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+45 / -45 degree bi-directional fabrics


kepEZ

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Most of the time plans call that bid fabrics be cut in 45 degree fashion for lay-up as I see it. Since my supplier can supply +45 / - 45 degree multiaxial fabrics for a very small premium over 0/90 degree fiber orientation, does it make more sense to buy this instead?

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Most of the time plans call that bid fabrics be cut in 45 degree fashion for lay-up as I see it. Since my supplier can supply +45 / - 45 degree multiaxial fabrics for a very small premium over 0/90 degree fiber orientation, does it make more sense to buy this instead?

What he may be selling is the biaxial fabric which is basically two unidirectional fabrics (without the cross hairs) laid on top of each other and stitched together (lightly) Ounce for ounce this fabric is actually stronger (I believe about 20%) than the standard knitted fabric since all of the strands are straight and don't have to weave in between other stands. If the weight is the same and if the quality of the binder is good ( a big quesiton-- the binder is that chemical which binds the epoxy, or other resin, to the glass, as without it, there is no binding).

 

The fuselage parts of the aerocanard kit are made of this material.

 

ACS and wicks sell what they call bidirectional woven (as opposed to knitted).

 

However if you take a 90degree biderectional and cut it on a 45 degree angle, you have 45 degree fabric. It may be a little easier to handle. the waste that you will have at the beginning and end of the roll will be used for many future layups.

 

The main thing is to get fabric from a reliable manufacturer. Don't cheap out here as using bad glass is tantamount to building a metal plane out of corroded aluminum.

 

Be advised that if glass fabric is moistened with water, the binder becomes compromised, for our uses.

I Canardly contain myself!

Rich :D

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Well I asked them over and over again, whether the material is suitable for use with epoxy and they assured me it is. I didnt tell them I intend to use it in aviation since they would back right off citing liability. They also told me they export it to a finnish wind turbine manufacturer on a regular basis, they manufacture special "tension controlled" fabrics for them. The only problem is their lightest fabric is %30 heavier than what the plans call for.

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Well I asked them over and over again, whether the material is suitable for use with epoxy and they assured me it is...

Until I know there are many types of treatment to the roving yarn, depending on the fiber(glass, carbon, aramide, boron, etc), before the industry make the fabric or cloth.

The glass fiber is treated with Silane to proper bond of the matrix to the fiberglass.

Then we can build our fighters.:D

Alexandre Souto

Cozy Mark IV

Ch 09, Go Retracts!

Brazil

http://www.maddyhome.com/canardpages/pages/voolivrebrasilia/exindex.html

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.........depending on the fiber(glass, carbon, aramide, boron, etc), .........

I saw a guy out at the airport last summer doing a layup with his son. I can recognize Kevlar, Carbon Fiber and Fiberglas pretty easily at a distance but the stuff he was working with was different.

 

I shouted over at him "Hey ...... is that Boron you're working with there?"

 

The guy looked at his son and then back at me a said "He ain't none too bright, but he's the only boy I've got."

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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