infusion issues - mostly relating to infusion mesh

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#1

So I’ve gotten the basic workings of infusion down, and now my only real issue involves being able to easily remove the infusion mesh from my part, which is critical because of the way the piece will eventually be cut - I can’t integrate the mesh inside the carbon plies because it’ll show up visually at various cut points.

Anyways, I tried using a perf release film (P3) but am having pretty seriously problems getting a full wet out before my resin front hits the vacuum port. In fact, I’m using MTI hose right now and what happens is the hose gets saturated and the vacuum draw stops resin intake from the intake line so resin stops permeating the perf holes leading to essentially no wet out at the far side of the intake (at the vacuum draw - there is just not enough time for the part to get wet out).

What are my solutions to this? I know that in another thread I was reading through someone mentioned Airtech P1, who’s holes are much wider (0.045" instead of P3’s 0.15), and then I also saw Airtech P which has even denser spacing. Is this pretty much my only solution? I have no idea where to order small volumes of this stuff in the US, most carriers only stock P3.

I guess maybe increasing my break zone of just econoply might help? On the part I just tested my MTI/vacuum hose was resting directly above the infusion mesh so the resin rushed to it and then saturated the vacuum draw. I’d like to find a more elegant solution than that though.

Are there any other release plys that release more easily than econoply J, so I could lay my infusion mesh on top of that without any perf film?

Thanks!

#2

I always use P1 perfs on my infusion. I have a hard time finding it in small quanities.I’ve even punched holes in my P3 perf film just to get a job done. I imagine the viscosity of your epoxy would be important in your infusion too. Mesh is a bitch without it though.

#3

You do not need to use a perforated release. You can just use a release coated nylon peel ply, this work pretty well. If you really want to use a perforated release, P31 is made for infusion, has many perforations and large holes.

#4

P31 has very little and very small holes.

This topic has come up many times.

For infusion:

MP22 (Airtech)
P
P1
P16

For wet bagging:
P3
P31

For prepreg:
P31 and others. (totally depends on prepreg)

#5

Can you post a picture of your set up?

#6

1: You can use peelply only. Mesh goes on top of that, and you peel it all off the part, then cut.
2: You can add a brake zone. Putting the MTI hose on top of the end of mesh is not going to work. Put it a few inches away from the part, and make sure your mesh is cut to slightly undersize of the part.
3: follow others for what film to use. I don’t know this information.

#7

So this was close to the answer I was hoping for. Does a nylon coated peel ply have better release properties than the run-of-the-mill retail polyester peel-plies? I’m using airtech econo-ply J.

As for the P, P1 and P16 perf style release films, anyone have a good line on where to order them in smaller quantities in the US?

Thanks!
Chetan

#8

Target for econolease. That one is release coated. However, it can still be a pig to release. Peelply is a bit of a misleading name. It really is the release film that does the job.

Another option is Compoflex, peelply, release film and mesh functions in one layer. Works great.

#9

I will agree with your suggestions for perforations are correct, however you can definitely also use P31 perforation for infusion, and is commonly used.

“P31 a high bleed infusion perforation.” http://www.amtcomposites.co.za/products/vacuum-bag-infusion-consumables/release-film

" P31 is a standard perforation style for resin infusion and gives a fast resin transfer. Nominal hole diameter is 0.6mm." http://www.ecfibreglasssupplies.co.uk/p-1878-a2200-orange-release-film.aspx

** Ill make a slight retraction. Looking at airtech specs, hole perforation size is same as P3. So not sure if local chinese and other manufacturer specs are different than airtechs, or if I was sadly mistaken by calling it P31 when in fact it was another…

#10

Sounds like a great product :eek:. Thanks for showing this to me. I sent them an email asking for a sample roll; I gave them some specifics about my process and am letting them decide what they think is best for me.

#11

Pref by the yard
http://www.aircraftspruce.com/catalog/cmpages/e2760releasesheet.php

#12

It seems that perforation standards vary among manufactureres, to make our lives miserable.

Airtech P31 are pinpricks, some 1" spacing.

http://catalogue.airtech.lu/product.php?product_id=496&lang=EN

#13

During my infusion, I usually end up with some carbon layers that don’t get wet out before my resin front reachs the vacuum line. These layers of carbon aren’t part of the finished piece and will be trimmed once the part is demolded.

My question is, because the entire part is still under vacuum and there are air voids in these dry carbon spots, will these spots draw resin from the fully and properly saturated carbon layers during the curing phase, once the pump is shut off and the resin line clamped?

Thanks
Chetan

#14

To answer my own question, yes, it appears that the resin has spread itself out through the rest of the part. Haven’t demolded yet so not sure what this means for the surface finish. I’d say 5 pct of the part was dry when I stopped feeding new resin in.