Fixing the Heat Headache in KHS Blow Molding
Ever deal with those annoying wall thickness variations or PET bottles that just look… off? Usually, it’s because your preforms aren’t heating evenly. You end up with pearlescence or structural weak points that make the whole batch look amateur. It’s frustrating. We’ve spent a lot of time figuring out how to kill those thermal gaps. The secret is in the quartz heater tubes—specifically, how we handle the radiation profile of the filament.
Why your heat is uneven
Here’s the thing: most standard tubes have “cold spots” right near the ends. It’s a common flaw. To fix this, we tweaked the filament winding density and cleaned up the purity of the quartz envelope. By getting the filament positioning exactly right, the infrared energy hits the preform consistently from top to bottom. No more guessing. You won’t have to mess around with your machine speed or air pressure just to over-compensate for a bad heater.
The gear inside
We use high-purity fused quartz. Why? Because it doesn’t burn out the moment things get stressful. These are designed to be simple drop-in replacements for your KHS setup. The high-grade material means you can push the operating temperatures higher without the tube warping or becoming “cloudy” to IR waves. **One quick heads-up:**double-check your voltage and wattage before you order. Our tubes can handle a lot of heat density, but if you run them at the absolute limit, your reflectors are going to feel the strain. And please, keep your reflectors polished. A dirty reflector makes even the best tube perform like a cheap one.
Getting them running
The best part? These fit the footprint you already have. You don’t need to rewire your racks or call in a specialist for a total overhaul. Just swap the old tubes out, recalibrate your heat zones, and you’re good to go. Just keep an eye on your cooling blowers. High-density heating cuts down your cycle time—which is great—but it does dump more ambient heat into the oven. Make sure your blowers can handle the extra load so your electronics don’t start sweating.