Stopping the “Cold Spot” Headache in Fiberglass Tunnel Kilns
Most infrared lamps stop at about a meter. That sounds fine until you’re actually running a fiberglass tunnel kiln. When you string those short lamps together, you get these annoying gaps—cold spots—at every single joint. It ruins the consistency. To fix that, we build continuous heating units that stretch past 2 meters. No gaps. No surprises. Just a steady, uniform heat that hits the glass exactly the same way from start to finish. The tricky part about going long You can’t just stretch a quartz tube and call it a day. If you do, the filament sags or just burns out. It’s a mess. We spend a lot of time dialing in the voltage and wattage so the heat stays consistent from one end to the other. Just a heads-up: you’ll want to check your power cabinets. These longer units pull more load. If your electrical setup is feeling a bit tight, we can just split things into zoned arrays. It still works, but it’s easier on your breakers. What’s actually inside We use high-purity quartz to hold the tungsten filament. For fiberglass annealing, the “flavor” of the heat matters. You don’t want to scorch the surface while the core stays cold. Depending on how thick your glass is, we can coat the lamps to shift the emission from shortwave to medium-wave. We also use heavy-duty connectors. Why? Because a 2-meter tube moves and expands a lot when it gets hot, and you don’t want it snapping under the pressure. A few things to keep in mind Installing these is a bit of an art. You need a steady hand and a mounting frame that doesn’t budge. If the frame bows even a little, the tube can snap during a thermal cycle. It’s a nightmare you want to avoid. And look, the trade-off for all that great coverage is that these long lamps are a bit more fragile than the short ones. My advice? Have a clear, written plan for how to swap them out. You don’t want to be figuring it out on the fly while your entire production line is sitting dead for a day.