Abstract

Disclosed is a method for preparing a polytetrafluoroethylene superfine powder by combining ultraviolet rays with ozone and carbon tetrachloride. The method comprises the following steps: quenching a dry polytetrafluoroethylene raw material in liquid nitrogen, and crushing into a grain size of 100-1000 μm with a pulverizer; then placing same in a tray on a platform of an ultraviolet irradiation box, sealing the ultraviolet irradiation box, and injecting ozone thereto, wherein the weight ratio of the injected ozone to the polytetrafluoroethylene raw material in the tray is 0.1%-0.5%; turning on a control mechanism of a spraying device to spray CCl4 onto the polytetrafluoroethylene raw material in the tray, wherein the weight ratio of the sprayed CCl4 to the polytetrafluoroethylene raw material in the tray is 3%-8%; continuously irradiating for 8-12 hours with ultraviolet rays; discharging waste gases after the irradiation is completed; and taking out the polytetrafluoroethylene powder and putting same into an airflow crushing system for sufficient crushing, so as to obtain a polytetrafluoroethylene superfine powder with a grain size of 0.2-5 μm.

IPC Classes  ?

• C08J 3/28 - Treatment by wave energy or particle radiation
• C08F 114/26 - Tetrafluoroethene
• B02C 19/06 - Jet mills
• B02C 21/00 - Disintegrating plant with or without drying of the material

Abstract

Disclosed is a method for preparing a PTFE superfine powder by combining γ rays with ozone and hydrogen peroxide. The method comprises: quenching a dry polytetrafluoroethylene raw material in liquid nitrogen; crushing same into a polytetrafluoroethylene powder having a grain size of 100-1000 μm with a pulverizer; then placing same into a container on an automatic production line of a cobalt 60 device; first spraying hydrogen peroxide and ozone on the automatic production line, and then irradiating when passing through the cobalt 60 device, wherein the irradiation dose is 40-60 KGy, and the radiation time is determined according to the radioactivity of the cobalt 60 device; conveying the radiated polytetrafluoroethylene powder out of the radiation chamber via the automatic production line; and placing same into an airflow crushing system for sufficient crushing, so as to obtain a polytetrafluoroethylene superfine powder with a grain size of 0.2-5 μm. According to the method provided by the present invention, using the automatic production line can further improve the production efficiency while the degradation rate of polytetrafluoroethylene can be increased.

IPC Classes  ?

• C08J 3/28 - Treatment by wave energy or particle radiation
• C08F 114/26 - Tetrafluoroethene
• B02C 19/06 - Jet mills
• B02C 21/00 - Disintegrating plant with or without drying of the material