Cotton Fibers-Growth Production

       Cotton Fibers-Growth  Production

          Cotton is the king and Silk is the queen of textile world .Both are dominating the clothing area of the human essentials though the man-made technology developed to the extent of fulfilling the need of clothing. Cotton maintained its value in the history and continued to gain importance in present and future. History says, cotton was known by the people who lived 5000 years back. People were knew the technology of growing the cotton plant, spinning the yarn and get it woven. As we came to know, cotton dominating countries were India & surrounding countries, Egypt, Australia and American continent. Among these India was the main country producing cotton fiber. Cotton is one of the prime farming of Indian agriculture.

Cotton belongs to biological genus gossypium of Malvaceae family. The fiber is completely composed of cellulose.

Production of Cotton Fiber:

Cotton is cultivated in the Soil which is heavy and in an environment of frost free period and in moderate rain fall. Now a days even cotton plants are cultivating in lands of less rain fall but with getting land irrigated. The plants usually grow to to height of 1 to 2 meters depends on area and environment. It has 3 to 7 lobes with large size leaves give pods or boll containing seeds. These cotton seeds are surrounded by fibers grown from the surface of the seed. The boll of cotton seed is supported by flower makes plant & farm looks very beautiful and indicates the farmer to initiate harvesting.

Harvesting is done both mechanically as well as by hand. Boll picking machines and stripers are used in many developed countries. These machines will picks and separate the pods without damaging the plants .But in some developing countries still the cropping is done by farmer hand. Harvesting taken place only after the flower dried & pods gets open itself to sun shine. For cropping, the pods are in a state of complete dried & fibers gets free to exposed sunlight. The picked pods are taken for ginning process. Cotton covers 2.5 % of the worlds cultivated land.

Ginning & Packing of Cotton Fibers:

Ginning is the mechanical process of separating the fibers from the skin of the seeds. This process requires the fibers on attached to the seed must be free from moist. The machines are developed for greater efficiency and productivity have the mechanism of feeding cotton seeds passing though cylinders mounted with sharp saw and pinned belts. The machines separate the seed and fibers as well as through out the trash include dust particles, husk, leaves etc, whatever comes from the farm along with cotton pods.

                The fibers comes out from the gin machine are packed in compact form called ‘’Bale’’ with specific weight to send it to spinning mills for yarn manufacturing.

Organic Cotton Fibers:

                Organic cotton fibers are not differ from regular cotton fibers. Cotton plants are grown naturally without the use of synthetic fertilizers or pesticides. From sewn of seeds to harvesting of cotton pods involved use of biological cycles only.

Agricultural chemicals used for better yield with better quality. The intention behind to avoid use of fertilizers or any kind of chemicals in cotton cultivation is to protect the environment and soil. To have organic cotton and avoid use of pesticides, system had been developed in global level that regulate and control the process of cotton farming, which will include giving approval and supporting to the farmers to grow organic cotton. Each and every stage the process is monitored and certified by the governing body of organic cotton.

                Sustainable cotton project of the global leaders is helping formers to change their production of conventional cotton to organic cotton by avoiding chemicals and support biological growth. Organic cotton growth found successful in many countries like Turley, India, China, Pakistan, Brazil,  Australia , US and African Countries  mainly Egypt. And global apparel brands like Nike, Wallmart,C&A,H&M,etc have switched to organic cotton.

GOTS is the certificating body of global organic cotton and below is their vision and mission for textile industry.

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[The Global Organic Textile Standard (GOTS) was developed through collaboration by leading standard setters with the aim of defining requirements that are recognised world-wide and that ensure the organic status of textiles from harvesting of the raw materials through environmentally and socially responsible manufacturing all the way to labelling in order to provide credible assurance to the consumer.

Since its introduction in 2006 the Global Organic Textile Standard has already demonstrated its practical feasibility. Supported by the growth in consumption of organic fibres and by the remarkable demand for unified processing criteria from the industry and retail sector, it has gained universal recognition, enabling processors and manufacturers to supply their organic textiles with one certification accepted in all major markets. With the introduction of the logo and labelling system the GOTS is already visible not only on the shelves of natural textile shops but large-scale retailers and brand dealers as well. This is a milestone in consumer recognition and a strong acknowledgement of our reliable quality assurance concept.(Courtesy : GOTS)]

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Extra Long Staple (ELS)Cottons:

Fiber staple length has been classified into three groups.

