Inside a hemp decortication line

Decortication separates the two useful parts of a hemp stalk. Fluted rollers crush and bend the stalk so the brittle woody core (hurd) shatters while the flexible bast fiber survives; a shaking screen lets hurd pieces drop through, and moving air pulls dust and fines to a cyclone and filter. What comes out is a stream of fiber, a larger stream of hurd, and a sizable share of dust.

Controls

Labels

Animation speed

Feed rate of stalk

Breaker roller speed

Faster rollers break hurd more completely but also chop and dust the fiber.

Step through it

Opening the baleA spiked drum tears retted stalks off the bale so they reach the line as a loose, even mat.
Breaker rollersPairs of fluted rollers bend the stalk back and forth. The woody core snaps into short chips while the long bast fibers flex and stay whole.
Screening the hurdA shaking screen lets the loose hurd chips fall through into a pile, while tangled fiber rides across the top to the baling press.
Catching the dustFans pull air through a hood over the screen. The cyclone spins out heavier fines, and a bag filter catches the finest dust so it never reaches the workers' air.
Pushing too hardDouble the feed without speeding the rollers and the stalks pass through half broken, leaving hurd stuck in the fiber.

Where the mass goes

A hemp stalk is mostly woody core. Reviews put hurd at roughly 70 to 75 percent of the stalk and bast fiber at about a quarter to a third, though variety and growing season swing it widely: North Carolina variety trials measured decorticated bast from about 14 to over 30 percent of the straw. Decortication also turns a surprising amount into fines, with published figures of roughly 15 to 33 percent of stalk mass.

The model here is simplified. It starts with 28 percent fiber, 57 percent hurd and 15 percent fines at low roller speed, and shifts mass toward fines as speed rises. Most fines are shattered core, so hurd plus fines stays near the 70 to 75 percent core share. The cleanliness flag compares feed rate to roller speed using a teaching rule, not a measured machine curve.

Try it: set roller speed to 800 rpm. Fines climb toward 30 percent and the flag warns the fiber is getting chopped. Then drop to 300 rpm and raise feed to 2 t/h: now the line is overfed and shive stays in the fiber.

Why dust control matters

Breaking dry plant stalks throws off fine dust that coats equipment and hangs in the air. Lines like this one enclose the breaking and screening sections, keep air moving through hoods, and send it through a cyclone and a fabric filter before it leaves the building.

Sources

Fiber Hemp Variety Trial Results: 2023 to 2024NC State Extension
A critical review of industrial fiber hemp anatomy, agronomic practices, and valorization into sustainable bioproductsBioResources (peer reviewed, NC State University)
Hemp: From Field to Fiber, A ReviewTextiles (MDPI, open access)

How to cite this model

Avid Solutions International. (2026, November 11). Inside a hemp decortication line [Interactive 3D model]. Avid Field Lab. https://avidsolutionsintl.com/explore/hemp-decortication

Last updated November 11, 2026

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