http://ir-heater-tools.com/en/tags/preforms/ Recent content in Preforms on Essential Infrared Heating Tools Hugo en-us Sun, 31 May 2026 04:22:27 +0800 http://ir-heater-tools.com/en/posts/why-are-my-pet-preforms-turning-white/ Sun, 31 May 2026 04:22:27 +0800 http://ir-heater-tools.com/en/posts/why-are-my-pet-preforms-turning-white/ <p><img src="http://ir-heater-tools.com/images/3d4a3d4a92b1ce7cc4373019fe6191a8.png" alt="Why are my PET preforms turning white"></p> <p>You see it on the line: preforms coming out of the heating tunnel looking chalky, almost white. The bottles that follow are weak at the base, hazy on the walls, and your scrap rate is climbing. In stretch blow molding, whitening isn’t just a cosmetic issue. It’s a clear sign the material isn’t hitting the right temperature profile before it hits the mold. More often than not, the root cause is right there in the heating system. As infrared emitters age, drift out of band, or lose output stability, the preform skin heats unevenly. The core never catches up. You get surface crystallization—whitening—and the process ends up fighting itself just to make a stable bottle. We work on infrared heating systems for blow molders, and we see this problem across Sidel, Krones, SIPA, Husky, SACMI, and Nissei ASB lines. The fix isn’t guesswork. It’s matching emitter technology and control to the preform geometry and the machine cycle.</p>