On the blow molding line, preform temperature swings kill yield and stretch your cycle time. When the heating tunnel can’t hold setpoint, you start seeing weak necks, blown sidewalls, and scrap piling up. More often than not, the fix is staring you right in the face—inside the oven, in the insulation board. What we’re really talking about, technically We make oven heating box insulation boards for the infrared zone on PET stretch blow molding machines. The core is high-temperature mineral wool board, laminated with low-emissivity reflective layers to keep the heat on the preforms instead of bleeding out into the frame. They’re cut to match standard tunnel widths and mounting hole patterns, and the edges are sealed to cut leakage. The specs are straightforward: 1200–1500 mm length, 200–300 mm width, 15–25 mm thickness, continuous rating to 650°C. We match up to common lamp holders and wiring paths so you can drop the board in without re-engineering the oven. Why this matters in practice Infrared heating only works when the radiation is stable and repeatable, with as few cold spots as possible. A worn, porous insulation board bleeds heat, so the heaters chase the temperature and drift becomes inevitable. Swap it out for a board that’s sized and sealed properly for the tunnel, and you get tighter preform heating across the row—fewer alarms, less energy draw. On the floor, that means fewer temperature-related rejects, more consistent bottle weight, and more uptime between maintenance windows. Here are the things that actually trip people up Installation is quick, but the oven has to be cool and the lamps out—otherwise you risk cracking the board. Always verify the mounting hole pattern and clearances around the lamp sockets, especially on older Sidel, Krones, SIPA, Husky, SACMI, and Nissei ASB machines where oven tolerances can vary. And keep the reflective surface clean; heavy deposits cut reflection and throw the heating balance off. You can expect longer service life than standard boards, but still inspect at each lamp change for heat fatigue along the edges.