System and method for fiber cleaning, alignment, and sizing

1 . A method of processing plant fibers, said method comprising the steps of:

decorticating plant stalks to separate bast fibers from hurd;

then separating the bast fibers and the hurd into separate process streams comprising a bast fiber stream and a hurd stream;

then routing the bast fiber stream to a chopper assembly, wherein the chopper assembly is configured to cut the bast fibers using a blade to reduce an average length of the bast fibers;

then routing the bast fiber stream to a shredder assembly, wherein the shredder assembly comprises a feed roller, a shredding roller, and a first bed disposed below the shredding roller, wherein the feed roller is configured to feed the bast fibers to the shredding roller, wherein the shredding roller is configured to rotate about an axis of rotation, wherein the shredding roller comprises a plurality of pins extending radially outward from an outer surface of the shredding roller, wherein each pin of the plurality of pins has a cylindrical body that tapers to a point at a distal end of the pin, wherein the cylindrical body of each pin is generally perpendicular to the axis of rotation of the shredding roller, wherein the pins of the shredding roller are configured to pull the bast fibers off of the feed roller as the shredding roller rotates, wherein the shredding roller is configured such that the plurality of pins contacts the bast fibers on the first bed when the shredding roller rotates, thereby combing the bast fibers and conveying the bast fibers along the first bed;

then routing the bast fiber stream to a coarse cleaner assembly, wherein the coarse cleaner assembly comprises a rotating drum and a second bed disposed below the rotating drum, wherein the second bed has a plurality of bed openings extending through the second bed, wherein the rotating drum is configured to rotate about an axis of rotation, wherein the rotating drum comprises a plurality of beater bars extending radially outward from the rotating drum, wherein the rotating drum is configured such that the plurality of beater bars contacts the bast fibers on the second bed when the rotating drum rotates, thereby causing larger impurities to separate from the bast fibers and fall through the plurality of bed openings in the second bed;

then routing the bast fiber stream to a fine cleaner assembly, wherein the fine cleaner assembly comprises a cleaning roller configured to rotate about an axis of rotation, wherein the cleaning roller comprises a plurality of teeth extending radially outward from the cleaning roller, wherein the cleaning roller is configured such that the plurality of teeth contacts the bast fibers when the cleaning roller rotates, thereby causing smaller impurities to separate from the bast fibers; and

then routing the bast fiber stream through a carding machine comprising a carding drum and at least one working roller.

2 . The method of claim 1 , further comprising the step of routing the hurd stream to a hammer mill and then to a vibrating sieve configured to separate the hurd from impurities in the hurd stream.

3 . The method of claim 1 , wherein each of the plurality of bed openings in the second bed has a width that is adjustable in size, wherein the method further comprises the step of adjusting the width of one or more of the plurality of bed openings in the second bed to control a mass of the larger impurities that fall through the plurality of bed openings in the second bed.

4 . The method of claim 3 , wherein the second bed comprises a plurality of bars arranged in parallel to each other, wherein the step of adjusting the width of one or more of the plurality of bed openings in the second bed comprises adjusting a spacing between one or more of the plurality of bars.

5 . The method of claim 1 , wherein the step of separating the bast fibers and the hurd into separate process streams comprises routing the bast fibers and hurd to a vibrating screen, wherein the vibrating screen has a plurality of screen openings sized to allow a majority of the hurd to fall through the screen openings while a majority of the bast fibers do not fall through the screen openings.

6 . The method of claim 1 , wherein the chopper assembly comprises a conveyor configured to convey the bast fibers to a reciprocating blade disposed above an anvil.

7 . A system for processing plant fibers, wherein the system comprises:

a chopper assembly configured to cut bast fibers using a blade to reduce an average length of the bast fibers;

a shredder assembly disposed downstream of the chopper assembly, wherein the shredder assembly comprises a feed roller, a shredding roller, and a first bed disposed below the shredding roller, wherein the feed roller is configured to feed the bast fibers to the shredding roller, wherein the shredding roller is configured to rotate about an axis of rotation, wherein the shredding roller comprises a plurality of pins extending radially outward from an outer surface of the shredding roller, wherein each pin of the plurality of pins has a cylindrical body that tapers to a point at a distal end of the pin, wherein the cylindrical body of each pin is generally perpendicular to the axis of rotation of the shredding roller, wherein the pins of the shredding roller are configured to pull the bast fibers off of the feed roller as the shredding roller rotates, wherein the shredding roller is configured such that the plurality of pins contacts the bast fibers on the first bed when the shredding roller rotates, thereby combing the bast fibers and conveying the bast fibers along the first bed;

