Two Component Silicone Sealant For Insulating Glass
Double Glazing Silicone Sealant is a two-part silicone formulation for air filled insulating glass. Part A is the base and Part B is the curing agent. Part A is smooth and white. Part B is black. After mixing these two parts, the material will cure to high-modulus, high elasticity, weather-resistant, neutral curing silicone sealant.
Two component silicone sealant for insulating glass has great weatherability that make sure the seals remain good condition and tensile strength and adhesion do not change significantly.
Two component silicone sealant
Two components, high-modulus, high elastic recovery and durable double glazing silicone sealant.
Neutral Curing. No corrosion for metal, coated glass, concrete and marble(granite).
Fast Curing with wide application temperature.
Great compatibility with many commonly used neutral silicones.
Excellent adhesion to different aluminum spacers and many other accessories.
Great weather ability. Cold and heat resistant. No corrosion. Perfect resistance to ozone and UV radiation.
Silicone Sealant for insulating glass is used as a secondary sealant for dual-seal insulating glass units. Due to the high moisture vapor transmission rate of silicone sealant, it is not suitable to use in the fabrication of single seal insulating glass units. For dual-seal insulating glass units, the primary seal of polyisobutylene(Sunvol 385 hot melt butyl sealant) is required to prevent moisture vapor transmission into the airspace. See below double glazing diagram.
Figure: Double Glazing Diagram
Note: Compatibility test is recommended on all materials that will be in direct contact with SS-809 double glazing silicone sealant.
Component A is white. Component B is black. After mixing A and B, the product will be black.
Please consult sales service staff for the testing report.
Before applying Double Glazing Silicone Sealant, please read Safety Data Sheet for safe use, physical and health hazard information. The Safety Data Sheet is available by contacting your sales service staff.
Preparation work before usage
Adhesion and compatibility test should be applied before sealant use.
Sunvol may provide assistance in performing adhesion and compatibility tests before using Two Component Silicone Sealant.
After passing the tests, the sealant could be used for insulating glass seals.
Normally the working environment temperature should be not lower than 10℃ (50℉), relative humidity should be not lower than 40%.
Good ventilation conditions, fire prevention, explosion protection and other safety measures are required for sealant operation.
Glass surface clean
Clean all glass and plastic surfaces by using solvent. Commonly used solvents include isopropanol, xylene or butanone. Cleaning cloths should be clean, oil-free and lint-free. Use “double cloth wiping method” to clean the surface of the adhesive material: soak a clean cloth block with solvent and wipe the adhesive surface in only one direction. Before the solvent volatilization, immediately using a second piece of dry and clean cloth to wipe off the solvent on the surface. Solvent is not allowed to dry on the surface. The glass must be sealed within 1 hour after cleaning, otherwise it must be cleaned again.
Glass is also ok to be cleaned in a suitable automatic washing machine.
Double Glazing Silicone Sealant base and curing agent should be completely mixed by using airless mixing system. Silicone sealant for insulating glass is well compatible with commercial two-part silicone dispensing machine in the market.
The cure rate may be adjusted by changing the base-to-curing agent mix ratio from 8:1 to
12:1 by volume (Normally base-to curing volume mix ratio 10:1). Sealant physical properties are not significantly changed over range. Changes in the ambient temperature and humidity will affect the snap time.
Test before applying sealant
Mixture uniformity test – Butterfly test
This test is used to test the mixing property of two-part double glazing silicone sealant.
How to test:
Extrude the mixing glue into the center of A4 white paper. Folding the paper to flatten the sealant, and then open the paper to observe the silicone sealant. The evenly mixed structure sealant should have no different color stripes. If there are white stripes appear on the sealant, it means that the mixing sealant is uneven.
If the testing result shows the mixing is uneven, the mixing machine should be checked and adjusted appropriately and retest until the mixing is even.
Snap time test
This test is used to test the curing speed of two-part double glazing silicone sealant and then confirm the mix ratio.
How to test:
Put an appropriate amount of evenly mixed silicone sealant in the beaker. Dip a small round bar or a small scraper into part of the sealant. Start timing from the mixing of the silicone sealant, draw out the small round bar(scraper) every 5 minutes and observe whether the sealant is snapped.
If no snap occurs, re-dip the small round rod (scraper) in the sealant, and draw out it from the sealant every 5 minutes. Repeat this operation until the silicone sealant is snapped, and record the time from the beginning of timing to the time of breaking.
The snap time of normal proportion silicone sealant is between 20 and 90 minutes. Otherwise, the ratio should be adjusted.
Note: Curing agent (Part B) has high reactivity and is easy to fail due to hydrolysis. Therefore part B cannot be exposed to the air for a long time and it need to be sealed storage.
Other tests such as tab adhesion test.
These tests should be performed when lots of base or curing agent are changed, or each time the production line is started.