Carbon fibre contstruction in non-structural body panels?

[PlatinumZealot]

I am slightly interested in how "non-stressed" body parts made of CFRP are constructed. Things like the type of fabric, resin and the number of layers, how its cured etc.

[flynfrog]

This could be anything... The fabric you posted appears to be a 12k 2x2 twill weave. Id guess a prepreg vac bag cure. Either a uv inhibited resin or sprayed with a uv blocking clear coat to keep it from yellowing.

I have also done some wet lay and brushed on additional resin to get a better surface finish.

[bettonracing]

Keep in mind that body panels are stressed with aero loads (think: middle of the bonnet flopping around on the front straight) and their own weight (think sagging roof).

Are You interested in cosmetic parts only (e.g. dashboard w/ stickers) or body panels with cosmetic finishes?

Regards,

H. Kurt Betton

[Tim.Wright]

I believe infused parts are pretty common also in prodcution parts because there is less labour required for the layup and you get a good surface finish due to the higher resin content than pre-preg. The surface finish can be good on both sides of the part if you use a closed mould too.

A lot of companies are researching this route because it lends itself to automation a lot easier. This is due to the dry fibres being much easier to handle than the tacky pre-pregs which require a lot of finessing during layup.

Tim

[PlatinumZealot]

Keep in mind that body panels are stressed with aero loads (think: middle of the bonnet flopping around on the front straight) and their own weight (think sagging roof).

Are You interested in cosmetic parts only (e.g. dashboard w/ stickers) or body panels with cosmetic finishes?

Regards,

H. Kurt Betton

Bumpers, bonnet, front splitter, side skirts. Things that are not as critical to the structure of the car. You take them off and the stiffness of the chassis is not affected. Parts like those.

Just the ins and outs.. I actually have a fibre-glass DVD and there is a carbon fibre part at the end, but it didn't fully explain the technicalities of making carbon fibre parts. That part was of some guy making one of those aerodynamic pedal cars.

[riff_raff]

n smikle,

Automotive body panels (like fenders and hoods) are usually more concerned with cosmetics than strength. And their outer mold lines tend to incorporate lots of compound surface curvatures. It's easier to use weaves rather than uni's for these layups where ultimate strength is not paramount.

Automotive parts also require high production rates. So, as Tim.Wright notes, out of autoclave and resin infusion processes are a must. Dry cloth lay-ups with resin transfer molding (RTM) or vacuum assist resin transfer molding (VARTM) is commonly used.

Here's some recent news on the subject:
http://www.compositesworld.com/news/tor ... rts%282%29

riff_raff

[marcush.]

For starters:

http://view.communigator.co.uk/?vcabid= ... 26/01/2011


ACG has invented (?) a system called Zpreg wich uses preimpregnated cf layups that can be warm preformed to easy layup and then cured to their finished state.As I understand a lot of the small scale manufacturers use this system .It is capable of achieveing class A body surface quality.