Getting the Ink Right Without Breaking the Glass
When you’re trying to bake silk-screen prints right into the tempering process, it’s all about a delicate balancing act with heat. You need it hot enough to fuse that ink into the glass, but if you push it too far, you risk weakening the glass or—even worse—watching your crisp design bleed into a blurry mess. That’s where short-wave infrared (IR) lamps in the annealing lehr save the day. Keeping the lines sharp We rely on high-wattage quartz halogen lamps because they hit the surface fast. Really fast. Here’s why that matters: if the heat creeps in too slowly, the ink has time to migrate. You end up with fuzzy edges. By using lamps with high power density, we can blast the surface to get that ink cured instantly. The best part? The bulk of the glass doesn’t have time to soak up all that excess heat, so the pane stays strong. The gear under the hood These aren’t your average lightbulbs. They usually run on high-voltage circuits so they don’t pull too much current across those long lehr banks. We stick with R7s or SK15 connectors. Why? Because quartz tubes expand when they get hot, and these connectors don’t wiggle loose when things start heating up. We also often use coated quartz tubes. This tweaks the light spectrum so the heat actually sinks into the ink instead of just bouncing off the glass like a mirror. The catch Now, there is a trade-off. High-intensity lamps are great, but they’re power-hungry. You can’t just toss them into an old setup and hope for the best. Your transformers and wiring need to be ready for that initial power surge when they kick on. And a word of warning: keep an eye on your cooling fans. If the airflow in the lehr isn’t dialed in, those lamps will burn out way too fast. The heat builds up right at the pinch seal, and before you know it, you’re replacing bulbs again.