Spray Coating
Term: Spray Coating
Category: Coating Method
Definition: Spray coating is a coating technique used to deposit thin and even coatings onto a surface by spraying a liquid solution or suspension into fine droplets and propelling them toward the substrate. The coating material can be a polymer solution, paint, or colloidal dispersion. After spraying, the solvent evaporates and leaves a solid film. Sometimes the film is heated or chemically bonded to make it stronger. This method makes it easy to control thickness and can cover large or oddly shaped surfaces quickly.
How it Works:
- The coating solution is placed in a spray gun or atomizer.
- Pressurized air or gas converts the liquid into fine droplets (atomization).
- The atomized droplets are directed toward the substrate surface.
- Droplets impact, spread, and coalesce into a continuous layer.
- The solvent evaporates or the coating is cured/dried to form a uniform film.
- Parameters such as spray pressure, nozzle design, distance, and movement affect coating thickness, coverage, and uniformity.
Common Uses:
- Commonly used for applying hydrophilic or antimicrobial coatings on catheters, stents, and implants.
- Polymer or ceramic coatings on medical devices, and protective or decorative coatings in industrial, automotive, and electronic applications.
Related Content and Resources:
5 Common Coating Methods: Dip, Spin, Spray, Flow, & Meniscus
