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Insulating glass is widely used in construction, transportation, cold storage, and other industries due to its good heat insulation, sound insulation, energy-saving, anti-condensation, and other properties. The durability of the insulating glass determines the length of its service life. Therefore, current domestic and foreign standards have put forward requirements for the durability of insulating glass. This paper introduces the durability performance requirements and testing methods of insulating glass standards in China, the United States, the European Union, and Japan, and compares and analyzes the similarities and differences in the dew point test, UV resistance, and weather resistance requirements and testing methods of insulating glass.

The current standards involved in the durability test of insulating glass include: 

1. Chinese standard GB/T11944-2012 "Insulating glass", 

2. American standard ASTME2190-10 "Standard Specification for Performance and Evaluation of Insulating Glass", 

3. ASTME546-14 "Standard Test Method for Dew Point of Sealed Insulating Glass Unit" 

4. ASTME2188-10 "Standard Test Method for Performance of Insulating Glass", 

5. ASTME2189-10 "Standard Test Method for Anti-fogging Test of Insulating Glass",

6. European Standard EN1279-2: 2018 "Building Glass-Insulating Glass Unit-Part 2: Water Vapor Permeation Long-term test methods and requirements for building glass", 

7. EN1279-3: 2018 "Building glass-hollow glass unit-Part 3: Long-term test methods and requirements for gas leakage rate and gas concentration deviation", 

8. EN1279-4: 2018 "Building glass-hollow Glass unit-Part 4: Test methods for physical performance of edge sealing materials and plug-ins", 

9. EN1279-6: 2018 "Building glass-Insulating glass unit-Part 6: Factory production control and periodic inspection", 

10. Japanese standard JISR3209: 1998 "Insulating Glass", 

11. Australian Standard AS/NZS4666: 2012 "Insulating Glass Unit", etc.

1. Dew point test

The dew point of hollow glass refers to the temperature at which condensation starts in the cavity. If the dew point of the insulating glass is higher than the ambient temperature, visible water vapor will appear on the inner surface of the cavity during normal use, resulting in a decrease in its thermal insulation and light transmission performance, and the insulating glass will fail. Table 1 lists the similarities and differences between the dew point performance requirements and detection methods of different standards.

Standard
GB/T 11944-2012ASTME2190-10
ASTME546-14

EN 1297-6:2018JISR3209: 1998
Sample
Products or 15 510mm*360mm samples
12 pieces(505±6)mm*(355±6)mm sample
Samples whose moisture content of the desiccant cannot be tested
Products or 350mm*350mm samples
Performance requirements
Initial dew point<-40 
No requirement for initial dew point, final dew point after weather resistance test ≤-40 
cannot be tested
Initial dew point<-35
Detection environment
Temperature(23±3)
Relative humidity 30%--75%
Temperature(24±3) 
Temperature(23±2)
Relative humidity
50%±5%
Room temperature
Sample placement time before testing
More than 24h
More than 24h
At least 3 days
More than 24h

Table 1 The similarities and differences of dew point performance requirements and detection methods of different standards

2. Ultraviolet resistance performance test

Ultraviolet resistance is an index to measure the durability of UV radiation during the use of insulating glass. For hollow glass with poor sealant quality, contaminated spacers, and high water vapor content in the cavity, at a certain temperature, after ultraviolet radiation, the inner surface will have to fog condensation and pollution, and sealant deformation, Affect the performance of the glass. Table 2 lists the similarities and differences of the UV resistance performance requirements and testing methods of different standards.

Standard
GB/T 11944-2012
ASTME2190-10
ASTME546-14

EN 1297-6:2018
Sample
2 pieces 516mm * 360mm sample
2 pieces (505±6)mm * (355±6)mm sample
2 pieces (502±2)mm * (352±2)mm sample
Performance requirements
After the test, the inner surface of the sample has no signs of fogging or condensation, and the sealant has no obvious deformation
After the test, the inner surface of the sample has no signs of fogging
After the test, the inner surface of the sample has no signs of fogging or condensation
Irradiation source and sample placement method
One 300W UV bulb is placed in the center of the test box, and two samples are placed diagonally above the light source
One 300W UV bulb is placed in the center of the test box, and two samples are placed diagonally above the light source
Two options are available: ① 1 300W UV bulb, placed in the center of the test box, and 2 samples placed above the light source; ② 300W UV bulb is located in the common corner area of the 4 samples, and 4 samples are placed vertically in front of the bulb
Temperature in the box
(50±3)
(50±3)
(60±3)
Cooling water temperature
(16±2)
(21±2)
Below 30
Irradiation time
168h7 days(168±4)h
Observation time after irradiation
Observe immediately, if there is condensation, leave it for 1 week and observe again
Observe immediately, if there is fog, observe again on the 2nd day, and observe again on the 7th day if there is fog
Observe immediately, if there is condensation, leave it for 7 days and then observe
Observation conditions
There are 2 fluorescent lamps at each corner of the observation light box, under the background of scattered light, 600mm away from the sample
In the dark room, two 20W white cold light lamps are behind the sample, at least 1.5m away from the light source, 500-750mm away from the sample, observation of transmission and reflection
Observe that the inner wall of the light box is black, and there are two 20W fluorescent lamps at the two corners in front of the sample, 1m away from the sample, and observe the transmission and reflection.

