Carbon and Flax Fiber Layup

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palumpia
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Joined: Sat Dec 26, 2015 10:37 am

Carbon and Flax Fiber Layup

Post by palumpia » Wed Aug 09, 2017 11:24 am

Hello everyone

in my new ski design i want to do a layup with uni CF and a biax flax fiber under and over the wood core. does anyone has some experience with this kind of layup?

Any answers gratefully received

Thanks palumpia

24Dave
Posts: 101
Joined: Mon Oct 03, 2011 2:14 pm

Post by 24Dave » Wed Aug 09, 2017 2:17 pm

never even seen flax fabric at least any intended to be a laminate layer. Black Diamond Helios seem to describe flax as part of the core like this:

https://www.skibaumarkt.de/en/product/b ... 0-x-14-cm/

dps core looks like the same material:

https://www.wildsnow.com/15521/outdoor- ... ood-stuff/

mammuth
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Location: somewhere in the alps

Post by mammuth » Wed Aug 09, 2017 2:20 pm

http://bcomp.ch/en/products/amplitex

you need high pressure to get a decent flax/epoxy laminate, otherwise it tends to become heavy afaik
Tom

pmg
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Location: Sonthofen

Post by pmg » Mon Aug 14, 2017 10:16 am

AFAIK flax has great dampening properties, and I think dampening along the length of the ski is more important than torsional dampening, hence I use thin Uni flax and normal triax/biax carbon. I love riding the results!

Hannes
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Location: NRW, Germany

Post by Hannes » Sun Aug 20, 2017 7:41 pm

I made a pair with flax biax and uni glass. It was a very smooth ride but heavy as mammoth wrote. The pressure of a vacuumsetup ist not high enough to get a good fibre-resin ratio.
Next pair will get glass triax and a thin layer Uni flax. I will take a closer look at the amount of resin I use.

mammuth
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Location: somewhere in the alps

Post by mammuth » Mon Aug 21, 2017 2:37 pm

5bar pressure says bcomp afair
Tom

SleepingAwake
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Post by SleepingAwake » Sat Aug 26, 2017 11:56 pm

The fiber volume content you get with a flax fabric depends hugely on the fabrics architecture. With the stitched biax or the uni fabric from bcomp the fiber volume ratio is quite good. It seems tho that you need a lot of resin as well, as the density of flax is so low. So a fabric with 350gsm is just thicker than 350gsm of glass and will use therefore more resin to impregnate. But on the other hand it is stiffer than 350gsm of glass as well.

You will get the most damping effect when the fibers are in off axis. Furthermore has flax the biggest advantage if used in a design for stiffness. Therefore I like to combine biax flax at +-45° for torsion with UD carbon or glass. Over the years I made multiple ski like this and love the results.

Here a video of my last build: https://youtu.be/o11Q4Iv7LuI

Cheers, Reto

skidesmond
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Post by skidesmond » Thu Aug 31, 2017 5:29 pm

I use flax with Uni CF exclusively now. I ordered my flax from Bcomp. I just made a pair of skis and I used Entropy Resin that has about a 2:1 ratio. I used 28oz of epoxy with the appropriate amount of hardener. The ski is 174cm with 72mm at the mid point.

The trick to spreading the resin on the flax is to pour resin on a third to half the ski and spread it out. Otherwise the resin will soak straight down into the flax before you get a chance to spread it out evenly. Also you need to be rather quick about it.

I pressed this last pair at 45psi. I get good penetration of resin throughout the layup.

I'll post the specs, weight and pics of the skis when they are done in a few days.

Dodwood
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Joined: Fri Apr 26, 2019 11:47 pm

Re: Carbon and Flax Fiber Layup

Post by Dodwood » Sat Apr 27, 2019 6:10 am

Hi, I'm planning to use Bcomp flax on my next pair. What sort of weight of biax flax and uni cf have you used?

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