Jute fiber is a long, soft, shiny best fiber that can be cut into thick, strong threads. It is mainly produced from the genus Corcharas. Jute is one of the most affordable natural fibers, and second only to cotton in quantity and variety used. Jute fibers are mainly composed of plant materials cellulose and lignin. It falls into the category of bust fiber along with kenaf, industrial hemp, flax (linen), ramie, etc. The industrial term for jute fiber is raw jute fibers white-brown and 1-4 m long. Jute is also called golden fiber for its color and high cash quality.

Jute cultivation and yarn making process, types of jutes and many more interesting facts by Pritish Kumar Halder

Jute cultivation process

To increase jute, farmers spread seeds on cultivated soil. When the plants are around 15-20 cm tall, they are thinned. About four months after planting, the harvest begins. Trees are usually cut after flowering. The stalks are cut close to the ground. The stalks are tied in bundles and soaked in water for about 20 days. This process softens the tissues and breaks the hard pectin bond between the busts and allows the process to separate the fibers. It is then stripped from the stalk of the long strand and washed in clean, flowing water. They are then hung or spread on the roof to dry. After 2-3 days of drying, the fibers are bound in bundles.

Raw jute Dying

The climate suitable for jute growth is a warm and humid climate, which is provided by the monsoon climate in the fall season immediately after the summer. Temperatures above 25˚ C and relative humidity of 70% -90% are favorable for successful cultivation. Additional requirement during jute sowing is 160-200 cm rainfall per week. River basins or waterlogged or loamy soils are best for jute cultivation. Cultivation of jute in red soil may require high doses of fertilizer and the best pH range of 4.8-5.6 is required for its cultivation. Ideal for plain or soft or lowland jute cultivation. As jute seeds are small in size, the land should be prepared for fines, which can be carefully tied to the land.

Types of jute

There are three types of jute, such as-

  1. White jute b. Tossa jute c. Mesta jute

a. White jute

Corchorus capsular, commonly known as white jute, is a shrub species in the Malvaceae family. The plant originated in China but is now native to Bangladesh and India and has spread to many parts of tropical Africa. It is also cultivated in the Amazon region of Brazil. It is one of the sources of jute fiber. Which is considered to be of better quality than the fiber obtained from the main source of jute, Corchorus olitorious. The leaves are used as food and the leaves, unripe fruits, and roots are used in traditional medicine.

b. Tossa jute

Tosa jute or Corchorus olitorious is a local thought in South Asia. It is developed for both fiber and culinary purposes. People use the leaves as an ingredient in a mucilaginous potherb called molokhia. Bangladesh and many other countries in Southeast Asia and the South Pacific commonly use jute for their fiber. Tosa jute fiber is soft, silky, and stronger than white jute. This variety shows good stability in the Ganges delta climate.

c. Mesta Jute

Mesta jute is a hybrid of white jute and tosa jute. Although this type of jute was not historically popular historically, the political complexities of India’s turbulent independence made the production of this type of jute paramount.

Different defects/faults in jute fiber

Rooty Jute: This problem occurs due to improper retting underwater. These faults see on the root end area in jute.

Specky jute: These defects occur due to insufficient washing which causes the outer barks to adhere to some places. Speck in jute is a major defect that lowers the quality of Jute fibers.

Dazed fibers: These defects see on jute fiber due to over-retting in water, for this reason, jute fiber loses strength and luster and becomes bad for spinning.

Runners: Runner is a defect where a long and hard barky ribbon of fibers remains in jute fiber.

Hunka: Hunka is a jute defect, for this reason, jute show hard and barky.

Mossy jute: Fibres from short plants that cannot be properly steeped and cleaned contain broken pieces of jute sticks etc.

Croppy Jute: This defect is shown on the top end of the fiber. For this reason, the top end of the fiber becomes rough and hard. These defects usually occur due to careless steeping.

Knotty jute: This type of defect in jute fibers is caused by insect bites or punctures.

Flabby or hairy jute: These defects occur due to careless stripping, fiber loses firmness, and becomes flabby and hairy.

Heart damage: These defects occur when jute fiber contains excess moisture in baled and the bale center becomes badly tendered in some cases, fibers are reduced to powder.

