Why glass cracks in annealing

Tue, 28 Jul 2026 09:01:03 +0800

Cutting through ultra-thick glass slabs is a nightmare. The internal stress in those blocks is intense, and when a cutting wheel hits cold glass that thick, it’s like trying to carve through a brick. You end up with jagged, ugly edges and cutting wheels that burn out way too fast. We found a better way. Instead of fighting the glass, we use shortwave infrared (IR) lamps to pre-heat the exact path where the cut is going to happen. Here’s the thing about heat: standard heaters just warm up the surface. That doesn’t do much for a thick slab. But shortwave IR actually sinks deep into the glass. It doesn’t melt the material—that would be a disaster—but it does make it “softer.” It lowers the resistance just enough so the wheel glides through. It feels less like a struggle and more like a smooth slice. And your tools will thank you. When you’re cutting cold, the friction creates these brutal heat spikes that chew through carbide or diamond edges. It’s a grind. By prepping the path with IR lamps, you take the pressure off. The cutting force drops, which means your wheels last way longer. You spend less time cursing at a broken tool and more time actually keeping the line moving. But you can’t just crank the heat and walk away. If you go too heavy on the wattage or leave the lamps on too long, you’ll trigger thermal shock. Then you’ve got uncontrolled cracks everywhere. It’s all about the balance—how close the lamp is, how long it stays on, and how thick the glass is. Plus, those lamps put off a ton of heat. If your cooling system isn’t up to the task, you’re going to fry your conveyor electronics. It takes a bit of tweaking to get the timing just right. But once you do? The glass snaps clean every single time.

Cracks on Infrared Heating Experts

Why glass cracks in annealing