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The evaluation method and performance advantages of gas-filled insulated glass.

1. The preface

Inflatable insulating glass is to replace the drying air in the original insulating glass unit with other drying gas. In addition to air, the gas used to fill the insulating glass can also be filled with stable inert gases, such as ammonia, gas, and oxygen. Filling the insulating glass with inert gases (mainly oxygen, etc.) helps to improve heat insulation and sound insulation, and other performances, improving thermal insulation and energy saving effect.

At present, common inflatable insulating glass is mainly divided into two categories: one is slot aluminum inflatable insulating glass, and the other is warm edge inflatable insulating glass. The current relevant standards for judging the quality of inflatable insulating glass are 

Chinese standard GB/T 11944-2012 "Insulating Glass"

international standard ISO 20492-2010 "Insulating Glass for Architectural Glass Part 3: Gas Concentration and Gas Leakage"

ASTME2190-2019 "Insulating Glass" Glass Performance Evaluation Criteria" and 

European Standard EN 1279-2018 "Architectural Glass - Insulating Glass Units" part 2-3

Among them, the national standard GB/T 11944·2012 stipulates that the initial gas content of the inflatable insulating glass unit should be 285%, and the gas content should be 0% after the gas sealing durability test; the American standard ASTME 2190-2019 stipulates that the initial gas concentration is 90% %, N 80% after aging test; International standard ISO 20492-2010 and European standard EN 1279·2018 both stipulate initial gas charge concentration N 85%, annual leakage rate Li S%. Among them, the European standard EN 1279-2018 is the most demanding and the most reasonable.

2. The production of inflatable insulated glass

Following the Chinese national standard GB/T 11944-2012 and the European standard EN1279-2018 test method, Jinan LIJIANG Glass used a fully automatic insulated glass inflatable production line to make a channel aluminum inflatable insulating glass and a thermoplastic warm-edge inflatable insulating glass for performance comparison. The inflatable insulating glass is produced in a well-known deep-processing glass factory in China, and the specific production method is carried out under the provisions of the European standard EN 1279-2018. Among them, the dew point test and ultraviolet radiation resistance test are carried out according to the national standard GB/T 11944-2012; the moisture seal durability test is carried out according to the national standard GB/T 11944-2012 and the European standard EN 1279-2:2018; the gas seal durability The tests were carried out according to the national standard GB/T11944-2012 and the European standard EN 1279-3:2018 respectively.

2.1 The slot aluminum inflatable insulated glass

Under the same process conditions, the inflatable insulating glass with the size of 502 mm*352 mm is made, the first sealant is MF910G butyl hot-melt sealant for insulating glass, and the second sealant is MF840 two-component polysulfide insulating glass. Sealant (high modulus) and MF881-25HM silicone structural sealant, the number of polysulfide insulating glass is J1#~J50#, and the number of silicone insulating glass is S1#~S50#.

2.2 The thermoplastic warm edge insulated glass

Under the same process conditions, the gas-filled insulating glass with the size of 502mm><352mm is made, the first sealant is MF910SG thermoplastic spacer for insulating glass, and the second sealant is MF840 two-component polysulfide insulating glass special sealant (high modulus) and MF88L25HM silicone structural sealant, the number of polysulfide insulating glass is L1#~L50#, and the number of silicone insulating glass is G1#~G50#.

3. The research on the properties of gas-filled insulated glass

3.1 The insulated glass dew point test

The rise of the dew point of the insulating glass is caused by the outside water entering the interlayer and not being absorbed by the desiccant. The level of dew point directly reflects the quality of the insulating glass, which is one of the performance indicators for testing insulating glass. According to the method specified in 7.3 of the national standard GB/T 11944-2012, the test results are shown in Table 1:

Test itemsStandard requirementTest results
Thermoplastic warm edge inflatable insulated glassSlot aluminum gas-filled insulated glass
Dew point
MF840
(high modulus)
<-40℃
(Measured-60℃)
L1#~L15#
No condensation or frost
L1#~L15#
No condensation or frost
MF881-25HMG1#~G15#
No condensation or frost
S1#~S15#
No condensation or frost

Table 1 The insulated glass dew point test results

It can be seen from Table 1 that the dew point test of thermoplastic warm-edge gas-filled insulating glass and channel aluminum gas-filled insulating glass can meet the requirements of GB/T 11944-2012 standard.

