FILTER AND METHOD FOR MAKING A FILTER

摘要

A filter is provided which includes an organic vapor adsorbing layer, a first particulate removal layer, and a second particulate removal layer. The organic vapor adsorbing layer includes porous adsorbent beads which allow air or gas to flow therethrough with little resistance and provide increased surface area by virtue of the pores. The particulate removal layer can be made from an electrostatic and/or polytetraflouroethylene. The filter can have a figure or merit greater than about 10 and a capacity for permanently adsorbing organic vapors, wherein the figure of merit is calculated based upon a fractional efficiency determined for particles having a size of 0.3 .mu.m in an air flow having a velocity of 10.5 ft./min. and for Frazier permeability at 0.5 inches H2O.