Getting Your PET Preform Heating Just Right
If you’ve spent any time around a blow molding machine, you know the struggle. You need the preform to hit that sweet spot—the glass transition temperature—without accidentally scorching the plastic. It’s a balancing act. That’s why we build our halogen infrared lamps the way we do. We focus on high-intensity shortwave radiation because it’s the fastest way to get that heat exactly where it needs to go. Let’s talk power. We spec these lamps with high wattage and voltage to really push the heat flux. By using a high-voltage tube, we can keep the filament longer without the current getting out of control. This is a big deal because it keeps the lamp from burning out when you’re pushing the machine hard. But here’s a tip: make sure your voltage matches your power supply. If you try to “over-clock” the tube just to hit a certain temperature, you’re going to fry that tungsten filament way sooner than you should. The build quality matters. We use high-purity quartz glass because, frankly, these things take a beating from thermal shock. We also offer different coatings to tweak the emission spectrum. This helps the heat soak into the PET plastic more evenly, so you don’t end up with hot spots. When it comes to installation, we stick with R7s or SK15 connectors. They’re simple, standard, and they just work. You can drop them right into most machines. Plus, they create a tight electrical connection, which means you don’t have to worry about arcing when the machine starts vibrating during a high-speed run. Real-world use. These lamps live in the oven, firing away while the preform rotates. Because it’s shortwave radiation, the heat hits the plastic directly. The best part? Your machine frame doesn’t soak up nearly as much heat. Just a heads-up, though. These tubes pack a massive amount of heat into a tiny space. You’ve got to make sure your ventilation and cooling fans are up to the task. If your cooling is weak, your reflectors might warp or your wiring could actually melt. Keep them cool, and they’ll last. Simple as that.