3.2 The insulated glass UV radiation resistance test

This indicator is to investigate the performance changes of the produced gas-filled insulating glass under ultraviolet irradiation, to detect the UV stability of the sealant, and to test whether the sealant for gas-filled insulating glass contains organic volatiles that affects sight. According to the method specified in 7.4 of the national standard GB/T 11944-2012, the test results are shown in Table 2.

Test itemsStandard requirementTest results
Thermoplastic warm edge inflatable insulated glassSlot aluminum gas-filled insulated glass
UV radiation resistantMF840
(high modulus)
There is no trace of fogging, condensation or contamination on the inner surface of the glass and no obvious deformation of the sealantL16# L17#J16# J17#
MF881-25HMG16# G17#S16# S17#

Table 2 The insulated glass UV radiation resistance test result

Japan Standard Thermoplastic Warm Edge Jia Gong Shi JinshanTest items require the inflatable hollow glass tank tube to be in the middleglassUV resistant

It can be seen from Table 2 that the UV radiation resistance test of thermoplastic warm-edge gas-filled insulating glass and channel aluminum gas-filled insulating glass can meet the requirements of the GB/T 11944-2012 standard.

3.3 The insulated glass water vapor seal durability test

The action of water and moisture in the environment during the use of gas-filled insulating glass will accelerate the aging of the sealant, thereby accelerating the speed of water vapor entering the hollow glass cavity, and ultimately making the insulating glass invalid. Water-vapor sealing durability is one of the important indicators to determine the service life of the gas-filled insulating glass. This test part is tested according to the national standard GB/T 11944-2012 and the European standard EN 12792 2018.

3.3.1 The Chinese National Standard GB/T 11944-2012

The specific test is carried out according to the method specified in 7.5 of GB/T 11944-2012. After the test, the dew point of the gas-filled insulating glass is tested. The experimental results are shown in Table 3.

Test itemsDew point test temperatureTest results
Thermoplastic warm edge inflatable insulating glassSlot aluminum gas-filled insulating glass
Water vapor seal durabilityMF840
(high modulus)
-60℃
No condensation or frost
L1#~L11#J1#~J11#
MF881-25HMG1#~G11#S1#~S11#

Table 3 Dew point test results of moisture seal durability test

It can be seen from Table 3 that after the water-vapor sealing durability test of thermoplastic warm-edge gas-filled insulating glass and slot aluminum gas-filled insulating glass is tested at -60 ℃ dew point, there is no condensation or frost on the glass, indicating that the water-vapor sealing performance is good.

3.3.2 The European Standard EN 1279・2:2018

The prepared inflatable insulating glass samples were sent to the German IFT (Rosenham) testing center for testing under the European standard EN 1279-2. The test results are shown in Table 4.

Test itemsThe standard requirementTest results
Thermoplastic warm edge inflatable insulated glassSlot aluminum gas-filled insulated glass
MF840
(high modulus)
T i,av-0.21%1.1%
T f,av-0.30%2.0%
I av≤20%2.30%4.5%
MF881-25HMT i,av-0.20%3.5%
T f,av-0.20%3.7%
I av≤20%0.24%2.1%

Table 4 Test results of EN1279-2 inflatable insulated glass

Note: see… is the initial average moisture content of the desiccant; A dish is the final average moisture content of the desiccant; the heart is the average moisture penetration index

It can be seen from Table 4 that the water vapor permeability index of thermoplastic warm edge inflatable insulating glass and grooved aluminum inflatable insulating glass can meet the requirements of EN 1279-2:2018, but the water vapor sealing durability of thermoplastic warm edge inflatable insulating glass is better than Slotted aluminum gas-filled insulating glass.

