MANUFACTURING METHOD OF PVDF MEMBRANE FOR WATER TREATMENT IMPROVING MEMBRANE PROPERTIES

摘要

The present invention relates to a method for manufacturing a PVDG membrane for water treatment having improved membrane properties. The prevent invention provides a PVDF membrane for water treatment, in which a hollow fiber membrane manufactured after passing through a coagulating solution in manufacturing processes of solution production-discharging-coagulation-winding when a PVDF hollow fiber membrane is manufactured is stretched and wound under optimal conditions, and slit type pores are formed with an asymmetric structure in a surface and cross-section of the membrane by a post-treatment process in which a secondary stretching process is performed. The slit type pores of the PVDF membrane for the water treatment may have the asymmetric structure to improve water permeability, thereby realizing a high flow rate. Also, a sterical hinderance effect between removed particles within raw water may occur by the formation of the slit type pores to improve an antifouling property. Also, a PVDF crystal structure may be changed by the stretching process to improve strength. Thus, the PVDF membrane for the water treatment of the prevent invention may not be deteriorated in strength and flow rate characteristics even through the PVDF membrane are used for a long time to stably perform the water treatment process, thereby reducing producing costs and maintenance expenditure.