This article systematically introduces the concept, characteristics, functions, application fields, selection considerations, and solutions to common problems of general industrial powder coatings. It focuses on the applications of general industrial powder coatings to help everyone better understand what general industrial powder coatings are, as well as their characteristics and functions.
What Are General Industrial Powder Coatings
General industrial powder coating is an environmentally friendly coating in 100% solid powder form, using thermosetting resins (such as epoxy, polyester, or a combination of both) as the main film-forming materials, with pigments, fillers, and additives added.It contains no organic solvents, has extremely low VOC (volatile organic compound) emissions during spraying, and the powder that does not adhere can be recycled and reused. It is an economical and environmentally friendly coating material.
Characteristics of General Industrial Powder Coatings
The main characteristics of general industrial powder coatings are as follows.1. Balanced Performance (Core Advantage)
Unlike pure epoxy (extremely strong corrosion resistance but poor weather resistance) or pure polyester (excellent weather resistance but slightly weaker adhesion), it achieves a balance among adhesion, flexibility, hardness, and outdoor durability through an epoxy-polyester hybrid system, meeting the comprehensive requirements of most ordinary industrial products.
2. Economical and Efficient
The raw material cost is moderate, and the powder utilization rate exceeds 95%. It has high spraying efficiency and relatively low overall coating costs.
3. Environmental Protection and Safety
It is a 100% solid powder coating with almost zero VOC emissions, no fire hazards, and complies with environmental regulations.
4. Good Decorative Performance
It can provide various surface effects such as high gloss, matte, sand texture, and metallic texture, with rich colors and good leveling performance.
5. Wide Applicability
It has good adhesion to common metal substrates such as steel and aluminum, and can meet the coating requirements of most indoor and outdoor industrial metal products.
Functions of General Industrial Powder Coatings
The main functions of general industrial powder coatings are reflected in the following aspects:1. Basic Protection Function
It forms a dense coating on metal surfaces, effectively preventing rust, corrosion, and wear, extending the service life of industrial products such as mechanical equipment, storage racks, and hardware components.
2. Decorative Enhancement Function
It provides rich colors and gloss effects (high gloss/matte/sand texture, etc.), covers substrate defects, and improves product appearance quality and added value.
3. Cost Reduction and Efficiency Improvement Function
The powder can be recycled and reused during spraying, achieving high overall utilization. In addition, it does not require solvents, eliminating solvent costs and environmental treatment costs, resulting in lower overall coating costs.
Application Fields of General Industrial Powder Coatings
The specific application fields of general industrial powder coatings are as follows.1. Metal Products and Hardware Field
It is widely used for storage racks, guardrails, valves, pipe fittings, fasteners, and other products, providing basic corrosion protection and wear resistance.
2. Mechanical Equipment Field
It is applied to agricultural machinery tools, engineering machinery components, machine tool housings, motor housings, and other products, combining protection and appearance requirements.
3. Warehousing and Logistics Field
It covers storage racks, pallets, logistics turnover boxes, and other products, where coatings are required to have scratch resistance and impact resistance.
4. Household Appliances and Furniture Field
It is used for outdoor air conditioner units, electrical control cabinets, office furniture, fitness equipment, and other products, focusing on decorative performance and surface texture.
How to Select General Industrial Powder Coatings
When selecting general industrial powder coatings, we may face the problem of not knowing how to choose. Based on our industry experience, we recommend paying attention to the following aspects when selecting general industrial powder coatings.1. Select the Resin System According to the Application Environment
(1) Indoor Environment (General Corrosion Protection)
Select epoxy-polyester hybrid powder coatings, which provide the highest cost performance and good adhesion, but have average weather resistance (not suitable for long-term sunlight exposure).
(2) Outdoor Environment (Weather Resistance Required)
Pure polyester powder coatings must be selected, as they have strong UV resistance and are not prone to chalking or fading under long-term sunlight exposure. For high-rise buildings or highly corrosive coastal environments, the weather resistance grade should be further improved (such as Qualicoat Class 2).
2. Match Adhesion According to Substrate Material
(1) Ordinary Steel
General-purpose types (epoxy-polyester or pure polyester) can be used. When pretreatment is properly performed (phosphating), adhesion performance is excellent.
(2) Galvanized Sheet / Stainless Steel
Special powder coatings should be selected (usually epoxy or special polyester systems), because ordinary powders have poor adhesion to zinc layers or dense oxide layers and are prone to peeling.
