This article systematically introduces the concept, characteristics, functions, selection considerations, and common problem-solving measures of household appliance powder coating. It focuses on the specific applications of household appliance powder coating in the home appliance sector to help readers better understand what household appliance powder coating is, as well as its characteristics and functions.
What Is Household Appliance Powder Coating
Household appliance powder coating is an environmentally friendly coating material in a solvent-free, 100% solid powder form. It is specially designed to provide an integrated surface treatment solution combining protection and decoration for the metal housings and components of home appliances such as refrigerators, washing machines, and air conditioners.Characteristics of Household Appliance Powder Coating
The main characteristics of household appliance powder coating are as follows.Environmentally Friendly and Efficient: Zero VOC emissions, recyclable overspray powder, high material utilization, and one-coat, one-bake application.
Excellent Decorative Properties: Available in a wide range of colors and capable of achieving various effects such as high gloss, metallic finishes, and matte finishes. Excellent surface leveling enhances the overall appearance and quality of home appliances.
Protection and Durability: The dense coating provides water resistance, alkali resistance, impact resistance, and scratch resistance, effectively protecting appliance housings. Some products also offer customized functions such as easy cleaning or antibacterial properties.
Functions of Household Appliance Powder Coating
The main functions of household appliance powder coating are reflected in the following aspects.1. Decorative Enhancement: Improving Product Appearance and Quality
It provides a wide range of color options, such as silver, champagne, and starry blue, as well as various surface effects, including high gloss, matte, and metallic finishes, meeting the requirements of integrated home appliance and home furnishing designs and personalized designs.
The excellent leveling performance of powder coating creates a smooth, mirror-like coating surface, significantly enhancing the perceived quality of home appliance appearance and brand value.
2. Protective Function: Extending Service Life
(1) Corrosion and rust protection: The dense coating effectively isolates moisture, oxygen, and corrosive media, preventing metal housings from rusting.
(2) Scratch and wear resistance: The coating has high hardness (≥1H) and good impact resistance (≥30 kg·cm), enabling it to withstand everyday impacts and scratches.
(3) Chemical resistance: It resists the effects of cleaning agents, oil stains, sweat, and other corrosive substances. Some kitchen appliance coatings also feature easy-cleaning properties, including oil and water repellency, allowing oil stains to be wiped away easily.
How to Choose Household Appliance Powder Coating
When selecting household appliance powder coating, we may encounter the challenge of not knowing how to make the right choice. Based on our industry experience, we recommend focusing on the following aspects when selecting household appliance powder coating.1. Confirm Compliance with Relevant Standards
Product compliance is the foundation of selection. Current industry standards such as T/CASME 275—2022. Thermosetting Powder Coatings for Household Appliances, can be used as a reference. This standard specifies product classification, requirements, test methods, and other aspects. T/CEAC 119-2025. Powder Coatings for Household Appliances, published at the end of 2025. also provides a basis for production inspection.
2. Select the Main Resin System According to the Service Environment
Different resin systems determine the weather resistance, corrosion resistance, and cost characteristics of the coating. Selection can be made based on whether the appliance will be exposed to outdoor environments.
(1) Epoxy-Polyester Hybrid (E/P): This is the most widely used system in the home appliance sector. It combines the strong adhesion of epoxy with the decorative properties of polyester and is mainly used for indoor appliances such as refrigerators, washing machines, and microwave ovens. Its curing conditions are typically around 180°C × 15 minutes.
(2) Pure Polyester (PE): If the product needs to withstand UV exposure and maintain its color over long periods, such as outdoor air conditioner units, a pure polyester system cured with TGIC or HAA should be selected. It provides excellent outdoor weather resistance. Among them, polyester/HAA systems offer greater advantages in terms of environmental performance and cost, but pinholes may occur when the coating thickness exceeds 120 μm.
3. Precisely Match Specific Functional Requirements
Different home appliances have specific coating requirements, so attention should be paid to customized functions during selection.
(1) Kitchen appliances, focusing on easy cleaning: For range hoods, cooktops, and similar products, easy-clean powder coating should be selected. Its principle is to reduce the surface tension of the coating, giving it oil- and water-repellent properties, excellent resistance to vegetable oil, vinegar, soy sauce, and alkaline cleaning solutions, as well as good cleanability. Relevant performance requirements include pencil hardness ≥1H, adhesion Grade 0. and impact resistance ≥30 kg·cm.
(2) General indoor appliances, focusing on decoration and protection: For refrigerators, washing machines, freezers, and similar products, key considerations include leveling performance, which provides a mirror-smooth surface, gloss level, with a range of 10–95% achievable, and edge coverage. Resistance to yellowing and chemical media such as acids, alkalis, and detergents is also required.
4. Consider Processing Requirements and Special Applications
(1) Low-temperature curing requirements: For heat-sensitive substrates such as electric iron soleplates and plastic composite components, low-temperature curing powder coating, such as coatings curing at around 130°C, should be selected.
(2) Compatibility with the coating process: Household appliance powder coatings are mainly applied by electrostatic spraying. During selection, it is necessary to ensure that the powder application efficiency and spraying area meet the efficiency requirements of production line operations.
Applications of Household Appliance Powder Coating
Household appliance powder coating may be required in various areas of our daily lives. Its main application fields are as follows.1. Indoor Major Appliances: Core Application Field
This is one of the most mature and widely used home appliance categories for powder coating, mainly due to its excellent decorative properties and basic protective functions.
