What are the drying requirements for TPE materials?

In the processing of TPE materials, drying is a critical step in ensuring product quality. Although most TPE materials have low hygroscopicity, moisture absorption can occur during storage, transportation, or handling if the packaging is damaged, the environment is high in humidity, or the material is exposed to air for extended periods. Even trace amounts of moisture can cause a series of problems during subsequent high-temperature processing (such as injection molding and extrusion). So, what are the specific drying requirements for TPE materials? Below is an introduction from the editors of Shenzhen Zhongsuwang TPE.

The drying requirements for TPE materials are as follows:

1. Determining whether drying is necessary:

Not all TPE materials or all production batches require drying. The key is to evaluate the material's storage conditions and exposure time. If the material is stored in its original sealed packaging, in a dry environment, and used quickly after opening, drying is generally not necessary. However, if the packaging has been opened for an extended period of time or has been stored in a humid environment, drying is recommended as a precautionary measure, especially when product appearance and performance are critical.

2. Drying Method:

For TPE that requires drying, the most common and recommended method is to use a hot air circulation dryer (oven). This equipment provides stable, uniform temperature and airflow.

3. Drying Parameters:

Temperature: The drying temperature is typically set approximately 10-20°C below the melting point of the TPE material, or refer to the supplier's specific recommendations. Excessively high temperatures may cause material degradation. Typical ranges may be between 60°C and 90°C, depending on the specific TPE type.

Time: Because TPE has relatively low hygroscopicity, drying times generally do not require the same extended drying time as nylon. A general recommendation is to dry for 2-4 hours at the set temperature. Again, the optimal drying time should be determined by referring to the supplier's data or through small sample testing.

Environment: Ensure the drying environment is dry and has a flow of air to promote evaporation and removal of moisture.

4. Precautions:

Avoid overdrying: Excessively long drying times or high temperatures may degrade the TPE's molecular chains, impairing material properties.

Timely Use: Dried TPE should be put into production as soon as possible to prevent it from absorbing moisture again. Dried materials should be stored in sealed containers.

Reference to supplier recommendations: Different TPE grades, formulations, and suppliers may have different drying requirements. The most reliable source of information is the technical data sheet (TDS) or technical support provided by the material supplier.

Relationship with fillers: If highly hygroscopic fillers (such as certain inorganic powders) are added to the TPE formulation, more stringent drying conditions may be required.

Thus, while TPE materials do not have the extremely demanding drying requirements of some plastics, ignoring their potential for moisture absorption can cause unnecessary processing problems and compromise the quality of the final product. Therefore, carefully evaluating and implementing appropriate drying procedures based on material storage conditions, production requirements, and product quality expectations is critical to ensuring smooth TPE processing and satisfactory product performance.