Inside the Factory: How Polar Seal Builds a Better Window Seal

If you’ve ever watched a window being built from start to finish, you know it’s surprisingly fascinating. This video gives a close-up look at one of the most important steps in window manufacturing: sealing the glass pack.

At Polar Seal, this process is all about precision, consistency, and long-term performance—not shortcuts.

Sealing the Glass Pack With Butyl Rubber

Each insulated glass unit starts with multiple panes of glass brought together into a single sealed system. To lock everything in place, Polar Seal uses butyl rubber as the primary seal.

Butyl rubber is incredibly effective because it forms an airtight barrier that prevents gas from escaping and moisture from getting in. That airtight seal is critical for keeping argon gas trapped between the panes.

Argon is a dense, non-toxic gas that slows down heat transfer. By filling the space between the glass with argon and sealing it properly, the window insulates far better than air-filled units.

The “Air Hockey Table” Effect

One of the coolest parts of this process is how the glass moves through the sealing station. The glass packs glide smoothly across what’s essentially a giant air hockey table.

Air pressure lifts and supports the glass, allowing it to move effortlessly and stay perfectly aligned during sealing. This reduces stress on the glass, improves accuracy, and helps ensure a consistent seal every time. It’s not just efficient—it’s mesmerizing to watch.

Why the Super Spacer Matters

Between the panes of glass sits another critical component: the spacer. Polar Seal uses Super Spacer, a high-performance foam spacer designed to outperform traditional aluminum or metal spacers

Unlike metal spacers, Super Spacer doesn’t conduct heat or cold easily. This “warm-edge” design helps keep the interior glass surface warmer in winter and cooler in summer. The result is better energy efficiency and a much lower chance of condensation forming along the edges of the glass.

Built to Last Longer

Super Spacer is made from a flexible structural foam, which allows it to expand and contract naturally as temperatures change. Windows go through constant thermal movement, especially in climates with hot summers and cold winters.

Because the spacer flexes instead of fighting that movement, it puts less stress on the seals over time. When combined with butyl rubber, this system creates a longer-lasting, more reliable seal than traditional spacer systems

What This Means for Homeowners

All of this factory detail boils down to real-world benefits:

• Better insulation and lower energy bills

• Reduced risk of seal failure

• Less condensation around the edges of the glass

• Longer window lifespan

It’s easy to overlook what’s happening inside a window you can’t see. But this sealing process—argon gas, butyl rubber, Super Spacer, and precision handling—is what separates a high-quality window from an average one.

And yes… it’s also just really cool to watch.

Please check out our blog post to learn about other details that Polar Seal puts into their windows.