The sisal leaf contains three types of Fibres, namely (1)
mechanical, (2) ribbon, and (3) xylem.
The mechanical fibers are
mostly extracted from the periphery of the leaf. They have a
roughly thickened-horseshoe shape and seldom divide during the
extraction processes. They are the most commercially useful of the
sisal fiber.
Ribbon fibers occur in
association with the conducting tissues in the median line of the
leaf. They are the longest fibers and compared with mechanical
fibers they can be easily split longitudinally during processing.
Xylem fibers have an irregular
shape and occur opposite the ribbon fibers through the connection
of vascular bundles They are composed of thin-walled cells and are
therefore easily broken up and lost during the extraction process.