lots of thin layers VS. few thick layers?

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#1

I make carbon fiber sports equipment and it need to be able to stand up to a good deal of impact.

I’m looking at materials costs and i’m wonder if i should continue with mulitple layers of fiblerglass in my parts or switch to one or two thick layers? Does anyone know how this would affect the strenght of the parts? The thickers layers are cheaper per ounce.

any experience with something like this?

thanks!

#2

Multiple thinner layers gives you four advantages:

  1. If you are working with woven fabrics you can typically get a better Vf with lighter/thinner fabrics than you can with thicker/heavier ones. This is due to the magnitude of the crimp of the thicker fabrics.

  2. If you are working with woven fabrics the reduction of crimp on the lighter fabrics can increase strength.

  3. Lighter fabrics are typically easier to reliably saturate with resin. Thicker fabrics can “hide” and hold voids.

  4. Thinner fabrics allow you to use many varying fiber orientations which increases the impact strength. If you only use 1 layer of woven you only have fibers in 2 directions (0/90). If you move to 2 layers you can have 4 directions (0,90,+45, -45). If you move to 4 layers you can have 8 directions (0/90, +/-45, +22.5/-67.5, +67.5/-22.5).

That all being said, 1 or 2 layers may meet your strength requirements. This is were practical testing is a must.

Adam

#3

Ok, all good reasons. I think i will stick with the multiple layers.

Thanks!

#4

Great explanation :).