Jute fiber cultivation
Raw jute bales brought by trucks from jute farms or suppliers are unloaded and deposited in the warehouse of jute mills. Raw jute in the form of bales is processed in jute mills to make hessian, sacking, jute yarn, bags, and other useful products.
In the selection process the raw jute bales are opened to detect any defects and the defective part is removed from the mora by experienced workers.
Raw jute bales are classified into two parts i.e. 150 kg weight and 180 kg weight with or without cutting of the head portion.
The bales are mixed according to the end use like hessian weft, sacking wrap, sacking weft, etc. After selection, the jute bales are taken to the softening section by workers called Gariwala and Bajawala.
The softening process makes Jute Morah soft and stackable. Two methods are used for softening: the use of a softening machine and the use of a jute fine spreader. Generally, an emulsion plant with a jute softener machine is used to smoothen and soften the barky and sticky raw jute.
The emulsion plant consists of a gear pump, motor, vat, jet sprayer, nozzle, emulsion tank, and jacket. In this softening process, jute becomes soft and pliable and suitable for carding.
Carding is a combination operation where jute bars are split and foreign matter is removed. Jute fibers are used to make ribbons which are called “slivers”. There are three different carding sections:
(i) Breaker carding
(ii) Internal carding
(iii) Finisher carding
After piling in the breaker carding machine the soft jute is hand-carded to appropriate weight. The machine produces raw jute in the form of a jute sliver for finisher carding by acting with various rollers. In this process, it is necessary to cut the root before feeding the material into the hand-feed breaker carding machine.
The finisher carding machine makes the sliver more uniform and regular in length and weight than that obtained from the breaker carding machine.
The finisher carding machine is similar to the breaker carding machine, it has more pairs of rollers, staves, pinning arrangement, and speed.
About 4 to 12 slivers obtained from the breaker carding machine are fed into this machine.
The material thus obtained is sent to the drawing section.
Drawing is a process of combining 4 to 6 slivers to reduce the width and thickness of the sliver. There are three types of drawing frame machines. In most mills, Hessian uses 3 drawing passages and Sacking uses 2 drawing passages.
The slivers received from the finisher carding machine are fed with four slivers onto the first drawing frame machine. The first drawing frame machines mix, equalize slivers, and double, level, and impart quality and color to two or more slivers. This machine consists of a delivery roller, pressing roller, retaining roller, follower screw sliders, check spring, back spring, crimping box, etc.
In the second drawing, the second drawing frame machine receives the sliver from the first drawing machine and uses six slivers per person and delivery. The second drawing machine produces more uniform slivers and reduces the jute to a size suitable for the third drawing.
In the third drawing, the third drawing frame machine uses the sliver from the second drawing. The third drawing machine is of high speed which makes the sliver more shapely and suitable for spinning. Comparison of three drawing processes:
Spinning is the process of making yarn from the sliver obtained from the third drawing.
The Jute Spinning Frame Machine is equipped with a slip draft zone and is also capable of producing quality yarn at high efficiency with an auto-drafting arrangement.