Table 2 The similarities and differences of UV resistance performance requirements and testing methods of different standards

3. Water vapor weathering performance test

The water vapor weathering performance test simulates the durability of the side sealing material of the insulating glass against water vapor under actual conditions of use. During the test, the sample is subjected to conditions such as high temperature, low temperature, high humidity, light, etc., and its water vapor weather resistance can be judged by testing the dew point of the sample before and after the test or the moisture content of the desiccant. The names of the water vapor weathering performance test items of different standards are different. Table 3 lists the similarities and differences of the water vapor weathering performance requirements and testing methods of different standards. Table 4 lists the similarities and differences of different standard water vapor weatherability test conditions.

Standard
GB/T 11944-2012
ASTME2190-10
ASTME546-14

EN 1297-6:2018
JISR3209: 1998
Project name
Water and air seal durability
Durability test
Long-term water vapor penetration test 
Accelerated durability test
Sample
15 pieces 510mm*360mm samples that passed the dew point test
6 pieces (505±6)mm*(355±6)mm samples that passed the dew point test
6 pieces (505±6)mm*(355±6)mm samples
6 pieces 350 mm * 350mm samples
Performance requirements
Test the moisture content of the desiccant before and after the test, and calculate the moisture permeability index I,I≤0.25,average value I≤0.20
After the test, the sample is not broken, and the final dew point≤-40
Test the moisture content of the desiccant before and after the test, and calculate the moisture permeability index I,I≤0.25,average value I≤0.20
After the test, the dew point≤-30
Test procedure
56 cycles of high and low temperature cycle test, plus 7 weeks of constant temperature and humidity test
14 days of high temperature test, plus 252 cycles of climate cycle test, plus 28 days of high humidity test
56 cycles of high and low temperature cycle test, plus 7 weeks of constant temperature and humidity test
Type 1: 7-day humidity and light resistance test, plus 12 heat and cold cycle tests,
Type 2: On the basis of Type 1, 7 days humidity resistance and light resistance test, 12 heat and cold cycle tests are added
Type 3 : based on the second type plus 14 days of humidity and light resistance test, 48 times of cold and heat cycle test
Sample placement conditions after the test
Not specified
At least 24 hours in a temperature of 23±3℃ environment
At least 7 days in a Temperature(23±2)℃ Relative humidity (50±5)%
At room temperature, at least 24 hours

Table 3 The similarities and differences of different standards of water vapor weathering performance requirements and testing methods

Standard
GB/T 11944-2012
ASTME2190-10
ASTME546-14

Test name
High and low temperature cycle test
Constant temperature and humidity test
High humidity test
Climate cycle test
Test temperature
(-18±2)-(53±1)
(58±1)
(60±3)
(-29±3)-(60±3)
Relative humidity
Above room temperature, ≥95%
>95%95% ± 5%
When the room temperature reaches 60℃ or more, the highest value
UV irradiation
NoneNoneNone
Above room temperature, there is ultraviolet radiation
Each test time
Each cycle 12h, 56 cycles (28 days)
7 weeks14 days before the climate cycle test, 28 days after the test
Each cycle 6h, 252 cycles (63 days)
Total test time
77 days105 days
Total humidification time
63 days52.5 days
Total irradiation time
-31.5 days
Standard
EN 1297-6:2018
JISR3209: 1998
Test name
High and low temperature cycle test
Constant temperature and humidity test
Humidity and light resistance test
Cold and hot cycle test
Test temperature
(-18±2)-(53±1)
(58±1)
(55±3)
(-20±2)-(50±3)
Relative humidity
Humidification above room temperature, 53 degrees greater than 95%
>95%
≥95%
None
UV irradiation
NoneNoneUV fluorescent lamp irradiation
None
Each test time
Each cycle 12h, 56 cycles (28 days)
7 weeks
Type 1: 7 days
Type 2: 14 days
Type 3: 42 days
6h per cycle,
Type 1: 12 times(2 days)
Type 2: 24 times(4 days)
Type 3: 72 times(12 days)
Total test time
77 days
Up to 60 days
Total humidification time
63 days
Up to 42 days
Total irradiation time
-
Up to 42 days

