Analysis of differences in durability performance requirements and testing methods of insulating glass standards at home and abroad.
Insulated glass is widely used in construction, transportation, refrigeration, and other industries due to its good thermal insulation, sound insulation, energy saving, anti-frost, and other properties. The durability of insulating glass determines its service life. Therefore, current domestic and foreign standards have set requirements for the durability of insulating glass. LIJIANG Glass introduces the durability performance requirements and testing methods in the insulating glass standards of China, the United States, the European Union, and Japan, and conducts a comparative analysis of the similarities and differences in the dew point test, ultraviolet resistance, and weather resistance performance requirements and testing methods of insulating glass. The current standards involved in the durability performance testing of insulating glass include:
Chinese standard GB/T 11944-2012 "Insulating Glass",
American standard ASTM E2190-10 "Standard Specification for Performance and Evaluation of Insulating Glass",
ASTM E546-14 "Dew Point of Sealed Insulating Glass Units" Standard Test Method",
ASTM E2188-10 "Standard Test Method for Performance of Insulated Glass",
ASTM E2189-10 "Standard Test Method for Fog Resistance Test of Insulated Glass",
EU standard EN 1279-2: 2018 "Architectural Glass-Insulated Glass Unit- Part 2: Long-term test methods and requirements for water vapor penetration",
EN 1279-3: 2018 "Architectural glass - Insulated glass units - Part 3: Long-term test methods and requirements for gas leakage rates and gas concentration deviations",
EN 1279- 4: 2018 "Architectural glass - Insulated glass units - Part 4: Test methods for physical properties of edge sealing materials and inserts",
EN 1279-6: 2018 "Architectural glass - Insulated glass units - Part 6: Factory production control and regular testing",
Japanese standard JIS R 3209: 1998 "Insulating glass",
Australian standard AS/NZS 4666: 2012 "Insulating glass unit", etc.
1. Insulating glass dew point test
The dew point of insulating glass refers to the temperature at which dew begins to condense in the cavity. If the dew point of the insulating glass is higher than the ambient temperature, during normal use, visible water vapor will appear on the inner surface of the cavity, resulting in a decrease in its thermal insulation and light transmission properties, and the insulating glass will fail. Table 1 lists the similarities and differences in dew point performance requirements and detection methods of different standards.
Table 1: Similarities and differences in dew point performance requirements and detection methods of different standards
| Standard | GB/T 11944-2012 | ASTM E2189-10 ASTM E546-14 | EN 1279- 4: 2018 | JIS R 3209: 1998 |
| Sample | Products or 15 pieces of 510mm*360mm samples | 12 pieces of （505±6）mm*（305±6）mm samples | 15 pieces of （502±2）mm*（352±2）mm samples whose desiccant moisture content cannot be tested | Products or 350mm*350mm sample |
| Performance requirements | Initial dew point＜-40℃ | There is no requirement for the initial dew point. The final dew point after the weather resistance test is ≤-40 | No request | Initial dew point＜-35℃ |
| Detection environment | Temperature（23±2）℃ Relative humidity 30%~75% | Temperature（24±3）℃ | Temperature（23±2）℃, Relative humidity 50%±5% | Normal temperature |
| Sample storage time before testing | More than 24 hours | More than 24 hours | At least 3 days | More than 24 hours |
2. The ultraviolet resistance performance test
Ultraviolet resistance is an indicator of the durability of insulating glass under ultraviolet radiation during use. For insulated glass with poor sealant quality, contaminated spacers, and high water vapor content in the cavity, at a certain temperature, after ultraviolet irradiation, fogging, water vapor condensation and contamination, and sealant deformation will occur on the inner surface. , affecting the performance of glass. Table 2 lists the similarities and differences in UV resistance performance requirements and testing methods of different standards.
