FILTER MATERIALS, ISSUES FOR FILTERING OF TOBACCO SMOKE, AND PROCEDURES FOR PRODUCING THEREOF

摘要

A filter material, particularly for tobacco-smoke filters, comprises fibrillated polyolefin sheet having main generally longitudinally-extending strands interconnected by interconnecting strands and having a substantial number of free ends formed by severing main strands and/or strands which would otherwise have constituted interconnecting strands, the strands having a thickness in the range 5 microns to 25 microns and at least 40 percent (preferably at least 70 percent) of the strands having a width not greater than their thickness.