Getting Glass Stress Relief Right with Long-Format IR Heaters
If you’ve ever worked with glass tunnel kilns, you know the headache of “cold spots.” When you’re pushing oversized sheets of glass through a system, those gaps between standard short lamps are a nightmare. You end up with uneven heating, and in this business, uneven means trouble. That’s why we build continuous infrared units that stretch past 2 meters. No gaps. No cold spots. Just a steady, reliable wall of heat.
The tricky part about long lamps
You might think making a lamp longer is just a matter of using a longer tube. It’s not. If you just stretch the quartz, you run into voltage drops and thermal expansion issues. If the power isn’t perfectly balanced from one end to the other, the filament temperature fluctuates. That’s how you get refractive index variations—basically, flaws in the glass that you can’t afford. To stop the tubes from sagging under their own weight when they get red-hot, we use heavy-wall quartz. It keeps the tube rigid and ensures the heat hits the glass exactly where it needs to.
Making it actually work in your shop
We stick to a continuous layout. By keeping the gaps between elements to an absolute minimum, we stop those annoying longitudinal stripes from showing up on your glass. And we don’t use cheap parts. We use industrial connectors that can take a beating in a high-heat environment without giving up. Depending on what kind of glass you’re running, we can also coat the quartz. This tweaks the emission spectrum so the glass absorbs the heat more efficiently. It means you waste less power and your ramp-up time drops significantly.
A few things to watch out for
These long-format lamps pack a punch. They put out a massive amount of heat, but that means your electrical panels need to be ready for the initial inrush current. If they aren’t, you’re going to have a bad day. Also, let’s be real: these tubes are fragile. One clumsy move during a replacement and you’ve got a cracked tube. To make life easier, we use specific mounting brackets. They give the tube room to breathe and expand as it heats up, so you aren’t putting mechanical stress on the ends. It just makes the whole process a lot less stressful.