Lithium Battery Extruder

This extruder is for the production of lithium battery separators includes a motor, a coupling, a gearbox, a multi-section screw, a gear pump, a filter and a die, which are connected in sequence and integrated into one body, and is characterized by: the multi-section screw A polyolefin resin feeding port is connected to one end near the gear box, and more than two oil filling ports are spaced apart on the multi-section screw between the polyolefin resin feeding port and the gear pump.

Lithium-ion battery separators can be divided into two categories: dry method and wet method according to different preparation processes. The wet method is also called phase separation method or thermally induced phase separation method. The wet lithium-ion battery separator is made by melting and extruding materials such as polypropylene or polyethylene and paraffin oil, and then biaxially stretching and extracting them to form a microporous polyolefin separator. Specifically, liquid hydrocarbons or some small molecular substances are mixed with polyolefin resin, and after heating and melting, a uniform mixture is formed, and then the temperature is lowered for phase separation, and a film is obtained by pressing, and then the film is heated to a temperature close to the melting point, and is stretched in two directions. By stretching the molecular chains to orientate them, and finally keeping them warm for a certain period of time, using volatile substances to elute the remaining solvent, an interconnected microporous membrane material can be prepared.

Paraffin oil is added separately through multiple filling ports designed on the extruder. On the one hand, it avoids insufficient melt pressure due to too much paraffin oil at the first oil filling port and poor plasticization of polyolefin resin. In addition, paraffin oil is added at multiple points. It can ensure that the polyolefin resin is fully mixed and plasticized with paraffin oil in time under different flow and shear conditions in the screw, which greatly improves the control of the phase separation process and the porosity of the product.