Powder coatings is one of the low-VOC (volatile organic compounds) environment-friendly coatings that consume little energy and have minimal adverse environmental effects that has been developed by the global coating industry.
It is one of the products that can hold its own against more traditional solvent varieties that include waterborne coatings, powder coatings, high-solid coatings, solvent-free coatings and UV-curing paints.
Future growth for the product is expected to be towards the development of low-temperature curing and fast curing varieties, film varieties, functional varieties, specialised varieties, artistic varieties and new curing agents.
Compared with traditional varieties, powder coatings and their coating process are advantageous in that they contain no organic solvents and the solid content is 100 per cent, according to the China Chemical Reporter. Resources are therefore saved and environmental pollution is minimised.
Unused fly powders can be recovered in the coating process, raising the utilisation rate of coatings.
The one-time coating film is rather thick, simplifying the coating process, increasing labour productivity and improving corrosion, weather and impact resistance.
The use of powder coatings can raise the utilisation rate to over 90 per cent, reduce the energy consumption by 30 - 50 per cent, cut down the labour cost by 30 - 40 per cent and replace three to five times the amount of traditional solvent coatings.
The average annual growth rate of powder coatings was 12.9 per cent from 1980 to 1990 and 11.9 per cent from 1990 to 2000, much higher than the overall growth rate of the world coating industry in that period.
It has been projected that powder coatings will develop at an average annual growth rate of six to seven per cent in the world in future and the total sales volume will reach $5.78 billion in 2005.
The highest growth rate, at seven per cent, is predicted in the Asia-Pacific Region, while output proportion will be highest in Europe.
Powder coatings mainly include epoxy/polyester (mixed) varieties, pure epoxy varieties, pure polyester varieties, polyurethane varieties and acrylic varieties.
Powder coatings is one of the sectors with high growth in the coating industry, says the report.
The total market volume of powder coatings in the world currently stands at $4.7 billion while the market volume in Europe accounts for nearly half of the total.
Recent regulations on environmental protection and the prevention of atmospheric pollution necessitate VOC emission to reach discharge limits within a prescribed time.
One of the principal benefactors of this move has been the solvent-free powder coatings market.
Various new powder coating varieties such as low-temperature curing varieties, UV curing varieties, small particle varieties, high weather-resisting varieties, low-temperature curing acrylic varieties for auto finish, anti-bacterial varieties and fluorine resin varieties have been developed to meet market demand.
Epoxy powder varieties are mainly used in underground cast-iron pipes, buried steel reinforcements, auto components and mechanical and electrical insulation parts.
Pure epoxy varieties have poor weather resistance and can only be used in environments with no requirements on weather resistance.
The output and the application of epoxy and polyester varieties have far surpassed pure epoxy varieties.
The output of polyester/TGIC and polyester (polyurethane)/IPDI varieties holds second place in powder coatings.
Their curing agents include Primide XL-522 produced in Rhom & Haas of the US, PowderLink PL-1174 produced in Cyanamid of the US and PT-910 produced in Ciba-Geigy of Switzerland, reports say.
Acrylic varieties have excellent weather resistance, sources say.
Their surface tension is, however, widely different from epoxy and polyester varieties.
Use with other varieties in the same coating line will cause shrink cavities.
Acrylic varieties must have special coating lines making it the biggest shortcoming for users.
Production cost is also relatively high.