Epoxy powder coating is a thermosetting powder coating composed of additives such as epoxy resin, curing agent, pigment, filler and leveling agent.
Epoxy powder coating is the earliest powder coating developed and applied among thermosetting powder coatings, and it is one of the main types of thermosetting powder coatings. There are many types of epoxy powder coatings. According to their use, they can be divided into anti-corrosion, decorative and electrical insulation powder coatings; according to their appearance, they can be divided into high-gloss, semi-gloss, glossy matte, matt and fine art powder coatings. Fine art powder coatings can be divided into wrinkle, orange, sand, hammer, moire, cotton, pattern, metallic flash and other powder coatings.
Epoxy powder coating has the following advantages:
1. The original materials of epoxy powder coating are abundant, and the price is relatively cheap;
2. The melt viscosity of the powder coating is relatively low, and the leveling of the coating film is good;
3. When the powder coating is baked and cured, there are few small molecule compounds released, and the coating film is not easy to produce shrinkage, pinholes or bubbles, etc.;
4. The adhesion to metal substrates is very good, no primer is required;
5. The coating film has high hardness, good scratch resistance, good physical and mechanical properties such as impact resistance and flexibility;
6. The water resistance, acid resistance, alkali resistance and salt water resistance of the coating film are very good, and it is suitable for the coating of anti-corrosion and anti-rust products;
7. There are many types of curing agents for the powder coatings, and the coating has good powder and color matching properties, and can be used to formulate various coating film appearances and uses;
8. The powder coating has good coating compliance and can be coated by air spraying, fluidized bed dip coating, electrostatic powder spraying and flame spraying methods;
9. The powder coating has a wide range of applications and can be used in decoration, anti-corrosion and electrical insulation.
Epoxy powder coating is suitable for decorative coating of indoor products, but not suitable for decorative coating of outdoor products. Epoxy powder coatings are mainly used for anti-rust and anti-corrosion purposes, as well as decorative applications for some indoor products, as well as for partial electrical insulation. Products coated with epoxy powder coatings include liquefied gas cylinders, kitchen appliances, cable trays, agricultural machinery, auto parts, construction materials, steel bars, scaffolding, mine supports, oil and gas pipelines, marine equipment, switch cabinets, instrumentation and instruments , Coating of household hardware, valves, pump bodies, motor rotors, copper bars, etc.
The fundamental characteristics of the mixture of epoxy resin, curing agent, pigment and additives require that in the preparation of powder coatings, the physical and chemical properties of the mixture will have some influence. First of all, the resin system must have the ability to soak the pigments and fillers, under the conditions of temperature and time, so that the resin and curing agent will have the smallest reaction. Products of average quality must be relatively easy to produce powder with the required particle size; the powder must remain mobile, without adhesion or agglomeration during transportation and storage, and no response under this condition. The most common application is static electricity, so powder particles must have the ability to charge. When heated, the powder must melt and move into a smooth and continuous film. The moist substrate stops curing under baking, and the coating obtained during this consumption process has the required mechanical chemical resistance.
In order to achieve these performance requirements, the mixture system requires a suitable melting range and condensing viscosity; in the addition system of these resins and curing agents, there must be a suitable active range, in the powder preparation, storage and output, curing and baking stages, etc. Use the appropriate temperature for each time. In order to transport users to different requirements of powder coatings, this can be composed of different epoxy resin/curing agent/additive systems.