Need Help GBC Mounting Adhesive Bubbling

[DPICopy]

Hello. I have a GBC Spire III 64T. I am trying to coat boards of 3/16" 'Ultra-Board' with 'Drytac M-Tac' white mounting adhesive. It's 51" roll adhesive and my boards are cut 48" wide.

I am getting serious bubbling on the left and right sides, effectively ruining most of the board (middle 32" are usable). I didn't get bubbling on my feeder board (same material) and I even ran ~16 linear inches of 3/16 foam-core through there with no bubbles. But when the 'Ultra-Board' went through it immediately bubbles on the sides. The rollers are set to less than 3/16" so it cannot be a simple tension issue. The roll adhesive goes straight to the roller (not around any other tension bars). The boards have all dust removed, so it is not bubbles from that either.

Has anyone else had such a problem? Or such problems with this particular machine?

Much appreciated

 

[DPICopy]

Photos of how machine would be set up and started:

 

[JamesLam]

Never used that machine so I am not sure how accurate the depth measurements are. I'm thinking pressure is either too low or high. Assuming you have a wide enough laminator one thought may be to run a strip along the sides of the Ultra Board to help maintain a more consistent pressure along the nip where it meets the board.

Did you check if the bubbling is between the board and the adhesive or between the board and the release liner? Can you perforate the adhesive and re-roll them? Possibly that can save some of your substrates.

As I'm in a stream of consciousness...are you sure the boards are a consistent thickness throughout?

Last thought, how old is the adhesive? Is it possible it is compromised or defective?

 

[DPICopy]

Never used that machine so I am not sure how accurate the depth measurements are. I'm thinking pressure is either too low or high. Assuming you have a wide enough laminator one thought may be to run a strip along the sides of the Ultra Board to help maintain a more consistent pressure along the nip where it meets the board.

Did you check if the bubbling is between the board and the adhesive or between the board and the release liner? Can you perforate the adhesive and re-roll them? Possibly that can save some of your substrates.

As I'm in a stream of consciousness...are you sure the boards are a consistent thickness throughout?

Last thought, how old is the adhesive? Is it possible it is compromised or defective?

I've used side-strips before. But there wasn't much overlap for that job to warrant it (~1.5" on each side).
Bubbling is indeed between adhesive and board (not adhesive and liner).
Never thought of perforating prior to coating. Not sure how I'd go about doing that effectively and uniformly (I sometimes am coating several boards in one run).
New adhesive, no defects there.

I agree that it may be due to a lack of uniformity in the boards OR something is off on my rollers. I switched to 38" adhesive and coated short-edge first and I had more success, but still got 1 or 2 boards with bubbling on an edge.
There is a little bit of subtle waviness on some of these boards. There is also something off with the roller, but not sure what. Maybe a pressure difference between the front and back rollers? Or the rollers are warped? Or the machine is tweaked/skewed?
Not sure.

But Thanks

 

[JamesLam]

Regarding perforating, I was thinking about perforating the boards that are already coated and run them under the rollers again. Possibly this may work. Might be worth a try if you feel it's worth the time.

 

[Humble PM]

Ran into this this week trying to help cut costs on an exhibition mounting onto 1.4mm mount board - I don't normally use this as it is cheap and nasty. 36x48" boards on a 41" roll of drytac SWA.
Reducing the nip on the rollers, and running sections of 10"x41" of the boards inbetween each sheet greatly improved the results.

I keep on thinking about putting teflon tape on the outfeed of the laminator.

Many years we bought 50 sheets of 8x4 5mm PVC from our supplier (we'd asked for Forex Classic, but they pursuaded us to use Foamalux, as it was so much cheaper). Couldn't get a single sheet to flood coat with adhesive across the length. Measured the material with a micrometer across the width- varied between 4.5 - 5.5mm, so was exactly within their stated tolarence. Bubbles just like you've got.

So it would be worth checking the "Ultra-Board" really is flat.

 

[DPICopy]

Regarding perforating, I was thinking about perforating the boards that are already coated and run them under the rollers again. Possibly this may work. Might be worth a try if you feel it's worth the time.

I've tried that. The bubbles still remain, just much smaller.

