A problem with processing dual fiber and seed hemp crops is that about 20% of the stalks in the field are male, which begin to die off as soon as they have pollinated their female counterpart. This introduces inconsistent fiber quality if the male stalks are left on the field past the seed harvest. The optimal time to harvest the seed is also the best time to recover the male and female stalks and pre-process them into two more commodities, namely the bast fiber and hurd core.
Current decorticator technology crushes the bast into the hurd, then, through repeated beatings decorticates the outer fiber from the inner woody core. Hurd contamination is a constant issue during the process for much of it becomes airborne dust that has to be immediately collected to avoid potential fires. Dual-purpose crops are not favorable & will not produce high grade fibers. This forces factories to only accept fiber only crops, in turn they lose the opportunity of seed returns & it has been noted that repeated passes are necessary to produce fine fiber.
The process begins with harvesting the entire crop when the seed is 60-70% mature & then leaving it in the field to dry. Once the stalks are baled, they arrive onto a bale roller that slowly unwinds the stalks onto a moving table where an operator aligns the stems against a backstop where they are re-cut to final length then fed into the processor. The outer bast is peeled away from the hurd- without any crushing or mixing- while the hurd is fed directly into a chipper. The hurd chips are blown into 1000kg totes for easy downstream handling. The peeled fiber is collected by suction & guided onto slowly turning reels that wind the fiber onto manageable spools for easier downstream processing as well. Below is a picture of early testing of a Dolores dual-purpose variety- NOTE: NO HURD CONTAMINATION!
Natural fiber that is stronger than fiberglas!