Rising temperatures cause polyethylene wax to lose its effectiveness for two main reasons. The first is a physical change in state. Polyethylene wax is a low‑molecular‑weight polyethylene that relies on its relatively high melting point (typically above 100 °C) and solid‑state hardness to provide functions such as scratch resistance, anti‑blocking, and matting at room temperature. When the ambient or processing temperature approaches or exceeds its melting point, the wax changes from a solid to a molten liquid. As a result, the properties that depend on its solid microcrystalline structure are significantly weakened or lost.
The second reason is chemical degradation. Elevated temperatures accelerate the thermal oxidation reaction between polyethylene wax and oxygen, leading to chain scission and the formation of oxygen‑containing groups such as carbonyls. This causes the wax to discolor (turning yellow or brown) and its performance to deteriorate. In addition, acidic substances released by other components in the formulation—for example, from the thermal degradation of PVC resin—can further accelerate the breakdown of the wax.
To address these problems, the following specific solutions can be implemented. First, check the actual temperature control of both the working environment and the processing equipment. Measure temperatures at critical points such as the barrel and the die to identify any localized overheating or inaccurate temperature controllers. If necessary, recalibrate the instruments or reduce the processing temperature.
Second, if the production environment is indeed subject to persistently high temperatures, consider switching to a polyethylene wax grade with better thermal stability and a higher melting point—for example, moving from a grade with a melting point around 100 °C to one of 120 °C or higher. Test the performance retention of the new wax under high‑temperature conditions.
Third, supplement the formulation with antioxidants, such as hindered phenolic antioxidants (e.g., Irganox 1010) or phosphite secondary antioxidants, to slow down thermal oxidative degradation. At the same time, check whether any easily decomposable acidic components are present in the formulation and adjust them accordingly or add acid scavengers.
Fourth, improve storage conditions. Keep polyethylene wax in a cool, well‑ventilated area away from direct sunlight and high‑temperature stacking, so that its performance does not deteriorate even before it is used.
Finally, if the problem persists, communicate with your supplier. Provide them with the actual processing temperatures and the failure symptoms you are observing, so that they can help you select a suitable high‑temperature‑resistant grade or develop a customized compounding solution. Always run pilot production trials to verify the effectiveness before switching over to full‑scale production. By following these steps, you can effectively resolve the issue of polyethylene wax failure caused by high temperatures.
