Method for preparing polytetrafluoroethylene hollow fiber membrane having high bonding strength

• Main Authors: CAO ZHIHONG, JI GENLIANG, ZHU DONGSHENG, SHEN LIQIANG
• Format: Patent
• Language: Chinese; English
• Published: 29.03.2019
• Subjects: PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; TRANSPORTING

A method for preparing a polytetrafluoroethylene hollow fiber membrane having high bonding strength is disclosed in order to solve a disadvantage that polytetrafluoroethylene hollow fiber membranes are high in pore size and cannot meet requirements on high-precision separation or filtration, and a disadvantage that wrapped polytetrafluoroethylene hollow fiber membranes are instable in pore size, insufficient in bonding strength and liable to shed. The method includes (1) a slitting step, namely a step of slitting a biaxially oriented polytetrafluoroethylene completely-sintered flat membrane having an average pore diameter range of 0.05-0.5 [mu]m into a polytetrafluoroethylene banded membrane; (2) a soaking step, namely a step of soaking the polytetrafluoroethylene banded membrane in low-molecular-weight polytetrafluoroethylene organic dispersion; (3) a wrapping and shaping step, namely a step of wrapping the soaked polytetrafluoroethylene banded membrane around the external wall of a stretched polytetrafluoro