Method of manufacturing a tow band

Abstract

A tow band (TB) for use in a cigarette filter is a tow band in which a plurality of filaments (F) made of cellulose acetate fibers are bundled together and crimped. In the tow band, a filament denier is not less than 6.0 and not more than 11.0, a total denier is not less than 5,000 and not more than 15,000, and a Cv value of the number of crimps of the tow band is not more than 4%.

1 . A tow band manufacturing apparatus comprising:
 a crimper configured to crimp and feed a yarn that is formed by bundling a plurality of filaments together, wherein   the crimper includes:
 a pair of rollers pivotally supported such that peripheral surfaces of the respective rollers face each other; 
 a pair of plate-shaped members positioned following the pair of rollers in a feeding direction of the yarn, the plate-shaped members being placed such that a gap is formed therebetween and such that plate surfaces of the respective plate-shaped members face each other; and 
 an urging member disposed in the gap, the urging member urging the yarn such that the yarn is pressed on the plate surface of one of the pair of plate-shaped members, and 
 at least a part of one of the pair of plate-shaped members, the part being adjacent to the pair of rollers, is disposed such that the gap increases gradually in the feeding direction of the yarn. 
   
     
     
         2 . The tow band manufacturing apparatus according to  claim 1 , wherein
 the one of the pair of plate-shaped members is disposed to form a slope that extends in the feeding direction of the yarn and that is inclined relative to the feeding direction by an inclination angle greater than 0° and less than 4°.   
     
     
         3 . The tow band manufacturing apparatus according to  claim 1  or  2 , wherein
 a smallest gap not less than 2 mm and not more than 7 mm is formed between the pair of plate-shaped members at the part of the one of the pair of plate-shaped members, the part being adjacent to the pair of rollers. 
 
     
     
         4 . The tow band manufacturing apparatus according to  claim 1 , wherein
 a gap between the pair of rollers is not less than 2 mm and not more than 5 mm.