Language
According to the latest data from the China Coatings Industry Association (CCOIA), the global coatings market will reach $202 billion in 2024, with a CAGR of 5.8% projected to 2029. China as the core market in the Asia-Pacific region, a total output of coatings in 2025 is expected to exceeds 36 million tons, the main business income of more than 420 billion yuan. Driven by the “double carbon” target, environmental protection policies continue to intensify. The “Coatings Industry” 14th Five-Year Plan clearly requires that by 2025, the proportion of environmentally friendly coatings must reach 70%. Water-based, UV, and powder coatings will become comprehensive alternatives to traditional oil-based coatings.
Iterative upgrading of coating production equipment has become the key to the transformation of the industry, the three major trends of equipment intelligence, environmental protection and high efficiency are becoming increasingly significant. In this paper, we will deeply analyze the logic of equipment selection for 6 major types of coatings, combined with the latest cases and policy requirements, to provide coatings enterprises with landable equipment configuration program.
2.1.Classification according to the dispersion medium/curing mode:
Water-based Coatings:
Definition: water as the main dispersion medium/diluent.
Characteristics: low VOC is more environmentally friendly, non-flammable, easy to clean, relatively slow drying speed, corrosive equipment to be considered, susceptible to microbial influences.
Common types: latex paint, water-based industrial paint, water-based car paint， water-based acrylic paint.
Impact on production: need to pay attention to corrosion-resistant materials, control of microorganisms, may require vacuum defoaming, drying energy consumption.
Solvent-Based Coatings:
Definition: Organic solvents such as toluene, xylene, esters, ketones, etc. are used as dispersion media/diluents.
Characteristics: excellent performance, fast leveling, high gloss, weather resistant, fast drying, flammable and explosive, high VOC, odor and toxicity.
Common types: industrial protective paints, car paint scratch repair, marine paints, wood paints and so on.
Impact on production: The core is explosion-proof safety! Equipment needs ATEX certification, workshop needs explosion proof design, solvent recovery/treatment system, good ventilation.
Powder Coating:
Definition: 100% solid powder, constructed by electrostatic spraying, heated melt leveling curing.
Characteristics: solvent-free, VOC close to zero, high utilization rate can be recycled, thick coating, good physical properties, color change is relatively troublesome, need high temperature curing.
Common types: epoxy, polyester, acrylic powder coatings for metal furniture, home appliances, building materials, automotive parts and so on.
Impact on production: Completely dry production, no liquid mixing; extrusion melt mixing is required; fine grinding is needed; efficient powder recycling system is required.
Radiation Curable Coatings (UV/EB):
Definition: UV coatings cure by ultraviolet light, EB coatings cure by electron beam. Typically 100% solids or high solids.
Characteristics: Seconds curing, energy saving, low VOC, excellent performance, high investment in equipment, special monomers/oligomers required, limitations on substrates and shapes.
Common types: coat for wood, plastic coatings, printing inks, electronics coatings.
Impact on production: The core is the curing equipment! Matching UV lamps/EB generators required; photoinitiators required for formulations; production environments need to be protected from light or managed at specific wavelengths.
2.2.Classification according to film-forming mechanism:
Physical drying: solvent volatilization film, such as nitrocellulose lacquer, part of the latex paint.
Oxidative polymerization: absorb oxygen in the air curing, such as alkyd paint.
Chemical crosslinking: curing by mixing the two components, such as epoxy paints, polyurethane paints or one-component moisture curing such as moisture-curing polyurethane..
Heat curing: Heat is required for curing, e.g. powder coatings, partial amino baking paints.
Radiation curing: Curing by polymerization initiated by UV or EB energy.
2.3 Classification by application:
Architectural coatings: internal and external walls, flooring
Industrial coatings: automotive, marine, containers, home appliances, coil, anti-corrosion
Wood coatings
Special coatings: fireproofing, antifouling, conductive, heat insulation, etc.
3.1. Water-Based Paint Production Equipment Configuration:
Core Equipment: High-speed disperser (pre-mixing), sand mill (vertical/horizontal pin-type is preferred – good airtightness and high efficiency), mixing tank/paint mixing kettle (with agitation), bag/cartridge filter. For high-gloss/high-demand paints, optional vacuum degassing equipment and a filler are available.
Key Selection Points:
Material: 316L stainless steel or higher is recommended for material contact parts to prevent corrosion and ionic contamination.
Microbial Resistance: The equipment should be designed to facilitate thorough cleaning and disinfection, avoiding dead corners. A CIP system is advantageous.
Vacuum Degassing: Essential for clearcoats and high-gloss topcoats; an effective degassing system is recommended.
Sealing: Fully enclosed vacuum loading is essential to minimize evaporation and contamination.
Pumps, Valves, and Piping: Corrosion-resistant stainless steel.
3.2 Explosion-Proof Equipment Selection for Solvent-Based Coatings:
Core Equipment: Explosion-proof high-speed disperser, sealed and certified sand mill, explosion-proof mixing tank/paint mixing kettle, filter, explosion-proof liquid filler.
Key Selection Points:
Explosion-proof safety is paramount. All electrical equipment, motors, and instrumentation must meet the corresponding explosion-proof grade standards.
