What is the production process of ePTFE membrane?

1. Raw material preparation: Select high-quality polytetrafluoroethylene (PTFE) resin as the basic raw material to ensure that its purity and performance meet the production requirements. For example, some manufacturers will choose a specific brand of PTFE resin to ensure the quality stability of the final product.
2. Mixing and additive addition: According to the specific performance requirements of the product, PTFE resin is mixed with an appropriate amount of additives (such as lubricants, antioxidants, etc.). These additives can improve the processing properties and final properties of the material, such as improving the flexibility and aging resistance of the membrane. During the mixing process, it is necessary to ensure that the additives are evenly dispersed in the PTFE resin to avoid affecting the product performance.
3. Extrusion molding: The mixed raw materials are heated to a certain temperature through an extruder to make them in a molten state, and then extruded through a specific mold to form a billet with a certain shape and size. Parameters such as extrusion temperature, extrusion speed and mold design have an important influence on the quality of the billet and need to be adjusted according to the specific production process.
4. Stretching treatment: This is one of the key steps in the production process of ePTFE membrane. The extruded blank is stretched under specific temperature and tension conditions to orient the PTFE molecular chains in the stretching direction to form a microfiber network structure, thereby increasing the porosity and air permeability of the membrane. The stretching can be unidirectional or bidirectional, depending on the requirements of the product. For example, bidirectional stretching can give the membrane good performance in both directions.
5. Sintering: The stretched membrane is sintered at high temperature to further cross-link and solidify the PTFE molecular chains, thereby improving the strength and stability of the membrane. The sintering temperature and time are key parameters that need to be strictly controlled to ensure that the performance of the membrane is optimal.
6. Post-processing: The sintered membrane is post-processed, such as cutting, inspection, packaging, etc., to meet the needs of different customers. Cutting can cut the membrane into different sizes and shapes according to customer requirements; inspection is to test the performance of the membrane to ensure that the product quality meets the standards; packaging is to protect the membrane from damage during transportation and storage.