Getting the Heat Right for Screen-Printed Marine Glass
When you’re trying to screen print and temper glass in one go, you’re basically walking a tightrope. On one side, you need the glass hot enough to soften so it can actually temper. On the other, you’ve got ink that will blister, bleed, or just straight-up burn if it gets too toasted. It’s a tricky balance. That’s why we lean on short-wave infrared (IR) lamps. Here’s the thing: you want the heat to sink deep into the glass, not just sit on the surface and fry your artwork. Short-wave IR is great because it punches through the glass faster. If you go too slow, the ink just sits there baking, and you end up with “ghosting” or weird discoloration. Nobody wants that. Now, managing the actual heat load is where it gets a bit more hands-on. We look at the glass thickness and the ink’s breaking point to figure out the right lamps. Using high-wattage density lamps means the glass spends less time under the heat. It’s a quick ramp-up. But you can’t just set it and forget it. You’ve got to tweak the lamp distance and the conveyor speed. If you miss the mark, the surface temp spikes and your print clarity goes out the window. But wait—fast heating isn’t a magic fix. It can actually create some weird stress points. Since the ink changes how the glass absorbs heat, the printed parts and the clear parts don’t always heat up at the same rate. If your lamp array isn’t perfectly uniform, you’ll see it in the glass. The best way to handle this is with zoned control. Basically, you adjust the power for specific banks of lamps to balance out how the ink is absorbing the heat. Then comes the quench. This is the make-or-break moment. You have to time the cooling perfectly to lock in the strength. If you go too aggressive with the quench, the ink and the glass will fight each other as they shrink. That’s how you get peeling. Get the timing right, and it’s a breeze.