Stop the Chips: Why We Preheat Glass with Infrared
Glass is stubborn. It’s brittle, and the second you hit it with a cutting wheel, you’re creating a massive stress point in one tiny spot. If that glass is cold, the break doesn’t always follow your line. It wanders. That’s how you end up with those annoying chips and shards along the edges that ruin a good piece of work. The fix? We warm it up first using infrared (IR) lamps. How it actually works Think of IR lamps as a way to put energy straight into the glass without wasting time heating up the air around it. When the glass gets warm, the internal surface tension relaxes. It makes the fracture move in a straight line. No wandering, no jagged edges—just a clean, satisfying snap. It makes a world of difference, especially when you’re dealing with thick sheets or tempered glass that usually likes to fight you. The tricky part: Finding the sweet spot You can’t just blast the glass with heat and hope for the best. It’s a balancing act between how much power you’re using and how far away the lamps are. If you mount them too close, you get hotspots. Those hot spots cause the glass to expand unevenly, and you might actually crack the sheet before the blade even touches it. That’s a nightmare. We aim for a “heat curtain”—a steady, even glow across the whole cutting zone. The trade-offs you need to know Shortwave IR lamps are great because they heat up fast. Really fast. But they’re picky. If your conveyor belt speeds up or slows down even a little, your surface temperature swings. And you can’t just crank the power to fix it. If you do, you risk warping the machine frame or frying your wiring because the cooling fans just can’t keep up with that kind of heat. Plus, one size doesn’t fit all. A 4mm sheet needs a totally different setup than a heavy 12mm piece of architectural glass. If your distance is off, you’re either throwing away electricity or risking a broken sheet. It takes a bit of tweaking, but once you nail it, the results speak for themselves.