Prepainted Steel Sheets – Category and Film Thickness of Primers

Prepainted Steel Sheets – Category and film thickness of primers

The caregory of the primer includes epoxy, polyester, acrylic acid, polyurethane, etc.
In general, the primer is chosen in accordance with the usage, environment condition, processing stage and
finish coat. The film thickness of the primer is usually 5-7 um.

A. Epoxy Primer

The epoxy primer has a strong adhesion to the base metal and good properties in waterproof, alkali-proof and
chemical resistance, which is the original primer for the coiled steel, having a poorer flexibility than
that of other primers.

B. Polyester primer

The primer has strong adhesion to the base metal and excellent flexibility. which is relatively sensitive to
damp environment and has a chemical resistance poorer than that of epoxy primer.

C. Water-soluble acrylic acid primer

The primer of this kind has strong adhesion, excellent flexibility, lower organic solvent and low-
temperature curing.

D. Polyurethane primer

The primer of this kind has excellent chemical resistance, durability and flexibility.