Stopping Glass from Cracking During Tempering
When you’re tempering glass, you’re basically walking a tightrope. You need to get the heat up fast, but if you do it too aggressively, the glass snaps. That’s thermal shock. It happens when one part of the glass gets hot way faster than the rest, and before you know it, you’ve got a crack and a wasted piece of material. To stop this, we use a combination of shortwave IR lamps, some very specific reflectors, and power controllers that can keep up with the pace.
Why we don’t just “blast it” with heat
You can’t just flip a switch to 100% and hope for the best. That’s a recipe for disaster. We use shortwave IR because these lamps react almost instantly. When we pair them with SCR or thyristor controllers, we can tweak the power in milliseconds. It means we can ease the glass into the heat or pull back the second a sensor notices things are getting too uneven. It’s a much gentler way to handle a violent process. And then there’s the reflector. Most people overlook it, but it’s doing the heavy lifting. By using polished aluminum or gold coating, we make sure the heat actually hits the glass instead of just warming up the machine’s frame. You get the surface temperature you need faster, which means you don’t have to overwork your lamps.
The messy side of high power
Here is the reality: pushing massive amounts of thermal energy takes a toll on your gear. When you run these lamps at full tilt, your electrical bus feels it. Plus, the ambient heat can get intense. If your fans aren’t pulling enough air or your ventilation is lacking, you’ll start seeing the lamp connectors degrade. Eventually, the quartz envelopes just burn out. One last tip:check your reflector alignment every single week. It sounds tedious, but if the focal point shifts even a tiny bit, you’ll get “hot spots” on your glass. That completely ruins the work your power controllers are doing and brings you right back to the thermal shock you were trying to avoid in the first place.