Nylon vs. polyester peel ply

[benglish300]

That was my reaction too after i pulled a 4x4 section up with 2 fingers effortlessly. Very similar. I still set my resin break and gel times the same when I made the switch from Green Mesh to compoflex. Comp One typically has it. Contact fibertex directly and ask for a sample, they gave me a 10 foot roll of every product they had available in the states at the time.

[groper]

it probably costs more than all 3 consumables put together too... none the less, good find...

[benglish300]

its slightly more expensive than the green mesh and econostich together per yard, but not by much. When you add the time saved though stripping consumables off parts, its a no brainer.

[rwatson]

Originally Posted by groper

What myth? you CAN secondary bond without grinding (and save your health). You just have to use the right material and process;
http://www.tc.faa.gov/its/worldpac/techrpt/ar06-28.pdf

Yes, its a bit of a crap shoot -
"Uncoated polyester peel plies were easily removed from laminate surfaces after curing and produced good bonds with both adhesives for all textures (GIC> 850 J/m2, cohesive failure). Super Release Blue-coated polyester peel ply created surfaces that bonded very poorly in both cases (GIC< 94 J/m2, adhesion failure), the result of the transfer of the peel-ply siloxane coating to the composite surface. Nylon peel plies were more difficult to remove from the laminate and, in the coarser weaves, could not be removed without damaging the laminates. Laminate surfaces prepared with nylon peel plies bonded well with AF555 (GIC> 750J/m2, cohesive failure). Laminate surfaces prepared with nylon peel plies bonded poorly with MB1515-3 (GIC<150 J/m2, adhesion failure). This may be explained by the transfer of nylon to the prepared surface, which was found during SEM and XPS analysis.."

It might explain why there is still a lot of debate over sanding V straight peel-ply.

What is this AF555 and MB1515-3 ?

[hoytedow]

Those are new technology adhesives.
Maybe this will help. http://www.jams-coe.org/docs/Flinn-830am%20Thursday.pdf

[rwatson]

Originally Posted by hoytedow

Those are new technology adhesives.
Maybe this will help. http://www.jams-coe.org/docs/Flinn-830am%20Thursday.pdf

It was very interesting reading, and the testing methods were valuable, but the conclusions were even more disparate.

The final page "No single technique can currently explain whether or not a good bond will result."

Looks like individual testing will still be a big part of critical projects.

[tomherrick]

Can someone recommend a vacuum setting (or range) for laminating 1708 biaxial with CSM using epoxy and the Airtech polyester econoply peel ply? I've got some tweaking to do on my vacuum system but it's holding 25Hg just fine.

[rwatson]

"Boeing this week reported a manufacturing flaw on its 787 Dreamliner, the world's first commercial jet built mostly from composites, nine weeks after entry into service. Engineers found some delamination, or separation of baked composite fibers, in parts of the rear fuselage.....
The move to inspect all 68 A380s in service came as Qantas Airways (QAN.AX) grounded one of its planes for up to a week following the discovery of 36 separate cracks in wing parts....
The Airbus and Boeing problems are nonetheless "worrying because it means neither manufacturer has been on top of everything," he said. "Both planes were two-to-three years late, and yet we're seeing these unusually early problems.

The first round of inspections, which covered one third of the fleet, applied only to jets that had exceeded that number of flights. Aircraft already approaching or beyond the threshold must now be checked and repaired within weeks.

The damaged L-shaped parts, which fix the wing skins to their underlying frame, are "not a primary load-bearing structure," Airbus spokesman Stefan Schaffrath said.

Cracks have been discovered in a "handful" of the 4,000 such brackets on each aircraft, he added. "The safe operation of this aircraft is not at stake."

"


http://www.reuters.com/article/2012/...8171DI20120208

[benglish300]

Originally Posted by tomherrick

Can someone recommend a vacuum setting (or range) for laminating 1708 biaxial with CSM using epoxy and the Airtech polyester econoply peel ply? I've got some tweaking to do on my vacuum system but it's holding 25Hg just fine.

Your infusing right? The higher the pressure the better simply put, but you can infuse just fine at 25 Hg (not to say dont attempt to pull more gravity). If you want to get real technical, check out the infusion forum on this site. Lots of good stuff.

[tomherrick]

Nope, not infusing. Just wet laminating.

I've been reading other threads on the subject and one very experienced person says there's no such thing as too much pressure; another very experienced person says that too much pressure will make the peel ply nearly impossible to remove. Certainly, the amount of epoxy resin used will have a major effect, but in a 50/50 glass/resin layup I'd hoped that there was some rule of thumb.

[benglish300]

Originally Posted by tomherrick

Nope, not infusing. Just wet laminating.

I've been reading other threads on the subject and one very experienced person says there's no such thing as too much pressure; another very experienced person says that too much pressure will make the peel ply nearly impossible to remove. Certainly, the amount of epoxy resin used will have a major effect, but in a 50/50 glass/resin layup I'd hoped that there was some rule of thumb.

Same theroy applies really for vacuum bagging. Although a word of caution, whenever bagging at pressure higher than simple "clamping" pressure, its a good idea to add some perforated release film to your consumables. Not only does it help with pulling up resin filled breather, but it helps meter the amount of resin being absorbed. I've had misreable results early on in my career by neglating to use it at high vacuum pressures.

[CatBuilder]

Originally Posted by tomherrick

Nope, not infusing. Just wet laminating.

I've been reading other threads on the subject and one very experienced person says there's no such thing as too much pressure; another very experienced person says that too much pressure will make the peel ply nearly impossible to remove. Certainly, the amount of epoxy resin used will have a major effect, but in a 50/50 glass/resin layup I'd hoped that there was some rule of thumb.

25 Hg is plenty for regular vacuum bagging.

Also, the peel ply (if you get the right stuff) will peel right off all the way to 30 Hg or whatever your meter and pump goes up to.

The ability to peel the peel ply off has more to do with the kind of peel ply than vacuum.

The experienced person who said too much vacuum will make the peel ply hard to remove didn't buy the right peel ply.

[tomherrick]

The peel ply is here; I got the AirTech polyester stuff. Now I'm waiting on perforated release film. This is different than vacuum laminating wood... ...but I'm getting there.

Thanks

[CatBuilder]

Originally Posted by tomherrick

The peel ply is here; I got the AirTech polyester stuff. Now I'm waiting on perforated release film. This is different than vacuum laminating wood... ...but I'm getting there.

Thanks

Excellent, Tom.

Always waiting on something... I sure know that feeling.

Got the Corecell I ordered in November in last week.