Jute

Jute is a long, soft, shiny vegetable fiber that can be spun into coarse, strong threads. It is produced from plants in the genus Corchorus, which has been classified in the family Tiliaceae, or more recently in Malvaceae.
Jute is one of the most affordable natural fibers and is second only to cotton in amount produced and variety of uses of vegetable fibers. Jute fibers are composed primarily of the plant materials cellulose (major component of plant fiber) and lignin (major components of wood fiber). It is thus a ligno-cellulosic fiber that is partially a textile fiber and partially wood. It falls into the bust fiber category (fiber collected from bust or skin of the plant) along with kenaf, industrial hemp, flax (linen), ramie, etc. The industrial term for jute Fiber is raw jute. The Fibers are off-white to brown, and 1–4 metres (3–12 feet) long.

[pic] Jute Plant

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%

Classification of Jute:

White jute (Corchorus capsularis) Several historical documents (including, Ain-e-Akbari by Abul Fazal in 1590) state that the poor villagers of India used to wear clothes made of jute. Simple handlooms and hand spinning wheels were used by the weavers, who used to spin cotton yarns as well. History also states that Indians, especially Bengalis, used ropes and twines made of white jute from ancient times for household and other uses.

[pic]

Tossa jute (Corchorus olitorius) Tossa jute (Corchorus olitorius) is an Afro-Arabian variety. It is quite popular for its leaves that are used as an ingredient in a mucilaginous potherb called molokhiya popular in certain Arab countries. The Book of Job in the Hebrew Bible mentions this vegetable potherb as Jew's mallow.
Tossa jute fiber is softer, silkier, and stronger than white jute. This variety astonishingly showed good sustainability in the climate of the Ganges Delta. Along with white jute, tossa jute has also been cultivated in the soil of Bengal where it is known as paat from the start of the 19th century. Currently, the Bengal region (West Bengal in India, and Bangladesh) is the largest global producer of the tossa jute variety. (1)

Physical Properties of Jute Fiber:

Density-1.47gm/cc
Average Fineness-20 denier, i.e weight in gm. of 900 metres of filament
Tenacity-4.2gm/denier
Average Extension at break-1.2%
Average Stiffness-330 gm/denier
Average Toughness Index-0.02
Swelling water (area) 40%
Specific heat 0.34 cal/g/c0
Specific internal Surface 10-200m2/g
Hygroscopicity (Average regain at 65% relative humidity)-13%

Chemical Properties of Jute Fiber:

Holocellulose 82-85%
Alpha Cellulose 58-63%
Hemicellulose 21-24%
Lignin 12-14%
Pactin 0.2-0.5%
Fat & Wax 0.4-0.8%
Protein 0.8-1.5%
Mineral Materials 0.6-1.1% (2)

Process Flow Chart of Jute Yarn Manufacturing

Selection of jute for a batch according to jute grade
↓
Piecing up
↓
Softening and Lubricating
↓
Conditioning or Pilling
↓
Breaker Carding
↓
Finisher Carding
↓
First Drawing
↓
Second Drawing
↓
Third Drawing / Finisher drawing
↓
Spinning
↓
Jute Yarn
↓
Twisting
↓
Spool winding
↓
Yarn package
↓
Delivery

(3)

Flow process diagram of jute:

[pic]

Jute Manufacturing in Jute Mills:

Raw jute in the form of bales is processed in jute mills to produce hessian, sacking, jute yarn, bags, and other useful products. Raw jute bales from jute fields or suppliers, carried by trucks are unloaded are stacked in the jute mills godown.

Selection: In the selection process, raw jute bales are opened to find out any defect and to remove the defective portion from the mora by experienced workers. Raw jute bales are of two types i.e. 150 kg weight and 180 kg weight with or without top portion cutting. The bales are assorted according to end use like Hessiean weft, Sacking wrap, Sacking weft etc. After selection, jute bales are carried to softning section by workers called Gariwala and Bajawala.

Batch & Batching: A number of bales of jute selected for the purpose of manufacturing a particular type of yarn in known as batch.
Batching cover all the process preparatory to carding.
The main purpose of batching is to add oil and water to make the jute fiber flexible, soft and stiff free.

Objective of batching:

1. To make the fiber flexible and extensive.
2. To remove hardness, stiffness of lower jute fiber.
3. To prevent the production of lower quality yarn.
4. To make the fiber for effective carding.

The manufacturing designation of common sorts of yarns are:

1. Hessian Warp Yarn: must be good, strong, clean and free from specks with high luster. A batching containing 70% hard jute and 30% soft jute gives good result.
2. Hessian Weft Yarn: should be clean and softer than Hessian Warp Yarn. For light hessian weft yarn, a batch of 50 % hard jute and 50% soft jute is quite satisfactory. For heavy hessian weft yarn, a batch of 30% hard jute and 70% soft jute is needed. In this case, 30% Tossa may be used.
3. Sacking Warp Yarn: should be good & strong. A batch containing 60% hard jute & 40% soft jute. 70% to 80% low grade Tossa jute can be used in the sacking warp batch.
4. Sacking Weft Yarn: sacking weft yarn produced from all types of wastes, dirt etc. They are very harsh

Softening: In softening process jute morahs are made soft and pliable. Two methods are used for softening; use of softening machine and use of jute good spreader. Generally an emulsion plant with jute softener machine is used to lubricate and soften the bark and gummy raw jute. The emulsion plant consists of gear pump, motor, vat, jet sprayer, nozzles, emulsion tank and the jacket. In this softening process jute becomes soft and pliable and suitable for carding.

Emulsion: Jute fiber is consists of lignin. So, it is hard and brittle. Easy break down due to abrasion and mechanical treatment. To make it soft and easy, a mixture of some lubricating agents is used.