1.       Short Staple-Up to 1,1/8inch long

2.       Long Staple-Between 1,1/8 inch to 1,1/4 inch long

3.       Extra Long Staple-Between 1,3/8inch and 2 inch long

Extra-long staple cotton fibers are belongs to biological specie Gossypium barbadense and staple length of 1,3/8 inch to 2 inches even to 2.5 inches .American pima cotton and Egyptian giza are the main Extra-long staple fibers we find easily in mills use. But other Extra-long fibers also developed in many other countries, but the output per hectare is less than pima and Giza. The countries which are successfully producing extra-long fibers are America, Egypt, Australia, Peru,Israil, Central Asian republics of Tadzhikistan, Turkmenistan and Uzbekistan ,China, West Indies and India.

These Extra Long Staple fibers are of very much demand in the production of fine quality fabrics with better hand feel, soft and strength. The application of these long fibers are of importance in meeting new fashion trends ,fittings as well as comfortness when used with other fiber combination.

The Extra Long Staple fibers cultivated in India are SUVIN in parts of Tamilanadu. And Hybrid DCH32 & Hybrid TCHB 213 are among the  10 commercially cultivated fibers finding in Karnataka, Tamilanadu and Madhya Pradesh. SUVIN is the only fiber belongs to the species Gossypium barbadense.

 

Pima Cotton: Pima cotton staple length are better than other fibers grown in US , Australia, Egypt and in other few countries. Originally this ELS fibre grew by Indianpima in south eastern US. Later it grows in other countires.

Giza: Giza Cottons are the long staple fine micro used for super fine light weight fabrics especially top weights. This variety is grown in Egypt closer to Nile river. The climatic condition of this land has good soil, good humidity and average temperature required for continuous growth of lengthy staple fiber.

Source:Based on qualification and knowledge of the blogger.

Cotton fiber | Cellulosic fiber | Vegetable fiber | plant fiber | natural fiber

 Cotton fiber | Cellulosic fiber | Vegetable fiber | plant fiber | natural fiber

Biological spiecies: Cotton fiber. This is the natural fiber extracted from cotton plant belongs to the biological family Gossipium under the category Mallow. 

Cotton growing countries : The cotton is grown in the tropical and sub-tropical of the globe and continents America, Africa, India, Australia. These are the major continents, major area of the globe, contributing to the growth of the cotton. American cotton,that is Pima cotton. African cotton, that is from country Egypt, Egyptian cotton. Indian cotton and Australian cotton. Even these are the major countries or continents growing cotton, but countries that is middle east countries, Europe countries, Pakistan, Bangladesh,even China, are all  growing cotton. But totally compared to globe, India is the major country contributing cotton production.

Chemistry of cotton fiber : The major content of cotton substance contained in the cotton fiber is cellulose, is the natural chemical element found in cotton fiber contributing about 90 to 92 % of its content in the cotton fiber. But this cellulose not only found in cotton plant, cellulose is also available in forest trees and other plants in woods. But in other wood and forest trees, the cellulose available is only 40 to 45%.But in case of cotton fibers, it is more than 90%.Because of this substance cellulose, the cotton is having demand. It gives the quality; it gives comfortness and other required properties of the clothing. The natural God gifted fiber cotton plant.

Cotton cultivation environment : The environment required to grow the cotton plant are, its required plenty of sunshine and moderate rain  fall of  about 60 to 120 cms. And soil need to be very heavy. And the cotton plant grows in frost free period.

Cotton plant : The cotton plant is having number of flowers. Each flower is producing a pod. The petals of the flower are covering this pod. When flower gets dried, the ball of the cotton fibers, that is compact form of the cotton fiber, that is wet conditioned fibers are packed together in the of the ball. The ball is called as pod. And in this pod, the number of fibers produced in the origin, that is the origin of the fibers are the seeds. The Seeds are covered with the fibers. The pod containing both seeds and the fibers. Both are attached together. Seed producing the fibers.

Cotton pod contain fibers with seeds

          When harvesting time comes, these all pods, that is when these pods almost all in their dried form (90% of the pods are dried), the harvest taking place in the sunshine period. These pods are plucked by the farmers. And collected and kept for drying. Plucked cotton fibers along with seeds are called the raw fibers or raw cotton. This raw cotton fibers are not only a mixture of seed and fiber but also containing the foreign impurities like husk, dried leaves, dust & dirt and other unwanted natural stains, etc,.

Cotton ginning : The raw cotton taken to the Ginning process. Here we have not written that process.In this Ginning process, the raw cotton fibers are separated from the seeds. That is the process of separating fibers from the seed and cleaning it or free from the dust & dirt and foreign impurities. And make the fiber pure one is called the Ginning process. This Ginning process is processed in the roller Gins. In olden days, it was done by hand rolled gin. Slowly the technology has been updated and improved. Nowadays automated ginning machines are used. The efficiency of the Ginning machines per day or per hour are improved a lot as technology has been improved.

