The Importance of Powder Coating and Pre-Coating in Clean Room Doors

When it comes to clean room doors, every detail matters — from structural strength and sealing to surface finish. One of the most critical yet often overlooked elements is the surface treatment, particularly powder coating and pre-coating. These coatings are not just about aesthetics; they play a vital role in ensuring durability, hygiene, and compliance in controlled environments.

Powder coating is a dry finishing process where a fine powder composed of resin and pigment is electrostatically applied to the metal surface and then cured under high heat. This results in a smooth, uniform, and highly durable finish. In clean room applications, powder coating offers several key advantages. It provides a smooth, non-porous surface that resists the buildup of dust, microbes, and other contaminants. It is also highly resistant to chemicals, disinfectants, and cleaning agents frequently used in cleanroom maintenance. Moreover, powder-coated surfaces are known for their exceptional resistance to scratching, impact, and general wear and tear, making them ideal for high-traffic areas.

On the other hand, pre-coating involves applying a protective layer to the metal — usually galvanized iron (GI) — before it is fabricated into the final door or panel. These pre-coated GI sheets are treated with polyester or epoxy-based coatings, offering uniform surface protection from the start. The benefits of pre-coating include consistent and even finishes, improved corrosion resistance, and reduced manufacturing time, as there’s no need for post-fabrication painting. Additionally, pre-coated sheets are environmentally friendly, as they emit minimal volatile organic compounds (VOCs) during the process.

When comparing powder coating and pre-coating, both serve critical purposes in clean room door manufacturing. Powder coatings, typically applied at a thickness of 60–80 microns, offer superior surface protection and flexibility for recoating if needed. Pre-coated sheets, with coating thicknesses of about 30–35 microns, provide cost-effective and efficient production, especially for modular cleanroom systems.

While powder coating is applied after fabrication and offers higher surface resilience, pre-coating is done before fabrication, ensuring core protection throughout the manufacturing process.

In cleanroom environments such as those in pharmaceutical, biotechnology, healthcare, and electronics industries, surfaces must resist microbial growth, withstand rigorous cleaning, prevent particle accumulation, and maintain long-term integrity. Improperly treated doors can corrode, peel, or flake over time, leading to contamination risks, increased maintenance, and potential non-compliance with regulatory standards.

At Lucky Deep, we prioritize coating excellence in our clean room doors. We use powder-coated GPSP GI sheets with thicknesses of 0.8 mm and above, and pre-coated GI sheets ranging from 0.6 mm to 0.8 mm with a 30–35 micron coating. Our coating process ensures uniform adhesion and durability, aligned with the strict requirements of ISO-certified cleanrooms and GMP-compliant facilities.