Table 4 The similarities and differences of different standard insulating glass water vapor weathering performance test conditions

4. Gas weathering performance test 

The gas weathering performance test is to simulate the durability of the side sealing material to the gas seal of the insulating glass under the actual conditions of use. For argon-filled insulating glass, after the weather resistance test, not only the water vapor sealing performance, but also the gas sealing performance must be considered. The Japanese standard does not have a special test item for argon-filled insulating glass, while the national standard, EU standard, and American standard all have separate regulations on the weather resistance of argon-filled insulating glass. Table 5 shows the similarities and differences of the weather resistance requirements and testing methods of different standards for argon-filled insulating glass.

Standard
GB/T 11944-2012
ASTME2190-10
ASTME546-14

EN 1297-6:2018
Project name
Gas seal durability
Durability test
Long-term test of gas leakage rate and gas concentration deviation
Sample
4 pieces 510mm*360mm samples
6 pieces (505±6)mm*(355±6)mm samples that passed the dew point test
2~4 pieces (502±2)mm*(352±2)mm samples, samples with gas concentration greater than 15%
Performance requirements
After testing the test gas content, it should be ≥80%
After the test, the sample is not broken, the average argon concentration≥80%(v/v), the argon concentration of each block≥50%(v/v)
Test gas leakage rate L, average rate L≤10*10, maximum rate L≤12*10, the deviation of the declared concentration of gas concentration before and after the test does not exceed 5%
Test procedures and conditions
28 cycles of high and low temperature cycle test plus 4 weeks of constant temperature and humidity test, the experimental conditions are the same as GB/T 11944-2012 water and air seal durability performance
The same as  ASTME2190 and ASTME2188 durability test
28 cycles of high and low temperature cycle test plus 4 weeks of constant temperature and humidity test, the experimental conditions are the same as EN 1297-6 water and air seal durability performance
Sample placement conditions after the test
At least 24 hours in a temperature of 23±2℃,
Relative humidity 30%~75%
At least 24 hours in a temperature of 23±2
At least 2 weeks and not more than 6 months in a temperature of 23±2℃,
Relative humidity (55±5)%

Table 5 The similarities and differences of different standard argon-filled insulating glass gas weather resistance test requirements and detection methods

Through the analysis and comparison of the current national, American, EU, and Japanese standards on the durability of insulating glass, the author believes that the durability requirements and testing methods of insulating glass in different countries and regions are quite different, whether it is dew point test or UV radiation resistance. The test is still a weather resistance test. The performance requirements and test conditions of the American Standard are relatively strict. Therefore, it is recommended that the manufacturer:

(1) It is necessary to fully understand the differences in standards of different countries and regions, and use corresponding standards to test products according to the country and region where the customer is located, to ensure that the product quality meets the requirements, thereby improving market competitiveness;

(2) At present, the durability of insulating glass in my country is affected by the quality of raw materials, and the overall quality level needs to be improved. The key raw materials that affect the performance of insulating glass are sealants, spacers, desiccants, etc., and must be tested for durability. Raw materials are used to make hollow glass.

At the same time, based on the above analysis results and the author's long-term insulating glass inspection experience, it is also recommended that my country's national standards consider the following two points in future revisions:

(1) Before the dew point test and after the weather resistance test, how long the sample can be placed before the test of the dew point or weather resistance performance index needs to be specified in conjunction with the characteristics of the raw materials and the use of the product. For the rubber strip type and part of the hollow glass with built-in louvers, due to the limitation of material or structure, the desiccant has a slow moisture absorption speed, and the length of the storage time will affect the test results.

(2) Cancel the requirement that the test specimens that have passed the initial dew point test must be used in the water-gas seal durability test. In the long-term test, the author found that some glasses failed the dew point test. After completing the water vapor seal durability test of the national standard, the water permeability index result was qualified; some rubber-striped insulating glass, after completing the durability test of the American standard, the dew point It will decrease, and the dew point of some samples will drop from above -40℃ to below -60℃. The author believes that no matter what the initial dew point of the sample is, it is necessary to conduct a weather resistance test. Because the initial dew point is unqualified, it is largely related to the manufacturing environment of the glass and the initial state of the desiccant used. The weather resistance test examines the sealing ability of the entire system of insulating glass. Before and after the test, the changes in weather resistance performance indicators will analyze the products for the company. Quality issues are very important.

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