Does TPE material need to be dried?

In the plastic and rubber processing industry, material drying is a common pretreatment step. Drying is especially crucial for hygroscopic materials like nylon and PC. Otherwise, moisture will evaporate during high-temperature processing, causing bubbles and silver streaks in the finished product, and even affecting material performance. So, does TPE material need to be dried? The following editors from Shenzhen Zhongsuwang TPE will explain this question.

Whether TPE material needs to be dried depends on the specific application scenario and processing requirements, as follows:

For TPE materials used in general molding processes (such as extrusion, single-component injection molding, and cast film), drying and baking are not required before molding. However, drying is required in the following situations:

For encapsulated TPE products, such as encapsulated ABS, PC, and PA, if the product requires a high surface gloss, it is recommended to dry the material before molding to prevent any residual moisture in the TPE pellets from evaporating during molding, resulting in air streaks and poor appearance. For situations where high gloss is required for the product's appearance, such as high-end tools and electronic products, drying the TPE material is recommended.

If the rubber compound is not promptly sealed after opening and the relative humidity in the warehouse is high, this may cause the TPE pellets to exceed the moisture limit. In this case, baking before molding is necessary.

During the drying process, it is important to carefully control the drying temperature and time. Generally, SEBS-based TPE/TPR requires a higher drying temperature than SBS-based TPE/TPR. Higher-hardness TPE/TPR requires a higher drying temperature than lower-hardness TPE/TPR. For lower-hardness TPE/TPR (below 60A), a drying temperature of 60-80°C and a drying time of 2 hours are recommended. For higher-hardness TPE/TPR (above 60A), a drying temperature of 80-90°C and a drying time of 2 hours are recommended.

In general, whether to dry TPE materials should be based on a comprehensive assessment of material properties, storage conditions, processing requirements, and supplier recommendations. Only by following the correct processing procedures can we ensure that TPE materials can achieve optimal performance and produce high-quality products.