Test box for resistance to yellowing and aging of exterior wall coatings

Anti-yellowing aging test chamber can do two kinds of testing:aging and anti-yellowing.

Aging:the machine can promote the increase of sulfurrubber deterioration,to calculate the change rate of tensile andelongation before and after heat.It is generally thought that testfor one day at 70℃,in theory as exposed to the atmosphere for 6months.

Anti-yellowing:this machine stimulates the atmosphereenvironment,driven by the sun ultraviolet radiation.Itsgenerally thought that the appearance change at 50℃ for 9hours,in theory as exposed to atmosphere for 6 months.

FEATURES

1) To simulate outdoor weathering, the UV aging testersexposes materials to alternating cycles of UV light and moisture at controlled, elevated temperatures. It simulates the effects of sunlight using special fluorescent UV lamps. It simulates dew and rain with condensing humidity and/or water spray.
2) The UV accelerated weathering tester is the simplest, most reliable, and easiest to use weathering tester available. With thousands of testers in use worldwide, it is the world's most widely used weathering tester.

TEST STANDARDS

JIS-P8127,ASTM D1148…

SPECIFICATION

A test box for evaluating the resistance to yellowing and aging of exterior wall coatings is designed to simulate the environmental conditions that exterior surfaces face over time. This includes exposure to UV light, high temperature, humidity, and other environmental factors that lead to color degradation, yellowing, and material aging. Below is an overview of the features, applicable standards, and environmental conditions for this type of test chamber.

1. UV Light Simulation: The test box is equipped with UV lamps that replicate sunlight's ultraviolet rays. The intensity and exposure time can be controlled to accelerate the degradation process of exterior wall coatings, providing insights into their long-term performance in outdoor conditions.

2. Temperature and Humidity Control: The chamber can simulate the effect of different climates on exterior coatings. It typically operates within a temperature range of 40°C to 80°C, while humidity levels can be controlled from 40% to 90%. This allows testing of coatings under various high-humidity or dry heat conditions.

3. Accelerated Aging: By using a combination of UV radiation, heat, and humidity, the test box speeds up the natural aging process. This helps assess the potential for yellowing, cracking, and other forms of deterioration that might occur over several years in actual outdoor exposure.

4. Automatic Control and Monitoring: The test box is equipped with advanced digital controllers that enable precise regulation of temperature, humidity, and UV exposure. Real-time monitoring of the test conditions is possible, ensuring accuracy and consistency throughout the testing process.

5. Energy Efficiency: Many test boxes are designed to be energy-efficient by using high-performance UV lamps and thermal insulation materials, which help to minimize energy consumption during extended tests.

The testing of yellowing and aging resistance of exterior wall coatings generally follows recognized industry standards:

1. ISO 4892-3: This international standard outlines the method for accelerated weathering testing of plastics and coatings, which includes UV exposure, and is used to evaluate the aging and yellowing resistance of exterior coatings.

2. ASTM G154: This standard from the American Society for Testing and Materials specifies procedures for accelerated exposure to UV light and is often used to evaluate coatings, paints, and other materials.

3. GB/T 16422.1: This Chinese national standard provides a methodology for accelerated weathering testing on coatings and materials exposed to UV light, ensuring that coatings can withstand outdoor conditions.

4. EN 927-6: This European standard applies to the weathering testing of exterior wood coatings and is used to assess the durability and yellowing resistance of such coatings, though it may also be relevant for other coatings on exterior surfaces.

1. Ambient Temperature: The test box typically operates within a temperature range of 10°C to 40°C, to simulate outdoor environmental conditions.

2. Power Supply: The box typically requires a power supply of 220V ± 10%, 50Hz, although specific models may have different power specifications depending on the system.

3. Humidity Control: The chamber is capable of regulating relative humidity, typically ranging from 40% to 80%, to simulate various climates and assess how different humidity levels influence the coating's aging and yellowing.

4. Ventilation: Adequate ventilation is crucial to ensure proper airflow and to avoid overheating during testing, which could distort the results or damage the chamber components.

1. Sample Preparation: Exterior wall coating samples are applied to standardized substrates such as metal, plastic, or wood.

2. UV Exposure: The test box's UV lamps are activated for a set period, typically several hundred to a thousand hours, depending on the accelerated aging schedule.

3. Temperature and Humidity Cycling: The chamber will cycle between temperature and humidity conditions to simulate the real-world effects of temperature fluctuations and moisture exposure.

4. Post-Test Evaluation: After the test cycle, the samples are assessed for changes in color (yellowing), cracking, chalking, or other forms of deterioration.

By accurately replicating environmental conditions and following established standards, this test box allows manufacturers to assess the durability, yellowing resistance, and overall performance of exterior wall coatings under accelerated aging conditions.