Getting Your PET Blow Molding Lamps Right
If you’ve ever spent time sourcing replacement lamps for a Sidel or any other big-brand line, you know the headache. It’s never just about “finding a bulb.” The real struggle is matching the heat density and the physical size. Nobody wants to spend their weekend rewiring an oven just because a replacement part didn’t quite fit.
The truth about heat and voltage
Here is the thing: we build our lamps to handle high-voltage loads—often hitting 400V. We do this to cram as much wattage as possible into a small quartz tube. Why? Because that’s the only way to get the heat to penetrate the PET wall fast enough without scorching the outside. If your machine is built for 2500W and you try to cheat it with a lower-wattage bulb, you’re going to have a bad time. You’ll end up with under-heated preforms and walls that thin out during the blow cycle. But wait—there’s a catch. Even the best lamp can’t fix old mirrors. If your reflectors are oxidized and cloudy, the heat just bounces around instead of hitting the plastic.
The nitty-gritty: Connectors and Glass
Compatibility usually comes down to the ends of the tube. We stick to R7s and Sk15 connectors so you can just slide them in and go. Inside, we use halogen-filled quartz glass. It’s a clever little cycle that puts evaporated tungsten back onto the filament, which keeps the bulb from burning out prematurely. Some of our tubes even have special coatings. They shift the infrared spectrum, basically “steering” the heat exactly where the plastic absorbs it best.
Swapping them out
You can toss these into about 95% of the blowing machines on the market. We mirrored the exact dimensions and electrical footprints of the OEM parts, so it’s a simple swap. Just slide the lamp into the socket, lock it, and you’re done. One quick tip: these high-density lamps put out a lot of heat. A lot. Make sure your cooling fans aren’t clogged with dust or debris. If they are, you’ll start seeing your lamp holders warp over time, and that’s a mess nobody wants to deal with.