Synthetic Fabric as Alternative to Plastic Body Panels for Cars

"we are at the same time considering a flexible synthetic fabric..."

I just got to ask, is it stain resistant and what wash cycle must I use?

Actually, fabric was used for early aircraft quite successfully and continues to be used in some circles.

However, carbon fiber rules these days. Extremely light and extremely strong. It is reasonably easy to work with, too.

Here is a LINK to a sailplane made from carbon fiber. It has a 36 foot wingspan and weighs 155 pounds!

I didn't mention it in my first post but the solution has to be cheap, not structural(it is just a cover)

Carbon fiber is great but definitely not cheap.

I want to focus on the fabric option and understand if it makes sense to consider it.

I think it could. It doesn't require molds.

You start from rolls, then cut the fabric as you need it and then depending on the kind of material you can glue or weld it.

It's light, and offers basicly all the things a normal polypropylene compound body panel offers.

Just, it's flexible(which means it has to be tensioned if you want to give the car a particular shape).

Also we're wondering how it could be attached to the frame, something quick and cheap.

It all has to be seen from the point of view of cost savings and time production reduction.

Honesty, I think you have bigger mountains to climb if you are talking about production

I don't know where you intend to market such a vehicle,but you will undoubtably have some sort of safety standards to meet and building what amounts to a kite with wheels isn't going to provide much in the way of crash protection.

Additionally, whatever you dope the fabric with will most likely be far more expensive than the fabric when you start considering it must be UV resistant and robust to flex, shear, and temperature extremes.

Perhaps you should enlist a materials engineer and a structural engineer. Then you will probably need someone who can wade through all the codes and legal hurdles/requirements.

Then again, if this is just some college project, you probably can get away with seran wrap and some imagination. ;-)

Listen to the suggestion about AIRCRAFT if you need covering only. A company called "Aircraft Spruce," at www.aircraftspruce.com can provide all the materials and advice you might need.

You could also contact the Experimental aircraft association for their library of books.

Google ,"Fabric aircraft Construction."

Excellent! I was going to leave that link, but you did a good job with that and some other useful information.

the problem becomes that the tubular frame must withstand and contain/redirect all of the crash energy AND the resulting motor/gearbox displacement into the passenger area. Certainly you won't be able to sell a car that can't survive at least a minimal crash level standard. Certainly no country on the planet would allow you to sell a vehicle that could not meet a minimal safety level. A cloth cover will be nothing more than cosmetic. Carbon fiber however can take the PLACE of the tubular frame, and provide it's own structural integrity.

but if carbon fiber is out of the question, consider blow molded/rotomolded UHMWPE, again, you may not need much in the way of a structural frame since the plastic is a structure in of itself. in fact you could probably rotomold almost the entire car structure from UHMW. They certainly rotomold entire boats from the stuff. look at golf carts as an example of what can be achieved. metal attachment with bolts or pop rivets is easily done.

Look at how GM's Saturn division built their vehicles outer shells. they built a sheet metal tub/unibody frame and used snap-rivets to attach compression molded urethane body panels to the frame. the panels achieved a class A painted finish but would pop right out if the ding was relatively minor. Saturn did a lot of stupid things but this one was a keeper if you ask me. it allowed the base frame to remain the same but radical outward appearance changes from model year to model year without a lot of reengineering the hard stuff and redoing crash testing.

All of the engine and structural aluminum castings were made using the lost foam process which allowed short runs with little changeover cost. for cost savings they did a lot of things right, but they did a lot of other things (primarily electrical) wrong.

What we have is a situation similar to that of the first Smart car(which hasn't been sold in the US). It had a hugely resistant frame which in case of crash, didn't absorb much energy being very stiff, with bad consequences for the passengers.

With the second Smart they made it a bit longer to place some "crash absorbers".

The new Smart car has polypropylene compound body panels and this is what's under

I believe safety issues could be solved placing some sort of "crash box" under.

In case how'd you see a solution with conventional plastic body panels for the bumpers and fabric for all the rest?

This is where this idea is coming from, I'd like to see if it's possible to make better looking and more car-looking like.

It might sound weird but this "thing" is road legal in EU.

Anyway, thanks for all your replies and excuse me if i might have a weird way to write but English is not my first language.

AR

Are you looking the fabric options as a temporary measure for your test vehicle or a production option? If it is production I would have to agree with the post about not being able to get the car certified for sale anywhere due to the weakness of the structure. Unless you strengthen the underlying structure at which point you buy back the weight and cost savings you gained from the fabric.