Coating testing is categorized into four types: physical performance, processing performance, resistance, and hygiene indicators.

(1)Physical Performance:Solid content, viscosity, relative density, cleanliness, color, flowability, and particle size of the coating.

(2)Processing Performance:Gloss, adhesion, slipperiness, scratch resistance, extensibility, and impact resistance of the coating film.

(3)Resistance:Acid resistance, sulfur resistance, high-temperature resistance, and corrosion resistance.

(4)Hygiene Indicators:

Coating Evaluation

Apart from physical performance, all other tests must satisfy the following three conditions:

(1)Appropriate Substrate:

(2)Correct Film Thickness:

(3)Complete Curing: When determining if a coating is suitable for a specific type of food, reliance solely on the results of coating tests is insufficient. Instead, practical canning trials should be the determining factor.