Getting the Heat Right for Silk-Screened Glass
Here’s the problem when you’re combining silk-screening and tempering: you’re fighting a battle of physics. You need the glass hot enough to get that strength and stress, but if you push it too far, you’ll burn the ink or watch your pattern start to bleed. It’s a tightrope walk. We handle this by using custom quartz infrared heaters. The goal is to separate the surface temperature from the heat soaking into the core. The trick with wavelengths It really comes down to whether you use short-wave or medium-wave lamps. Short-wave hits the surface fast and hard. For silk-screened patterns, that’s a gamble you don’t want to take. Instead, we use a tuned quartz mix that shifts how the heat is emitted. By tweaking the wattage per centimeter, we can get the glass to that tempering sweet spot without hitting the point where the ink just gives up and decomposes. Finding the balance We build these heaters to handle high-voltage loads so the heat stays consistent across the whole sheet. Think about a 2000mm lamp. If the voltage dips at the ends, you get cold spots. That means uneven tempering and patterns that look distorted. To stop that—and to keep the lamps from burning out during fast cycles—we use heavy-gauge tungsten filaments. Then there’s the conveyor speed. It’s always a trade-off. If you speed up the line, you need more wattage to hit your temperature. But more wattage increases the risk of scorching your ink. Your options are simple: slow the line down to save the pattern, or get more precise lamps to keep your output high. Setting it up We use standard industrial connectors, so these are basically drop-in replacements. But the mounting is where people usually mess up. If the lamps are too close, you get hot spots. Too far, and you’re just throwing energy away. We recommend a rigid frame. It keeps a precise gap so the heat profile stays flat across the glass. Simple, but it makes all the difference.