The mixture of these elements is called Emulsion.
Oil – 25%
Water – 74.5% Emulsifier – 0.5%

Stainless Emulsion: In an emulsion, the oil percentag8e is less and water percentage is high. This emulsion is applied to jute yarns which are used to make carpets.

Stainless Emulsion recipe is
Water – 92% to 95%
Oil – less than 1% Emulsifier – 0.5% to 1%

Characteristics of Emulsion:

1. Should be stable for the specific time.
2. No harmful effects on either machine or jute.
3. Should have high softening capacity.
4. It must be odorless, colorless, cheap and available.
5. The droplet of emulsion will have to be very small that it can penetrate into fiber easily.

Requirements of Oil:

1. No harmful effect on either machine or jute
2. Color must be acceptable.
3. It should not be sticky.
4. Have no objectionable odor.
5. Cheap and plentiful supply.

Requirement of water:

1. Should be free from color, odor, and hardness.
Requirements of Emulsion:

1. Reduce surface tension and stabilizes the emulsion.

Emulsion mixing according to season:

|Jute |Monsoon |Dry |
|White and Tossa |22% to 24% |25% to 27% |
|Mesta |24% to 26% |27% to 29% |
|Cutting |28% to 30% |31% to 35% |

Emulsion preparation technique:
1. Paddle type machine
2. Colloidal machin
3. Ultrasonic machine

Procedure of Emulsification:

[pic]

Defects of Emulsion:

1. Creaming Cause
· Improper oil selection
· Inaccurate ratio of oil, water and emulsifier
· Agitation is not to be good Solution
· Keeping the size of droplet as small as possible
· Marinating high specific gravity
· After making the emulsion, it should not keep in more time storage.

2. Breaking Cause
· If Oil droplet is bigger internally. Solution
· High speed re-agitation of emulsion mixture.

Softening Machine:

1. Single softener machine
2. Tandem softener machine
3. Good spreader softener machine

Construction:

The softener machine is constructed of following parts:

1. Feed sheet
2. Feed roller
3. Flutted roller
4. Delivery sheet
5. Delivery roller

Working Principal:

The softener machine working on the following principal:

1. Feed material is provided by the feed sheet to the machine as input material.
2. This material will pass through the feed roller to flutted roller.
3. A spray is settled over flatted roller to spray emulsion mixture on the feed material, than the material will pass through the delivery sheet as delivery material.

Conditioning or Piling and pile breaking:

Conditioning or piling refers to the rest stage, in which jute is given after the water and oil have been applied. It lasts longer with low grade batching to allow the hard barky root material to become softened before passing on the cards.
The main function of pile breaker is to break the pile and serve it to the carding machines. The softener machine output material carried by pile men through bile to the pile place for pilling. During piling superficial moisture penetrates inside Fiber and "Thermo fillic" action take place which softener the hard portion of the root. After piling for nearly 24 hours the pile breakers carry the material to the carding machine.

Generally root cutting is done after piling near the hand feed breaker carding machine. The root weight varies from 5 to 7% of the total weight of jute.

|Type of jute |Grading |Pilling time (Day) |
|Long Jute |Good |2 |
| |Medium |3 |
| |Low |4 |
|Cutting |- |4 to 8 |
|Mesta |Good |5 to 6 |
| |Low |6 to 7 |

[pic]

Jute Carding:

The process by which long reeds of jute while passing through high speed pinned roller and broken down into an entangled mass and delivered in the form of ribbon uniform weight per unit length called jute carding.
Objectives of jute carding

1. To breakdown and split up of the fiber.
2. To make the sliver uniform weight per unit length.
3. To remove dirt/dust.
4. To individualize and parallelize the fiber.
5. To produce spinner able fiber.
6. To mix different quality of jute.

Types of Carding Machine:

1. According to processing a. Mono Carding Machine b. Dual Carding Machine c. Tandem Carding Machine
2. According to Cylinder a. Half Cylinder (Breaker) b. Full Cylinder (Finisher)
3. According to the use of strikes a. Up Striker b. Down Striker

Breaker Carding Machine:

In this carding machine, the primary function of jute carding is done by the action of worker and cylinder and the cleaning action is done between worker and stripper.
Main parts of breaker carding machine are:

1. A big cylinder
2. Feed sheet
3. Pin feed roller
4. Sheel
5. A pair of stripper
6. A pair of worker
7. A pair of tiny cylinder
8. Doffer
9. Delivery roller
10. Brash roller
11. Roll framer

[pic]

In different jute mills the carding operations has been carried out in two ways:

a. Hand feed breaker carding
b. Roll feed breaker carding

The material after piling more than 24 hours is used in hand feed breaker where the material after piling for 12 hours used in the roll feed carding.
In the Breaker carding machine soften jute after piling is feed by hand in suitable weight. The machine by action with different rollers turns out raw jute in the form of jute sliver for finisher carding. In this process root cutting is necessary before feeding the material to the hand feed breaker carding machine.

Finisher Carding:

Finisher carding machine make the sliver more uniform and regular in length and weight obtained from the Breaker carding machine. Finisher carding machine is identical to the Breaker carding machine, having more pair of rollers, staves, pinning arrangement and speed. Nearly 4 to 12 slivers obtained from Breaker carding machine is fed on this machine. The material thus obtained is send to drawing section.

[pic]

(4)

REFERENCES:

(1) http://momenur.blogspot.com/2011/12/my-assignment-work-on-jute-spinning.html (2) http://www.thesmarttime.com/dyeing/jute-dyeing.html (3) http://textileflowchart.blogspot.com/2015/01/flow-chart-of-jute-spinning-process.html (4)
http://momenur.blogspot.com/2011/12/my-assignment-work-on-jute-spinning.html