This article systematically introduces the concept, characteristics, functions, application fields, selection methods, and common problem-solving measures of outdoor table and chair powder coating. It focuses on the functions of outdoor table and chair powder coating to help everyone better understand what outdoor table and chair powder coating is, as well as its characteristics and applications.
What Is Outdoor Table and Chair Powder Coating
Outdoor table and chair powder coating is an environmentally friendly solid powder coating specially designed for outdoor environments. It addresses two major challenges faced by outdoor furniture: aging and chalking caused by UV radiation, and corrosion caused by wind, rain, and temperature changes.Characteristics of Outdoor Table and Chair Powder Coating
The main characteristics of outdoor table and chair powder coating are as follows.1. Excellent Weather Resistance and Corrosion Resistance
This is its most core characteristic. With pure polyester resin as the main binder, it can effectively resist UV radiation and prevent the coating from chalking and fading due to prolonged exposure to sunlight. At the same time, it also has excellent salt spray and humidity resistance, enabling it to withstand the erosion caused by wind, rain, and moisture. Some high-performance products even provide 8 to 10 years of engineering warranty or coating integrity assurance.
2. Excellent Physical Protection
Outdoor tables and chairs inevitably undergo movement and scratching, so the coating needs to be sufficiently durable. The coating formed by this type of powder coating is tough and has good impact resistance, scratch resistance, and wear resistance, effectively protecting the surface of tables and chairs.
3. Rich Decorative Options
While ensuring protection, it also provides diverse decorative effects. Different colors, gloss levels (such as high gloss, flat, and low gloss), as well as special textures such as sand texture, hammer texture, metallic, or pearlescent effects can be selected according to design requirements.
4. Outstanding Environmental and Economic Benefits
Powder coating itself contains no organic solvents, and VOCs (volatile organic compounds) emissions during the spraying process are nearly zero. Unadhered powder can also be recycled and reused, resulting in less material waste and making it a choice that combines environmental protection and economic efficiency.
Functions of Outdoor Table and Chair Powder Coating
The main functions of outdoor table and chair powder coating are specifically reflected in the following aspects.1. Long-Term Resistance to Outdoor Aging
This is its most fundamental function. Outdoor tables and chairs are exposed to sunlight, wind, and rain throughout the year. The coating formed by powder coating can effectively resist the damage caused by these natural factors.
(1) UV Aging Resistance
Coatings based on pure polyester resin can effectively absorb or reflect UV radiation, preventing the coating from chalking, fading, and losing gloss due to prolonged exposure to sunlight, thereby maintaining the long-lasting appearance of tables and chairs.
(2) Moisture and Corrosion Protection
The dense coating can effectively block moisture and corrosive media such as salt spray and acid rain, protecting metal substrates from rust and wooden substrates from decay.
2. Providing Strong Physical Protection
Outdoor tables and chairs inevitably undergo movement, impact, or scratching, and the coating provides a necessary physical barrier.
(1) Scratch and Impact Resistance
The coating has high hardness and strong adhesion, effectively resisting impacts and scratches during daily use and preventing excessive surface damage.
(2) Temperature Change Resistance
It can adapt to significant temperature changes between day and night and between winter and summer in outdoor environments. The coating does not crack or peel off, maintaining structural integrity.
3. Providing Aesthetic and Environmental Value
While providing protection, it also takes into account decorative properties and environmental friendliness.
(1) Rich Decorative Effects
It can provide a variety of colors, gloss levels (high gloss/matte), and textures (sand texture, hammer texture) to meet the requirements of different outdoor space design styles.
(2) Green and Environmentally Friendly Process
As a 100% solid coating, it produces nearly zero VOC emissions during the spraying process. Unadhered powder can be recycled and reused, making it an energy-saving and environmentally friendly surface treatment method.
Application Range of Outdoor Table and Chair Powder Coating
Outdoor table and chair powder coating is commonly used in the following fields.1. Outdoor Leisure Tables and Chairs
This is the most direct application field for powder coating. Relevant industry standards also clearly identify it as a major applicable product for “thermosetting powder coatings for outdoor leisure furniture.” Specific applications include:
(1) Public Places
Park benches, community leisure chairs, outdoor seating in commercial streets, facilities in scenic area rest areas, supporting facilities in amusement parks, etc.
(2) Home and Courtyard
Tables and chairs in villa gardens, terrace furniture, leisure chairs beside swimming pools, wrought-iron tables and chairs on balconies, etc.
(3) Commercial Places
Outdoor dining areas of restaurants/cafés, outdoor rest facilities at hotels and resorts, etc.