Sealing: The equipment must be well sealed to minimize solvent volatilization and is typically equipped with a nitrogen blanket.
Solvent Recovery/Treatment: A solvent recovery device or high-efficiency exhaust gas treatment system is strongly recommended.
Ventilation: The production workshop must have forced ventilation, with local exhaust ventilation in the equipment area.
Material: Stainless steel is resistant to solvent corrosion.
Grounding: Prevent static electricity accumulation.
3.3. Core Equipment of Powder Coating Production Line:
Core Equipment: High-speed color mix machine, extruder, cooling belt/crusher, ACM mill/micronizer, cyclone separator + bag/cartridge dust collector, screening machine, filling/packaging equipment.
Key Selection Points:
Extruder: Twin-screw extruders offer more efficient mixing, achieve uniform dispersion of nano-scale fillers, and significantly reduce agglomeration.
Grinding System: Vertical mills are suitable for fine powder production (800 mesh and above), with 15-25% lower energy consumption per unit than roller mills. They are suitable for high-end plastic masterbatches, electronic-grade fillers, and other applications.
Roller mills still hold a 40% market share in the 300-800 mesh range and are suitable for applications with lower fineness requirements, such as general building material fillers and agricultural mineral powders.
Powder Recovery Efficiency: Recovery system design directly impacts cost and environmental performance. High-efficiency cyclones and precision dust removal are standard features.
Dust Control Throughout the Process: Sealed equipment connections and a negative pressure design prevent dust escape. Operator protection is also required.
Material: Extruder components and the grinding chamber require wear-resistant treatment.
3.4. Key Points for Selecting UV-Curing Coating Equipment:
Core Equipment: High-speed disperser, sand mill (selected based on viscosity), mixing tank/paint mixing kettle, filter, filler machine , with the core being the UV/EB curing equipment.
Key Selection Points:
UV curing equipment: Lamp type, power density, beam width, cooling system, reflector efficiency, and nitrogen inerting. LED-UV is the trend: energy-saving, cold light source, and long life.
EB curing equipment: Electron beam generator power, beam width, and shielding safety.
Formula Compatibility: The equipment must match the absorption wavelength of the photoinitiator used in the formulation.
Production Environment: Avoid stray light interference (especially UV); EB requires strict radiation protection.
Basic Equipment: Similar to solvent-based/water-based, but be aware of the material’s potential high viscosity or thixotropy.
1.Q: What exactly does “explosion-proof” mean for solvent-based paint production equipment? How can I confirm that the equipment meets the requirements?
A: “Explosion-proof” means that the equipment is designed and manufactured to prevent potential internal sparks, hot surfaces, or mechanical sparks from igniting the surrounding flammable gas, vapor, or dust atmosphere.
How to confirm:
Check the certification mark: The equipment must bear a nationally or internationally recognized explosion-proof certification mark. These marks are usually engraved on the equipment itself or on the nameplate.
Check the certificate: Request and verify a valid explosion-proof certificate from the equipment supplier to confirm that it is applicable to the hazardous materials and area classifications in your production environment.
Not only the equipment itself, but also the motor, switches, control cabinet, lighting, and even tools and operating procedures must meet the overall explosion-proof requirements of the workshop.
2.Q: I primarily produce water-based paints. Can I completely avoid explosion-proof equipment?
A: Not entirely.
Core Equipment: Water-based paints use water as the dispersion medium and are inherently non-flammable. Therefore, core production equipment such as dispersers, sand mills, and mixing tanks generally do not require explosion-proof certification. For pure water-based systems, core production equipment generally does not require explosion-proof certification. However, a detailed risk assessment must be conducted based on the specific formulation, including any flammable solvents, and any production steps that generate combustible dust, to determine the explosion-proof requirements for the entire factory.
3.Q: How do I choose the right paint tinting machine?
A: Three key factors apply:
1. Demand and Accuracy:
Large batches with a small variety of products: Choose a large-capacity, high-speed automatic slurry dispensing machine.
Small batches with a large variety of products/high frequency: Focus on equipment with high accuracy (±0.1g/ml) and fast color change. Key Considerations:
Pump Technology: Plunger pumps offer the highest accuracy (especially for small dosages).
Weighing Feedback: Essential to ensure absolutely accurate dosing.
Cleaning/Color Changes: The faster the better (a rinsing-free colorant pump system is optimal).
2. Colorant Compatibility: Confirm whether the colorant is water-based, solvent-based, or UV-cured.
Equipment contact material must be compatible (e.g., 316L stainless steel for corrosion resistance, certain plastics for solvent resistance).
High-viscosity or easily sedimented colorants require equipment with agitation or circulation.
3. System Type (Key Decision)
Colorant Pump System (Mainstream Recommendation):
Separate pump and piping for each color.
Advantages: High accuracy, fast color changes, no cross-contamination.
Disadvantages: Higher initial cost (number of pumps = number of colors).
Switching Valve System:
Multiple colors share a small number of pumps and main lines, switched by valves.
Advantages: Capable of handling a wide range of colors, potentially lower initial cost.
Disadvantages: Color changes require piping cleaning, potential for residual contamination.
