloth. The fiber is in short supply. I posted a few weeks ago about this and the Japanese ramping up R&D to produce C-Fiber in much larger quantities at much lower prices. The basic market domination thingie they do so well, if I may generalize a bit. What I really admire is how Japanese industry gauges how long they dominate an industry then move on. Perfect example was steel production. They were already planning leaving stell in anticipation of India dominating steel production. The migratory nature of industry is the prime reason you have all those mills and equipment gathering dust. That's OOT I think. The site reference.It's back there among my posts somewhere.

UV epoxy resin is out there:
http://news.thomasnet.com/fullstory/457731

I suspect carbon fiber is 'too' abrasive to be woven with machines meant for conventional polymer or natural fabric.

I would recommend exploring another fiber, rami, that has a wealth of extraordinary properties, as a cloth, it's market has not been exploited in N America. I've been thinking about it for about 10 years and never had an outlet for the suggestion till you asked. Resembles linen, extremely strong and durable fabric compared to other natural fibers, breathes very well. Has a real future as a luxury fabric in couture. Ask your community foundation to send me a letter of commendation. I don't know why, but I'm susceptible to that kind of recognition and like to frame and hang stuff like that.

http://www.swicofil.com/products/007ramie.html

[WhiteBlue]

It is the fiber and not the fabric which is sometimes short in supply. Carbon fiber textiles have been used for a very long time. It could be that the design calls for a unidirectional orientation of each layer. In that case the machines would use rovings of fibers and no woven fabric tapes. Heating resins has additional functions to crosslinking. You need to keep the resin fairly viscous during the lay up. Later you want it to penetrate and make a solid matrix aroun d the fiber without porosities. The heat will help you to achieve that by making the resin flow easier.

[flynfrog]

I had a meeting with my community rehabilitation foundation, and their main focus currently is getting the closed factories in my area up and running again. The major ones are a Weaving factory and a Knitting factory, both still have all machines still in them, and apparently they have been given over to the borough.

Anyways, what is so hard about making Carbon Fibre cloth? From the project airplane catalog that I have from 1997, it shows the weaves available from Rutan, and none of it seems very complex.

So, the question here is: Can conventional weaving machines be used to weave CF cloth, and is it the cloth or the thread that is in shortage?

ALSO:

After reading alot about how CF molds are done, and the autoclave process for curing, I was struck by the thought of "Why aren't the UV curing resins used?" For $5000, you can build a 3 axis cnc machine that will handle blocks of polycarbonate at 4'x4'x8'. Since the mold would be carved out of clear plastic, is it reasonable to assume that molds like that could be used with UV curing resins to reduce cure time from hours to seconds?

Thanks, I know it is alot of rambling, but it is a very exciting proposition to my local community!

the UV resins are fine for surf boards but pre preg epoxy cure resins are decades ahead of uv resins as far as toughness and durability plus you would have to layup the plane in the dark

you could build a 3 axis for 5000 but it would be plus minus large fractions of inches when you need a machine that will do a few thou

[xpensive]

flynfrog wrote:

water jetting is far from the preferred method. Water jetting can result in alot of edge delamination and full on blow outs. most places still use carbide and diamond cutters. Water jetting on composites needs a backer usually water but something as large as a 787 would need a insanely huge water tank

I belive that I said that onventional machining was difficult, but diamond-coated tools works.
There are many references of water jet cutting of carbon-fibre laminates, often with an abrasive additive. I believe that you can see the result in any RC-model shop.

There are also laser-cutting references. The comment on the water-tank size I do not understand.

[WhiteBlue]

He said that you have to have water behind the component that you were cutting with water to avoid edge delamination. How would you do that but by a big tank?

[xpensive]

Thank's for explaining WB. Hmmm...good question that one, I'll ask around.

[flynfrog]

the problem with laser is you get glass transition temps on your cuts that can lead to brittle fractures

there are also problems with normal cutting too you can have all of these same problems but they are some what easier to control

[WhiteBlue]

THX for the great input here flynfrog!! It is quite entertaining to discuss composite manufacturing technique with you. most of the stuff I would never have figured out by myself without a lot of studying.

I recently visited a helicopter factory in Bavaria. The rotor blade factory is stunning. Something I would also like to see is the rotor blades of 5 MW wind turbines.

[flynfrog]

THX for the great input here flynfrog!! It is quite entertaining to discuss composite manufacturing technique with you. most of the stuff I would never have figured out by myself without a lot of studying.

I recently visited a helicopter factory in Bavaria. The rotor blade factory is stunning. Something I would also like to see is the rotor blades of 5 MW wind turbines.

I am by no means an expert Ive only worked in the field for a few years but ive made quite a few screw ups in that time .

they have just started to make turbine blades about 40 minutes from where I used to live.

http://www.tpicomposites.com/

[WhiteBlue]

The news item on the factory opening is great. I did not know that wind energy is growin g at an exponential rate in the US. They managed the growth of one decade in the last 2 years =D> =D> =D>

[xpensive]

However exciting the rotor blades of a large windmill might be, wind-energy is and will forever be a deadend energy-wise, just a public hoax sponsored by ignorant politicians and journalists.

Compared to a reasonably sized nuclear reactor, say 1200 MW come rain or shine, it would take some 800 so called "5 MW" wind mills to replace just one of those.
If you have wind, that is.

Ooops, lost the thread there, sorry guys...

[WhiteBlue]

sorry for the dig. but have you checked lately where all those green backs are being invested? the money decides the future. right now tons of money is invested and made in wind and not in nuclear.

[xpensive]

You are talking about Germany now, correct? Besides, without the gargantuan subsidies from the tax-payers, nobody would give a s*** about that nonsense.

Without the politics, you would see investments in nuclear en masse.

[WhiteBlue]

Believe me wind has a long way to go to absorb a fraction of the tax payers money that has gone into nuclear and is already comitted to go into nuclear energy. We happen to have a strong position in wind and I'm proud of that, but others are catching up fast. Read the source flynfrog mentioned and look at the CAGR or check the UK planning act on wind which is stunning. Besides wind is creating real jobs that will be around forever as these units will continue to generate a lot of service and replacement business over the decades. Btw, one of those 5MW turbines can easily power the Singapore night race. They are no toys any more.