Table 2: Similarities and differences in UV resistance performance requirements and testing methods of different standards
| Standard | GB/T 11944-2012 | ASTM E2190-10 ASTM E2189-10 | EN 1279- 4: 2018 |
| Sample | 2 pieces of 510mm*360mm samples | 2 pieces of (505±6)mm*(355±6)mm samples | 2 pieces of (502±2)mm*(352±2)mm samples |
| Performance requirements | After the test, there is no trace of fogging, condensation or contamination on the inner surface of the sample, and the sealant has no obvious deformation. | After the test, there is no fogging on the inner surface of the sample. | After the test, there is no visible dirt, pollution or fogging on the inner surface of the sample. |
| Irradiation source and specimen placement | One 300W UV bulb is placed in the center of the test chamber, and two specimens are placed diagonally above the light source. | One 300W UV bulb is placed in the center of the test chamber, and two specimens are placed diagonally above the light source. | Two options are available: ① One 300W UV bulb is placed in the center of the test chamber, and two samples are placed diagonally above the light source; ② The 300W UV bulb is located in the common corner area of 4 samples, and the 4 samples are placed vertically in front of the bulb |
| Temperature inside the box | （50±3）℃ | （50±3）℃ | （60±3）℃ |
| Cooling water temperature | （16±2）℃ | （21±2）℃ | Below 30℃ |
| Irradiation time | 168h | 7days | （168±4）h |
| Observation time after irradiation | Observe immediately. If there is condensation, leave it for 1 week and then observe again. | Observe immediately. If there is condensation, observe it the next day. If there is still condensation, leave it for 1 week and then observe it. | Observe immediately. If there is condensation, leave it for 1 week and then observe again. |
| Observation conditions | There are two fluorescent lamps at each corner of the observation light box. Observe at a distance of 600mm from the sample under scattered light background conditions. | Dark room, two 20W white light cold light lamps behind the sample, at least 1.5m away from the light source, 500~750mm away from the sample, transmission and reflection observation | The inner wall of the observation light box is black, and there are two 20W fluorescent lamps at each corner in front of the sample, 1m away from the sample, for transmission and reflection observation. |
3. The water vapor weather resistance test
The water vapor weather resistance test is to simulate the durability of the edge sealing material of insulated glass against water vapor sealing under actual use conditions. During the test, the sample must experience high temperature, low temperature, high humidity, light, and other conditions. The water vapor weather resistance performance of the sample can be judged by testing the dew point or desiccant moisture content of the sample before and after the test. The water vapor weather resistance test items of different standards have different names. Table 3 lists the similarities and differences in the water vapor weather resistance performance requirements and testing methods of different standards.
Table 3 Differences in water vapor weathering performance requirements and testing methods of different standards
| Standard | GB/T 11944-2012 | ASTM E2190-10 ASTM E2188-10 | EN 1279- 4: 2018 | JIS R 3209: 1998 |
| Project name | Water vapor sealing durability | Durability test | Long-term water vapor penetration test | Accelerated seal durability test |
| Sample | 15 pieces of 510mm*360mm qualified samples after dew point testing | 6 pieces of (505±6) mm * (355±6) mm samples after dew point testing | 15 pieces of (502±2)mm*(362±2)mm qualified samples after dew point testing | 6 pieces of 350mm*350mm qualified samples after dew point testing |
| Performance requirements | Test the moisture content of the desiccant before and after the test, and calculate the moisture penetration index I, I≤ 0.25, average value I ≤ 0.20 | The sample is not broken after the test, and the final dew point is ≤-40℃ | Test the moisture content of the desiccant before and after the test, and calculate the moisture penetration index I, I≤ 0.25, average value I ≤ 0.20 | Dew point after test ≤ -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 humidity 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 | Category 1: 7-day moisture and light resistance test, plus 12-word hot and cold cycle testCategory 2: Based on Category 1, add a 7-day moisture and light resistance test and 12 hot and cold cycle tests.Category 3: Based on Category 2, add 14 days of moisture and light resistance test and 48 times of hot and cold cycle test |
| Sample placement conditions after testing | Not specified | At least 24 hours in an environment with a temperature of 23℃±3℃ | Temperature (23±2)℃ Relative humidity (50±5)% at least 1 week | Room temperature, at least 24 hours |
4. The gas weathering performance test
The gas weathering performance test is to simulate the durability of the edge sealing material of the insulating glass to gas sealing under actual use conditions. 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. Japanese standards do not have special test items for argon-filled insulating glass, while national standards, EU standards, and American standards all have separate regulations on the weather resistance performance of argon-filled insulating glass. Table 4 shows the similarities and differences in gas weathering performance requirements and testing methods of different standards for argon-filled insulating glass.
