Fixing Those Annoying Heat Spots in Your KHS and Sidel Blow Molders
Ever pull a batch of bottles and see that cloudy, pearlescent look? Or maybe the walls are way too thin in some spots and thick in others. It’s frustrating. Usually, it just means your thermal field is off—you’ve got hot and cold spots in the oven that are messing with your PET preforms. We’ve spent a lot of time building replacement lamps for Sidel SBO and KHS systems specifically to kill those dead zones and get your quality consistent again. The nitty-gritty on the heat Here is how we handle it: we tweak the filament winding density to control exactly how the heat radiates. If you’re chasing faster cycle times, you’ll want a lamp with higher wattage to get that heat density up. Just a heads-up, though. Double-check that your power supplies can actually handle the load. If you push them too hard, you’re just asking for a premature burnout. Why the glass matters We use high-purity quartz glass. Why? Because it lets shortwave infrared light pass right through. Instead of just scorching the surface of the plastic, the heat actually penetrates the material. As for the install, it’s easy. Most of these use standard R7s or SK15 connectors. They’re designed to be drop-in replacements, so you can just wire them up and go without messing around with your existing lamp holders. What to watch out for in the shop When you swap out your OEM lamps for these, you’ll notice the heat field stabilizes. It makes a huge difference in how much scrap you throw away during start-up. But there is a trade-off. If you crank up the wattage to boost your throughput, your oven’s ventilation has to work harder. Make sure your cooling fans are up to the task. If the heater block gets too hot, you risk warping your reflectors, and that’s a headache nobody wants.