A substrate is any material being bonded, coated, or taped. The physical and chemical properties of the substrate, such as its surface energy, porosity, and thermal expansion rate, dictate which adhesive chemistries will work. In a typical joint, the adhesive forms the bridge between two substrates.
Make sure you wipe down the substrate with IPA before applying the primer.
Always check the surface energy of a new plastic substrate, as low surface energy materials like polypropylene will reject most standard adhesives.
Do not mix it up with
- Adherend: A substrate is the base material itself, while an adherend is a substrate specifically prepared and used in an adhesive joint.
Related terms
Adherend
Each of the parts in a bonded joint; the surface the adhesive has to grip.
Surface energy
A measure of how strongly a solid surface attracts liquids, which decides whether an adhesive can wet it.
Substrate failure
A joint failure where the bonded material itself breaks before the adhesive or the interface gives.