Laminate Sample #2: Prepreg Carbon / Epoxy on 15mm Nomex Honeycomb Core
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- Опубликовано: 6 янв 2020
- Laminate Sample #2 in the Explore Composites! Material Library:
15 mm Nomex honeycomb cored panel with epoxy prepreg carbon skins. All the basic processing steps for building cored prepreg parts. Target weight based on the laminate schedule is 245g - this one came out at 248g! Pre-preg is nice that way - you get a very reliable resin content.
Resin is Gurit SE84LV.
This panel was cured in one-cook. Twill weave 200g surface plies combined with a single ply of 300g unidirectional to make .5mm skins. 150g glue film is co-applied with the unidirectional after being debulked together. Overall thickness is 16mm.
For more on laminating with pre-pregs, check out this article:
explorecomposites.com/article...
See the rest of the information on this laminate sample at:
explorecomposites.com/materia... 
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how much more interesting this would be if u realized most ppl are looking for greater detail of the process. That includes what exactly each sheet is and what it does. The properties and uses of the final product etc would be great too. I suspect many viewers are familiar with the carbon fiber part and had to look up the nomex.
So glad to hear you think more information would be helpful. I agree - there are so many details and things that need lots of explaining. This is a big part of the future of the EC! project - I just have to get it done! There is a long-form article on pre-preg basics on the EC! web site but videos are on my list - good ones are a lot of work though!
Have you done any bending tests on this laminate sample? I would love to see how strong it is. I'm doing a similar layout, but I'm having problems with the adhesive, it's not curing well using only vacuum and the nomex separates prematurely from the carbon fiber while doing bending tests.
I haven't done anything on this sample but have done them before with nomex coreed panels - both bending and PATTI-type adhesion tests. Are you able to see a difference between the top and bottom skin adhesion? What kind of weight glue-film are you using to bond the core? There are lots of variables! Shoot me an email with pictures and maybe I can help: chris at explorecomposites dot com
Hi! Are you using any specific type of wood for the frame around the honeycomb? Which one would you recommend?
Wood isn't ideal because it has moisture in it which boils off in the cook - so dry wood is the best. Plywood strips are good - here I just grabbed whatever was around.
This is only an issue on flat panels with free honeycomb edges - because the bag crushes it back. Usually edges would be ramped, replaced with strips of stable foam core, or butted into a corner, making the problem go away.
hi, thank you for the video. But I am trying to use honeycomb with PTFE coated fabrics? In this case which method I shall prefer? Please advise an adhesive that bonds the honeycomb with PTFE coated fabrics. Please advise. Thanks in advance
Are you trying to bond to the PTFE? I don’t know if that will work... what are you building?
@@ExploreComposites I am trying to build a sandwich panel with Nomex honey comb ads core and PTFE coated fabrics as skin
Are multiple cooks possible ? Like consolidating the skins first and then adding the film with honeycomb... Especially in the context of complex shapes.
Yes, that would be the typical way to make anything complicated or requiring better outer-skin compaction. One challenge can be keeping very light skins in the mold while you fit core /cook and outer skin. Often parts are kept vacuumed into the tooling with a perimeter seal feature after the first skin is cooked to prevent pre-release.
@@ExploreComposites Random question, what kind of core do you think they use in MotoGP to make carbon fibre swing arms ? I want to try to make own, off the shelf aluminium ones are expensive.
Thanks for the response.
@@SONO4B11T I have no idea, but for high end competition parts like that I would guess any core is probably Rohacell or similar, but that parts like that may be mostly solid except in the open web areas where there is flat-ish panel. Core can be a liability of parts like that with lots of varying stresses and torsional loads. I am sure that carbon is going to be more expensive than aluminum when tooling and engineering is considered. And the connection details where metal hardware interfaces with composite are a concern...
Is using peel ply on prepreg standard practice?
Yes. It is generally a good idea if you are going to secondary bond or finish the surface. Down side can be that dry peel ply pulls resin out of the laminate - a problem with thin parts. You can buy pre-preg peel ply though and this is the best option - but it's expensive.
@@ExploreComposites What would happen if you were to use wet lay peel ply on prepreg?
@@drewvigne You can use the same dry peel ply as you'd use with wet layup, but it will steal some resin (30-50g/square meter or so) from the laminate. Put it on dry. All the prepreg sample videos I have use dry peel ply... got to get some prepreg some time to show the difference.
@@ExploreComposites thanks for the info!