Coating equipment is an indispensable and important part of modern industrial manufacturing systems. It is widely used in industries such as automotive, home appliances, hardware, shipbuilding, engineering machinery, furniture, and rail transportation. Its core task is to apply coatings evenly on the surface of workpieces to form protective, aesthetic, and functional coatings. Due to the complex working conditions in the coating process, which involve airflow, liquids, powders, chemical reactions, high-temperature drying, and corrosive substances, the materials used in the manufacturing of coating equipment must be reliable in performance and adaptable to ensure long-term stable operation, high-quality coatings, and operational safety.
Reasonable material selection for coating equipment requires engineers to fully understand the performance characteristics of various materials and make comprehensive judgments based on the equipment’s operating environment, process requirements, and economic principles. Coating production line manufacturers will analyze the load and material requirements of common components based on the functional structure of the coating equipment, explore the applicability of different materials in coating equipment, and their pros and cons, and propose comprehensive strategies and development trends for material selection.
I. Basic Structure and Key Components of Coating Equipment
Coating equipment typically consists of a pretreatment system, coating supply system, spraying devices, conveyor system, drying equipment, recovery system, ventilation and exhaust system, and control system. The structure is complex, and the operating environment is varied. Each system performs different functions, requiring different materials.
The pretreatment system involves high temperature, high humidity, and strong corrosive chemicals.
The spraying system involves high-speed airflow, high-voltage electrostatic, and electrical discharge hazards.
The conveyor system must bear the weight of the workpieces and operate for long periods.
Drying equipment involves high-temperature heating and thermal expansion issues.
The ventilation system requires corrosion-resistant and anti-aging pipes and fan structures.
The waste gas treatment and coating recovery system must handle flammable, explosive, or highly corrosive gases and dust.
Therefore, the material selection must align with the specific working conditions of each functional area, without a one-size-fits-all approach.
II. Basic Principles for Material Selection in Coating Equipment
When selecting materials for different parts, the following basic principles should be followed:
1.Prioritize Corrosion Resistance
Since the coating process frequently involves corrosive media such as acidic and alkaline solutions, organic solvents, coatings, and cleaning agents, the material must have excellent chemical corrosion resistance to prevent rust, perforation, and structural degradation.
2.High Temperature Resistance or Thermal Stability
Components operating in high-temperature drying rooms or sintering furnaces must have high-temperature strength, good thermal expansion coefficient matching, and resistance to heat aging to cope with temperature changes and thermal shocks.
3.Mechanical Strength and Rigidity
Structural bearing parts, lifting systems, tracks, and conveyors must have sufficient strength and fatigue resistance to ensure stable operation without deformation.
4.Smooth Surface and Easy Cleaning
Coating equipment is prone to contamination by coatings, dust, and other pollutants, so materials should have a smooth surface, good adhesion resistance, and easy cleaning properties to facilitate maintenance.
5.Good Processability and Assembly
Materials should be easy to cut, weld, bend, stamp, or undergo other mechanical processing, adapting to the manufacturing and assembly of complex equipment structures.
6.Wear Resistance and Longevity
Components that frequently operate or have friction contact must have good wear resistance to extend service life and reduce maintenance frequency.
7.Electrical Insulation or Conductivity Requirements
For electrostatic spraying equipment, materials must have good electrical insulation properties; while grounding protection devices require materials with good electrical conductivity.
III. Analysis of Material Selection for Key Components in Coating Equipment
1.Pretreatment System (Degreasing, Rust Removal, Phosphating, etc.)
The pretreatment system often requires chemical treatment of workpiece surfaces with high-temperature acidic or alkaline liquids. This environment is highly corrosive, making material selection particularly critical.
Material Recommendations:
Stainless Steel 304/316: Commonly used for phosphating and degreasing tanks and pipes, with good acid and alkaline resistance and corrosion resistance.
Plastic Lined Steel Plates (PP, PVC, PE, etc.): Suitable for highly acidic environments, with relatively low costs and strong corrosion resistance. Titanium Alloy or FRP: Performs well in highly corrosive and high-temperature environments but at a higher cost.
2.Spraying System (Automatic Spray Guns, Spray Booths)
The key to spraying equipment is atomizing the coating, controlling flow, and preventing paint accumulation and electrostatic discharge risks.
Material Recommendations:
Aluminum Alloy or Stainless Steel: Used for spray gun housings and internal channels, offering good corrosion resistance and lightweight properties.
