No one wants to spend heavily on insulated glazing only to see it fail after few years.
Yet this is quietly happening to most vacuum insulated glazing.
And the cause is bad edge seal.
- Invisible Seal Cracks
Cracks in vacuum glass edge seals are usually not as obvious as broken glass.
They are microscopic failures: a hairline crack quietly spreads along the seal interface, with almost no visible sign. Yet that tiny crack connects the vacuum cavity to the outside air, causing the vacuum level to drop rapidly and thermal performance to collapse.
By the time you notice that the window no longer insulates as well as before, the seal may have failed long ago. (The same principle also applies to argon-filled insulating glass: edge sealing is equally critical.)
- Why Does That Happen?
The root cause is thermal stress.
Glass and edge-sealing materials have different coefficients of thermal expansion. Days are hot and nights are cool, while the temperature difference between summer and winter is even greater. With every temperature change, the glass and sealing material expand and contract at different rates, generating stress at the seal interface.
If the sealing material is brittle glass-frit solder, repeated stress accumulation will eventually cause the joint to crack.
Glass-frit sealing has a shear strength of only 3.45 MPa. Under repeated long-term thermal and mechanical stress, that figure leaves little margin for durability.
- Flexible Edge Sealing Is Our Answer
SuperVIG®’s all-metal sealing process solves this problem in two ways:
First, metallurgical bonding eliminates interface weaknesses at the source.
The active solder chemically reacts with the glass substrate. The resulting interfacial compounds closely match the thermal expansion coefficient of glass, preventing stress concentration caused by expansion mismatch.
Second, the metal joint resists creep and can “absorb” stress.
Unlike brittle glass-frit solder, a metal joint has a degree of plastic deformability. Under thermal and mechanical stress, it can release stress through slight deformation instead of allowing it to build until fracture.
This is why all-metal sealing can achieve a shear strength of 20 MPa—
nearly six times that of glass-frit sealing and 1.67 times that of silver-paste sealing.
- Our Confidence Comes From Data
20 MPa is more than a number.
It means SuperVIG® vacuum glass has sufficient seal-strength margin to remain intact under temperature cycling, wind pressure, and installation stress during building use.
It means the vacuum state is expected to remain largely unchanged from the day of installation to ten years later.
Structural stability is the foundation of reliable long-term thermal performance. SuperVIG® gets every detail right, starting with the edge seal.
