Consistent Surface Activated Acrylic Curing
Surface Activated Acrylic Adhesives by Any Other Name…
Surface activated acrylic adhesives are also called structural acrylics, surface initiated acrylics, two part no-mix acrylics, aerobic acrylics and cold-bonding acrylics. It would be lovely if we could all use the same language – but that’s the way it is – so now that we know what type of product we are discussing – we’ll move on.
Surface activated acrylic adhesives are two component materials consisting of an acrylic resin component and an initiator. Generally the initiator is a water thin material that is wiped or sprayed onto one substrate and the adhesive is applied in a bead or pattern of beads onto the other. Upon assembly, the resin and initiator mix sufficiently to cause acrylic curing. This process provides very fast strength development of the bond. The fixture can be achieved in under a minute, minimizing clamp time or work in progress time.
The factors affecting surface activated acrylic curing include temperature, ratio of initiator to adhesive and gap.
The acrylic curing process looks like this…
Apply a THIN layer of initiator to one surface by either a fine mist spray or wiping.
- Apply a bead or drop of adhesive to the center of the mating surface. (Use sufficient adhesive so a very small bead of adhesive is seen around the entire bond area after assembly.)
- Press the assembly together using sufficient force to spread the adhesive thinly (0.02”).
- Assemble parts as soon as practical but at least within two hours of applying the initiator.
- Clamp for the length of time listed as the upper limit of the fixture time.
- Note – For bonding motor magnets apply the initiator to the can and the adhesive to the magnet.
For further assistance with adhesive selection and usage advice, please contact Permabond.