PART 1. Powder Spraying and Fluorocarbon Painting
1.1 Raw Materials for Powder Spraying
The raw materials for powder spraying include polyurethane (PU), polyurethane resin, epoxy resin, hydroxyl polyester resin, and epoxy/polyester resin, which can be prepared in various colors.
1.2 Characteristics of Powder Spraying
Spraying devices include manual and automatic hanging, with simple construction and a coating thickness of over 30 microns. It is resistant to impact, abrasion, corrosion, and weather, and the coating price is cheaper than fluorocarbon.
The main weakness of powder spraying is susceptibility to UV radiation from the sun, which can cause natural fading. However, colored aluminum profiles are now available in the market, used for aluminum doors and windows, and are sprayed with ordinary aluminum profile powder, increasing the variety of colors for aluminum doors and windows while enhancing their corrosion resistance.
1.3 Fluorocarbon Painting
Another type of electrostatic spraying is liquid spraying, also known as fluorocarbon painting or curium oil in Hong Kong. It is a high-end spray painting method with a relatively high price. In China, this technology is widely used for aluminum curtain walls. Due to its excellent characteristics, it is increasingly valued and favored by the construction industry and users. Fluorocarbon painting offers excellent color fading resistance, frost resistance, corrosion resistance to atmospheric pollution (acid rain, etc.), strong UV resistance, strong crack resistance, and the ability to withstand harsh weather environments, which ordinary coating methods cannot match.
1.4 Differences Between Powder Spraying and Fluorocarbon Painting
Powder spraying and fluorocarbon spraying processes are indeed very similar on the surface, but there are also many differences. In summary, the following points can be noted:
① Price: The price of fluorocarbon spraying is approximately 10,000 RMB per ton higher than that of powder spraying.
② Actual Usage: Fluorocarbon spraying is primarily used on the surface of curtain wall aluminum and outdoor profiles, while most indoor profiles are powder sprayed. However, with the extensive use of heat-insulating profiles and energy-saving doors and windows, fluorocarbon-sprayed aluminum is also widely used in the high-end market. Except for a small number of villas and government projects that use fluorocarbon spraying for thermal insulation profiles, powder spraying is used for others.
Qingdao COATOP Machinery and Technology Co., Ltd., provides professional powder coating solutions with a fast construction period, strong processing capacity, and guaranteed quality to meet customers' needs to the greatest extent possible.
PART 2. Powder Coating Consumption Cost Control
The production line technology of powder spraying equipment in China has a long history of development, with many manufacturers, but the overall performance and quality level of the equipment vary.
One important reason is the scarcity of manufacturing enterprises with excellent economic strength and technological level. Driven by economic interests and lacking research on key technologies such as static electricity and aerodynamics, mutual plagiarism makes it difficult to ensure product quality.
Electrostatic technology plays a crucial role in powder spraying technology. Both users and manufacturers of electrostatic powder spraying hosts need to have a deep understanding of the electrostatic phenomena during the powder spraying process.
With the advancement of technology, advanced electrostatic powder spraying equipment has entered the market, and its performance has basically met the following needs:
a. Uniform and high-quality coating film
b. Maximum powder coating rate at one time
c. Overcoming the Faraday shielding effect to effectively coat workpieces with complex geometric shapes
d. Better realization of workpiece overcoating
During the operation of the automatic spraying production line, aluminum profiles of different shapes and sizes are often hung on the same conveyor chain simultaneously, with horizontal intervals between them, and varying heights.
These horizontal gaps and height differences are the main reasons for powder blind spraying. To reduce the resulting waste of powder materials, our company's modern automatic spraying production line applies a spray gun automatic on/off control system.
An array-type photoelectric sensor (also known as a light curtain) is installed at the entrance of the spray chamber to automatically detect the presence, size, and shape of the workpiece. The information detected by the light curtain is transmitted to the spray gun on/off control system to ensure that the required spray gun is automatically activated for spraying when the workpiece passes through the spray gun.
The spraying equipment with a spray gun on/off control system greatly saves powder coating, reduces wear and tear on spray gun components, and saves labor costs by reducing the empty spray of the spray gun.
The main factors affecting powder material consumption in painting operations are:
a. Powder quality: Good quality powder can cover 10-12m² per kilogram, while poor quality powder may only cover 4-6m². The difference between the two is almost twice, but the price difference is not significant.
b. Coating thickness: The thickness of flat powder spraying film is generally 60-80 μm. The spraying thickness of sand grain powder is 50-70 μm, and orange grain powder spraying with a thickness of 90-110 μm. Of course, the thicker the coating, the greater the amount of powder consumed.
c. Equipment: If there is a problem with the recycling system of the spraying equipment, it will cause dust overflow or excessive scattering loss, reduce the powder loading rate of the spray gun, make it difficult to apply powder to the grooves, and the powder accumulated in the grooves will be taken away with the workpiece.
The powder electrostatic spraying host is crucial in the entire spraying system, as it directly affects the uniformity, flatness, and one-time powder application rate of the coating film.
