Powder coating for iron castings
Powder coating is a 100% solids powder
coating without solvent-free. It has a solvent-free, non-polluting,
recyclable, environmental protection, saving energy and resources,
reduce labor intensity and high mechanical strength.
Types of powder coatings
The types of powder coatings include
thermosetting and thermoplastics.
Thermosetting powder coatings use thermosetting resin as the
membrane material, and join after curing agent in the cast iron
surface formation of hard coating, because the molecular weight of
thermosetting resin is low, so the coating has good leveling
property, and it can make iron castings have higher corrosion
resistance, mechanical performance and decorative.
Thermoplastic powder coating is melting in the spray temperature,
and cooling solidified to form membrane, because the processing and
spraying method of thermoplastic powder coating is simple, powder
coating just need to heat melt, leveling, cooling solidified to form
membrane, does not require complicated curing device.
The advantages of powder coatings
1. Powder coating is non-toxic,
non-solvent and non-volatile toxic substances.
2. The utilization of raw materials is higher, the powder sprayed
can be recyclable, the use of more than 99%.
3. One-time construction, it does not need to first coat, will be
able to get enough of the film thickness, and easy to automated
operation, the production efficiency is high, can reduce the cost.
4. Powder coating has better adhesive power, impact strength and
toughness, corner coverage is high, it can make the iron castings
surface have higher corrosion resistance and wear resistance.
5. Powder coating is easy to store, transport safety and
The disadvantages of powder coatings
1. The coloring of powder coating is difficult, and the adhesive
property of casting surface is poor.
2. Powder coating affected by pressure, temperature and humidity is
easy to cake.
3. Baking temperature is higher, the appearance of coating is poor,
and it is not fitted for the appearance of complex castings.
4. Powder coating process is more complex, manufacturing costs are
The common problem of powder coatings
1. The glossiness of coatings is not enough or fade.
2. The glossiness of coatings is too high.
3. There is foreign body on the coatings.
4. There have shrinkages and pinholes on the coatings.
5. The adhesive power and mechanical strength of powder coatings are
Powder coatings can improve the corrosion resistance, wear
resistance and impact strength of the
iron castings. Moreover it can extend the useful life of the
In China, using powder coating for
iron foundries is just
beginning, with the development of powder coating technology, powder
coating will become more popular.