a coarse cleaner assembly disposed downstream of the shredder assembly, wherein the coarse cleaner assembly comprises a rotating drum and a second bed disposed below the rotating drum, wherein the second bed has a plurality of bed openings extending through the second bed, wherein the rotating drum is configured to rotate about an axis of rotation, wherein the rotating drum comprises a plurality of beater bars extending radially outward from the rotating drum, wherein the rotating drum is configured such that the plurality of beater bars contacts the bast fibers on the second bed when the rotating drum rotates, thereby causing larger impurities to separate from the bast fibers and fall through the plurality of bed openings in the second bed;

a fine cleaner assembly disposed downstream of the coarse cleaner assembly, wherein the fine cleaner assembly comprises a cleaning roller configured to rotate about an axis of rotation, wherein the cleaning roller comprises a plurality of teeth extending radially outward from the cleaning roller, wherein the cleaning roller is configured such that the plurality of teeth contacts the bast fibers when the cleaning roller rotates, thereby causing smaller impurities to separate from the bast fibers; and

a carding machine disposed downstream of the fine cleaner assembly, wherein the carding machine comprises a carding drum and at least one working roller.

8 . The system of claim 7 , further comprising a decorticator disposed upstream of the chopper assembly, wherein the decorticator is configured to decorticate plant stalks to separate bast fibers from hurd.

9 . The system of claim 8 , further comprising a vibrating screen, wherein the vibrating screen is disposed downstream of the decorticator and upstream of the chopper assembly, wherein the vibrating screen has a plurality of screen openings sized to allow a majority of the hurd to fall through the screen openings while a majority of the bast fibers do not fall through the screen openings, wherein the vibrating screen is configured to separate the bast fibers and the hurd into separate process streams comprising a bast fiber stream and a hurd stream.

10 . The system of claim 9 , further comprising a hurd processing unit disposed downstream of the vibrating screen and configured to receive the hurd stream, wherein the hurd processing unit comprises a hammer mill and a vibrating sieve disposed downstream of the hammer mill, wherein the hammer mill is configured to reduce a size of the hurd, and wherein the vibrating sieve is configured to separate the hurd from impurities in the hurd stream.

11 . The system of claim 7 , wherein each of the plurality of bed openings in the second bed has a width that is adjustable in size.

12 . The system of claim 11 , wherein the second bed comprises a plurality of bars arranged in parallel to each other, wherein the width of each of the plurality of bed openings in the second bed is defined by a spacing between adjacent bars of the plurality of bars, wherein the spacing between adjacent bars is adjustable.

13 . The system of claim 7 , wherein the chopper assembly comprises a conveyor configured to convey the bast fibers to a reciprocating blade disposed above an anvil.

14 . The system of claim 7 , wherein the fine cleaner assembly further comprises a transfer roller disposed downstream of the cleaning roller and a trash roller disposed downstream of the transfer roller, wherein the transfer roller is configured to rotate in an opposite direction of the rotational direction of both the cleaning roller and the trash roller, wherein the trash roller has saw-tooth wire clothing on an exterior of the trash roller, and wherein the trash roller is configured to remove remaining impurities from the bast fibers.

15 . The system of claim 14 , wherein the fine cleaner assembly further comprises a mote knife assembly comprising an edge disposed below the trash roller and a suction hood, wherein the edge and suction hood of the mote knife assembly are configured to remove the remaining impurities from the trash roller by suction.

16 . The system of claim 7 , wherein each pin of the plurality of pins has a height of about 7-8 millimeters (mm) from the outer surface of the shredding roller to the distal end of the pin, wherein the cylindrical body of each pin has a diameter of approximately 4 mm, and wherein each pin of the plurality of pins is approximately 6 mm apart from each adjacent pin.

17 . The method of claim 1 , wherein each pin of the plurality of pins has a height of about 7-8 millimeters (mm) from the outer surface of the shredding roller to the distal end of the pin, wherein the cylindrical body of each pin has a diameter of approximately 4 mm, and wherein each pin of the plurality of pins is approximately 6 mm apart from each adjacent pin.