Ginning and Manufacturing By Ethan

Gin is short for en-“gin” Ginning Gin is short for en-“gin” Ginning is the first stage of processing cotton – separating the lint from the seed. The process of ginning is either done by hand or a small hand crank (primarily in poorer countries) or a by a ginning machine (gin a for short). In Australia gins a are located in cotton areas a to avoid costly transport. a Also, in Australia most a cotton is ginned with saw a gins, which are fast moving a circular saws that grip the a fibres and pull them a through narrow slots.

The Ginning Process The cotton is transported to a gin using a machine called a moon buggy Once the cotton has arrived at the gin, the cotton is vacuumed into tubes that carry it to a dryer. For the ginning process the cotton must be at a moisture level of 5%. - If the cotton is too moist it forms ‘neps’ or lumpy ball of fibre - If the cotton is too dry the fibres break or may cause static electricity The cotton is dried in a ‘dryer’ Then the cotton gets blown along by warm air to the pre-cleaning area, through several stages of cleaning equipment to remove leaf trash, sticks, dirt and other foreign matter.

Opening and Blending After being ginned, the bales of cotton are selected to satisfy the requirements of a particular end use. They are then laid down in a row (called a ‘laydown’), opened and loosened so the fibres can relax. The bales are then blended through a range of machines to ensure a consistent and homogenous blend of fibres.

The Cleaning Process Inclined and horizontal cleaners: use spiked cylinders which spin around and drag the cotton screens, causing leaf trash, stalks and dirt to drop out. Stick machine: spins the cotton around cylinders, throwing out sticks and burrs. Impact Cleaners: beats the cotton between rows of spiked rollers and saws. Extractor-feeder: feeds the cotton into the gin stand and removes more trash Gin Stand: separates the seed from the cotton with a saw gin. Saw Gin: a row of circular saws with sharp teeth around the edges. Gin Stand

Ginning Process

The raw fibre, now called lint, has any remaining trash removed and makes its way through another series of pipes to a press where it is squashed into bales under very high pressure. Each bale weighs approximately 227kg. Samples are taken from each bale for classing and the bales are wrapped in stretchy white cotton fabric to protect the lint.

Products From Ginning Seeds Trash Lint The seeds make up about 55% of the seed cotton weight that comes from the farms. Used in various products such as oil, plastics, cosmetics and margarine. The remaining 10% of the seed cotton is classed as waste product or trash. Can be used in ethanol manufacturing or in products that clean up oil spills. Can also be used a fertiliser. Lint Lint makes up approximately 35% of the seed cotton weight. After being separated the lint is compacted into bales and then mostly transported to Australian ports for transport to other countries.

Carding The next step in the ginning process is carding. The fibre is fed into a carding machine, which individualises, aligns and further cleans the fibres, before condensing them into a single continuous strand called a ‘sliver’. Carding machine

Drawing and Combing Drawing: is the process where the fibres are blended, straightened and the numbers of fibres reduced to receive a desired density. Also this improves the evenness of the sliver. Combing: this process removes any final waste from the cotton and makes it finer, stronger, smoother and more expensive compared to carded yarns.

Spinning Spinning is the process of twisting the fibres to a yarn of a certain weight. There are 2 main spinning systems used commercially to produce cotton: ring spinning and rotor spinning.

Ring Spinning Ring spinning was perfected as a process by the end of the nineteenth century. There are currently more than 213 million ring spinners installed worldwide. Ring spinning is best suited at handling short-staple yarn production, with it being accountable for around 60%. Cotton in Australia is mainly spun by ring spinners.

Rotor Spinning This was introduced in the mid 1960’s. Today there are over 9 million rotors installed worldwide which account for 30% of short staple yarn products. Sliver is fed into the machine and combed and individualised by the opening roller. The fibres are deposited into the rotor where air current and centrifugal force deposits then along the groove of the rotor where they are evenly distributed. The fibres are twisted together by the spinning action of the rotor, and the yarn is continuously drawn from the centre of the rotor. The resultant yarn is cleared of any defects and wound onto packages.

Weaving Weaving is one of two of the processes of turning the cotton fibres into fabric Is when two sets of yarn are crossed under and over each other to lock them tightly together. The yarn running across a fabric is the weft The yarn running down a fabric is the warp The warp yarns are set up first The weft yarn is then carried at great speed by a jet of air across the warp yarn The machines use 2380 metres of yarn a minute

Knitting Is the second method of turning cotton fibres into fabric Links the yarn together by looping it through itself through a series of chains A circular machine is used to knit the fabric and it uses 78 metres of yarn each minute Knitted fabric is stretchy but not as strong as woven fabric It curls when cut

Dyeing and Finishing Dyeing: Cotton can be dyed many different colours at various stages of processing. This is normally done using computer-controlled colour machinery. Finishing: is the process that gives the fabric its final appearance, feel and practical attributes. Finishing can include softening, water repellence or permanent press.