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Polyurethane spray coatings are composed of two highly chemically reactive components; upon mixing, they react rapidly, resulting in a sharp increase in viscosity. Without appropriate equipment for conveying, metering, mixing, spraying, and cleaning, this reaction cannot be controlled, and such spraying equipment is necessary. This device features a stable material conveying system, an accurate material metering system, a uniform material mixing system, an excellent material atomization system, and a convenient material cleaning system. Due to the fast curing speed of polyurethane spray coatings and the short time required for them to penetrate the substrate, high requirements are placed on substrate preparation. The steel substrate is generally required to be sandblasted to Sa2.5 grade; areas where stress tends to concentrate, such as edges, corners, and welds, should be smoothed, and the appropriate primer should be applied. The substrate must be dry before spraying, free of any substances such as dust, rust, and grease that could impair the adhesion of the coating. The surface treatment of substrates such as plastic, rubber, and concrete should be carried out strictly in accordance with the manufacturer’s installation procedures. The construction interval for polyurethane spraying is generally kept within 12 hours; if this interval is too long, it may result in poor adhesion between layers. If it exceeds 12 hours, it is recommended to use an adhesion promoter between construction layers to ensure project quality. During the spraying process, it is necessary to strictly control the pressure difference between components A and B, with this difference generally kept within 2 MPa. If the pressure difference is too large, it means that the two components cannot be mixed in the prescribed ratio; such an imbalance can lead to a range of problems such as bubbling, stickiness, and poor mechanical strength of the material.