Primer

Primer is a thin, reactive undercoat applied to a substrate before an adhesive or sealant, changing the surface so that the bond holds. It is used where the base material is difficult to bond, such as silicone rubber, glass, some plastics, painted or anodised metal, or where the joint must survive heat, moisture, fuel and long-term outdoor exposure.

A primer is not glue. It wets the surface, carries adhesion-promoting chemistry into the micro-texture, and often acts as a barrier that stops plasticiser migration or moisture ingress from attacking the bond line. The applied film weight is small, usually a wipe or a thin spray, and the open time before the adhesive is applied matters as much as the coverage.

How to choose and apply

Match the primer to both the substrate and the adhesive chemistry, because a primer formulated for silicone will not necessarily serve an epoxy or a polyurethane. Clean the surface first, since no primer can compensate for oil or release agent. Then apply a thin, even film and let the solvent flash off fully, as trapped solvent becomes a weak layer.

JOME provides a silicone surface treatment primer coating agent, listed in our Primer category.

As an exporter of Primer from China, JOME prepares the compliance and shipping documents audits require.