2. Supporting and Extended Applications
Thanks to their excellent weather resistance and corrosion resistance, the same type of powder coating is also widely used for other metal facilities in the same outdoor environments:
(1) Protective Facilities
Outdoor guardrails, fences, railings, stair handrails.
(2) Public Facilities
Light poles, road signs, signposts, garbage bins, playground equipment.
(3) Extended Applications
Sports equipment, bicycle racks, cable grids, agricultural machinery, etc.
How to Choose Outdoor Table and Chair Powder Coating
When selecting outdoor table and chair powder coating, we may face difficulties in determining how to make the right choice. Based on our industry experience, we recommend focusing on the following aspects when selecting outdoor table and chair powder coating.Key selection points are summarized below.
1. Determine the Resin First
(1) Epoxy Resin
Although it offers good corrosion resistance and hardness, it has poor UV resistance. When used outdoors, it will quickly chalk and fade and therefore must not be selected.
(2) Pure Polyester Resin
This is the correct choice for outdoor furniture powder coating, offering excellent UV resistance and weather resistance.
2. Check the Performance Grade
Select the Configuration According to the Environment
According to the environment where the tables and chairs are placed, the following grades can be referenced:
| Weather Resistance Grade | Typical Application Environment | Reference Standard/Series |
| Standard Weather-Resistant Type | Ordinary urban environments, residential courtyards, non-coastal and non-high-sunlight areas | Qualicoat Class 1 / AAMA 2603 |
| High Weather-Resistance / Super Weather-Resistance Type | Strong sunlight, high humidity, or general industrial areas | Qualicoat Class 2 / AAMA 2604 |
| Fluorocarbon / Premium Weather-Resistance Type | High salt spray in coastal areas and extremely harsh climatic conditions | AAMA 2605 (Highest Grade) |
High-performance pure polyester powder coating can provide an outdoor service life of 7–15 years under proper maintenance.
3. Check Process Compatibility: Curing and Substrate
(1) Curing Conditions
Confirm that the curing temperature and time of the selected powder are compatible with your spraying line. For example, curing conditions may vary significantly among different product series (such as 170°C/20 min vs. 200°C/7 min). The substrate temperature of the workpiece must be used as the basis.
(2) Substrate Compatibility
Confirm that the coating is suitable for your table and chair substrates, such as aluminum and galvanized steel.
4. Focus on Environmental Protection and Health
(1) HAA System
This is an environmentally friendly pure polyester system that does not contain TGIC. It is safer and more environmentally friendly and represents an industry trend.
(2) Low VOC
Powder coating itself produces almost no VOC emissions, making it a green process.
Common Problems and Solutions for Outdoor Table and Chair Powder Coating
The most common problems encountered during the use of outdoor table and chair powder coating are mainly reflected in the following aspects. Based on our industry experience, we propose corresponding solutions to help effectively solve powder coating problems you may encounter.1. Chalking, Fading, and Gloss Loss Caused by UV Aging
Problem: Outdoor tables and chairs are exposed to sunlight for long periods, causing the coating to chalk, fade, and experience a significant reduction in gloss. This is the most common and destructive problem with outdoor powder coatings.
Cause: Photo-oxidative degradation is one of the main causes of aging in outdoor powder coatings. After UV radiation is absorbed by polymers, the polymers enter an “excited state” and subsequently decompose to generate free radicals, resulting in damage to the chemical structure of the coating. Ordinary polyester resins have limited resistance to UV radiation.
Solutions:
(1) Select a Highly Weather-Resistant Pure Polyester System
Outdoor tables and chairs must use a pure polyester resin system. Indoor powder coatings containing epoxy components must not be used. Super-durable polyester resins are preferred, such as modified resins containing UV-resistant structural units such as triazine rings, which can significantly improve gloss retention.
(2) Add Anti-Aging Additives and Nanofillers
The formulation should contain UV absorbers such as benzotriazoles, hindered amine light stabilizers (free radical scavengers), and nano-inorganic powders such as nano-TiO₂, SiO₂, and CeO₂. The organic-inorganic synergistic effect can significantly improve UV aging resistance.
(3) Confirm the Weather Resistance Grade
According to the environment where the tables and chairs are located (ordinary urban areas/strong sunlight/coastal areas), select products with the corresponding weather resistance grade, such as Qualicoat Class 2 or AAMA 2604 and above.
2. Boiling Water Blistering and Reduced Adhesion of the Coating
Problem: After outdoor tables and chairs are used for a period of time in rainy or high-humidity areas, blisters and water spots may appear on the coating surface, and adhesion may deteriorate. This is particularly noticeable in textured coatings such as sand textures.
