In the realm of vacuum insulating glass (VIG), the most common and critical questions revolve around edge sealing, stress resistance, and longevity of the vacuum. Below we explain how HaanGlas VIG addresses these issues—not as marketing claims, but backed by technical design, manufacturing strategy, and real tests.

Edge Sealing: Why it matters & HaanGlas’s approach

The edge seal is the “gatekeeper” of vacuum performance. If the seal fails, gas ingress causes vacuum degradation, worsening thermal performance. Earlier approaches—using organic resins or glass frits—face challenges: permeability to moisture/gas, thermal stress, and the need for high-temperature sealing that may anneal tempered glass.

On HaanGlas’s FAQ about vacuum glazing page, they describe how traditional methods (organic materials, frit) have limitations, then highlight HaanGlas’s low-temperature metal edge sealing method, which keeps glass temperature below ~250 °C during sealing. This avoids damaging temper stress and ensures stronger and more stable bonding.

The low-temperature metal seal not only preserves the internal stress profile of tempered glass but also tolerates differential expansion, resisting seal fatigue under cyclic thermal loading. Because the metal seal is more ductile than rigid frit, it can absorb small dimensional shifts, reducing the risk of microcracks.

Moreover, HaanGlas employs designs with no evacuation holes—so the glass surface remains flat and there’s no weak point around a hole.

By combining metal sealing + getter materials + optimized edge geometry, HaanGlas ensures that edge leakage is extremely slow (in ideal units, <10⁻⁴ to 10⁻⁵ Pa/year), preserving vacuum over decades.

Stress Resistance & Tempered Glass Strategy

A second set of concerns: will the stress from pressure differences, temperature swings, wind loads, or mechanical impacts cause cracking? And if cracks form, will they lead to seal failure?

HaanGlas addresses this via fully tempered VIG. On their “Fully tempered vacuum insulating glass features” page, they discuss how tempered VIG achieves surface stress > 90 MPa, yielding 3–5× higher strength compared to annealed glass.

Tempering benefits include:

Higher impact resistance (e.g. resisting hail, windborne debris).

Safe breakage behavior: glass fragments into small < 10 mm pieces rather than dangerous shards.

Better handling during manufacturing, shipping, and installation.

 

Because HaanGlas uses low-temperature metal sealing (rather than high-temperature frit that would anneal or partially relieve glass stress), the temper profile is preserved.

Under wind loads or thermal cycling, the combined design of micro-pillars, uniform spacing, and robust seal geometry helps minimize stress concentration at edges. The metal seal acts as a compliant buffer rather than a rigid barrier, further reducing crack initiation risk.

Long-Term Vacuum Retention: What keeps the vacuum alive?

Even with perfect sealing and strong glass, minor gas ingress over years is inevitable (through diffusion, microleaks, or outgassing). So vacuum retention depends on buffer systems and design:

Getter materials are embedded (e.g. strips or tiny getters) which absorb residual gases that may desorb or leak, maintaining low internal pressure.

The extremely low permeability of metal seals — especially compared to polymer or resin seals — slows gas ingress to negligible rates.

The initial vacuum level is made extremely low (10⁻⁴ Pa or better) to give a cushion against slow leakage.

The design tolerances and edge geometry minimize stress that could open micro-paths.

Because of this, HaanGlas confidently advertises a lifetime beyond 25 years for vacuum retention and performance.

In many test reports, VIG units sealed by HaanGlas retain > 90% of their original vacuum after many years of lab aging, temperature cycling, and humidity stress tests. (You can find those in our Certificates & Test Reports section.)

Putting it all together: durability you can trust

The low-temperature metal edge sealing preserves temper stress and yields better durability than traditional glass frit or polymer methods.

The fully tempered glass resists mechanical and thermal stress, and breaks safely if damaged.

Getter systems + ultra-tight seal geometry ensure that any residual leakage is slowly controlled, maintaining vacuum for decades.

Quality control and lab testing (accelerated aging, humidity, thermal cycles) validate that the VIG units stay within spec over lifetime.

So when a client worries, “Will the vacuum last? Will the glass crack? Will the seal fail?” — the HaanGlas design philosophy answers: Yes, if manufactured correctly, VIG will maintain performance over the long haul.

Call to Action

If you’re evaluating VIG for your project and have concerns about durability, edge sealing, or long-term vacuum retention, contact us via our Contact Page. We can provide accelerated aging test data, seal cross-sections, temper stress reports, and lifetime retention curves to help you validate performance.