Fiberglass and carbon arrangement

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motoman
Posts: 243
Joined: Thu Jan 15, 2015 5:52 am
Location: Ukraine

Fiberglass and carbon arrangement

Post by motoman » Thu Jun 23, 2016 1:41 pm

Hello everybody summertime,
in addition to the repair of the premises this really hot summer we are going to experiment with carbon.
I have found a few topics about carbon and found them really useful. But still got some questions. Stop me if I've touched the previously mentioned topic.

Let me start from very beginning.
Previously we have used 600 gram triaxial fiberglass (21 oz). And in the result we have got really stiff snowboards without any additional reinforcement. Even the coach of slalom snowboard team said that snowboards were almost good for them)). They use really stiff stuff.
The situation might be different if we use 19 oz fiberglass but problem is that we can't find it on the market and only 17 oz is available but still we have to test it.

So, what we are going to do. We decided to experiment with biaxial fiberglass with carbon reinforcement. There going to be two incomes: lower weight and stiffness.

The first question is about 0, 90 degree fiberglass.
One supplier told me that some companies order this type of fiberglass for snowboard manufacturing.
I have read that 0, 90 degree fiberglass is useless in ski or snowboard construction since 90 degree makes no sense as no efforts acts in this direction. But I think that it helps to keep 0 degree fibers into place during torsion. But still it is not enough to withstand torsional moments so there have to added carbon
Have anybody ideas on this point of view?

The second question is about +45 - 45 biaxial fiberglass.

Actually we have already did snowboard with such material. It was our first experiment)) Thank the universe it was successful and we still keep on going.
There were two minuses. This snowboard combined incongruous characteristics. It was too soft and to heavy. Biaxial fiberglass was to heavy. I don't remember but I guess 300 gram/m2 or more in each direction.

Now we ordered samples with less weight and are going to strengthen it with 200 gram/m2 carbon fiber.

Here is the picture of possible arrangement of first and second variant.
Image
I have more arrangement ideas, but lest start with simplest variants.

PS. A lot of commercial companies are show off that they use biaxials in their snowboards. For instance Capita and DC.

Please do not hesitate to share your experience))

Gilo
Posts: 62
Joined: Sun Feb 03, 2013 7:36 am
Location: Somerset - the flatlands

Post by Gilo » Thu Jun 23, 2016 4:10 pm

hello motoman

I use 45/45 biax and then carbon fibre and am pleased with the results.

on my 180 skis I use an ash/poplar core 2-12-2.

15.5oz biax fibre glass and then 3.50z uni directional carbon fibre. The skis are stiff enough, light and poppy, but heavy enough no to be too easily deflected.

If you go to www.easycomposites.co.uk you will see the materials I use.

hope this helps

Gilo

motoman
Posts: 243
Joined: Thu Jan 15, 2015 5:52 am
Location: Ukraine

Post by motoman » Thu Jun 23, 2016 11:44 pm

Gilo,
we are experimenting with selcom products.
We are going to experiment with 14 oz fiberglass reinforcing it with 7 oz carbon fiber.
Also we will use paulownia birch core for tests.
I read that in order to achieve the desired result (I mean desired rocker of camber or whatever) the fibers have to be the same on the bottom and on the top. Especially when you don't use heat.

Do you calculate the stiffness before you make your skies?
For instance before I used excel file to calculate stiffness.

Best regards

Artur

Gilo
Posts: 62
Joined: Sun Feb 03, 2013 7:36 am
Location: Somerset - the flatlands

Post by Gilo » Fri Jun 24, 2016 1:51 am

hello Motoman

That sounds to me as if it would be pretty stiff - that's heavy carbon fibre.

I didn't use excel to calculate things but made what I see as my standard core 2-12-2 which is ash, poplar ash stringer, poplar, ash and then played around with fibre weights until I had something I liked and worked for me.

I want to arrive at a point where I have a couple or 3 standard cores dependent upon ski type and then play with the stiffness by varying the carbon fibre content and layout. I will stick with the biax fibre glass as a standard also to further cut down on the variables.

Good luck

Gilo

Gilo
Posts: 62
Joined: Sun Feb 03, 2013 7:36 am
Location: Somerset - the flatlands

Post by Gilo » Fri Jun 24, 2016 1:54 am

Also - yes, a symmetrical lay up is best, but I have done asymmetrical also (extra carbon on the top) and have had no issues with camber/rocker loss.

I cure at ambient temperatures and use slow resin, When I de-mould I then let things settle for a week before I start finishing the ski.

I haven't experienced any changes in the rocker/camber profile when in use either - not that I have noticed anyway.

Gilo

motoman
Posts: 243
Joined: Thu Jan 15, 2015 5:52 am
Location: Ukraine

Post by motoman » Fri Jun 24, 2016 11:05 am

We cure under the temperature.
I would like more or less calculate stiffness before layup.
Also arrangement plays big role (length and width of carbon strips)

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