Comparison of Outer Casing Materials for Salt Spray Chambers

Salt spray  chambers are primarily used to evaluate the stability of products under salt spray conditions. Whether metallic or non-metallic, products can undergo corrosion due to moisture and salt in the natural environment, leading to performance degradation, such as metal rusting or circuit board corrosion.

Given the corrosive nature of the test environment, the outer casing of a salt spray test chamber cannot be made of metal or materials susceptible to salt spray corrosion. Currently, the main materials used in the market are fiberglass-reinforced plastic (FRP), rigid PVC, and PP board.

1. Fiberglass-Reinforced Plastic (FRP), also known as GFRP, refers to a composite material made of glass fibers reinforced with unsaturated polyester, epoxy resin, or phenolic resin. Depending on the resin used, it can be classified as polyester FRP, epoxy FRP, or phenolic FRP. FRP is lightweight yet rigid, non-conductive, stable, mechanically strong, and corrosion-resistant, with low production costs. However, it has limited recyclability. Early manufacturers commonly used FRP for the outer casing.

2. PVC Board offers excellent chemical stability, corrosion resistance, high hardness, strength, self-extinguishing properties, reliable insulation, smooth surfaces, and ease of processing. In the past, PVC was considered a premium thermoforming material, capable of replacing some stainless steel and other corrosion-resistant synthetic materials. However, despite the emergence of new materials and processes, many manufacturers still opt for FRP due to cost considerations in an increasingly competitive and low-margin industry.

3. PP Board has low density, is easy to weld and process, and boasts superior chemical resistance, heat resistance, impact resistance, and environmental friendliness, being non-toxic and odorless. It is one of the most eco-friendly engineering plastics available. The primary colors are white and beige, though custom colors can be produced upon request.

As an environmental testing equipment manufacturer with over a decade of experience, we recommend PP board as the preferred material for salt spray test chamber casings due to its long service life, environmental benefits, and cost-effectiveness.