3.4 The insulated glass gas seal durability test

The introduction of thermoplastic warm edge spacers can improve the energy-saving effect of insulating glass, especially in reducing condensation on the edges. However, due to the change in ambient temperature, the gas in the hollow cavity of the insulating glass is always in a state of thermal expansion or contraction, so the sealant is in a state of stress for a long time. The gas sealing durability is a measure of the sealing (ammonia concentration retention rate) performance before and after the aging of the insulating glass. This test part is tested according to the national standard GB/T 11944-2012 and the European standard EN 1279-3:2018 respectively.

3.4.1 The Chinese National Standard GB/T 11944-2012

The specific test was carried out according to the method specified in 7.7 of GB/T 11944-2012, and the gas concentration was tested with a portable inert gas analyzer (Spark Co., Ltd., Finland). The experimental results are shown in Table 5.

Figure 1 The test results of EN1279-2 for grooved aluminum gas-filled insulated glass MF840 (high modulus)

Figure 1 The test results of EN1279-2 for grooved aluminum gas-filled insulated glass MF840 (high modulus)

Figure 2 EN1279-2 test results of thermoplastic warm edge inflatable insulated glass

Test items

Testing standard requirements

Test results

Thermoplastic warm edge inflatable insulated glass

Slot aluminum gas-filled insulated glass
Argon-gas seal durabilityMF840(high modulus)
Before the test%
After the test%
Gas reduction%
-

≥85
≥80
-
1.18#

91.8
91.0
-0.8
1.19#

94.4
93.6
-0.8
1.20#

96.6
95.8
-0.8
J18#

97.7
96.4
-1.3
J19#

95.9
94.8
-1.1
J20#

97.5
96.2
-1.3
MF881-25HM
Before the test%
After the test%
Gas reduction%
-
≥85
≥80
-
G18#
95.3
94.4
-0.9
G19#
95.1
94.2
-0.9
G20#
94.2
93.4
-0.8
S18#
96.3
95.2
-1.1
S19#
96.9
95.9
-1.0
S20#
96.7
95.9
-0.8

Table 5 Gas seal durability test results

It can be seen from Table 5 that after the gas sealing durability test, the content of inflatable gas is N 80%, which is in line with the national standard GB/T 11944.2012; but the sealing performance of thermoplastic warm-edge inflatable insulated glass (concentration retention rate of nitrogen gas) is better than that of a grooved aluminum type Inflatable insulated glass.

3.4.2 The European Standard EN 1279-3:2018

To test the gas leakage rate of gas-filled insulating glass in line with the European standard EN 1279-3:2018 and improve the testing capability of domestic gas-filled insulated glass, our company introduced a medium-sized insulating glass from the TUV Rheinland Nederland B. V. insulating glass testing institution in the Netherlands in October 2018. Empty glass unit gas leakage rate tester (see Figure 3 and Figure 4), the measured test results are shown in Table 6:

Figure 3 The gas chromatograph equipment

Figure 3 The gas chromatograph equipment

Figure 4 The gas flow meter and sample holder

Figure 4 The gas flow meter and sample holder

Table 6 Test results of EN1279-3 inflatable insulated glass

Test itemsStandard requirementTest results
Thermoplastic warm edge inflatable insulating glassSlot aluminum gas-filled insulating glass
Gas side leak rate / L(%)MF840 (high modulus)≤1.00a-11.21#
0.81a-1
1.22#
0.83a-1
J21#
0.87a-1
J22#
0.89a-1
MF881-25HMG21#
0.75a-1
G22#
0.77a-1
S21#
0.89a-1
S22#
0.88a-1

It can be seen from Table 6 that the gas leakage rates of thermoplastic warm-edge gas-filled insulated glass and grooved aluminum gas-filled insulated glass can meet the annual leakage rate of 0.00% of the European standard EN1279-3:2018, but the thermoplastic warm-edge gas-filled insulated glass The gas leakage rate is lower than that of the grooved aluminum gas-filled insulating glass.The prepared gas-filled insulated glass samples were sent to the German IFT (Rosenham) testing center for testing under the European standard EN 1279-3. The test results are shown in Table 7.

