Lithium battery separator wet production process

Lithium battery separator wet production process
According to whether the orientation is simultaneous during stretching, the wet process can also be divided into wet biaxial asynchronous stretching process and bidirectional synchronous stretching process.
Wet step stretching process:
1) Feeding: Pre-treat raw materials such as PE and pore-forming agent according to the formula and transport them to the extrusion system.
2) Casting: the pretreated raw materials are melted and plasticized in a twin-screw extrusion system and then extruded from the die to form a cast slab containing a pore-forming agent.
3) Longitudinal stretching: longitudinally stretching the cast slab.
4) Transverse stretching: stretching the cast slab after longitudinal stretching to obtain a base film containing a pore-forming agent.
5) Extraction: the basement membrane is extracted with a solvent to form a basement membrane without pore-forming agent.
6) Shaping: the base film without pore forming agent is dried and shaped to obtain a nanoporous membrane.
7) Slitting: Cut the nano-microporous membrane into finished membranes according to customer specifications.
Wet synchronous stretching process:
The process flow of wet synchronous stretching technology is basically the same as that of asynchronous stretching technology, except that it can be oriented in both horizontal and vertical directions during stretching, eliminating the need for a separate longitudinal stretching process. However, the problem of synchronous stretching is that the vehicle speed is slow, and the second is that the adjustability is slightly poor. Only the transverse stretching ratio is adjustable, and the longitudinal stretching ratio is fixed.
The wet asynchronous stretching process enhances the uniformity of the diaphragm thickness, and the product has high transparency, no scratches, excellent optical properties and surface properties. It is a diaphragm with comprehensive performance and occupies an important position in the high-end diaphragm market. performance of the lithium battery separator.