Peel Ply vs sandblast vs both

General Composites Discussions Engineering Talk
#1

I need some papers here, or actual data.
Which is a better bonding surface? I can either cure one layer of FB with peel ply, or I can sandblast it. If anyone has done one ply before, you know it’s a bitch to deal with. Curls up like crazy, meaning sandblasting is NOT easy.

Thanks

#2

It has been demonstrated that the peelply surface is not the best for bonding.
use of sandpaper and air blowing on degreased surfaces is what works best.

#3

Also look into your glue. You want either glue failure, or substrate failure, not adhesion failure.

Perhaps a methacrylate?

#4

I obv agree with all that has been said above but cannot find actual data - I saw some stuff from a guy at Williams F1 on exactly this and would be great if you could post anything you actually find. Remember also the type of peel-ply can have an effect, eg release coated where release agent is left on the actual part

#5

I might try to tape the edges down and sand. It’s too large for our sandblaster, and I got VERY strange results in my peel tests.
I did 2 panels, one with the peelply only skin, and the other was the sandblasted. I did the FLoating Roller peel.
Layup was S2 skin, adhesive polymer layer (prob’ can’t say WHAT), and then the base substrate.

While each sample was about the same peel strength, and the adhesive pulled from the substrate…on the peelply surface, I actually had lifting of the adhesive layer from the S2 skin in certain areas…
So the peelply surface was the weaker one, even though it failed on the substrate side.

#6

Probably the adhesion on the peel ply surface is weaker because:

  1. the adhesive is put on an already broken surface.
  2. such surface is resin based and not fiber based.
  3. peel ply leaves some amount of micro residues on the surface. If it is release agent coated, well, I let you imagine…
#7

Here is a paper I found posted by DallasB84 on secondary bonding.

http://www.compositescentral.com/showthread.php?t=6535