 

[DPICopy]

Ran into this this week trying to help cut costs on an exhibition mounting onto 1.4mm mount board - I don't normally use this as it is cheap and nasty. 36x48" boards on a 41" roll of drytac SWA.
Reducing the nip on the rollers, and running sections of 10"x41" of the boards inbetween each sheet greatly improved the results.

I keep on thinking about putting teflon tape on the outfeed of the laminator.

Many years we bought 50 sheets of 8x4 5mm PVC from our supplier (we'd asked for Forex Classic, but they pursuaded us to use Foamalux, as it was so much cheaper). Couldn't get a single sheet to flood coat with adhesive across the length. Measured the material with a micrometer across the width- varied between 4.5 - 5.5mm, so was exactly within their stated tolarence. Bubbles just like you've got.

So it would be worth checking the "Ultra-Board" really is flat.

There is a subtle waviness to the UltraBoards, the certainly not as much as a corrugated plastic. I think I may try running them through the machine at a tighter setting prior to coating to see if it will improve at all.
Thanks for your response.

 

[JamesLam]

There is a subtle waviness to the UltraBoards, the certainly not as much as a corrugated plastic. I think I may try running them through the machine at a tighter setting prior to coating to see if it will improve at all.
Thanks for your response.

Are your rollers crowned or a consistent diameter across the nip? If they are crowned you may very well have to increase the pressure. Regarding the pressure gauge, on my GBC Falcon occasionally it goes out of whack and has to be adjusted. It's just a magnet attached to a metal rod that moves up and down in conjunction with the top heated roller. If yours is the same it may be giving you a false reading. If your material is coming off of a roll make sure that you do not have too much tension on the clutch. Sometimes that can lead to waves in the adhesive or laminate and air pockets can form. Let me know how you make out.

 

[DPICopy]

Crown is a new term for me. Thanks. The manual doesn't mention crown, but it sounds like pretty much all laminators today have a crown. I just checked with three strips of 3/16 material and it looks like there is a big pressure difference across the nip. Left strip freely moves, center is firm and doesn't, and right moves with a lot of friction.

Based on this little experiment, I am suspecting that either the frame is off or something is faulty with the pressure system springs.

I appreciate all your help.

 

[JamesLam]

Crown is a new term for me. Thanks. The manual doesn't mention crown, but it sounds like pretty much all laminators today have a crown. I just checked with three strips of 3/16 material and it looks like there is a big pressure difference across the nip. Left strip freely moves, center is firm and doesn't, and right moves with a lot of friction.

Based on this little experiment, I am suspecting that either the frame is off or something is faulty with the pressure system springs.

I appreciate all your help.

Crown refers to the middle of the rollers having a slightly larger diameter then the ends. Generally the feed rollers may be crowned whereas the pull rollers are not.

The problem may be that you may have crowned rollers and/or the nip can be off. Either way the nip occasionally requires adjustment (we check and adjust ours every six months or so).

RULE #1, make sure the power is off and you are locked out before you gain access to the machine.

Next, make sure your machine is level and locked in place. If your machine has a dedicated location perfect, but if you move it around it may require levelling more frequently.

For our Falcon 60+ the sides of the machine are removed to access the adjustment nuts on each side. You would loosen one side (you'll need two wrenches) and tweak the nuts up or down to adjust the pressure. Make sure to lock in the adjustment nuts before testing as they may shift when you tighten them. We use 2" wide strips of release paper on each end (don't worry about the middle). Put the strips in place, lower the roller until it just makes contact. The wheel may have a sweet spot where it just hangs with no tension one way or the other, if not no worries, just apply enough pressure where you can slide the release strips in and out without binding. This is all about feel and the friction should feel the same for both strips. If not tweak it again until satisfied. On that note don't kill yourself, it needs to be close (and you will know it) but not perfect.

Once you have it dialed in you may have to re-adjust the gauge before you replace the side panels.

Now this is for our Falcon 60+, the Spire series may have different configurations. The operator manual that I found online https://media.mybinding.com/media/manuals/spire-iii-series-laminator-manual.pdf states/warns that there are no serviceable parts inside so you have to make the call how far you go with this. If unclear get a hold of your manual and tell your sales rep you want the schematic.