Jute spinning process

The main function of jute spinning units is to convert jute fiber into yarn for various end uses. The type of jute yarn that is made can be classified according to the application/use such as fine yarn, hessian yarn, carpet, sacking yarn, etc. various, etc.

The processing sequence in jute spinning is-

1. Jute selection

After drying, the raw jute is packed in jellies in the form of 150 kg or 180 kg bells for easy movement. The bells from the mill godown are taken to the selection department where all the jute bells are opened to search for any jute and to remove the defective part from the bend by experienced workers. After selection, the jute boundaries are driven by workers in the softening/batching department.

2. Batching section

Batching is the process of mixing oil and water in jute. A batch is a mixture of fibers with different types of jute fibers for a particular class of yarn. The section where jute is prepared for carding is called batching house. In this section, the fibers are conditioned for easy processing in the resulting processes by adding oil and water. The ready-to-pick wrap is processed with a softener or spreader machine to fit the jute fiber bundles for subsequent carding operations. As it passes through these machines, the oil in the water mixture is applied to the jute for its moisture or lubrication.

3. Batching emulsion recipe

Jute batching emulsion usually consists of three products such as mineral oil, water, and an emulsifier. The most commonly used mineral oil is Jute Batching Oil (JBO), a medium distillate produced by petroleum refiners. JBO lubricates the fiber and makes it flexible. Water provides adequate moisture to the fiber and increases its extensibility. The emulsifier reduces the surface tension and stabilizes the emulsion.

4. Softener process

The softener machine is used for batching of sucking yarns, its raw materials are low grade. It is a long machine consisting of 4 – 2 pairs of cast iron curved rollers. The lower part of the pair is driven by the side shaft and the top is the spring-loaded one by contacting the bottom of the pair. Long jute is conditioned 24 – 48 hours after softening and then ready to feed on the breaker card.

5. Carding process

The main objectives of jute carding are-

  1. Dividing the jute root longitudinal and breaking it transversely.
  2. Converting jute ghats into uniform fibrous strands, suitable for further processing
  3. Some amount of fiber is clean, orienting, and attenuating.
  4. Randomize the fibers among themselves.

Two types of carding machines are commonly used in jute processing, namely breaker card and finisher card and both roller and clear type.

6. Drafting process

The main objectives of the jute drawing frame are-

  1. Drafting finisher card slivers to make the spinning frame suitable for feeding.
  2. Doubling the slivers to reduce irregularities.
  3. Straighten and align the scales along the sleeve axis.

Jute drawing frames are divided into two types, according to the process of follar bars. Such as- push bar type and spiral or screw gill type.

7. Jute spinning

Most of the jute yarn is cut from the finisher drawing sliver and the spinning from the rove is basically limited to the finer range. Nowadays, however, most ring spinning is used for fine counting yarn directly from the sliver. The jute spinning frame is designated by the pitch distance between adjacent spindles. The main objectives of the spinning process are to draft, twist, and rotate.

  1. Drafting – In the case of yarn making, the process of reducing the assembly of fibers called sliver by flowing through different rollers thus straightening the individual fibers and making them more parallel is called drafting. Each pair of rollers moved faster than before.
  2. Twisting – In the production of yarn and rope, the process by which fibers or yarns are tied together in an uninterrupted strand, performed in spinning or playing operations is called twisting. The twisting side can be on the right, described as a Z twist, or on the left, described as an S twist.
  3. Winding – The process of making large yarn packages like the cone from different small yarn packages like ring cops using subsequent machinery is called winding. The winding process not only creates larger yarn packages, but also corrects spinning errors such as naps, hairiness, and wax.

Weaving process

The process of separating two series of thread warp and waffle yarn to produce a fabric of the desired quality is called weaving. This weaving department has separate looms for hessian and dismissal. Hessian loom, the shuttle whose materials (weft yarn) have been changed manually.

Damping –  In this process is damp, where the rolled woven fabric is uncontrolled and water is constantly sprinkled on it to provide the desired moisture. Each roll is typically 104 yards or 95.976 meters. This is done manually.

Calendaring – This process is similar to dressing calendaring fabric. Damp fabric renders the thread into the fabric through heavy roller pairs to expand and improve quality and appearance.