STUDY OF BAST FIBER
(JUTE)
MOHAMMAD RAZA MIAH(PH.D.)
DOCTOR OF ENGINEERING IN MATERIALS PHYSICS AND CHEMISTRY
UNIVERSITY OF CHINESE ACADEMY OF SCIENCES (UCAS)
DEFINE JUTE FIBER
• Jute is a long, soft, shiny important natural bast fiber that can be spun into coarse, strong threads. Jute fiber is
basically lignocellulosic, biodegradable, and renewable. Owing to its high tenacity and low extensibility, it is
traditionally used for producing packaging material. It is also stiff and harsh. Taken from two varieties of the
Corchorus plant, white jute and tossa jute which is softer, silkier, and stronger than white jute.
Why jute is called Golden fiber?
• Jute is considered as the golden fiber. It is so called because of its shiny brown color. It is the most affordable
natural fiber and is 100% biodegradable. It is made of cellulose and lignin plant material.
CLASSIFICATION OF JUTE FIBER
• In accordance with color, jute is two types
• 1. White jute (Corchorus capsularis)
• 2. Tossa jute (Corchorus olitorius)
• Classification of jute according to the quality (Geographical distribution according to Bangladesh):
• 1. Jat
• 2. District
• 3. Northern
CLASSIFICATION OF JUTE FIBER…
• A. Jat:
▪ Jat is the finest quality jute with firm
▪ It has good color and length
▪ It has a good luster
• This type of jute fiber grows in the district of Mymensingh, Dhaka and Comilla.
CLASSIFICATION OF JUTE FIBER…
• A. Jat:
▪ Jat is the finest quality jute with firm
▪ It has good color and length
▪ It has a good luster
• This type of jute fiber grows in the district of Mymensingh, Dhaka and Comilla.
• i. Hard district:
• The hard district jute is better than the soft district. It mainly grows in the district of Faridpur.
• ii. Soft district:
• This type of jute grows in the district of Noakhali, Pabna, Barisal, Jessore, Khulna, Sylhet, Lower Comilla, Chittagong
and some parts of Dhaka.
CLASSIFICATION OF JUTE FIBER…
• C. Northern:
▪ Northern jute is of somewhat inferior quality.
▪ The fiber is dull-colored fluffy hairy and barky.
▪ Generally medium length and weak.
• This type of jute grows in the District of Rangpur, Dinajpur, Bogra and Rajshahi.
CHEMICAL COMPOSITION OF JUTE
• Jute is composed of 65% cellulose and 35% natural wages, oils and cements (lignin).
• The chemical composition of jute is given below:
• Cellulose....................................... 65.2%
• Hemicelluloses ...............................22.2%
• Lignin ............................................10.8%
• Water soluble ................................1.5%
• Fat and wax ..................................0.3 - 1.0%
MICROSCOPIC VIEW (LONGITUDINAL AND CROSS-
SECTIONAL) OF JUTE
• The presence of hemicellulose in jute fibers makes it hygroscopic, second only to wool. Tossa jute is slightly
more hygroscopic than white jute. Jute fiber swells on the absorption of water. Lateral (cross-sectional)
swelling of jute fiber (about 30% on average) far exceeds its longitudinal swelling (0.4 %).
Fig: Microstructure of jute fiber
MICROSCOPIC VIEW (LONGITUDINAL AND CROSS-
SECTIONAL) OF JUTE…
• Cellulose: Cellulose of jute fiber is highly crystalline and it constitutes the main building materials of its
ultimate cells. The degree of polymerization (DP) of jute is reported to be one of the lowest among vegetable
fibers. And according to one estimate, it is 1150.
• Hemicelluloses: Hemicelluloses like Cellulose is a chain molecular substance but is distinguishable from the
latter in having a relativity short chain length (DP not more than 150) and being mainly composed of pentsans,
hexosans, and uronic acid. It is soluble in 18% aqueous alkali.
• Lignin: Lignin is a complex polymer that functions as a structural material in plants. The structural unit of lignin
are aromatic alcohols with a phenyl propane backbone, such-as p-coumaryl alcohol, etc. lignin from all sources
contains similar types of functional groups such as hydroxyl, methoxy, dioxymethylene, complex, etc. which are
increase the fiber strength and also reduce the flexibility and extension of the fiber.
PHYSICAL AND MORPHOLOGICAL STRUCTURE OF JUTE
FIBER
• Morphological Structure:
• Jute fiber is a multicellular fiber. It is formed as a cylindrical sheath made with single fibers joined together by
the three-dimensional network from top to bottom of the steam.
