Hydrophobic EPTFE Membrane Pore Control Process
1Optimize Raw Material Selection and Pre-forming
- Select PTFE resins with appropriate molecular weight and particle size distribution
- Uniformly mix the resin with lubricant to create a homogeneous paste
- Control lubricant content and mixing time precisely
- Ensure consistent distribution of components for uniform pore formation
Key Consideration: Insufficient lubrication causes uneven stretching, while excess leads to larger, irregular pores.
2Regulate Stretching Parameters
- Control the stretching ratio - higher ratios produce larger pores
- Adjust stretching speed to avoid uneven pore distribution
- Select stretching direction (uniaxial or biaxial) based on pore structure requirements
- Uniaxial stretching creates elongated pores; biaxial produces isotropic pores
3Fine-tune Sintering Conditions
- Control sintering temperature within optimal PTFE range
- Higher temperatures reduce pore size by shrinking voids
- Adjust sintering time to balance stability and pore retention
- Control cooling rate to prevent excessive fibril contraction
Note: Rapid cooling preserves larger pores by minimizing fibril contraction during cooling phase.
4Implement Post-Treatment Adjustments
- Use calendering (controlled compression) for finer pore sizes
- Apply laser drilling or chemical etching for precise pore creation
- Consider surface modification techniques to influence pore openings
- Modify surface tension at pore edges for final size tuning
Specialized Application: Laser drilling creates precise, uniform pores but is typically reserved for specific high-performance applications.