(1) Refrigerators and freezers: Used on housings and internal metal components to provide a smooth, attractive surface and corrosion protection.
(2) Washing machines: Protects the housing from water stains and detergent exposure during daily use.
(3) Air conditioners (indoor units): Used for housing coating, providing a wide range of color and texture options, such as high gloss, matte, and metallic effects.
(4) Other indoor appliances: Such as microwave ovens, disinfection cabinets, rice cookers, dishwashers, electric heaters, dry-cleaning machines, and other appliances.
2. Outdoor or Special-Environment Appliances: Focus on Weather Resistance and Functional Performance
For appliances that need to withstand sunlight, rain, or special operating environments, the coating needs to provide stronger weather resistance and customized functions.
(1) Air conditioners (outdoor units): UV-resistant pure polyester systems should be selected to ensure that the coating does not chalk or fade during long-term exposure.
(2) Kitchen appliances (range hoods, cooktops, etc.): In addition to high-temperature and oil resistance, easy-cleaning (self-cleaning) coatings can also be applied. Their oil- and water-repellent properties make oil stains easier to wipe clean.
(3) Electric water heaters: Often used in outdoor or humid environments and therefore require excellent water and corrosion resistance.
Common Problems and Solutions for Household Appliance Powder Coating
The most common problems encountered during the use of household appliance powder coating are mainly reflected in the following aspects. Based on our industry experience, we have proposed corresponding solutions to help effectively address powder coating problems you may encounter.1. Craters and Pinholes
Causes: Caused by contaminants with low surface tension. Sources include oil and water in compressed air, inadequate pretreatment cleaning, contamination from mixing different powders, and impurity particles in the curing environment. Pinholes are often caused by substrate corrosion or the evaporation of residual pretreatment solution when heated.
Solutions:
(1) Install a high-efficiency oil-water separator in the compressed air system and inspect it regularly.
(2) After phosphating, the workpiece must be thoroughly rinsed with pure water to remove residual solution.
(3) Strictly clean the powder spraying system to prevent cross-contamination between different powder systems.
(4) Degassing agents such as benzoin or leveling agents can be selected to improve surface tension and reduce defects.
2. Particles and Impurities
Causes: An excessive proportion of ultrafine powder (<10 μm) can easily cause agglomeration and form powder bumps after spraying. Sludge and rust residue in pretreatment tanks may remain on the surface if not thoroughly washed away. Contaminants in the curing oven or oil dripping from the suspension conveyor chain can also cause surface defects.
Solutions:
(1) Strictly control the powder particle size distribution. When the volume fraction of ultrafine powder exceeds 10%, the powder booth should be stopped and cleaned.
(2) Replace the water in the pretreatment rinsing tank regularly and add a high-pressure water rinsing process to ensure that there is no residue on the workpiece surface.
(3) Regularly clean the curing oven, oil collection trays on the overhead conveyor chain, and air ducts.
3. Coating Peeling
Causes: Incomplete degreasing and rust removal, insufficient workpiece surface temperature during curing, such as insufficient local temperature caused by heat absorption by hangers, or incompatibility between the original coating or protective film and the repair coating.
Solutions:
(1) Strengthen the degreasing and rust removal processes during pretreatment to ensure the quality of the phosphating film.
(2) Use an oven temperature profiling instrument to measure the actual surface temperature of the workpiece rather than relying solely on the oven display temperature. Appropriately increase the set temperature during winter or when using heavier hangers.
(3) Before repair, sand the existing coating with 300-grit sandpaper to create a rough surface and improve adhesion.
4. Rough and Uneven Surface Texture
Causes: Insufficient melting and leveling of the powder, which may be related to low curing temperature, improper film thickness, or poor leveling properties of the powder itself.
Solutions:
(1) Select high-quality powder with good leveling properties. When necessary, add leveling agents, such as hyperbranched polyester modifiers, to reduce melt viscosity.
(2) Control the coating thickness at 60–80 μm and avoid excessive or insufficient thickness.
(3) Set the appropriate baking temperature and time according to the powder's technical requirements to ensure sufficient melting and leveling time.
5. Insufficient Curing, Low Hardness, and Poor Impact Resistance
Causes: Insufficient curing temperature or time, resulting in incomplete resin crosslinking; excessive workpiece density or high thermal capacity, resulting in uneven heating.
Solutions:
(1) Use an oven temperature profiling instrument to measure the temperature curves of workpieces in different areas under full-load conditions and ensure that they reach the curing window required by the powder.
(2) Reasonably adjust the number and arrangement of hanging parts to ensure smooth hot-air circulation and uniform heating of the workpieces.
(3) After confirming that the surface of a non-conforming workpiece is clean, it can be placed back into the oven for a second curing cycle.
If you encounter difficult-to-resolve problems while using household appliance powder coating, please feel free to contact us at any time for professional technical support. We are happy to discuss solutions together and contribute to the development of the powder coating industry.
We hope this article provides you with a professional and reliable reference for the powder coating industry. We sincerely welcome your inquiries regarding powder coating product performance, industry standards, application methods, precautions, or any other related questions. Please feel free to leave us a message or contact us directly at any time so that we can provide you with more detailed product information, demonstration videos, or customized solutions, helping you gain a comprehensive understanding of the product's functions and advantages.
