Fixing Those Annoying Heat Spots in Your KHS Blow Molders
Ever pull a batch of PET bottles off the line and see those weird “cold spots” or that cloudy, pearlescent look? It’s frustrating. Usually, it means your wall thickness is all over the place, and your bottles aren’t as strong as they should be. Most of the time, the culprit is your infrared (IR) lamps. They either degrade over time or just aren’t hitting the preform where they need to. That’s why we make replacement lamps that slide right into your KHS machine—designed to hit the same thermal sweet spot as the originals, if not a bit better. The nitty-gritty on heat and power We’re obsessive about the wattage and voltage. Why? Because the last thing you need is a power controller tripping in the middle of a run. When you have a lamp built for high-voltage operation, you get a much more concentrated blast of heat. This lets you speed up your cycle times without sacrificing quality. You get a consistent, tight heat profile across the whole preform. We also use high-purity quartz glass so the bulbs don’t burn out prematurely. And we make sure the filament is centered perfectly—down to a fraction of a millimeter. If that filament sags even a little, your heat field shifts, and you’re back to square one with uneven bottles. Getting the heat inside the plastic It’s not just about how hot the lamp gets; it’s about where that heat goes. We use special coatings to tweak the IR spectrum. Instead of the heat bouncing off the surface of the PET, it actually penetrates the material. As for the fit, we stick to standard R7s or Sk15 connectors. They snap in securely, which means you don’t have to worry about arcing at the contact points when the system is switching at high frequencies. A quick heads-up on the trade-offs These are direct replacements. You can swap them out and wire them up without having to rebuild your oven housing. Easy. But here is the thing: if you decide to crank up the heat density to fix some old oven issues, your cooling blowers are going to work harder. If you push the wattage beyond what the OEM originally called for, the ambient temperature inside the machine will climb. Just keep an eye on your cooling system. You don’t want the oven shell overheating while you’re chasing the perfect bottle.