Engineering Plastics (e.g., POM, PTFE): Used for coating flow components to prevent paint clumping and clogging. Anti-static Composite Materials: Used for the walls of the spray booth to prevent static accumulation that could lead to sparks and explosions.
3.Conveyor System (Tracks, Hanging Systems, Chains) Coating lines often use chain conveyors or ground roller conveyors, which bear heavy loads and operate for extended periods.
Material Recommendations:
Alloy Steel or Heat-treated Steel: Used for sprockets, chains, and tracks with high strength and excellent wear resistance.
Low-alloy Wear-resistant Steel: Suitable for areas with severe wear, such as turning tracks or inclined sections.
High-strength Engineering Plastics Sliders: Used in friction reduction and buffering systems to reduce noise and enhance smooth operation.
4.Drying Equipment (Hot Air Furnace, Drying Boxes) The drying area requires continuous operation at temperatures ranging from 150°C–300°C or even higher, with high demands for metal thermal stability.
Material Recommendations: Heat-resistant Stainless Steel (e.g., 310S):
Can withstand high temperatures without deformation or oxidation.
Carbon Steel + High-temperature Coatings: Suitable for mid to low-temperature drying tunnels, cost-effective but with a slightly shorter lifespan.
Refractory Fiber Insulation Layer: Used for internal wall insulation to reduce heat loss and improve energy efficiency.
5.Ventilation and Exhaust System
Used to control airflow, prevent the spread of toxic and harmful substances, and ensure a clean workshop and worker safety.
Material Recommendations:
PVC or PP Ducts: Resistant to acid and alkaline gas corrosion, commonly used for acid mist and alkaline mist exhaust.
Stainless Steel Ducts: Used for transporting high-temperature or paint solvent-containing gases.
Fiberglass Fan Impellers: Lightweight, corrosion-resistant, and suitable for chemical coating environments.
6.Recovery and Waste Gas Treatment Devices
During powder coating and solvent-based coating processes, dust and volatile organic compounds (VOCs) are generated, requiring recovery and purification.
Material Recommendations:
Carbon Steel with Spray Coating + Anti-corrosion Coating: Used for recovery bins and dust removal rooms, cost-effective. Stainless Steel Filter Shells: Suitable for environments with high solvent concentrations and severe organic corrosion.
Activated Carbon Bins and Catalytic Combustion Devices: Involves high-temperature reactions and requires high-temperature resistant metals or ceramics.
IV. Environmental and Safety Factors in Material Selection
Coating workshops often face the following risks:
Flammability and Explosion of Organic Solvents: Materials should have anti-static and anti-spark properties, with reliable grounding connections.
Dust Explosion Risks: Avoid materials that are prone to dust accumulation or ignition, especially in enclosed spaces.
Strict VOC Emission Control: Material selection should consider environmental sustainability and avoid secondary pollution.
High Humidity or Corrosive Gases: Use anti-oxidation, anti-corrosion, and weather-resistant materials to reduce equipment maintenance frequency.
When designing, coating production line manufacturers should consider material selection, structural design, safety standards, and operating conditions together to avoid frequent replacements and safety hazards.
V. Economic and Maintenance Considerations in Material Selection
In the manufacturing of coating equipment, not all parts require expensive high-performance materials. A rational material gradient configuration is the key to controlling costs and ensuring performance:
For non-critical areas, cost-effective carbon steel or regular plastics can be selected.
For highly corrosive or high-temperature areas, reliable corrosion-resistant and high-temperature materials should be used.
For frequently worn parts, replaceable wear-resistant components can be used to enhance maintenance efficiency.
Surface treatment technologies (such as spraying, anti-corrosion coatings, electroplating, oxidation, etc.) significantly improve the performance of ordinary materials and can replace some expensive raw materials.
VI. Future Development Trends and Material Innovation Directions
With the advancement of industrial automation, environmental regulations, and sustainable manufacturing, material selection for coating equipment faces new challenges:
Green and Environmentally Friendly Materials
New low-VOC emission, recyclable, and non-toxic metals and non-metals will become mainstream.
High-Performance Composite Materials
The use of fiberglass-reinforced plastics, carbon fiber composites, and others will achieve a synergistic enhancement of lightweighting, corrosion resistance, and structural strength.
Smart Material Applications
“Smart materials” with temperature sensing, electric induction, and self-repairing functions will gradually be applied to coating equipment to improve automation levels and fault prediction capabilities.
Coating Technology and Surface Engineering Optimization
Laser cladding, plasma spraying, and other technologies will enhance the surface performance of ordinary materials, reducing material costs while extending service life.
Post time: Sep-15-2025
