1. Introduction
2. Principle of Ginning

“Ginning is a process of separation of cotton fibres from cotton seeds”. Main object of ginning is to remove the cotton fibres from cotton seeds.As we know that cotton fibres obtained directly from farms have cotton seeds and many other impurities like dirt, dust and plant leaves with it. Therefore it is necessary to make cotton fibres free from these impurities.Second object of ginning is to remove dirt,dust and leaves during ginning. Now these day ginning of cotton is performed by different types of machines available.From the field, seed cotton moves to nearby gins for separation of lint and seed. The cotton first goes through dryers to reduce moisture content and then through cleaning equipment to remove foreign matter. These operations facilitate processing and improve fiber quality. The lint is removed from the saw teeth by air blasts or rotating brushes, and then compressed into bales weighing approximately 500 pounds. Cotton is then moved to a warehouse for storage until it is shipped to a textile mill for use.

Types of ginning:

  • Saw ginning
  • Roller ginning
3. Saw Ginning

Saw ginning provides more clean cotton compared with manual or handheld separation process of seed from cotton.Saw-tooth type cotton gin is special used to separate long fiber from seed cotton, meanwhile effectively remove cotton trash and dead cotton to get clean lint.It is an ideal equipment for processing hand-picked cotton and mechanical harvested cotton.Saw-tooth cotton gin consists of cleaning part and ginning part. Ginning part consists of front box, middle box and back box. Middle box is also called working box.The two feeding rollers send the seed cotton into cleaning part.

After being struke by the spiked roller, seed cotton becomes fluffy and is thrown onto the upper U type channel saw roller and rotate with it. When passing the wire brush, some bulky trash and dead cotton fall onto the lower U type channel saw roller, and are discharged through spiral conveyor. Seed cotton is brushed down to lint slide by rotary brushing roller and flow into the front box. Cotton stirring roller in the front box throws the clean and fluffy seed cotton to saw blade.

Saw-teeth pull seed cotton into working box and make it rotate with saw blade. At the operating point of the ginning ribs, fibers are pulled away by saw-teeth and enter into the back box, where they are brushed into lint course and sent to lint cleaner. Cottonseeds are blocked by the ribs, and discharged out of the machine through cotton seed finger.

4. Roller Ginning

Modern ginning is automatic ginning where productivity is maximized. For industrial purposes, this type of ginning technology is more preferable.Before cotton arrives at the spinning mill to spin into thread and woven into the fabric, it makes the journey from field to bale. Cotton needs about five months to grow from a planted seed to a ready plant.

  • The harvesting machine named cotton picker plucks fluffy seed cotton out of the plant’s boll and leaves a trail of burrs and sticks behind.
  • The machine empties the pulled cotton into a tractor-drawn buggy.
  • The machine builds the seed cotton into a humongous rectangular block called a module.

A truck transports the module to the processing plant, which is known as a cotton gin. Once the cotton arrives at the processing plant, sticks and burrs are removed as well as any lingering debris and seeds. A truck dumps the module into a feeder, which moves the packed seed cotton into a dispenser.The ground seed cotton falls onto a conveyor belt, which leads to the hot box, then the hotbox mixes the seed cotton with hot air, which allows the moisture to evaporate, making the seed cotton easier to clean.

Advantages of Roller Ginning of Cotton:

  1. Saw ginning ensures the quality of fiber is better which is better than the other process.
  2. High production because of the use of advanced technology in the ginning process.

Disadvantages of Roller Ginning of Cotton:

  1. The moisture of seed mixes up with fiber in processing which causes cake cotton fault.