Stopping Glass from Shattering During Tempering
In the glass business, the danger zone is always the switch between heating and cooling. That’s where things usually go wrong and you end up with a pile of shards. To get around this, we use short-wave quartz infrared lamps. They’re great for “instant tempering” because they can pivot their power output on a dime, which is exactly what you need to keep thermal shock from ruining your batch. Why the speed matters Thermal shock happens when one part of the glass gets way hotter than the rest too quickly. The tension just snaps the piece. To stop that, you need a heat source that can hit full blast instantly—and just as importantly, shut off just as fast. Since the tungsten filament in these lamps has almost no thermal mass, it doesn’t “linger.” When you pair them with an SCR or a fast-switching thyristor, you can tweak the power in milliseconds. It means you can get the surface temperature up without any lag, making sure the heat actually reaches the core before the glass moves down the line. The gear inside We house the filaments in high-purity quartz tubing. We do this because quartz doesn’t warp under extreme heat and it lets that short-wave radiation slide right through. The energy goes straight into your glass, not into the lamp housing. You can push these lamps to high wattages over short lengths to get a ton of heat in a small space. But a word of warning: high-density tubes get scorching. If your oven’s airflow isn’t strong enough to pull the heat away from the lamp ends, you’ll fry your connectors. The real-world trade-off The best part? These lamps usually slide right into most existing tempering lines. Because they react so quickly, you don’t need those massive transition zones in your oven, which saves you a lot of floor space. But there is a catch. Quartz is finicky. It hates contamination. If you touch the tube with your bare hands during installation, the oil from your fingerprints creates a hot spot. That spot will overheat, and the quartz will crack.**Use lint-free gloves.**Every single time. Otherwise, you’ll spend your weekends replacing tubes.