Information on Powder Coating

Introduction

Among the oldest traces of metal coating left by human being is the great Egyptian monument " Tot Ankh Amoon " thousands of years ago. Since those days till recent decades the only player in the field of metal coating was the liquid form of paint.

"Better coating and less polluted environment", this was the heading under which an extensive research was applied, resulted by the presenting of powder coating (100% solid paint, consist of a homogeneous mixture of binders, pigments and additives) in mid-50's.

The actual launch for powder coating was in the 80's, where powder coating became the fastest growing industrial coating worldwide.

Powder coating consumption in Arab Countries

Arab 22 Countries consumption of powder coating is increasing rapidly, from 1'500 MT in late 80's up to 20'000 MT in Y2K, but this consumption is still low if compared to other regions in the world, it only covers about 3% of the world consumption.

The consumption share of Arab Countries is expected to increase with time according to latest studies. Table # 2 is showing that Europe (world leader in powder coating consumption) consumption growth is estimated to be 5-7 % were it is estimated for Arab Countries to be around 12 %.

Table 1: Regional distribution of powder coating, 1995

Region	MTon	%
Western Europe	240 000	46
North America	119 000	23
Rest of world	161 000	31

Table 2: Comparative growth rates for coatings 1995-2000 in percent

Region	Powder coating	All coating
Western Europe	5-7	0-1.5
North America	12	2
Asia Pacific	15	3-4
Rest of world	12-20	2-4

Benefits of Powder Coating

*Quality: A superior consistence and uniform finish without sags, drips, or bubbles accompanied by high mechanical and chemical resistance properties.

*Environmental: No VOC (Volatile Organic Compound) emission, which means that conservation of material without polluting environment.

*Economical:
-One step coating.
-Less skilled labor needed.
-High efficiency (95 %) 1 Kg Powder = 2.5 Kg Liquid Paint .

Benefits of powder coating can be summarized in 5E's-Environmental compliance, Energy savings, Efficiency, Excellence of finish, and Economy

Types of Powder coatings

1-        Polyester / TGIC : Exterior Coating (high durability and weather resistance)
2-        Epoxy / Polyester : Interior Coating
3-        Epoxy / Hardener : used for functional coatings (high chemical resistance)
4-        Polyurethane and acrylic: minor use in Arab countries and Europe

Finishes of powder coatings:

One of the benefits for powder coatings is that it can give more than one finish as per request like: smooth film, wrinkled, Hammer, Texture, sand structure, Antique finish and others.

Powder coating production consists:

1) Weighing of raw materials: According to the formula and quantity for the specific production

2) Mixing: Mixing of raw materials is carried out in a special mixer, which will take in account the different densities of raw materials.

3) Extrusion: Mixed Raw materials under goes a hot melt compounding process where it becomes a hot, homogeneous paste.

4) Cooling and Kibbbling: The hot paste is Passed through a cold rolls where it becomes a brittle film and through the kibbler this film is a crushed into 3-5 cm chip

5) Grinding and sieving: The chips are grounded to a fine particles powder (less than 100 micron ) by means of a continuous process, then sieved to remove any over size powder

6) Packing: Powder is packed in cartons of 20 or 25 Kg, then sent to store for storing or shipping

Source: RISE Powder Coating