(3) Castings (Cast Iron / Cast Aluminum)
The surface is rough and may contain pores. High-leveling and high-penetration powders should be selected, or conductive primers should be applied first to cover defects.
3. Match Technical Performance Indicators According to Requirements
(1) Mechanical Strength (Impact Resistance / Bending Resistance)
If the workpiece requires post-processing (such as punching or bending), the coating needs good flexibility. Confirm that impact tests (≥50kg·cm) and bending tests (≤2T) meet requirements.
(2) Chemical Corrosion Resistance (Acid / Alkali / Oil Resistance)
If the coating contacts chemicals (such as chemical equipment or valves), pure epoxy powder coatings should be preferred, as their chemical resistance is far superior to hybrid systems.
(3) Hardness and Wear Resistance
If high hardness is required (such as storage racks and tools), high-hardness formulations (≥2H) can be selected. However, excessively high hardness often reduces flexibility, so a balance is required.
4. Determine the Final Solution According to Appearance and Cost
(1) Appearance Effects
Options include high gloss (>85°), matte (20°-70°), sand texture, wrinkle texture, or metallic texture (containing metallic powder). Sand texture/wrinkle texture can cover substrate defects, while metallic powder provides strong decorative effects but has higher costs and requires attention to spraying stability.
(2) Cost Budget
Epoxy-polyester hybrid systems have the lowest price; pure polyester outdoor systems have medium prices; systems containing metallic powder or special functions (such as antibacterial and flame-retardant properties) have the highest prices.
Common Problems and Solutions of General Industrial Powder Coatings
The most common problems during the use of general industrial powder coatings are mainly reflected in the following aspects. Based on our industry experience, we have proposed corresponding solutions to help effectively solve the powder coating problems you encounter.1. Cratering, Orange Peel, and Particle Problems
(1) Cratering (Volcano-Like Defects)
Possible Causes:
Compressed air contains oil and water, or degreasing during pretreatment is insufficient.
Solutions:
Install a high-efficiency oil-water separator and regularly drain water. Check the concentration of the degreasing bath to ensure complete oil removal.
(2) Orange Peel (Poor Leveling)
Possible Causes:
Powder particle size is too coarse or the curing oven heating rate is too fast.
Solutions:
Require the supplier to control particle size (D50≈35-40μm). Reduce the heating rate in the front section of the curing oven and extend melting and leveling time.
(3) Particles (Surface Raised Spots)
Possible Causes:
Environmental dust or recycled powder that has not been screened.
Solutions:
Clean the spray booth environment. Filter recycled powder through a 200-mesh screen before reuse.
2. Coating Peeling and Powder Falling Problems
Possible Causes:
Unqualified pretreatment (insufficient degreasing, missing phosphating film, or excessive phosphating film thickness) is the main cause. Secondly, insufficient curing results in incomplete cross-linking.
Solutions:
Strictly implement the process of degreasing → water washing → phosphating (or silane treatment). Use the cross-cut test to verify adhesion during each production shift. Use an oven temperature profiler to measure the actual workpiece temperature, ensuring that the curing window reaches 180-200°C × 10-15 minutes.
3. Impact Cracking and Powder Falling During Bending Problems
Possible Causes:
Over-curing (excessive temperature or excessive curing time) causes the coating to become brittle; or the powder itself has insufficient flexibility.
Solutions:
Calibrate the curing oven temperature control system to avoid excessive temperature and excessive curing time. If the process is normal, replace with a high-toughness powder coating (required impact resistance ≥50kg·cm, bending resistance ≤2T).
4. Poor Scratch Resistance and Easy Scratching Problems
Possible Causes:
Insufficient curing (under-baking) or low resin content in the formulation.
Solutions:
Ensure that the curing temperature and time meet requirements. If curing is normal, require the supplier to increase the pencil hardness (≥2H).
If you encounter some difficult-to-solve problems during the use of general industrial powder coatings, please feel free to contact us at any time to obtain professional technical support. We are willing to discuss solutions together, promote the development of the powder coating industry, and advance industry progress.
We hope this article can provide you with a professional and reliable reference regarding the powder coating industry. We sincerely welcome you to consult us regarding powder coating product performance, industry standards, application methods, precautions, or any related questions. We look forward to your inquiries through messages or direct contact at any time, so that we can provide you with more detailed product information, demonstration videos, or customized solutions to help you fully understand all the functions and advantages of our products.
