Methods for cutting materials

Abstract

The present disclosure is directed, in part, to a method of cutting or shearing tow fibers, bundles thereof, and/or other materials or bundles thereof. The method comprises rotating a drum comprising a cutting assembly comprising a cutting device about a longitudinal axis of a drive shaft, reciprocally moving a portion of the cutting assembly comprising the cutting device in a direction parallel to or transverse to the longitudinal axis as the cutting assembly is rotated about the longitudinal axis, rotating the cutting device at least 1,000 times per minute), and cutting or shearing the tow fibers, bundles thereof, and/or other materials or bundles thereof with the cutting device.

What is claimed is: 
     
         1 . A method of cutting tow fibers, the method comprising:
 rotating a drum about a longitudinal axis, the drum comprising a cutting assembly having a cutting device;   reciprocally moving a portion of the cutting assembly having the cutting device in a direction generally parallel to or generally transverse to the longitudinal axis as the cutting assembly is rotated about the longitudinal axis;   rotating the cutting device at least about 1,000 times per minute; and   cutting the tow fibers with the cutting device.   
     
     
         2 . The method of  claim 1 , comprising rotating the cutting device at least 1,500 times per minute. 
     
     
         3 . The method of  claim 1 , comprising rotating the cutting device at least 2,000 times per minute. 
     
     
         4 . The method of  claim 1 , further comprising biasing a cutting device-contacting member against an edge portion of the cutting device during the cutting step. 
     
     
         5 . The method of  claim 4 , comprising using a nip created between a portion of the cutting device-contacting member and a portion of the edge portion of the cutting device to shear the tow fibers. 
     
     
         6 . The method of  claim 4 , comprising sharpening the edge portion of the cutting device using the cutting device-contacting member during the rotating the cutting device step. 
     
     
         7 . The method of  claim 1 , comprising rotating the cutting device at a substantially constant rotational speed during the cutting step. 
     
     
         8 . The method of  claim 1 , wherein the drum comprises a transfer head, and wherein the cutting assembly comprising a retaining member, the method comprising retaining the tow fibers to the transfer head during the cutting step using the retaining member. 
     
     
         9 . The method of  claim 1 , comprising:
 rotating the cutting device at a first rotational speed while not cutting the tow fibers; and   rotating the cutting device at a second, different rotational speed while cutting the tow fibers,   wherein the second, different rotational speed is greater than the first rotational speed.   
     
     
         10 . A method of shearing a material, the method comprising:
 rotating a drum about a longitudinal axis, the drum comprising a cutting assembly having a cutting device;   reciprocally moving a portion of the cutting assembly having the cutting device as the cutting assembly is rotated about the longitudinal axis;   rotating the cutting device at least 1,500 revolutions per minute;   biasing a cutting device-contacting member against an edge portion of the cutting device; and   shearing the material in a nip created between a portion of the cutting device-contacting member and a portion of the edge portion of the cutting device.   
     
     
         11 . The method of  claim 10 , wherein the shearing the material step comprises shearing a nonwoven material and tow fibers. 
     
     
         12 . The method of  claim 10 , wherein the edge portion of the cutting device comprises a substantially flat portion, and wherein an opposing edge portion of the cutting device comprises a beveled portion. 
     
     
         13 . The method of  claim 10 , comprising rotating the cutting device at least 2,000 times per minute. 
     
     
         14 . The method of  claim 10 , further comprising sharpening the cutting device using the cutting-device contacting member. 
     
     
         15 . The method of  claim 10 , comprising rotating the cutting device at a substantially constant rotational speed during the shearing step. 
     
     
         16 . The method of  claim 10 , wherein the drum comprises a transfer head, and wherein the cutting assembly comprising a retaining member, the method comprising retaining the material to the transfer head during the shearing step using the retaining member. 
     
     
         17 . The method of  claim 10 , comprising:
 rotating the cutting device at a first rotational speed while not shearing the material; and   rotating the cutting device at a second, different rotational speed while shearing the material.   
     
     
         18 . A method of shearing tow fibers, the method comprising:
 rotating a cutting device at least 1,000 times per minute;   biasing a cutting device-contacting member against an edge portion of the cutting device; and   
       shearing the tow fibers in a nip formed at least partially intermediate the cutting device and the cutting device-contacting member. 
     
     
         19 . The method of  claim 18 , comprising:
 sharpening the edge portion of the cutting device using the cutting device-contacting member during the rotating step.   
     
     
         20 . The method of  claim 18 , comprising rotating the cutting device at a substantially constant rotational speed during the shearing step.