Jute, bast fiber

Potential resources of xylans are by-products produced in forestry and the pulp and paper industries (forest chips, wood meal and shavings), where GX and AGX comprise 25-35% of the biomass as well as annual crops (straw, stalks, husk, hulls, bran, etc.), which consist of 25-50% AX, AGX, GAX, and CHX [4]. New results were reported for xylans isolated from flax fiber [16,68], abaca fiber [69], wheat straw [70,71], sugar beet pulp [21,72], sugarcane bagasse [73], rice straw [74], wheat bran [35,75], and jute bast fiber [18]. Recently, about 39% hemicelluloses were extracted from vetiver grasses [76]. 

World markets for vegetable fibers have been steadily declining in recent years, mainly as a result of substitution with synthetic materials. Jute has traditionally been one of the principal bast fibers (toimage basis) sold on the world market however, the precipitous decline in jute exports by India (Fig. 2) indicate the decreasing market demand for this fiber that is vitally important to the economies of India (West Bengal), Bangladesh, and Pakistan. 

Among the bast textile fibers, the density is close to 1.5 g/cm, or that of cellulose itself, and they are denser than polyester, as shown iu Table 5. Moisture regain (absorbency) is highest iu jute at 14%, whereas that of polyester is below 1%. The bast fibers are typically low iu elongation and recovery from stretch. Ramie fiber has a particularly high fiber length/width ratio. 

Fig. 3. Cross sections (500x) of bast fibers (a), fiax (b), hemp (c), jute (d), kenaf and (e), ramie.

Fibers (see Fibers, survey) used in textile production can have a wide variety of origins plants, ie, ceUulosic fibers (see Fibers, cellulose esters) animals, ie, protein fibers (see Wool) and, in the twentieth century, synthetic polymers. Depending on the part of the plant, the ceUulosic fibers can be classified as seed fibers, eg, cotton (qv), kapok bast fibers, eg, linen from flax, hemp, jute and leaf fibers, eg, agave. Protein fibers include wool and hair fibers from a large variety of mammals, eg, sheep, goats, camels, rabbits, etc, and the cocoon material of insect larvae (sUk). Real sUk is derived from the cocoon of the silkworm, Bombjx mori and for a long time was only produced in China, from which it was traded widely as a highly valuable material. 

China jute Bast nr soft fibers A bunion Abntifon China... 

Jute is made from the bast fibers from Corchorus olitorus or C. capsullaris, also called Jew s mallow. The roots of these plants are used as food in Southeast Asia, and root ends, or jute cuttings, are used to make paper. 

Fig. 43,—Sclerenchyma fibers from different sources, i, Prom powdered cinnamon bark 2, End of bast fiber of flax stem showing transverse markings (6) 3, middle portion of flax fiber showing characteristic cross markings at b 4, bast fiber from cinchona bark 5, branched bast fiber from choke cherry bark 6. above, end, and below, median portion of bast fiber of jute. All highly magnified.

There are many kinds of natnral fibers, snch as bast fibers (flax, hemp, jute, kenaf, ramie, nettle, and mesta), leaf fibers (sisal, heneqnen, pineapple, abaca, oil palm, and screw pine), seed fibers (cotton), frnit fibers (coconnt hnsk, or coir), and stalk fibers (straw of varions kinds). They are not nsed for commercial WPG, primarily on economical reasons (except maybe Procell, see Table 1.1). Most of these fibers have fonnd applications in established indnstries, snch as textile indnstry (cotton, flax, jnte, ramie, hemp, and sisal) and paper indnstry (straw). 

Loading nose, 226, 232, 233, 236, 238, 239, 241, 242, 245, 253, 256, 265, 274 Long alkyl chain alkoxysilanes, 172 Long cellulose fiber, 79, 92, 98 Long natural fiber, 110 Abaca, 110 Bast fibers, 110 Cost of, no Cotton, 110 Flax, no Fruit fibers, 110 Hemp, no Henequen, 110 Jute, no Kenaf, 110 Leaf fibers, 110 Mesta, no Nettle, no Pineapple, 110 Ramie, 110 Seed fibers, 110 Sisal, no Stalk fibers, 110... 

Natural fibers can be classified as seed fibers (such as cotton), bast fibers (like flax, hemp, jute, kenaf, ramie), hard fibers (like sisal), fi-uit fibers (like coir), and wood fibers. The chemical composition and dimensions of some common agro-fibers are presented in Table 5.21. The origin of wood fibers can be sawmill chips, sawdust, wood flour or powder, cutter shavings, pulp or wood residues. As binders for these fibers, both thermosetting (like phenolic, epoxy, polyester) resins and thermosetting matrices [such as polyethylene (LDPE, HDPE), polypropylene (PP), poly(vinyl chloride) (PVC), polystyrene (PS)j can be used. Thermoplastic composites are, however, less expensive to process than thermosetting composites, in addition to their ability to be manufactured into complex shapes. 

Jute is produced from plants of the genus Corchorus, which includes about 100 species. It is one of the cheapest natural fibers and is currently the bast fiber with the highest production volume. The fibers are extracted from the ribbon of the stem. Among all natural fibers, jute fibers are easily available in fabric and fiber... 

Jute has also been used to make paper, although the entire plant is rarely used [64]. Pulp mills generally buy old jute sacks, cuttings, and waste wrapping material that are mainly bast fiber. Jute is usually pulped using either a chemical or by one of several chemimechanical processes. The Jute Technological Research Laboratory (JTRL) in Calcutta, India, has done... 

Kenaf is now being grown in several countries where the bast fiber is used for geotextiles and the pith is going into sorbents for oil spill clean up and animal litter. The production of pulp and paper from kenaf is growing, but it is only used for limited types of papers at present. The utilization of the whole plant of both jute and kenaf is under consideration for structural and nonstructural composites. Automotive interior door panels are now produced in Germany and the United States out of jute and kenaf bast fiber in combination with thermoplastics. 

Various fibers may be identified, or separated from each other, through sequential dissolution in various solvents. As seen in Figure 6, silk is soluble in HCOOH/ZnCli, while wool does not dissolve. For bast fibers it is possible to discern some types with phloroglucin/HCl under a microscope. Jute will stain red, while hemp is only slight pink, and ramie and flax are unaltered. With the use of Kuoxam, ramie is dissolved while flax remains undissolved. For these tests, it is absolutely necessary to use reference materials ... 

Bast fibers - such as flax, hemp, kenaf, ramie, jute, and nettle... 

---