Laminate Sample #11: Infused Flax / Epoxy on Cork Core
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- Опубликовано: 8 сен 2024
- Laminate Sample #11 in the Explore Composites! Materials Library:
This is my first foray into "bio-composites" (materials derived from largely un-fossilized plant matter) for the material library. I guess balsa core counts, but here the core AND the fiber reinforcement are plant-based in a direct kind of way.
The core is 6mm CoreCork N10 from Amorim. This was given to me as a sample by Core Composites, the US distributor for CoreCork products. Thank you!
Core Composites:
www.corecompos...
Amorim CoreCork:
amorimcorkcomp...
The fiber is 400g Biotex flax from Composites Evolution (purchased through Easy Composites, UK).
Composites Evolution:
compositesevol...
The resin is not directly bio-derived. It's the same Proset 114LV epoxy used in many of the other samples.
The part infused slowly but completely, much to my surprise! Doing it again, I would drill holes in the cork the same as I have done with foam and balsa in other samples. Leaving the dry stack under the bag for longer would help too.
I'm not sure what happened with the Compoflex hybrid peel ply/flow media. I have used it before and it works great and usually peels right off. This was cut off an old sample roll that may have been contaminated - or maybe I did something wrong. Will look into this more in the future because it is a good product to know about.
Fibertex Compoflex:
www.fibertex.c...
See the rest of the information on this laminate sample at:
explorecomposi...
Sorry about the shaky video! I didn't have the tripod so put the camera on some stacked paint cans - bad idea!
The natural fibres can be high moisture which boils off under vacuum. Pre dry the material or hold under vacuum for extended period before infusion maybe
Good points - doesn't take much moisture under a vacuum bag to make lots of problems - and it takes a while to boil off. I didn't appreciate how much cork is wood! Probably balsa has similar issues but I never noticed it much before.
It is good demo to know about bio composite sandwich manufacturing using VARTM. Kudos to the team....
Thanks! I have a bunch of other bio-composite materials and hoping to do more samples soon.
I have used 1mm NL20 recently with quadriaxial carbon fiber facings. Infuses beautifully, great combination.
Did you perforate the core or did resin work its way through... or just fed both skins? Did you mean 1mm or 10mm? I have some 2 or 3mm that I haven't tried yet... it is neat stuff.
@@ExploreComposites I mean 1mm thick. NL 20 is quite a bit porous, so it does not require additional perforations for the resin to flow through !
@@SuperYellowsubmarin Oh ok, neat! I'll have to try the thinner stuff - my feeling was that the 10mm would need to be perf-ed to really infuse well. It seems like a good alternative at 1-3mm to Soric-type cores - probably lighter too.
@@ExploreComposites right, it if quite soft so I wouldn't go thicker than 3mm. Foam is better above that. I compared with Soric LRC and weight-wise it seems barely lighter.
Thank you ! Exactly the video and the information I needed !!!
A lot of great information in these videos best bang for your buck
Really surprised you had issues with the compoflex. It could have been an old or contaminated piece.Good job . 👍👍🤙
It was a stupid mistake - I grabbed the wrong roll! The material I used here was for wet layup and wasn't meant to be fully infused with resin. I figured it out after I made this video but before I made #25 - where I use the right Compoflex and things go fine!
I Love your Chanel ..
👍🏻😃
Air leak lower left pleat or micro fissure in the plastic
Sehr schön
Looks more that the resin is out-gassing, I.e. the bubbles originate from the feeding spiral.
You might be right though this is epoxy and there shouldn’t be much there to off-gas.
@@ExploreComposites Expoxy also out-gasses quite a bit. Of course none of the desired ingredients, but it it is also hygroscopic, particularly the hardener. Water vapor also out-gasses provided you apply a deep enough vacuum.
The Compoflex didn’t work because it was the wrong kind - not meant for infusion! See Laminate Sample 25 for the right kind working for infusion...
ruclips.net/video/nbCGNrsFfaU/видео.html
I am no expert (nor even a beginner, yet) but I'll float a theory for what those bubbles are anyway: Could be moisture evaporating under the vacuum (and added heat from resin/table). I heard somewhere that flax fibres tend to have more moisture in them than carbon/glass does, and I imagine the cork might, too. The guys at Easy Composites Ltd seem to leave their flax fibres under vacuum for a while to draw out the moisture as much as possible.
Edit: ruclips.net/video/AD98L9XlCTU/видео.html this is the video I think.
Yes, that is a good theory! I agree with you. Moisture is a problem, and also perhaps that it takes a long time for air to escape from the cork so the resin front passes it by and the air is still trapped. A longer sit under full vacuum to remove all the moisture and air before infusing would help with both issues!
@@ExploreComposites It could be a couple of things: moisture in the core/flax fabric (it is generally recommended to condition/dry/leave under vacuum biomaterials if possible before infusion), the cure could have gotten too hot (moisture boiled off mid cure), or there is some sort of binder within the materials that reacted with the resin (often an issue with resin compatibility more commonly with styrene containing resins.).
I know a snowboards builder who uses flax in his boards... He leaves the cloth in the oven for quite a long time... Two reasons : moisture and dimensions... He says that when flax dries it tends to retract (hope it is the right english word) so when the board dries the camber (shape) changes..
Can the epoxy resin added color?
You could add pigment to epoxy - not sure if it would change how it flows - probably not.
What vacuum is being hsed
I'm sorry, I just don't see the value in the process. It seems like it would be much faster and just as sound if you pre soaked all the composite and then just vacumed out the air.
Flax and most other natural fibers are like little tubes and it is very hard to get the air out. That and the moisture that gets held in the fibers makes infusion a much better option than wet layup. I've tried and the result was a mess! People do use natural fiber pre-pregs with excellent results, so maybe I'm just doing it wrong.
@@ExploreComposites what you say makes sense and I understand the thought process. Have you tried plain old cotton ? I've never seen anyone use it and don't understand why that fibre wouldn't work.
You 100% had a leak in the bag.
You may be right - but “wood” is strange with all the moisture and open/closed cell structure. Finished surface didn’t look like a leaky bag - I’m puzzled too! Need more experiments…
@@ExploreComposites It was a valiant effort. Nothing wrong with first attempts.