Polypropylene melt-blown nonwoven was used as the substrate for the preparation of an air film. The nonwoven was immersed in the casting solution at first,and then respectively placed in the first coagulation bath,the second coagulation bath and the finishing liquid containing fluorine additive aqueous solution of 20 g/L. At last,the high temperature drying was carried out to obtain the air permeable and water resistant air film. With analyses and comparisons of the isopropanol alcohol content,the residence time of air,the composition of the first coagulation bath and the residence time of the first coagulation,the optimum parameters were found and the air film had an air permeability of 4. 7 L/min,a water blocking pressure of 16 kPa,a contact angle of 134. 2°,and a mean pore size of 2. 089 1 μm.
展开▼
