We present a series of analyses that differentiate between conventional paints and powder paints.
by Álvaro Orozco*
Powder coating is one of the most in-demand surface coatings in the industry in terms of metal parts. In recent years this type of coating has largely displaced conventional application systems becoming the most required in the metal processing industry and serving companies as demanding as manufacturers of hospital equipment, office equipment, lighting equipment, road signage, auto parts, motorcycle parts, shelves, appliances, pipes, profiles etc, just to mention some products that use this type of finish.
From its beginnings in the middle of the previous century (XX) electrostatic painting, although with some limitations and deficiencies, also showed a series of benefits in terms of the quality of the coating, counteracting corrosion and abrasion in a good way, as well as a high film thickness (reaching up to 500 microns) initially used as an electrical insulator.
Until then the advances have come by leaps and bounds where the application equipment and the machines and equipment involved in the process were technologically improved, progress was made in the different types of polymerization such as furnaces by ultraviolet light, significant progress was made in the quality of the different resins teaching different options of finishes and textures and qualities of the same coating, to expand more and more its range of colors and even adapt to coat other types of non-metallic substrates, such as the application on MDF and glass.
Its differential characteristics with the rest of the paints are multiple, where we find benefits and shortcomings if it is to compare with other conventional coatings.
Advantages of powder coating
Economic
- The use of the product can be between 95 to 98% due to the reuse of the powder with a due process.
- It is used as provided and it is not necessary to adjust viscosities or make mixtures.
- It is possible to achieve the automation of both surface cleaning and application processes, as long as the company has the infrastructure and financial muscle.
- On some substrates of round geometric figure it is only necessary to apply a single "hand", since the paint adheres to the contour of the piece.
Environmental
- Its presentation is in the form of a finely divided solid, does not contain solvents, therefore does not emit the large amounts of volatile organic compounds as generated by conventional paints, minimizing the impact on the environment.
- The storage of paints does not require places with high technical demands and only a place with normal environmental conditions is necessary.
Techniques
- The application is very simple and does not require qualified personnel to run it.
- Homogeneity in the applied layer due to electrostatic attraction.
- High thicknesses obtained in the final paint with a single application.
- Wide variety of colors, textures and effects, such as textured finishes, micro texturing, hammering, among others.
- Easy to correct errors during the application, since during the process the dust is easy to remove and allows to repair the defective application in an agile and simple way.
- High mechanical properties and abrasion resistance of the coating
Disadvantages of powder coating
- For the proper execution of the process, sufficient space must be available in the facilities where they are contemplated: pre-treatment tanks, parts mooring area, application cabin, place for application equipment, oven and area for hanging and handling of the pieces.
- The costs of the machinery used are usually high.
- The color changes are wasteful because they require that the trace of the previous color be completely eliminated throughout the system (cabin and equipment) in addition to changing filters since these should only be used one set for each color
- Although with the passage of time the appearance of the powder paint is improved, the texture is not totally optimal for mirror finishes such as that of a vehicle.
- High film thickness is usually a quality but on some occasions, such as where parts require a particularly low fit, such a high film thickness is taken as a defect.
- Undoubtedly, there is a whole series of considerations that must be taken into account when leaning towards one or another finishing option for a metal part.
* Álvaro Orozco is an Instructor of the Furniture Technology Center – Antioquia regional, of the National Learning Service (Seine). Email: [email protected] - [email protected]
Quería consultarles si tienen referencias de las máquinas de pintura en polvo marca Electron, es una marca de Turquía. Estamos en el proceso de la compra de un sistema automático pero la verdad no sé si son de buena calidad. Me podrían ayudar? . Saludos.