Bonding "stickyback 1

[notnats]

I posted this enquiry under welding bonding and fastener engineering, and only got one reply (thank you MadMango). Perhaps there might be more feedback here.

We use a material we buy as "stickybacK" and glue it to a stainless or galvanised steel sheet. It is used to hold a polymer letterpress printing plate in place during a scrubbing process in a warm water bath while the non-image areas of the plate are brushed away.

Over the last 10-15 years we have used several glueing systems, none of which are entirely satisfactory. The supplier of the stickyback is not helpful.

The stickyback is a floppy, tacky rubber-like sheet about 3mm thick. We prepare the side to be glued by roughening it with emery paper, then wipe it clean with acetone. We prepare the metal plate the same way.

We have used Rema Tip Top SC2000 glue which is a 2 part adhesive intended for conveyor belt repairs. It is difficult to apply evenly and lumps in the glue show through the stickyback and can show up on the printing plate.

We have used a 3M adhesive transfer system which is easier to apply.

Neither of them stick to the stickyback very well, and once it starts to peel back, water gets underneath and that's the end of the bond. We have chamfered the edge and used a silicone sealer around the edges to resist peeling. All these things help, but none are good.

We bought some stickyback pre-bonded to a stainless backing sheet from a large international supplier of pre-press materials. It looked great but didn't last any better than our own systems.

Does anyone have experience with this stickyback material? Can anyone suggest an improved bonding technique? Does anyone know who makes it?

Thanks for any help.

Jeff

 

[rnd2]

Would it be possible to use a permanent tacky type adhesive around the edge of the plates and pull a vacuum between the plate and the stickyback during the cleaning process?

 

[amorrison]

Doesn't 3M have people who help customers solve problems like this ?

 

[GregLocock]

That's agood idea, 3M are excellent at that sort of thing. It sounds to me like it might be worth looking at a different rubber sheet, perhaps the one you are using is unfriendly to adhesives.

You might also try scrubbing it with MEK.

Raychem make an etchant that will allow you to epoxy to PTFE - so it may be that they have something that will improve the surface of your sheet.

Cheers

Greg Locock

 

[automatic2]

The cardboard boxes that 'Printers Gum' from WR Grace came in where excellent for moving and storage. I still have a dozen in my garage after being out of the printing industry for 10 years. We used 'stickyback' strictly for the mounting of flexible plates onto the print cylinders in CID presses. I wouldn't roughen the print cylinder, you will have a very difficult time cleaning it after such a process, and the roughened surface is not as good as a very smooth surface for adhesion. You'll create an out of round situation as well.

In checking I see that Grace may no longer carry the product. A second check on the boxes sees that Williamson is the supplier.

http://www.williamson.ca/

 

[notnats]

thanks automatic2,

Not quite what we are looking for. We are not attaching the stickyback to print cylinders, but to a flat plate in a washout machine for processing letterpress or polymer plates. Plates are loaded, processed and unloaded every 15 minutes in a busy shop, and the stickyback is nearly continually immersed in water at about 35°C, often with detergent or alcohol or some "magic ingredient" added to it.

However the Williamson site is interesting and one of their products might replace the product we are using. Their recommendation of hot melt glue as a sealer might be a simple solution.

Thanks

Jeff

 

[cadcoke5]

I'm not familiar with your industry, so this is just an off-the-cuff answer.

Can thestickeyback be physically fastened to the plate? I imagine you don't want anything protruding onto the surface, but perhaps you can let the stickback fold around the corner and fasten it on the side or back side?

Joe Dunfee

 

[BobMcGee]

Hello: for those needing info on Flexo or Printing and related subjects, I can help.

Bonding a plate to a stainless steel sheet with stickyback(SB) is tough. We use many types and thicknesses of stickyback to bond a photopolymer printing plate to either a mylar carrier that mounts the plate on pins in the press or adheres directly to an aluminum or steel plate cylinder. Our plates are washed out before the SB is adhered to it because we use water and Cascade dishwashing dtergent to wash out the unwanted polymer after it is exposed to a negative and UV light.
The adhesive on SB is on both side with a thickness of either solid vinyl or a "foam" cushion type layer. Some adhesive are permanent after 24 hour other or not. This differential adhesive is so one side adheres to the plate and the other to the metal. The lighter bond is so you can reposition the plate just after mounting. The adhesion will build up after a few hours.
1. try the other side of the SB.
2. allow at least an hour for adhesion to build up.
3. any detergent, silicone, oil on the back of plate or SS will inhibit adhesion. Wipe down both SS and back of plate with a solvent degreaser (IPA) before applying SB.
SB distributers/suppliers in US:
Anderson & Vreeland, Bryan, OH

http://www.andersonvreeland.com

Dansen Prepress, Williamsville, NY

http://www.dansen.com