KNOWLEDGE SHARING

Cotton Fiber

Cotton is a cellulosic fibre. Cotton is used as a fibre because it has a large amorphous portion which makes the fabric comfortable.

It is also soft when properly ginned and has a high absorbency power hence making it easy to use for dyeing.

It is also said to have good strength and good drape ability.

Cotton Growing States

Maharashtra (26.63%), Gujarat (17.96%) and Andhra Pradesh (13.75%) and also Madhya Pradesh are the leading cotton

producing states, these states have a predominantly tropical wet and dry climate.

World Demand & Supply Situation

Area, production and productivity of cotton in india from 1950-51 onwards

Physical Properties of Cotton

• Color: The color of cotton fibre could be white, creamy white, bluish white, yellowish white or grey.

• Tensile Strength: Cotton is moderately strong fibre; tenacity is 26.5-44.

• The strength is greatly affected by moisture, the wet strength of cotton is 20%, which is higher than dry strength.

• Elongation at break: Cotton does not stress easily. It has an elongation break of 5-1%.

• Moisture Regain: Standard moisture regain is 8.5%.

Chemical Properties of Cotton

• Effects of Acids: Cotton is attacked by hot dilute acids or cold concentrated acids which it disintegrates. It is not affected by cold weak acids.

• Effects of Alkalis: Cotton has an excellent resistance to alkali. It swells in caustic alkalis but does not damaged. It can be washed in soap solution without any problem.

• Effects of Organic Solvents: Cotton has high resistance to normal cleaning solvents. Cotton is dissolved by the copper complexes, such as cuprammonium hydroxide, cupriethylene diamine and concentrated 70% H2SO4.

• Effects of Insects: Cotton is attacked by moth-grubs or beetles. • Effects of micro Organism: Cototn is attacked by fungi and bacteria.

Mildew will feed on cotton fabric, rotting and weakling the materials. mildews and bacteria will flourish on cotton under hot and humid condition. They can be protected by impregnation with certain types of chemicals. Copper Nepthenate is one of the chemicals.

Ginning

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 cotton is then air conveyed to gin stands where revolving circular saws pull the lint through closely spaced ribs that prevent the seed from passing through.

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.

A typical gin will process about 12 bales per hour, while some of today’s more modern gins may process as many as 60 bales an hour.

SPINNING MILL PROCESS FLOW CHART

INDIAN COTTON QUALITY

COTTON TEST REPORT

YARN TESTING

Uster – Tester

Hairiness

Single Yarn Strength and Elongation

CLASSIMAT TESTING

Total Faults : A1 to I2Serious faults : A4,B4,C4,D4,C3,D3,D2

Objectionable faults : A3,B3,C2,D2Long thick : EFGLong thin : H1+H2+I1+I2

PRESENTERS REMARKS

• The functioning of machines from Blowroom to Autoconer was explained using VIDEOS.

• Doubts raised by technicians were clarified.• As per feedback, this presentation and

interaction has helped people in enriching the knowledge on cotton and spinning activities along with quality parameters.

THANKSIts L. Narayana PrasadAgm-Quality , Spinning Division.