| 摘要 |
A crimped filament tow, suitable for use in making cigarette filter rods, is made by a process in which porous particles, such as activated carbon particles, are adhered to the filaments by an adhesive. Deactivation of the adsorbent surfaces of the particles by the adhesive is limited by loading the particles with a material, such as water, which can generate a gaseous emission, such as steam, from the particles so as to open up access to the adsorbent interior surfaces of the particles. <??>The filaments, which may be cellulose acetate, may have a cross-section having concave portions, such as are provided by multi-lobal cross-sections, in which the adhered particles may lie to protect them against shedding by abrasion of the filaments against machine surfaces. <??>The particles and the adhesive may be applied to the banded tow (3) at the same time, in the form of a dispersion of the particles in the adhesive, and may be applied directly before the crimping step. The crimped tow may then be heated to generate the gaseous emission from the particles as well as drying and curing the adhesive. <??>The product tow can be processed on standard equipment to make efficient filter rods from which cigarette filter tips can be made which give significantly increased and selective retention of key smoke constituents. <IMAGE>
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