Table 4 Similarities and differences in gas weathering performance test requirements and detection methods of argon-filled insulating glass in different standards
| Standard | GB/T 11944-2012 | ASTM E2190-10 ASTM E2188-10 | EN 1279- 4: 2018 |
| Project name | Gas seal durability | Durability test | Long-term test of gas leakage rate and gas concentration deviation |
| Sample | 4 pieces of 510mm*360mm samples | 6 samples after dew point detection (505±6) mm * (355±6) mm | 2~4 samples (502±2)mm * (352±2)mm, gas concentration greater than 15% |
| Performance requirements | The gas content after the test should be ≥80% (v/v) | After the test, the sample is not broken, the average argon concentration is ≥80% (v/v), and the argon concentration of each piece is ≥50% (v/v) | Evaluate the gas leakage rate Li, the average Lavg≤10*10-1*a-1, the maximum Lmax≤12*10-1*a-1, the deviation of the gas concentration before and after the test from the declared concentration 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 test conditions are the same as GB/T 11944 water vapor sealing durability performance | Same as ASTM E2190 and ASTM E2188 durability test | 28 cycles of high and low temperature cycle test plus 4 weeks of constant temperature and humidity test, the test conditions are the same as EN 1279-2 long-term water vapor penetration test |
| Sample placement conditions after testing | Temperature (23±2)℃, relative humidity 30%~75%, left for at least 24h | Place it in an environment with a temperature of (23±2)℃ for at least 24h | Temperature (23±2)℃, relative humidity (50±5)%, placed for at least 2 weeks and no more than 6 months |
Through the analysis and comparison of the durability performance of insulating glass according to the current national standards, American standards, European standards, and Japanese standards, LIJIANG Glass believes that the durability performance requirements and testing methods of insulating glass in different countries and regions are quite different, whether it is dew point test, ultraviolet radiation resistance,and whether it is a light test or a weather resistance test, the American standard performance requirements and test conditions are relatively strict.
Therefore, it is recommended that manufacturers:
(1) It is necessary to fully understand the differences in standards in different countries and regions, and use corresponding standards to test products according to the country and region where customers are located to ensure that product quality meets requirements, thereby improving market competitiveness;
(2) At present, the durability performance of insulating glass in some developing countries 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 they must be used after durable insulating glass is made from raw materials that have passed the performance test.
At the same time, based on the above analysis results and LIJIANG Glass’ long-term insulating glass testing experience, it is also recommended that some industry 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 must be left to test the dew point or weather resistance performance indicators needs to be specified based on the characteristics of the raw materials and the usage of the product. For strip-type insulating glass and some insulating glass with built-in louvers, due to material or structure limitations, the desiccant absorbs moisture slowly, and the length of time it is left will affect the test results.
(2) Cancel the requirement that the water vapor seal durability test must use samples that have passed the initial dew point test. During the long-term testing, the author found that some glass that failed the dew point test passed the water vapor sealing durability test of the national standard, but the moisture penetration index result was qualified; some strip-type insulating glass, after completing the durability test of the American standard, the dew point The dew point of some samples will drop from above -40 ℃ to below -60 ℃. LIJIANG Glass 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 insulating glass system. Before and after the test, the changes in weather resistance performance indicators have an impact on the company's analysis of the product.
