Powder paints for metal: pros and cons

Powder paints are an original product in the segment of paints and varnishes. This raw material consists of catalysts, coloring pigments and film formers. Today, this type of paint is the most profitable replacement for classic solutions..

Due to the high level of coverage obtained with the use of polyester powder formulations, they are widely used in the construction, automotive, and interior design industries. Most often they are used to paint furniture, sports equipment, household appliances, metal products or medical equipment..

Dyeing technology

The use of powder dyes is considered an environmentally friendly and waste-free dyeing method. The coating is formed from polymer powder, which is applied in an especially thin layer to the surface to be treated. After application, the surface must be reflowed at a temperature of 160 degrees Celsius, which requires special heat treatment chambers. The result is a uniform, continuous coating.

An interesting property of the paint is that the leftover powder can be put back into the reservoir, saving it for later use..

The use of powder paints makes it possible to obtain surfaces with imitation of various textures. This is one of the advantages of this product, because the texture of wood, marble, stone, formed by means of paint, looks beautiful and unusual..

Several types of surfaces can be distinguished:

  • matte;
  • glossy;
  • volumetric;
  • flat.

Technology pros

This technology has many advantages.. Let’s note the main advantages.

  • Possibility of applying the coloring composition in one thin layer (as opposed to painting with a liquid paint and varnish analogue). This property significantly increases the optimization of the process..
  • No need for viscosity control and solvent use. This reduces production costs.
  • Powder painting takes less time compared to liquid counterparts.

  • Environmental friendliness and safety are the undeniable advantages of powder-based paints. The absence of toxic compounds allows you to reduce the cost of ventilation systems and provide the premises with appropriate installations.
  • Maximum automation of the workflow reduces the requirements for employees, simplifies their training system.

Views

Powder paints are classified according to the method of film formation. Consider the main popular varieties.

Thermoplastic

The resins used are nylon, vinyl or polyester. A hard coating is formed by the hardening of resins after reflow. There are no chemical reactions when using these paints. This makes it possible to reheat and melt the powder. They are mainly used for painting metal and chrome-plated products..

The negative side of thermoplastic paints is that the protective film will disappear if the temperature is violated.

Thermoactive

This is the more common type of paint. The film is formed by a chemical reaction and transformation of the composition. Several types of resins are used for manufacturing..

The use of thermosetting paints reduces the risk of surface deformation during reheating to zero. Dyeing with thermoactive paints is used for products that are used in difficult conditions..

This material is actively used in mechanical engineering..

The components of both types of paints have good flowability, so that the paint does not stick if it gets on the skin or a foreign object that is not planned to be painted. Powders do not have a shelf life, over time they do not thicken, harden or tarnish.

Their main difference from liquid analogs is that there is no need for a solvent. Various pigments can be included to add depth and brightness to the product.

Benefits of paints

Economical technology, high speed of polymerization (fast solidification), compact size of the equipment and the possibility of reusing the remaining powder suggest a high advantage of solid paints over traditional paints and varnishes. Let’s highlight the main advantages of powder paints.

Profitability

Due to the technology and the ability to return unused material back to the tank, polyester powder is the most economical product compared to other types of paints.

High wear resistance

Powder paints, despite their environmental friendliness, are not inferior in terms of wear resistance to other materials in their segment. Such a coating will not require quick adjustment, since the composition is resistant to abrasion..

Uniform coverage

The use of heat treatment chambers ensures uniform distribution of polyester particles and pigment. The paint lays down in an even and even layer, while there are no visible transitions on the surface.

Additional protective functions

The uniform coating affects the distribution of loads and gives additional strength to the base, increasing the protection of the product. Due to its chemical composition, this material resists corrosion.

Ease of service

The ease of maintenance of the equipment and the coated product is a clear plus for powder coating. It is easy to apply the composition: even a beginner can do it.

Decorativeness

The wide variety of colors allows for a wide variety of finishes and textures. Gloss, matte finish, volumetric or metallic, texture of wood and marble – all this is possible when using this powder.

High adhesion

Powder paints have high adhesion to surfaces, and the type of surface can be universal. Due to its high adhesion, this paint option is suitable for a wide range of materials as well as stainless steel products..

Heat resistance

The baking method improves resistance to temperature extremes, strengthening the coating and providing reliable protection from thermal effects in the future.

Variety of colors

When mixing colors, you can get more than 5000 shades, simulate the properties of various textures, which is not available when working with liquid materials. If desired, you can choose a shade to match the interior composition, or perform surface finishing to accentuate individual functional areas.

Impact resistance

Immunity to mechanical damage makes powder paints especially popular. Polymer structure and processing technology increase the service life of the powder and coated material.

Water resistance

The water-repellent coating reliably protects against moisture and dust. It prevents the paint from peeling off the surface of the product. This property is especially appreciated by buyers..

Durability

The composition, resistant to decomposition and damage, allows for a long time to do without repainting the product. If you follow the staining technology, you will not have to carry out corrections or touch-ups of the surface for several years..

Chemical neutrality

The composition is neutral to chemical influences, and, therefore, resistant to them. The surface covered with this paint can be wiped using household chemicals.

Minuses

Powder painting technology has its drawbacks. These include the impossibility of correcting local deficiencies and defects. In the event of a marriage, it becomes necessary to completely repaint, which incurs significant material costs. In addition, the size of the products to be painted is limited by the size of the heat treatment chamber..

The requirement for special equipment and temperature conditions makes the use of powder paints at home difficult. Only if you have a complete set of equipment and a special oven will it be possible to paint yourself.

This process will be costly if only a few parts need to be painted. These paints are not suitable for painting parts to be welded in the future due to the lack of options for their restoration.. They cannot be tinted.

When working with hard paints, each color will have to be applied separately, mixing of powders is impossible.

Application methods

Dry powder paints are applied to the surface in two ways. Both consist in the transfer of an electric charge to the powder particles..

Electrostatic spraying

An industrial method of application, which consists in charging the powder particles with a corona discharge. The advantage of this painting is the ability to charge any modern powder materials. This reduces the sensitivity of powders to air humidity, reduces the cost of purchasing, operating and replacing equipment..

Tribo-static

This spraying occurs by rubbing one material against another. A Teflon tribostatic spray is used to apply dry powder. The advantage of this method is the transfer of charge without creating an electric voltage or ionic current between the powder particles and the spray gun. This makes it possible to apply the powder evenly and thinly. It becomes possible to use multi-jet nozzles in work, using paint more precisely and covering only the necessary areas.

This canned epoxy heat-resistant paint mixture has excellent technical characteristics..

The use of powder coatings for metal is a step forward in the paint industry. but this method is not universal.

Before using the powder coating technique, you should weigh the pros and cons. It is necessary to choose the most suitable option for the upcoming painting work.

In the video below you will see how metal is painted with powder paint..

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