Lessons in carbon fiber laying: Boeing 787

[bettonracing]

In my opinion, the cost of raw materials, as well as infrastructure (and the closed mind thinking that comes with it), are the largest driving factors for the lack of high volume composite manufacturing.

'Impregnated-fiber' composites also carry extra processes and design considerations for end manufacturers than 'fiber-reinforced-matrix' composites. (Read: You'll probably see more 'plastic' cars before You see more carbon cars in mass production).

Regards,

H. Kurt Betton

[riff_raff]

G-Rock,

OK, I won't say never. But the point of that Airbus study was that Boeing was nowhere near the composite production rates they needed to be at to meet the 787 production schedules. And Boeing is the world's foremost experts. So if they can't do it, who can?

And the point of my post was that if you can't do it for a low volume product like aircraft, just how the heck do you expect to make it work for a high-volume product like automobiles? It's not currently possible and I can't see it happening anytime in the near future.

bettonracing,

Price per pound is not an issue for composites in production cars. The price-point for materials (at least here in the US with CAFE standards) is about $30/lb. Which is within the cost/lb of most composite materials, even carbon/epoxy. The drawback is that the composite materials cannot be laid-up and cured anywhere near fast enough to meet even low production rates.

[bettonracing]

My sources indicate a significantly lower price point for materials in the automotive industry, even lower than the ~$10/lb for carbon. Have any reliable sources You're allowed to share? I'm also interested to see what standards You're using for cost.

Regards,

H. Kurt Betton

[riff_raff]

bettonracing,

Low modulus pitch-based raw material can be purchased for less than $10/lb.

http://www.zoltek.com/products/panex.php

But high modulus PAN-base fibers are still very expensive and the price tends to fluctuate with the price of natural gas.

Terry

[bettonracing]

I'm somewhat familiar with Zoltek. Ironic that earlier this year they wrote an article reiterating the cost problem with carbon for mass production: http://www.zoltek.com/industrynews/97/.
Regardless, <$10/lb is more the exception than the norm.

A couple sources supporting the $10/lb:
DoE: http://www.eere.energy.gov/commercialization/pdfs/2008_vehicle_technologies.pdf See page 20.

Quick Google:
http://www.cleanedge.com/story.php?nID=3997
http://clackhi.nclack.k12.or.us/physics/projects/materials/SMVF/materials.html
http://www.designnews.com/article/49118-Carbon_Fiber_Boosts_Blade_Performance.php

You may also come across a more common price point for carbon material in the $3 to $5 range.

Regards,

H. Kurt Betton

[kilcoo316]

Composite manufacturing is very difficult. Far more difficult than anyone is letting on.


Due to the anisotropic nature of the lamina, the laminate tends to warp during the cool down phase in the autoclave or mould. There are about 20-30 main problems, each of which can have around 10 origins.


To take a recent aircraft using composites extensively, The V-22 Osprey has a composite wing spar...

Due to the distortion that occurred in manufacturing, no 2 spars were close to identical. Which meant the ribs had to be manufactured uniquely for each one.

Composite distortion is a common problem within the industry right now, it has hit Boeing, it has hit Airbus... it is currently in the process of hitting Bombardier. None of them have a solution yet... mainly because it needs 1000+ solutions in 100 areas, not 1.

[connollyg]

If you thought an aircraft was tough

Have a look at this! http://en.wikipedia.org/wiki/Visby_class_corvette

G

[Conceptual]

I still say that the only plausible way to mass-produce carbon composites in this volume is to get the autoclave out of the mix. I know that someone shot down the UV curing resins before, but from what I have read, there are many newer resins that have comparable if not better qualities to the standard resins that are used.

And concerning windmill turbine blades...

One of the companies in China that I deal with actually manufactures wind turbines (7-10kW home units) that have a vertical shaft, so the blades are kinda different than a fan type blade. They contacted me in their search for a Chinese manufacturer that does Carbon Fibre blades, and the company that I connected them to is actually looking at a UV blocking polyurethane type coating (Rhino Lining). Since the blades are very light, and the coating that they are using is about .25mm, it should be a near indestructible unit.

I am just waiting for the comission check from the first purchase order! They want to buy 50,000 units, so my 3% is looking pretty nice!

[panchito401]

Does anyone have any experience with laser cutting CF? I have access to a pretty low powered machine (50w) with a 24x18" engraving area and was going to give it a whirl. I've been trying to teach myself CATIA and have the program give me accurate sizes for the layers to cut so I can build some sort of brackety type thing for fun and experience. But I only have access to a 3 axis CNC machine and a Laser... No diamond tipped cutters or waterjets for me.

thanks!

-f

[riff_raff]

Conceptual makes a very good point. A lot of companies working with high performance composites (including the one I work at) are switching over to "out-of-autoclave" resin systems to increase production rates.

[Carlos]

'Out-of-Autoclave' production automation of carbon fiber components ... I had memtioned a production machine on the first page of the thread ... being the Holidays I had time to research the company Quickstep of Australia which co-operated with Universities on the research behind the final production machines .. a very interesting process that will help to produce pieces quickly ... there's also a lot of talk about bioplastics as resins lately:
http://www.quickstep.com.au/what-is-qui ... step-works
http://www.quickstep.com.au/what-is-qui ... hitepapers
Australian University Co-Operation:
http://www.universitiesaustralia.edu.au ... _31_06.htm

[marcush.]

quite an old hat to me the move towards not using autoclaves anymore...
for most of the parts SCRIMP -resin infusion process works very well and of course the obvious thermoset products readily available ....theres not much sense in autoclaving most of the parts when you can get the same results without the bottleneck of the autoclave ...and the cost to run it.

[noname]

if you are looking for information about automation in composite manufacturing please look what Janicki Industries is doing for Boeing. unfortunately there is not much information available as both Boeing and Airbus are very resistant to even tell which companies are developing technologies for them.

even people designing the aircraft have limited access to information. we are provided with few-hundred-pages documents describing how to design the layups, where to place fasteners, what sizes of plies to use, etc. but there is no single word about manufacturing process. all we can get is "people in manufacturing wants us...".

benefits from using composites in aviation are starting to be visible on assembly level but most of them is expected to come from reduced maintenance costs. switching from metal to composite does not only means replacing one material with another but changes whole philosophy behind the design. composite component alone can act as structural member, acoustic and thermal insulation and be a part of heat exchange or electrical systems (and that's not all it can do). shortly - that mean less parts and better integrated structure (according to Being metallic fuselage section was being made from 1500 panels, composite section allows 80% reduction).

better integration equals stronger structure so you can use higher pressure inside (equivalent of lower altitude) and that improves comfort.

less parts equals shorter assembly time as well as smaller drag penalty due less steps and gaps. decreasing number of parts reduces number of localization to check during overhaul, also.

as far as maintenance is concerned composite have one advantage over metallic parts and its name is corrosion. again, if we can trust Boeing, because of that service time between major overhauls can be doubled and that, in case of plane like "Dreamliner", translates into more than 100 flights.

I am not sure if Boeing is actually the leader in, lets say "high scale", composite technology. they've decide to take big step with B787, maybe even to big (if you look for amount of problems they had, and still have to, overcame). personally I prefer Airbus's approach - gradually, step by step (with growing knowledge and confidence), increase of using composites in their designs.