Stop the Chipping: Why You Should Preheat Your Glass
Glass is a pain. It’s brittle, stubborn, and the second you hit it with a cutting wheel, you’re creating a massive stress point. If that glass is cold, the tension between your cut line and the rest of the sheet usually ends in a disaster—those annoying little chips or corner breakouts that ruin a perfectly good piece. The fix? Heat it up first. We use infrared annealing lamps to warm the surface, and it makes a world of difference. The “Why” Behind the Heat Think of it this way: IR lamps pump energy straight into the glass molecules. When you raise the surface temp, you’re basically relaxing the material. It becomes a bit more “forgiving.” Instead of the crack jumping sideways and chewing up the edge of your glass, the score line stays clean and moves in a straight line. It’s the difference between snapping a frozen twig and bending a warm one. What to Actually Use on the Floor If you’re setting this up on a cutting line, go with short-wave quartz halogen lamps. Why? Because they get hot fast. You can’t afford to wait ten minutes for a lamp to warm up while your conveyor belt is moving at full speed. You need heat density, and you need it now. One quick warning: don’t cheap out on your hardware. If you’re running high-wattage tubes (we’re talking 2kW+), your wiring and sockets need to be beefy. I’ve seen cheap sockets literally melt under the load. It’s not worth the risk. Getting the Balance Right Now, don’t go overboard. This isn’t about baking the glass. If you get it too hot, you’ll trigger thermal shock, and your sheet will crack before it even touches the cutter. It’s a balancing act between how far away the lamps are and how fast your belt is moving. The best way to handle this is with a PID controller. It keeps the temperature steady so you don’t get those “hot spots” that mess up your cuts. Usually, hitting somewhere between 60°C and 100°C is the sweet spot. Once you hit that, you’ll see those chipping rates drop off a cliff.