ELECTRET PROCESS AND PRODUCTS

摘要

Continuous processes for the preparation of electrets and the products produced thereby, including filter fabrics, are disclosed. The process employs a continuous film or continuous filaments in the form of a tightly packed warp having a warp density as determined by light transmission of not more than 40%. The continuous film or continuous filament in the form of a tightly packed warp are continuously fed one or more times through a corona charging station having electrodes disposed on both sides of the material being treated, the material being treated being simultaneously heated while being subjected to a corona discharge of from 6 KV to 20 KV direct current.