Powder coating is becoming increasingly popular today. What is it? This is a modern technology designed to produce high-quality decorative and protective coatings. In the work using polymer powders (hence the name - "powder"). They turn into a coating due to exposure to high temperatures. Because of this feature of the procedure, powder coating of metal and glass is most common.
Benefits
This process has several positive aspects. These include:
- Profitability. The fact is that such paint can be reused if it does not settle when sprayed.
on the treated surface. Thus, the loss of material is not more than 5%. By the way, this indicator for ordinary paints will be 8 times higher - about 40%. Also in this case, there is no need for solvents.
- Ease of use. Materials for this type of work are issued completely ready. This guarantees consistent high quality coatings. In addition, cleaning equipment after work is very simple, because the powder is easily removed from the parts.
- Speed. Powder coating does not require drying of the products before placing them in the oven. If surfaces coated with ordinary paint need to be dried for a rather long time, then in this case the process is reduced by several times.
- Durability. The technology of these works involves the polymerization of a layer of elastic plastic with a fairly high adhesion directly on the surface that is being painted. The result is a durable coating that boasts excellent electrical insulating and anti-corrosion properties, as well as resistance to various substances.
- Environmentally friendly. As already mentioned, solvents are not used in this case, which favorably affects the environment. Non-waste production also plays a role.
- Decorative. Powder paints make it possible to obtain a surface of any shade. The palette of materials presented today totals more than 5 thousand colors and shades with various textures. If desired, you can get a glossy or matte surface, as well as granite, moire, etc.
Powder coating as an idea for business
Given all the advantages of this type of work, it becomes obvious that such a business will be quite profitable. If you do not have the opportunity to immediately invest a large amount in your business, it is advisable to at least just find out how powder painting is done with your own hands.
But it is worth considering that you still have to spend money. First of all, you will need to take care of the availability of special equipment and a separate room. As the latter, a simple garage is quite suitable, but provided that there is enough space in it to accommodate all the tools and carry out the work directly. And what equipment is necessary for powder coating?
Camera
Work will be impossible without a special camera. It is in it that most of the entire process is carried out. A powder coating chamber is needed for air purification (recuperation process), in addition, it is due to it that it remains possible to reuse the material. Here, paint that does not hit the surface to be treated is sent to the filters, and then discarded.
Such equipment may have various sizes.Which one to choose - you need to decide in each case individually, having previously determined what products you plan to work with.
Stove and gun
You will also need a reflow oven. This is a prefabricated structure consisting of panels (their thickness is 100 mm). Thermal insulation material - basalt fiber. If you just try yourself in this type of work, it is not necessary to immediately buy a special oven. For this purpose, it is quite possible to use a conventional oven. However, to build a business, it is still recommended to purchase professional equipment.
Powder coating technology also requires a spray gun that allows the use of compressed air. As it is possible to use a compressor. If you have made a choice in favor of the latter, then note that a filter for high pressure must be installed on it.
Recuperator and transport system
Residues of powder paint are collected using a recuperator. Instead, at first you can use a cyclone type vacuum cleaner. In this case, you must first check the power supply in the room and make sure that there is grounding.
If you plan to work with bulky products, then you should also consider purchasing a transportation system. In it, the workpieces move on special carts that move on rails. Thus, a powder coating line is built. Such equipment improves the productivity of the process, ensuring its continuity.
Powder coating technology
The process of doing the work itself is divided, as already understood, into several stages:
- We will tell about each stage separately.Preparation of the product, or rather its surface, for processing.
- Application of powder paint.
- Polymerization, i.e. heating the product in an oven.
Preparatory stage: cleaning, degreasing
We can say that this stage is the most time-consuming. And it depends on him how high-quality and resistant the coating will turn out. In the process of preparing the surface, it is necessary to remove all contaminants from it, degrease it.
Cleaning is carried out by mechanical or chemical methods. The first option involves the use of steel brushes or a grinding disc. It is also possible to grind with clean cloth, having previously wetted it in a solvent.
The second cleaning option involves the use of an alkaline, neutral or acidic composition, as well as solvents. Their choice depends on how dirty the surface is, what material the product is made of, what type it is and what dimensions it has.
Phosphating and chromating
Further, a conversion sublayer can be applied to the product, which will prevent moisture and dirt from entering the coating. Phosphating and chromating procedures provide better adhesion and protect the surface from rust. For this purpose, iron phosphate (for steel), zinc (when working with galvanic cells), chromium (for aluminum) or manganese and chromic anhydride are most often used.
Then you will need to remove the oxides, which is carried out using abrasive and dry cleaning. The first is produced by means of abrasive particles (shot, sand), walnut shells. These substances are supplied by compressed air at a fairly high speed. As a result, particles “crash” into the surface of the product and bounce off of it along with contaminants.
Etching (chemical cleaning) is the removal of various contaminants using special etching solutions, the main components of which are sulfuric, hydrochloric, nitric, phosphoric acid or caustic soda. This method is considered more productive, however, after such processing, the product must be washed with solutions.
Passivation
This is the final step in the surface preparation phase.It is necessary to treat the part with compounds of sodium and chromium nitrate. This is done in order to prevent secondary corrosion.
After all the preparatory work is done, the product is rinsed and dried in an oven. Now powder coating of the surface can be carried out directly.
Paint application
What is powder coating technology itself? The prepared product must be placed in the chamber. Here, powder (paint) will be applied to it. If you have a dead end box, then it will be possible to paint only small details in it. Large items can only be processed in long chambers.
Most often, the method of electrostatic spraying is used for applying paint. In this case, powder spray guns are used. Such tools are also called spray guns or applicators. This device is a pneumatic atomizer with which an electrostatically charged substance is applied to a part that is pre-grounded.
Coating formation
We proceed to the next stage of work. The paint is applied, now you need to form a coating. First of all, the product is sent to the polymerization furnace. Such cameras can be different: vertical, horizontal, again, dead-end or walk-through, single and multi-pass.
The mentioned equipment for powder coating provides surface heating to a certain temperature - 150-220 aboutC. Processing lasts about half an hour, resulting in a film. At this stage, it is important that the part warms up evenly, which is possible only if the temperature in the chamber is stable.
Which mode to choose for processing a particular part depends on it itself, on the type of paint and equipment. After the polymerization is completed, the product must be cooled in air. All the work is done.
Fields of application
As you can see, powder coating is a rather labor-intensive work that requires certain investments. What products are exposed to it? The painting method in question is ideal for machining aluminum or forged products as well as galvanized surfaces.
Powder paints are now finding more and more "fans". Now they are used in instrumentation, and in construction, and in the automotive industry, as well as in other areas. With their help, they paint medical equipment, roofing materials, household appliances, objects made of ceramics, plaster and glass, furniture. Among motorists, powder coating of disks is becoming increasingly popular.
Business organization
These works in specialized centers today are quite expensive. If you want to try yourself in this matter, then in the presence of financial means you can quite proceed. Of course, not everyone can afford the powder coating line (automated system), but thanks to our recommendations, you can replace some elements with other tools at first.
Start with small items. It can be gypsum figurines, ceramic dishes and much more. First, try to paint something in your house (start with something that is not a pity to spoil). Gradually, you will have the necessary skills and dexterity, then you can take orders from friends. However, you should not expect a large income if you interrupt only one-time orders from individuals.
The best case scenario involves the presence of a large start-up capital. In this case, you can immediately purchase the necessary equipment and hire workers. Clients should be sought among enterprises engaged in the manufacture of metal products. Only the presence of such customers will allow your business to exist and grow.
