The paint selected for spraying should not have adverse effects such as corrosion on the substrate of the coated workpiece, nor should it cause damage such as abrasion to the spraying equipment.
1. Corrosive
To check whether the coating is corrosive to the coated material, the simple method is to soak the coated material in the coating for a certain period of time, then take it out and wipe it clean, and observe whether there is corrosion on the surface of the substrate. You can also use pH test paper to test the acidity and alkalinity of the coating. The influence of coatings on different substrates is also different. Some coatings will cause corrosion of steel or non-ferrous metals. Swelling and other adverse effects, so a corrosion test should be done before construction to avoid problems during construction. In addition, when using paint that is corrosive to metals, the parts of the spraying equipment that are in contact with the paint should be made of stainless steel, plastic and other corrosion-resistant materials.
2. Abrasiveness
The abrasiveness of the coating is related to the service life of the spraying equipment. The commonly used coatings are not very abrasive, but the coatings containing coarse and hard particles such as zinc-rich primers are more abrasive to the equipment, and the fluid will have Certainly abrasive. Therefore, when using highly abrasive paints, such as zinc-rich paints, enamel paints, and paints containing sharp and hard pigment and filler particles, it is necessary to choose matching equipment, such as using tungsten carbide cemented carbide. flow nozzle and pump valve seat. Air-containing resins and other wear-resistant plastics are used instead of metal as pump body materials for pumps designed to transport abrasive paint. Abrasion resistant tungsten carbide nozzles should be used when airless spraying with highly abrasive paints. Low-pressure spraying equipment cannot be used for high-pressure airless spraying. Doing so will not only damage the equipment quickly, but is also very unsafe.
