Sisal Hemp (Sisal)
Characteristics of Sisal
Sisal fiber (Sisal) is a cellulose fiber obtained from the leaves of the sisal plant, a plant in the Agave family known botanically as Agave sisalana. It grows well in Mexico, South American countries, Africa, and Asia. In Thailand, it is widely grown in Hua Hin District, Prachuap Khiri Khan Province.
The plant has a shape similar to a pineapple plant, short and stout; when fully grown it reaches a height of only about 3 feet. Leaves radiate outward from the stem in a spiky rosette all around. The leaves are thick and about 4-6 feet long, with a spear-like pointed tip and smooth edges. When mature, the color is grey-green to deep green. After 4 years of growth, the leaves can be cut and the fiber extracted, and the plant flowers after 4-8 years of growth.
Sisal thrives in areas with warm, humid air and well-draining soil. It is propagated using the small offshoots that grow from the parent plant, and it is commonly planted at the start of the rainy season.
Extracting Sisal Fiber
Today, fiber extraction is done by machine, which scrapes away the leaf pulp and cleans the fiber. However, hand extraction is also done by soaking the leaves in water to loosen the fiber, then cleaning the fiber, after which it is sun-dried or oven-dried and brushed to align the fibers neatly. This fiber extraction process must be done quickly after the leaves are freshly cut — if left too long, the sap inside will dry out, making the fiber difficult to extract.
Properties of Sisal Fiber
Sisal is a stiff fiber, cone-shaped with a slight bulge in the middle, and pointed, opaque ends. In cross-section, it appears square-shaped with a clearly visible lumen in the center. The cell walls are relatively thick, with high tenacity and elongation. It resists microorganisms in salt water well and absorbs water and moisture well.
Uses
Sisal is commonly used in industrial applications, for making rope for agriculture and shipping, packing twine, mats, handbags, and hats.