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Author: Site Editor Publish Time: 12-05-2025 Origin: Site
In modern industrial coating processes, coating uniformity is no longer merely an indicator of “aesthetic appearance,” but a core metric directly related to product corrosion resistance, mechanical protection, compatibility with subsequent processing, and overall service life. For manufacturing enterprises, even the slightest variation in coating thickness can be amplified during mass production, leading to unstable quality, increased rework costs, and higher energy consumption. Therefore, throughout the entire coating line, equipment and parameters that affect coating uniformity are given great attention. As the foremost executing component in the coating process, the nozzle’s structure and spray behavior are especially critical in determining coating consistency.
Among various nozzle types, the fan spray nozzle has become the standard configuration for nearly all industrial coating lines due to its controllable linear spray pattern, high stability, and wide applicability. To achieve truly stable and continuous coating uniformity, understanding the structural logic and spray characteristics of fan spray nozzles is essential.
A flat fan nozzle is a type of industrial nozzle that uses the geometry of the spray orifice and the design of the internal liquid channel to shear the liquid into a fan-shaped thin sheet spray under pressure. Its spray pattern unfolds linearly with predictable coverage and balanced flow distribution, making it widely used in industrial spraying processes such as coating, cleaning, pretreatment, and cooling. Its stability, controllability, and versatility make it a core component in continuous production lines and automated spraying systems.
Core Features of Fan-Shaped Nozzles:
Fan-Shaped Spray Pattern
The sprayed liquid expands in a fan shape, forming a linear and uniform spray width, which is especially suitable for conveyor line continuous spraying.
Uniform Flow Distribution
The flow density is stable in the center and naturally tapers off at the edges, effectively preventing sudden thickness changes or obvious streaks during spraying.
Multiple Spray Angles Available
Spray angles range from narrow (10°–25°) to wide (80°–120°) to meet different coverage widths and impact force requirements.
Pure Hydraulic Atomization with Simple Structure
Does not rely on an air source, resulting in low failure rates and easy maintenance, making it ideal for long-term stable operation in industrial production lines.
Controllable Droplet Size
Stable droplet sizes are formed within a specified pressure range, helping to improve coating surface smoothness and uniform adhesion.
Compatible with Various Media
Suitable for water-based coatings, cleaning solutions, chemical liquids, rust inhibitors, and other industrial fluids, offering strong compatibility.
The fan-shaped spray pattern produced by the fan nozzle exhibits distinct geometric regularity, a characteristic that enables engineers to pre-calculate the ideal distribution of the coverage area.
The contributions of the fan-shaped spray pattern to coating uniformity include:
smoother lateral coverage with less likelihood of local 'voids';
excellent flow density in the middle region of the spray, suitable for primary coverage;
a gradually fading edge structure that can naturally connect with adjacent nozzles;
stable spray trajectory without 'jumping' or deviation.
On automated spray lines, the speed of the conveying line is constant, and the stability of the spray pattern allows the coating system to accurately calculate the amount of mist, coverage width, and nozzle spacing, which is crucial for the final uniformity of the formed coating film.
The flow output of the fan-shaped nozzle is closer to the theoretical value, with almost no noticeable pressure loss fluctuations. This has the following effects on coating thickness:
The coating film thickness is in a "linearly controllable" state.
The more stable the flow, the easier it is to keep the coating thickness within the set range.
The coating film is less likely to have uneven "splash spots" structures.
It prevents local over-deposition or material shortage.
The nozzle is insensitive to upstream pressure fluctuations.
Factors such as pump startup, filter switching, and supply fluctuations are less likely to cause spray pattern drift.
For industries requiring high repeatability in spraying (such as automotive parts coating lines), stable flow performance significantly reduces quality variations.
It can be used with a variety of industrial fluids, including water-based coatings, cleaning solutions, chemical liquids, and rust inhibitors, offering strong compatibility.
The spray angle determines the spray width and the pressure density per unit area, as well as whether the coating can be evenly applied on different surfaces. Different spray angles are suited for different scenarios:
120° Wide Angle: Suitable for spraying large flat surfaces such as panels, door panels, and appliance housings.
65°–80° Medium Angle: Suitable for continuous spraying of metal structural parts and stamped components.
25°–40° Narrow Angle: Suitable for enhancing local adhesion or spraying in recessed areas.
By flexibly adjusting the spray angle, engineers can control the overlap rate of the spray width, ensuring that each area is covered within a reasonable range, thereby achieving maximum uniformity and minimizing coating waste.
In coating applications, droplet size directly affects the quality of the film formation. The characteristics of droplet distribution from a fan-shaped nozzle are as follows:
1. The particle size is stable and concentrated, which is conducive to uniform spreading of the thin film and avoids surface granularity caused by excessively large particles.
2. The coating particles are evenly distributed, improving the continuity of the film formation and reducing the risk of defects such as 'pinholes', 'voids', and 'craters'.
3. A combination of small to medium particle sizes is suitable for undercoating, phosphating, and pretreatment solution spraying, significantly enhancing adhesion and reaction effectiveness. The better the droplet stability, the higher the coating flatness, uniformity, and coverage integrity.
Uniform coating essentially means "high utilization," and fan nozzles offer numerous advantages:
Less overlapping spraying
Reduced paint waste
Lower energy consumption (due to lower pressure requirements)
Fewer reworks and cleaning cycles
If your coating system is aiming for higher uniformity, more stable spray patterns, longer service life, and lower maintenance costs, it is crucial to choose a nozzle supplier who truly understands your operating conditions, materials, and spray behavior.
Xinhou Nozzles provides customers with:
Fan nozzles made from various materials (stainless steel, brass, ceramic, PP, etc.)
Condition-adapted selection (spray angle, flow rate, pressure, droplet size, corrosion resistance)
Customizable spray hole structures, spray widths, and connection specifications
Strict quality control standards: spray pattern, flow rate, angle, and wear resistance testing
Reliable delivery schedules and long-term supply capabilities
Comprehensive nozzle solutions for coating, pretreatment, cleaning, and cooling industries
Feel free to contact Xinhou. We will provide your spraying production line with more stable, efficient, and reliable nozzle solutions.
