Silk screen mesh bonding is quick and effective with cyanoacrylate adhesive and activator. Cyanoacrylate activators speed the cure and dry the surface quickly. The process is simple and will have a screen print frame up and running again relatively quickly compared with some other mesh bonding adhesives.
Silk screen mesh is normally a woven material such as polyester, and the weave density dictates the viscosity adhesive you require. You need an adhesive that will penetrate the mesh but at the same time not flow uncontrollably.
It is a juggle to get the adhesive properties right – which is why using an activator after applying the adhesive can help even up the balance, allowing an adhesive viscosity that will have ample penetration into the silkscreen mesh but stopping the adhesive flow (potentially away from the bond area) and providing a tack-free cure by spraying with the activator.
Ensuring the frame is clean and free of any previous adhesive remnants is important. If using an aluminum frame, it is a good idea to degrease with acetone or isopropanol and abrade the surface. Two methods that will provide an excellent surface ready for bonding are abrading with 320-grade (approximate) carborundum grit paper or, if you have the luxury in your workplace, using a grit blaster. Once the surface has been roughened, it is essential to repeat the degreasing process. Mesh bonding should be done as soon as possible after surface preparation. Otherwise, a weak (and invisible) oxide layer will start to form again, resulting in a much lower strength bond.
Clean wooden frames also. Sand off any old cured adhesive. Make sure the surface is dry and dust free before bonding.
Stretch the mesh across the frame and weigh it down or clamp it. If necessary, use masking tape around the inner edge to keep a clean straight bonding area that does not encroach into the printing area. Do not use a knife to cut the tape or you could damage the mesh – instead, use the edge of a credit card.
Apply the adhesive around the edge. It should wick through the weave of the mesh and bond the mesh to the silkscreen frame.
If you wish, spray the surface with cyanoacrylate activator to speed up the cure and prevent surface tackiness. The adhesive cures to handling strength in seconds, so putting the silkscreen into service soon after bonding is possible.
Cyanoacrylates offer good chemical resistance to printing inks and form a strong bond between the frame and mesh to withstand the high tensile / slight peel force exerted on the mesh when a squeegee runs across it.
For further help with silk screen mesh bonding applications, please contact Permabond.