Comprehensive Overview of Jute
Composition, Properties, Defects and Applications
Chemical Composition of Jute Fiber
Chemically jute fiber has three main constituents:
1. Cellulose
2. Hemicellulose
3. Lignin.
Small amount of nitrogenous and inorganic material is present as well as variable amount of water.
Chemical composition of jute is given below in percentage-
Constituents | Percentage |
Cellulose | 40.8-47.5 |
Hemicellulose | 23.0-23.6 |
Acetyl Content | 3.6-4.7 |
Lignin | 22.2-23.5 |
Fats & Waxes | 1.7-2.4 |
Pectin | 0.5-0.7 |
Ash | 0.6-0.8 |
Physical and Chemical Properties of the Jute Fiber
Physical Properties
COLOR : Commercial jute varies from yellow to brown to dirty grey in color .
LUSTURE : It has natural silky lusture . The fibers are coated with a layer of woody material.
HANDLE AND APPEARANCE : Jute fiber usually feels coarse and rough to the best qualities are smooth and soft . Individual cell of jute fiber is polygonal, usually with five or six sides. It has thick walls and a broad lumen of oval cross section.
FINENESS : The individual cells of jute fiber “ultimate” are about 2.5 mm long and 18 micron in diameter . Single fiber length is 0.2 to 30 inch and fiber fineness lies between 1.9 to 2.2 tex .
TENSILE STRENGTH : Jute fiber is not so strong and not so durable . Individual fiber varies greatly in strength, owing to the irregularities in the thickness of cell walls. Tenacity of jute fiber is 40-70 g/tex .
ELONGATION : Jute fiber do not stretch to any appreciable extent . Jute has an extension at break of about 2%.
ELASTICITY : Jute tends to be a stiff fiber . Lignin, that cements the cells together, reduces the flexibility and extension of the fiber.
SPECIFIC GRAVITY : Specific gravity of jute fiber is 1.48 .
MOISTURE REGAIN : Jute is an unusually hygroscopic fiber . Its moisture regain is 13.75%. It can absorb as much as 23% of moisture under humid conditions. Moisture encourages deterioration of jute, which loses strength with age.
Chemical Properties
EFFECT OF ACID AND ALKALIES : Easily damaged by hot diluted or cold concentrated acids , but resistant to alkalis .
EFFECT OF BLEACHING : Not effected by oxidizing or reducing agent .
EFFECT OF ORGANIC SOLVENTS : Resistance to organic solvents .
DYE ABILITY : Jute fiber has good affinity to basic dyes , but light and wash fastness are poor .
Thermal Properties
EFFECT OF SUNLIGHT : Jute fiber may be damaged by sunlight . When jute is exposed to the light it gradually assumes a yellowish tinge. It is due presence of lignin in jute fiber.
EFFECT OF TEMPERATURE : Jute fiber scorches at high temperature .
FLAMMABILITY : Jute will ignite and burn but its flammability may be reduced by treating it with borax and boric acid mixture .
CONDUCTIVITY : Moderate conductor of heat and electricity .
Other Properties
EFFECT OF MICRO-ORGANISM: Jute has more resistance to microbiological attack than either grey cotton or flax. Lightly scoured jute has excellent resistance to micro-organism owing to the protective effect of the lignin.
Defects of Jute
Specky jute : Small , Black pieces of bark sticking to the fibers , due to pests or branching in the stem , both of which lead to the formation of harder bark which is difficult to ret .
Rootiness / Rooty jute : Tough , hard , stiff pieces of bark sticking to the lower end of the fiber caused rooty fiber .
Croppy fiber : Due to the improper rotting sometimes the top end of the fiber remain gummy harsh and hard .
Runners : Long strips of bark adhering to the stems for much of their length , caused by inadequate retting .
Knotty fibers : Having knots in the fibers or stick together due to punctures in the growing plants or insert bit . In this case difficult to separate the fibers from steam.
Dazed fiber: Due to over retting and storage in moist condition the jute fiber lost its lusture ,colour and strength .
Mossy jute: Fibres from short plants that cannot be properly stripped and cleaned contain broken piece of jute sticks etc.
Flabby or Fluffy jute: Due to careless stripping, fibre loses firmness and becomes flabby and hairy.
Heart damage: Excessive rotted damage fiber holds excess moisture in jute while baled.
Hunka: This type of jute fiber is hard and barky caused for non-removal of hard bark from the fibers.
Some Important Terms About Jute Fibers
ULTIMATES
The building units of jute fibers are called “Ultimates”. They are about 18 microns in diameter and 2.5 mm long. The ultimates are cemented together to form the “fibers” of commercial usage which run along the stem of the plant, branching and dividing, making up a mesh of fiber networks lying in layers around the cambium. There are usually between 6-20 ultimates in each cross section of a fiber.
LIGNIN
Jute fiber contains 10.8% lignin, which differs from the other two main components, cellulose and hemicellulose. It is not made up from sugar units. Lignin is an important constituent of wood and though its chemical structure has been under examination for more than 100 years its exact nature has not yet been established. It is believed that there is some kind of linkage between the lignin and the cellulose molecules. This linkage increases the fiber strength and also reduces the flexibility and extension of the fiber. It certainly contains methoxy and phenolic hydroxyl groups. Lignin is thought to be responsible for the wide color range of the jute fiber.
DIFFERENCE BETWEEN CELLULOSE AND HEMICELLULOSE IN JUTE FIBER
Cellulose in jute fiber is identical with that found in other cellulosic fibers. He building unit of long-chain cellulose molecule is the simple sugar, glucose, which has been made by the plant from the element carbon, hydrogen and oxygen.
The hemicelluloses molecular chains are very much shorter. Another difference between the two types of cellulose lies in the shape of the long chain molecules. The cellulose chain has many identical glucose units strung head to tail but the hemicellulose molecule has short side chains sticking out at intervals along its length. These side chains are acidic in nature which give jute is slightly acid reaction and its affinity for basic dye stuffs.
End Use of Jute Fiber
a. Jute is cheap and reasonably strong and is available in large quantities. These characteristics have enabled it to become an important fiber for sacks and packing cloths. Due to resistance to stretching force, jute bags are extensively used for storage and transport purpose, while they do not distort and shift position during stretching.
b. The finer qualities of jute are made into curtains and furnishing fabrics, mixed with wool, after treatment with caustic soda, jute is spun and woven into cheap clothing fabrics.
c. Jute is used in woven carpets as weft, warp, or pile, in tufted carpets as the backing material, in linoleum as backing and in carpet under lays and felts.
d. Familiar uses for jute include the following:
Sacks, bags, baling, and bundle cloths, bedding foundation, boot and shoe linings, cattle beddings, tarpaulins, furnishings, handbag, rope, packing for power cables, covering the underside of chairs and as webbing for supporting chairs, wall coverings, roofing felt, woven carpets, motor car body linings, prefabricated road and runways etc.
