Need help finding an adhesive to quickly bond 2 powder-coated metal plates together?

[Greg_G]

I have a new product that needs two 14ga powdercoated plates bonded together. One part is a 12"x12" solid sheet, the other is the same size but intricately cut. I am creating hundreds of these delicate parts, and the process needs to be fast.

Currently, I am using a spray adhesive on the delicate part, and pressing it onto the solid part, applying weights to hold pressure, and waiting 5 hours for it to set up. I think the absolute best solution would be a heat-setting spray glue that would quickly set in a heat press... or maybe fed into a conveyor oven ? I have tried contacting multiple companies like 3M, but they wont pay me any attention.

I have tried ALL the spray glues at the local hardware stores, and the only ones that work any good are the thick-bodied ones, but they always do a “webbing” effect when sprayed. Webbing absolutely does not work, since it bridges the gap of the delicate part and shows on the final product. All the other sprays are thin and only end up sticking in a few areas because the intricate side is not perfectly flat. Currently, we actually use a “sealant” to bond the parts, Its the best we have found so far is "Flex Seal" (flexsealproducts.com)

Maybe an adhesive roller system might also work for applying the adhesive ? (

https://www.hotmelt.com/collections/adhesive-roll-coaters)

Project requirements: 1) best if the bond is nearly clear when cured 2) bonds within 10–120 seconds. 3) be able to be applied to only 1 of the surfaces 4) Thick bodied since the parts are not always perfectly flat 5) compatible with polyester powder coat 6) if heat cured, needs to cure <250 deg f. so that the powdercoat doesn't melt 7) bond strength does not need very strong, its just artwork. 8) bond needs to be waterproof after cure, for outdoor use 9) A one-part spray seems best, since a two-part would require mixing and have a short shelf life

Thanks for your time and help.

Below is a sample of a similar product

 

[3DDave]

3M has a one part epoxy that requires a higher temp to cure -

https://multimedia.3m.com/mws/media...de-one-part-epoxy-adhesive-6101-off-white.pdf

It seems designed for this.

An out of the box idea is this -

Make up a pair of silkscreens that have depressions that accept the parts - one for the base and the other for the overlay.

Put a Part-A on one screen and Part-B on the other. Since the bond line is so thin it should work without mixing. Since they aren't mixed on the screen they won't cure on the screen.

The screens can be masked as needed to allow the epoxy to be only where needed so it won't squeeze out and can be a fast setting material.

You apparently have installation holes - those can be used on rods to keep the parts in alignment and a big stack of them can be clamped together to ensure good contact. Add some heat and I'm sure they will set up.

(Now I just need some fresh epoxy to make an experiment)

 

[MintJulep]

I'd suggest looking into pressure sensitive adhesive film.

 

[Greg_G]

Thanks 3DDave, It does look like a pretty good fit. I did forget to mention that none of them are the same, They have different text on them, plus we have 200+ shapes, so it would take a long time to make individual screen print templates.

The technical bulletin did mention that it could be applied by "jetting" I assume this includes using an air spray system ? But it says you cannot thin it, so I would assume it would be too thick to spray.

as for pressure-sensitive film, I have used VHB tape, but it takes a lot of time/concentration to apply the tape around shapes that have thin edges.

 

[epoxybot]

Have you tried contacting Ellsworth Adhesives? They represent a extensive range of adhesive manufactures.
"Ask the Glue Doctors"

 

[Greg_G]

I will contact Ellsworth Adhesives and see if they have any suggestions. Thanks