We’ve been working on a project for quite some time where we bond a layer of 282 style carbon to a counter top laminate. We have the aesthetics dialed in perfectly but in order to get a decent bond we have been using an epoxy in conjunction with a spray adhesive. It gives us a highly elastic bond but the customer does not like the “contact adhesive” feel to it.
We achieved a more rigid bond a while back with a considerably higher viscosity resin and some cabosil but now we’re not even able to achieve that bond since the laminate manufacturer changed the surface of the laminate to a harder epoxy.
Since the bonding directly to the laminate failed, we tried making our own laminate with a wood backing, laminate paper and carbon on top. This works better than the contact adhesive approach but the paper still delaminates from the wood.
We’re using ambient cure epoxy in a climate controlled 77 degrees and a hot room at 85F.
ANY suggestions would be helpful, I’m about to lose a big customer if we don’t figure this out.
Are you prepping the surface correctly? How are you prepping the surface? How much super 77 are you using? Too much might be your problem. Not only that, 77 from what I’ve herd does not work too well with epoxy. I could be wrong. There are adhesives formulated to work with epoxy but I’m not sure wwhat its called. How many days do you have left?
Are you sanding down the laminate surface prior to using your adhesive? Seriously, there are like a hundred options available. We use some adhesive where we bond tabs on to Kevlar which was infused with epoxy, the client attaches wires to it which are connected to a chopper and flown up to 16,000 feet high. This stuff will bond to just about anything, takes 12 hours to dry at room temp.
Are you just laying down fabric, or a cured sheet of carbon? How is the carbon bonding surface, shiney, or very dull and rough? What is this “paper” you talk about? There is no reason to have a stackup of wood - paper - carbon sheet.
If a finished carbon laminate, and you want that bonded onto the surface, make sure that 1: the carbon surface you are bonding is ROUGH. peelply surface or sanded to 180grit. Make sure there are no oils or anything on the wood. Also sand the wood to 60-80 grit. Use a structural adhesive, or a toughened epoxy. If you can, vacuum bag and heat the laminate.
Also, not sure about the “contact adhesive” feel you are talking about…the customer should not feel anything on the top surface, unless you are spraying both side for some reason.
We lay a dry 282 fabric onto the laminate, not a cured laminate. Due to the client’s requirements we can not bond a precured carbon sheet to the laminate.
Unfortunately, there is a reason for stacking up the different materials. The client is a very high end retailer and wants color to show through a very specific pattern in the carbon. We have tried 180 as well as 80 grit with no improvement to the bond. We have been vacuum bagging but I’m concerned it is pulling too much epoxy back out of the part. Unfortunately, backing down the vacuum compromises the surface finish we’re looking for.
The contact adhesive feel is between the carbon and the plastic laminate. I don’t see how it matters but they insist on trying to delaminate the panels. Unfortunately, the customer is always right and I need to make the part to his specifications.
I have not tried a significant amount of heat while curing (more than 90F) but I’ve tried no less than 15 different combinations of epoxies w/ and without spray adhesives.
We just ran a test using awlgrip to prime the plastic laminate so I’ll have to see how that turns out but I’m cautiously optimistic. Anyone know of a clear epoxy primer that works well?
I know everything we’re doing is counter intuitive and we would never do most of this for a typical part but this is an aesthetic application with extremely specific requirements for the look and feel of the product. We’ve got everything down except the bond from the carbon to the plastic laminate.
What kind of plastic? For most bonds I prefer using methylacrylate glues. Epoxy is way too brittle for most applications, laminating pieces togheter isn’t always possible.
Have you tried brushing or spraying on a coat of resin, letting it tack up, and then applying the carbon fiber? IMO, I find it best to do that, bag the fabric over the semi cured resin, debagging it, and then brushing more resin over the top.
what is the base countertop material. If plastic, sometimes NOTHING will stick. PP/PE has very very low surface energy, and hardly anything will stick to it, VER/epoxy/paint/etc. You say they want the color to show through, so I’m guessing the 282 is an open weave, and the color is the countertop.
Might look nice, but if that is the product, you really need to find a countertop coloring that is compatible to the resin you are using. If possible, get a pigment for a WOOD countertop, coat the wood, then apply the carbon fabric and finish the top. Then you have the countertop base, that is bonded well (wood holds resin well) to the fabric.
Have you tried bagging the parts? I often wrap plastic parts. The kind of plastic where, “they say” wont bond with the resin. I roughly sand the plastic, apply a coat of vinyl ester resin, then the fabric, bag it, remove it, and then brush on two layers of resin. I believe the VE resin bonds the best because I’ve never had problems with lifting. Even if I try to lift the edges. I use Hydrex 100 from Rychold. I think its Rychold.
Araldite 5052 is a laminating epoxy, not a glue, but anyhow. If your laminates are epoxy, bonding them as early as possible will allow more chemical bond. (although the mechanical bond is very good as well).
If polyester, weight as long as possible, to allow as much styrene to escape as possible. Bonding with epoxy on very fresh polyester laminate sometimes is not succesful.
