abstract |
The present invention relates to the preparation method of a kind of thin film, particularly relate to a kind of air filtration polytetrafluoroethylene film.Film thickness 15~20nm, Air permenbility is 100 120L/m 2 / s, filtering accuracy is more than 99.99%;Its preparation process includes: lubrication mixing: mixed with fluid lubricant by PTFE micropowder, stands 3~6 hours, form PTFE material at a temperature of 85 DEG C~90 DEG C;Fluid lubricant includes 10 30% that aerial kerosene and silicone oil, aerial kerosene addition are PTFE micropowder quality, and silicone oil addition is the 1 10% of PTFE micropowder quality;Base rolls;Degreasing modification: add the auxiliary agent accounting for PTFE micropowder quality 1 3%, PTFE base band is formed after 200 250 DEG C of longitudinal stretchings 1.5 2.5 times defat base band;Auxiliary agent includes the first elastic plastic by weight 1 3:1 mixing and the second elastic plastic;Drawing and setting: by defat base band cross directional stretch at 215 DEG C~235 DEG C, then sinter sizing;Cooling and solidifying.The PM2.5 interception result of the PTFE thin film of the present invention is good. |