Powder coating is composed of solid resin, pigments, fillers, and additives. It has the characteristics of no solvent pollution, 100% film formation, and low energy consumption. There are two major types of powder coatings: thermoplastic and thermosetting. Thermosetting powder coatings use thermosetting synthetic resin as the film-forming substance. Thermosetting powder coating is what that used for aluminum profile paint. During the curing process, the resin melts first and then solidifies into a flat and hard coating after chemical crosslinking. The appearance and various mechanical properties and corrosion resistance of the coating film formed by this kind of paint can meet the requirements of aluminum profile finish appearance.
Powder coating spray has become the main choice of aluminum profile coating technology for the construction and decorative industry due to its low VOC emissions, high strength, high weather resistance, high corrosion resistance, diversified designs, and high paint utilization.
Powder coating for aluminum profiles can be divided into epoxy-polyester powder coatings for indoor use, polyester TGIC powder coatings for outdoor use and polyester non-TGIC coatings, polyester powder coatings for super-durable outdoor use, and wood grain powder coatings. The gloss is divided into high gloss, satin, and matte according to different application fields. The surface texture can be divided into smooth, sand texture, and so on.
Aluminum extrusion plants generally have their stable powder coating suppliers to ensure stable color and coating film quality.
What Type of Powder Coating Is Good for Aluminum Profiles?
Based on the characteristics of aluminum profile coating film for architecture and decoration, the powder coatings should have the following performance requirements: high weather resistance, strong mechanical properties, good use and application, diverse color and high leveling appearance design, quite strong resistance erosive.
The curtain wall structure and door and window frames made of aluminum profiles have high requirements for weather resistance due to long-term exposure to the outdoors. In essence, the weather resistance reaction is a series of complex physical and chemical changes of the polymer coating film in the atmospheric environment, mainly photodegradation and water degradation, which causes the coating film to lose gloss, change color and off-powder. The powder coatings used in this aluminum profile have high requirements on weather resistance, and some require 10-15 years of discoloration. The weather-resistant powder coating system on the market uses polyester TGIC as the mainstream, and its comprehensive performance is excellent.
Aluminum profiles are required to have strong mechanical properties in the subsequent construction operations and long-term use of a coating, which are reflected in excellent impact resistance, flexibility, adhesion, and surface hardness.
Coating Film Performance
Powder coatings for aluminum profiles usually require a smooth appearance to reduce the generation of orange peel. With the development of aluminum profiles for construction and decoration, the variety of colored powder coatings is becoming more and more abundant, and there are new surface requirements every year.
The powder spraying in the aluminum profile industry has its characteristics, which require powder coating products to have better anti-interference and frictional electrification.
There are wide types of powder coatings used by aluminum extrusion manufacturers, and frequent cleaning operations are required. So the compatibility of the powder is more important. In the formulation design, because it is very difficult to achieve a short-term color change in a powder room, it is often avoided that the primary pollution in the powder room is prone to secondary pollution of recycled powder. Extrusion plant can avoid separate pollution by using separate powder feeders and dust filters for the two types of powder coatings before and after the color change.
At present, most aluminum extrusion plants use electrostatic spray lines. The friction gun is charged by the friction between the gun body and the powder particles. The friction of the powder is important.
Coating Mortar Resistance
Aluminum doors and windows are inevitably contaminated with mortar during the installation process, and its silicate composition will erode the coating film, and even cause the appearance of the coating to change significantly and blistering and flaking. Therefore, professional powder coatings for aluminum profiles need to have mortar resistance. Most aluminum profiles have a right-angle structure, and powder coatings are required to have good corner coverage, including balanced flow and corner coverage.
For the correct powder coating spaying for aluminum profiles in the extrusion factory, please refer to the article by FONNOV ALUMINIUM.