Cause: Moisture penetrates through microscopic defects in the coating to the substrate interface. Ester bond hydrolysis is a core chemical mechanism of polyester coating aging under humid and hot conditions. Sand-textured coatings are more prone to water resistance problems due to their rough surfaces and relatively high internal stress.
Solutions:
(1) Select Hydrolysis-Resistant Polyester Resin
Select polyester resins containing dialkyl side-chain structures. Steric hindrance and shielding effects can be used to inhibit contact between water molecules and ester bonds, thereby reducing ester hydrolysis.
(2) Low-Temperature Curing Sand-Textured Coating
For tables and chairs with sand-textured finishes, low-temperature curing formulations modified with dipentaerythritol (DPE)-modified polyester resin and additives can be selected. Their boiling water resistance is significantly improved, with gloss retention ≥94% under high-pressure boiling water at 120°C/2 h.
(3) Strengthen Pretreatment
Strictly implement the principle of “70% pretreatment, 30% coating,” ensuring that degreasing and phosphating/silane treatment of metal substrates are properly performed to improve the bonding strength between the coating and substrate.
3. Poor Adhesion and Early Corrosion
Problem: The coating peels or flakes off, or rust begins to spread from scratches and edges, significantly shortening the service life of tables and chairs.
Cause: Inadequate pretreatment (insufficient degreasing or poor phosphating) is the primary cause of poor adhesion. In addition, outdoor tables and chairs may involve thin-wall and thick-wall workpieces being cured on the same line. Thick-wall workpieces heat up more slowly, resulting in insufficient curing and inadequate coating density.
Solutions:
(1) Strictly Control Pretreatment
Ensure that every stage of degreasing, rust removal, phosphating/silanization meets the required standards, especially in areas prone to contamination such as welds and corners.
(2) Monitor Curing Conditions
Use an oven temperature tracking instrument to ensure that the substrate temperature of the workpiece reaches the powder curing requirements (normally approximately 180–200°C), rather than relying solely on the oven chamber temperature.
(3) Ensure Coating Thickness
For outdoor tables and chairs, a recommended coating thickness of ≥60–80 μm is recommended to ensure sufficient physical protection.
4. Low Powder Deposition in Dead Corners and Complex Structures
Problem: Complex areas such as welded joints, hollow patterns, and inner corners of tubular materials may have thin powder deposition or exposed substrate, becoming starting points for corrosion.
Cause: During electrostatic spraying, complex structures can create the Faraday cage effect (electrostatic shielding), making it difficult for powder particles to reach deeply recessed areas.
Solutions:
(1) Adjust Spraying Parameters
For dead-corner areas, reduce the electrostatic voltage, shorten the distance between the spray gun and workpiece, and extend the residence time to reduce the shielding effect.
(2) Manual Touch-Up Spraying
After automated spraying, manually apply touch-up spraying to complex structures at specific locations.
(3) Select a Primer Powder with Good Conductivity
When using a two-coat system, a primer powder formulation with better conductivity can be selected to help release the electrical charge.
5. Soft Coating Film and Surface Defects in HAA Curing Systems
Problem: Outdoor powders using environmentally friendly HAA curing systems may sometimes produce coatings that are relatively soft and have insufficient scratch resistance. In addition, HAA curing generates condensation water, which may cause surface defects such as pinholes and craters.
Cause: HAA (β-hydroxyalkyl amide) undergoes a condensation reaction with polyester. Water molecules are released during the curing process, and defects may occur if the formulation or process is improperly controlled. In addition, the crosslinking density of some HAA systems is slightly lower than that of TGIC systems.
Solutions:
(1) Select an Optimized Modified Formulation
Select super-durable polyester resin for HAA curing systems. Introducing rigid structures such as triazine rings can improve coating hardness and UV resistance.
(2) Optimize the Extrusion Process
Reasonably control the amount of accelerator used (such as approximately 0.4%) to balance curing temperature and coating performance.
(3) Pay Attention to the Application Environment
HAA systems are more sensitive to environmental humidity. Ensure that the compressed air is dry before spraying to prevent moisture from entering the coating.
If you encounter difficult-to-solve problems during the use of outdoor table and chair powder coating, please feel free to contact us at any time for professional technical support. We can jointly discuss solutions and promote the development of the powder coating industry.
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 product performance, industry standards, application methods, precautions, or any other related questions about powder coating products. We look forward to hearing from you at any time through messages or direct contact, so that we can provide you with more detailed product information, demonstration videos, or customized solutions to help you fully understand the various functions and advantages of our products.