• 1 . Macrostructure: Each fiber element visible by the naked eye, of a raw jute reed available commercially is
basically a group of about 5-15 ultimate cells, cemented together laterally and longitudinally by means of
intercellular materials being chiefly non-cellulosic in composition. Thus jute fiber is multicellular. For this, jute
fiber is much coarser than cotton which is unicellular. The ultimate cells are spindle-shaped and of variable size
in length and width, being on an average 2.5 mm long and 0.02 mm in width at the middle. The cross-section of
the ultimate cells is found to be polygonal with rounded corners. The layer of natural cement present between
the ultimate cells is known as middle lamella. Each ultimate cell has a thick cell wall and lumen, the central canal
with a more or less oval cross-section.
PHYSICAL AND MORPHOLOGICAL STRUCTURE OF
JUTE FIBER…
• 2 . Microstructure: The cell wall of each ultimate cell is composed of an outer thin primary wall and an
inner thick secondary wall, differing from each other in the molecular architecture. Both these walls of jute
ultimate cell are compared of ultra-fine microfibrils. While in the primary wall the fibrils are lying in a crisscross
manner, the fibrils are almost parallelly arranged as right-hand spirals in the secondary wall.
PHYSICAL PROPERTIES OF JUTE FIBER
• 1. Microscopic appearance: Jute is a multicellular fiber. The individual fiber shows nodes and cross markings
in longitudinal view and polygonal shapes in cross-section. Lumen is wider than the cell wall and shows
remarkable constrictions (irregular thickness) in the cell wall. Lumen broadens at the end of the fiber making
cell wall very thin. Externally fiber is smooth and lustrous.
• 2. Length and diameter: A single jute fiber has average length of 0.1 inch and a mean diameter of 12µ
(microns).The mean length/breadth ratio is around 90.
• 3. Density: The density of fiber is 1.48-1.50 gm/cm3
• 4. Moisture regain: Jute is highly hygroscopic in nature. Its moisture regain is 12-14% at standard condition.
• 5. Strength: The tenacity of jute varies from 3.5-7 gm/denier.
PHYSICAL PROPERTIES OF JUTE FIBER…
• 6. Color: Varies from yellow to brown to grey depending upon condition of growth and retting etc.
• 7. Elongation: Jute do not stretch to appreciable extent under tension. Its breaking elongation is 1-1.2%
under normal atmospheric condition.
• 8. Composition: Jute fiber contains cellulose (55-63%), hemicellulose (20-24%) and lignin (12-14%).
• 9. Conductivity: It is a very good insulator of heat and electricity.
• 10. Elasticity: Jute has lower elasticity due to its stiffness and rigidity. This has advantage of jute to be used as
bagging material as they retain their shape on loading.
CHEMICAL PROPERTIES OF JUTE FIBER
• In chemical composition jute is different from linen and cotton as it is composed of a modified form of cellulose
called lignocellulose, a compound of lignin and cellulose.
• 1. Action of alkalies: Strong alkalies degrade its strength. Jute loses its weight when it is boiled with dilute
caustic soda. The loss is mainly due to the removal of hemicellulose.
• 2. Action of oxidizing agents: Ordinary oxidizing agents have no action on jute.
• 3. Action of acids: Organic acids like oxalic acid, formic acid, mineral acids like sulfuric acid and hydrochloric
acid in dilute condition has no reaction at ordinary or cold conditions. With strong acids at boiling conditions
hydrocellulose is formed.
CHEMICAL PROPERTIES OF JUTE FIBER…
• 4. Action of microorganisms: Jute is more resistant to microbiological attack than grey cotton or flax. If it is
slightly scoured it has excellent resistance owing to protective effect of lignin. Sometimes jute fabrics are treated
with cuprammonium solution and then dried so that a film of green color is produced on the material which makes
it more or less rot-proof.
• 5. Action of sunlight: When jute is exposed to sunlight it gradually assumes a yellowish tinge. This is due to
color changes within the fiber connected with lignin molecules.
• 6. Action of heat: Jute like other textile fibers may not be degraded by heat. However, prolonged heating
operations degrade the fiber.
USES OF JUTE FIBER
• Jute fibers are environmentally friendly natural fibers that can be used as good alternatives in the reinforcement
of composite materials. Besides also used in hessian, scrim, canvases, packaging, ropes, carpet backing, clothing
fabrics, bags, floor coverings, wall coverings, upholstery and geotextiles. Knitted jute decomposes around plants
as they grow, providing natural mulch. Jute contains cellulose and wood fiber, and it has been developed for use
within the automobile, paper and bedding industries as non-woven, technical and composite fabric.