Table 7 Test results of EN1279-3 inflatable insulating glass

Test itemsStandard requirementTest results
Thermoplastic warm edge inflatable insulated glassSlot aluminum gas-filled insulated glass
Gas side leak rate, L,(%)MF840 (high modulus)≤1.00a-11#
0.65a-1
2#
0.66a-1
1#
0.79a-1
2#
0.99a-1
MF881-25HM1#
0.72a-1
2#
0.73a-1
1#
0.76a-1
2#
0.84a-1

It can be seen from Table 7 that the gas leakage rate of the thermoplastic warm-edge inflatable insulating glass and the grooved aluminum inflatable insulating glass can meet the requirements of the European standard EN1279-3: 2018 annual leakage rate of 01.00%, but the thermal properties are warm. The gas leakage rate of the side gas-filled insulating glass is lower than that of the grooved aluminum gas-filled insulating glass.

Figure 5 The test results of EN1279-3 for grooved aluminum gas-filled insulating glass

Figure 5 The test results of EN1279-3 for grooved aluminum gas-filled insulating glass

Figure 6 Thermoplastic inflatable insulating glass EN1279-3 test results

Figure 6  The test results of EN1279-3 Thermoplastic inflatable insulating glass 

3.5 5x Cyclic Gas Seal Durability Test

To further verify the gas sealing durability test performance of thermoplastic warm edge insulating glass, the laboratory examines its aging performance by increasing the number of gas durability test cycles. Cycle, gas concentration, and dew point test results are shown in Table 8

Table 8. Results of gas leakage after 85 times cycle gas seal durability test

Test itemsStandard requirementTest results
MF910SG+MF840 (high modulus)MF910SG+MF881-25HM
L23#L24#L25#G23#G24#G25#
5X Cyclic Gas Seal DurabilityBefore test/%≥8594.2    91.6    97.195.491.992.1
After the 1st cycle/%≥8093.290.996.494.791.891.7
After the 2nd cycle/%≥8093.090.595.794.691.791.5
After the 3th cycle /%      ≥80      93.090.895.293.891.992.0
After the 4th cycle/% ≥80  92.290.194.393.190.990.6
After the 5th cycle/% ≥8091.889.793.693.190.590.4
Total gas reduction/%-2.41.93.52.31.41.7
Gas leak rate/L/%<1.00a-10.97a-10.97a-10.92a-10.83a-10.88a-10.87a-1


It can be seen from Table 8 that the thermoplastic warm-edge insulating glass has a gas concentration of 80% after being cycled 5 times according to the requirements of the 7.7 gas sealing durability test in GB/T 11944-2012, which meets the requirements of the GB/T 11944-2012 standard for insulating glass; The annual gas leakage rate is 1.00%, which meets the requirements of the EN 1279-3:2018 standard, and has good resistance to cyclic aging. Based on the test results of Table 4, Table 5, Table 6, and Table 7, it can be seen that the water-vapor sealing durability and gas-sealing durability of thermoplastic warm-edge gas-filled insulating glass are good, meeting the national standard GB/T 11944-2012 and the European standard EN 1279- 2018 requirements.

4. The conclusion

Based on the above analysis, it can be seen that the test methods of the water-air seal durability test of the national standard GB/T 1944-2012 and the European standard EN 1279-2018 are consistent, but there are differences in the gas seal durability test. The European standard EN 1279-2018 requires The annual leakage rate is Lis 1%, this requirement further guarantees the gas sealing reliability and durability of the gas-filled insulating glass, and at the same time prolongs the service life of the gas-filled insulating glass products.

Energy saving and environmental protection are the guarantees of my country's sustainable development strategy. From the perspective of the national macro-control policy and the overall domestic environment, the insulating glass industry conforms to the national development direction of energy saving and safety and has broad development prospects and great potential. However, due to the large thermal conductivity of the aluminum spacer in the channel aluminum insulating glass, the resulting energy loss is also large. 

To solve the problem of heat loss at the edge of insulating glass, warm-edge spacers came into being and have been widely used in developed countries. In recent years, some developing countries have also introduced fully automatic warm-edge insulating glass production lines, which shows that the excellent energy-saving effect of warm-edge insulating glass has been recognized by everyone, and it is gradually developing in this area, and the potential market is large.


For more information about Jinan LIJIANG Glass insulating glass processing equipment and insulating glass processing accessories, please click here to learn more. 

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