Many plastic granules face the challenge of surface moisture. This surface moisture is introduced in various plastic processes or due to different climatic conditions such as cleaning and washing, higher humidity during monsoon times and reverse osmosis during winter.
This issue is common for polymers such as PE, PVC, PP, LDPE, HDPE, LLDPE or XLPE. These polymers are categorised as commodity and are used in various applications, including cables (PVC cables), packaging (PE films, HDPE bottles), household and kitchenware, caps and closures.
What Problem Does It Cause?
If this surface moisture is not removed before processing or during the conversion from the granular stage to any component stage, it may lead to a reduction in the physical properties of the material and a poor surface finish. This occurs because granules are brought into the molten phase by means of adding heat inside the screw barrel. At that moment, polymer bonds are in a vulnerable state, and steam formed from moisture evaporation becomes incorporated into the polymer structure, reducing its strength. Therefore, the ideal solution is to reduce the moisture level below its maximum permissible limit.
Surface drying thus refers to the process of removing moisture from the surface of plastic granules
Ideal Solution for Surface Drying: Hot Air Dryer
Bry-Air Hot Air Dryer supplies continuous hot air to the material granules stored in a hot air drying hopper. This process helps surface drying through the moisture deposition on the granular surface to evaporate and release into the atmosphere through the drying hopper exhaust. By doing this, we also increase the material temperature, bringing it to a safe hot conditioning stage. This aids in achieving a faster-melting temperature, providing extra time for the homogeneous mixing of the material inside the screw barrel.