ٍEXPORT

Powder Coating

06 Apr
Powder Coating

If you are looking for a durable coating, thicker than conventional paints with high quality properties, we introduce you our Powder Coatings which produce an excellent, smooth and appealing hard skin that highly reduces the risk of abrasion, scratch, corrosion, chipping, and fading. Our Powder Coatings are easy to use, highly durable and tough, as well as cost efficient. Furthermore, they are environment friendly. This product is solid and does not need a liquid carrier. You can find any color you desire and you can even compound them to gain a new mixture. Two main types of powder coatings are called thermoplastics and thermosets. Global usage of this coating is expanding every year because of its unique properties and high quality. These Coatings are used for metal and aluminum parts of cars, bicycles, house and construction applications and other similar things. Polyester, polyester epoxy, polyurethane, acrylics and strait epoxy are conventional polymers used for these coatings.
Powder coatings constitute about 15 percent of the total industrial market and they are used in a wide range of different products. Various industries recognize these Coatings as durable, high quality, efficient, cost saving and easy to use. These coatings are available in limitless colors and serve various decorative and protective functions. The final texture is excellent and smooth and highly durable.
As powder coating is an economical and eco-friendly product, it is recommended to be used widely instead of other kinds of conventional coatings. Its performance in high temperature and high durability in outdoor conditions as well as its ability to prevent corrosion, makes it an excellent choice.
Our company produces high quality Powder Coatings under modern technologies. Our products are very popular among various industries as well as household applications. A variety of colors are available and different purposes are covered by our products.
Our high quality Powder Coatings are produced by modern equipment, best material and based on several years of experience. All of the production process steps are highly controlled and final products are evaluated carefully by quality assessment labs.

What is Powder Coating?

As it is clear by the name of the product, this coating is a dry, powdery coating which can substitute other kind of conventional liquid forms of coating. Unlike liquid paints, this coating does not need a solvent for solving the binder and filler of the coating. This kind of coating is sprayed on the object by means of special electrostatic guns. As the powder is imposed electric charged by the gun, it adheres to the surface. This kind of coating is cured by means of heating. Heating causes the coating to flaw and melt and a hard, smooth and durable skin appears after cooling down.
Powder Coatings are used for metal and aluminum parts of cars, bicycles, house applications and other similar things. They are recently specialized for other materials like plastic and MDF as well. As it was mentioned above, these coatings are available in limitless colors and serve various decorative and protective functions. The final texture is excellent and smooth and highly durable.
Global usage of this kind of coating is expanding every year due to unique properties of these coatings and their high quality. It is widely used for aluminum and metal parts of windows and doors, as well as in various parts of the house like kitchen and bathroom (because they are moisture resistant). Construction consumption of this coating is enhancing in several countries such as China, Qatar, Mexico, India, Singapore, Vietnam, UAE and the U.S. Industrial usage of this product is more cost efficient than limited applications. Powder coating has also wide usage in agriculture applications and equipment, sport equipment, and computer, laptop, cellphone and electronic industries.
As it was mentioned above, this kind of coating is an economical and eco-friendly product, and so it is recommended to be used widely instead of other kinds of liquid conventional coatings. Its performance in high temperature and high durability in outdoor conditions as well as its ability to prevent corrosion, makes it an excellent choice for several industries.
Properties:
Powder Coating is solid and does not need a liquid carrier. It adheres to the surface by means of electric charge produces by spray guns and a heating process. This property allows it to form a thicker film on the object in comparison to common liquid paints and coatings (almost twice thicker than conventional coatings) without occurrence of any sagging and running.
Furthermore, there would be no difference between various direction of coating surface (horizontal and vertical).
One of the important properties of this coating is that it does not emit VOC (Volatile Organic Compounds) and this makes it environmental friendly.
This coating is represented in various colors and you can apply more than one color simultaneously before curing to obtain your desired color compound.
The particle size of Powder Coating range between 2 to 50 microns and it melts at 150̊C and cures at 200̊C. It takes around 10 to 15 minutes (at least) for coatings to cure and this time and temperature depends on the work and surface conditions. Heating process occurs in special ovens. The final surface smoothness depends on your preference and you can keep some degrees of orange peel appearance to hide defects of the product.
Resulted hard skin is very resistant, cost efficient, environment friendly and of course easy to use. It reduces the risk of abrasion, scratch, corrosion, chipping, fading, etc. This kind of coating is very tough and durable and lasts for a long time. On the other hand, powder coating is flexible and it is suitable for surfaces exposed to bending. Also the final surface will look great, and its look is very attractive.

Two types of Powder Coating

As it was mentioned above, two main types of powder coatings are called thermoplastics and thermosets.
In the formulation of thermoset coatings, there is a cross linker which reacts with chemicals of the powder while being heated in order to polymerize and this improves properties of performance.
Thermoplastic category does not have any cross linker and no additional reaction happens during heating and baking phase and the coating just flows and melts to form the final skin.
Polyester, polyester epoxy, polyurethane, acrylics and strait epoxy are conventional polymers used for these coatings.

