The Headache of Cold Spots (and How We Fix Them)
Most infrared lamps stop at about 1.5 or 2 meters. That’s fine for small jobs, but if you’re running a tunnel kiln for oversized glass, you’ve got a problem. Those gaps where the lamps meet? They create “cold spots.” It’s frustrating. You want a perfectly even heat, but instead, you get streaks. To stop that from happening, we build custom infrared units that push way past that 2-meter mark. The goal is simple: one continuous, steady flow of heat across the entire sheet of glass. The tricky part: Power and Voltage You can’t just stretch a quartz tube and call it a day. The longer the tube, the higher the electrical resistance. If you aren’t careful, you’ll deal with a massive voltage drop, and your heat will be all over the place. We spend a lot of time tweaking the filament diameter and the coil pitch to match your specific power supply. We also balance the wattage carefully. Why? Because the ends of the tube don’t breathe as well as the center, and without this balance, they’ll just overheat and burn out. What’s under the hood We use high-purity quartz to hold the tungsten filaments. For tempering, we stick with shortwave radiation. It hits the glass hard and fast, penetrating the surface exactly how it should. We set these up in tight rows. No gaps, no missed spots. Depending on what your control cabinet can handle, you can wire them in series or parallel. It’s flexible. A word of warning on fragility Here is the catch: the longer the tube, the more it wants to sag. A 2.5-meter lamp is a lot more “bendy” than a 1-meter one. If you aren’t careful, the quartz can actually snap under its own weight or crack as it expands from the heat. You’ve got to get your mounting brackets exactly right. Space them out perfectly. And if your kiln has a lot of airflow, make sure everything is locked down tight. You don’t want these things rattling around. It takes a little more time during installation, but it beats the hell out of replacing a shattered lamp in the middle of a shift.