The Process of Powder Coating

There are three steps for Powder coating Process:

1. Preparation of the object or the place to be coated, which is called pre-treatment.
2. Application of the powder by special spray guns.
3. Curing
Pretreatment Phase
At the pretreatment phase, all of the surface impurities including any kind of dirt, dust, oil, grease, oxides of metal, paint, or any other kind of waste material, should be removed from the surface by means of different mechanical and chemical ways. For example making use of spraying or submersion in chromates and phosphates are chemical ways of removing impurities. Shot blasting and sand blasting are some other methods of pretreatment which are suitable for wooden, gloss or plastic surfaces. You should select the best method of cleaning based on the part to be coated and impurities type.
Application Phase
After pretreatment and cleaning the surface, some special guns are used which spray the powder coating to the metal surface. The most common gun for powder coating application is called Corona gun which imposes a positive electric charge on the coating powder and then sprays it towards the object. The electrostatic charge of the powder causes it to adhere to the surface. There are different types of nozzles for spraying and nozzle selection depends on the purpose and the object to be coated. After spraying, the surface will be heated so that the powder flows and melts in order to form a uniform and smooth skin or film. After cooling down, a hard coating is gained. The surface can be heated prior to spraying in order to achieve better results.
There is another kind of gun which is called Tribo gun which imposes a positive charge on the powder by rubbing it to the walls of a tube (Teflon) inside the gun. The formulation of the powder used for this kind of guns is different from the conventional powders. Some problems of Corona guns, like back ionization, does not happen with Tribo guns.
You can also heat your substrate and then dip it into a powder filled bed. After initial adherence of the powder to the hot object, you should heat it further to complete curing process of the object.
There is another similar process which is called “fluidized bed” method. In this method depth of the powder in the bed is very low and this powder is charged by means of an electrostatic medium and creates a cloud above the bed. These charged particles adhere to the object as it comes near. In this process the object is not pre heated and it is just heated after powder adhesion.
In another method which is called EMB (Electrostatic Magnetic Brush) a roller is used to apply the powder on flat surfaces. This method is fast and highly accurate.
Curing 
After application of the powder coating on the object, it should be heated. The powder coating is usually cured at 200̊C for 10 to 15 minutes. Heating process can take place in special ovens or by laser. Heating time should be mentioned by the manufacturer.
When the powder is heated it melts and flows. In thermoset coatings, heated powder reacts chemically and forms a polymer. This process is called cross linking.
As it was mentioned above, resulted hard film is very resistant, cost efficient, environment friendly and easy to use. It reduces the risk of abrasion, scratch, corrosion, chipping, fading, etc. It is resistant to extreme conditions of weather, ultra violet light, moisture and chemicals. Powder coating is very tough and durable and lasts for a long time. Also the final surface will look great, and its look is very appealing.

Removing the Powder Coating from the surface:

You can remove Powder Coating by means of acetone and methylene. Thinners (organic solvents) are not effective at all. Recently benzyl alcohol is successfully used instead of methylene chloride which is carcinogen for human. Sulfuric acid can also remove this coating. Abrasive blasting is another effective method for removing powder coating. Another removing method is heating the object in high temperature for more than three hours (around 300-450̊ C).

Advantages:

As it was mentioned above, powder coating is an economical and eco-friendly product and it is recommended to be used widely instead of other kinds of coatings. Its performance in high temperature and high durability in outdoor conditions as well as its ability to prevent corrosion, makes it an excellent choice for several industries.

Powder Coating has several advantages in comparison to other types of paint and coating, including:
• Final skin of the powder coating is almost twice thicker than other types of coating and no sagging or running happens.
• As powder coating is solvent free it emits no or little VOC (Volatile Organic Compounds) and it causes them to be environment friendly, so you do not need to provide expensive equipment of pollution control.
• This kind of coating cures very fast in comparison to other liquid coatings.
• Final surface is very uniform with no apparent difference between directions of application.
• It is easy to use.
• It is cost efficient.
• It is flexible and can yield and bend.
• It is very durable.
• It is highly resistance to corrosion.
• It is resistant to extreme conditions of weather, ultra violet light, moisture and chemicals.
• It has an attractive and highly appealing final look.
Our company produces high quality Powder Coatings under modern technologies and our products are very popular among various industries as well as household applications. A variety of colors are available and different purposes are covered by our products.
Our high quality Powder Coatings are produced by modern equipment, best material, and based on several years of experience. All of the production process steps are highly controlled and final products are evaluated carefully by quality assessment labs.
Source: R & D Unit of Toseaye Pardis Sabz

Leave a Reply

Your email address will not be published. Required fields are marked *