Cotton bales

Cotton bale : When the Ginning process is completed, the outcome of the ginned fiber is having the pure cotton is packed and sold in the bale form. The bale is an international package form for the cotton. And this bale is measuring approximately about 1.400 x 0.53 x 0.69 m.And weight is around average 480 to 496 pounds in British system or 218 to 225 Kgs in MKS system. 

          Thus, in Ginning mill the raw cotton is purified into white cotton, not pure white cotton, but its free from other un wanted materials / impurities. And these bales are send to or sold to the spinning mills to process further  into the yarn, that is fibers are spun into yarn and then yarns are woven into fabrics.

Global cotton production: Now the total world production including all countries, all continent, all areas approximately about 25 million tons of cotton produced annually. But now a day, because of the variation in the climatic conditions, variations in the environmental requirements, that is required for the growth of the cotton plant, that is varying. Even the scarcity of water, limitations to irrigation or agricultural problems, natural calamities and one or the other reasons, now a day’s compared to olden days the cotton cultivation has gone down. The production of the cotton that is efficiency of the cotton grown worldwide has decreased. But the cotton has not lost its demand. This is the king of the cotton textile industry.            

Note: This note will be updated as and when required.                

Source: Based on the qualification and knowledge of the blogger had post graduation in Master of Technology in Textile Technology.

Textile fibers | Physical properties | Performance properties

Textile fibers | Physical properties | Performance properties

            Textile fibers are the flexible material composed of polymer chains made of molecules and are identified usually in terms of high length to low width ratio. Fibers are classified into Natural, Regenerated and Man-made.

Natural fibers are grown or cultivated or extracted. Grown natural fibers are exist from vegetable plants. Cultivated fibers are from animal source and Extracted fibers are from Mineral Materials.

Examples of fibers classified as vegetable fibers are Cotton, Jute, Hemp, etc.

Examples of fibers classified as animal fibers are Silk, Wool, etc.

Example of fibers classified as Mineral is asbestos.

            Regenerated fibers are a modified form of natural fibers. Examples of fibers modified based on cotton (Cellulosic) are Rayon, Viscose, Acetate, Tencel, Lyocel,modal,etc.

            Man-made fibers as drawn synthetically as per requirements. Examples of fibers in vogue are Polyester, Nylon, Acrylic, etc.

Fibers used for textile material end use should possess below prime properties.

1.      High Length to Width Ratio

2.      Surface Cohesiveness

3.      Tenacity

4.      Flexibility

5.      Uniformity

High Length to Width Ratio is the physical measurement indicator of fiber. The length should be minimum 100 times more than its width. This ratio in cotton is around 1400 and silk is around 33 x 10 to the power 6.

Surface Cohesiveness is the natural characteristics of fiber to hold one and each other when spun and gives strength to the yarn. This property of fiber will influence on yarn strength as well as its uniformity.

Tenacity of the fiber is the important property indicating the strength of fiber. This tenacity value will differ from fiber to fiber types. Adequate tenacity of the fiber will provide better durability of the end use.Cotton has 3.0 to 5.0 grams of force per denier(gf/d),Wool has 1.0 to 1.7 gf/d, polyester has 2.5 to 6.3 gf/d, nylon has 4.3 to 9.0 gf/d and Rayon has 2.4 to 3.0 gf/d.

Flexibility is the bending property of the fiber playing an important role in comfort to the fabri wear as well as gives better drapability.

Uniformity is pertaining to the shape of the fiber that considers the cross sectional area and longitudinal area of the fiber. The cross section of the fibers may vary from one fiber end to other end. Due to this non-uniform cross sectional areas, the resulted shape may affect the dye uniformity by poor dye fiber affinity. To give uniformity to the fiber, mercerisation process is applied with caustic soda.

Other fiber properties considered to define textile fibers are briefed are listed and briefed below are. These properties will decide with performance of the finished fabric

1.      Physical Shape

2.      Density

3.      Luster

4.      Color

5.      Moisture Regain

6.      Elastic Recovery and Elongation

7.      Resiliency

8.      Flammability

Physical shape : As discussed in the prime properties will play an major role in fabric performance especially in fabric drape, aesthetic, shade consistency as well as strength properties of the finished fabric or end use. Different fiber types have different shapes in cross sectional area apart from their longitudinal appearance. Natural fibers like cotton, wool, jute, silk etc possess their own shapes decided by their nature of their growth while the shape of man-made fibers like polyester,nylon,aramid,acrylic,are manipulated in manufacturing process. Now in the era of  21 cetury,we started to use the modified cellulosic fibers with different petent names and trademarks like Viscose,Rayon,Excel,Tencel,modal,etc…The content of these modified regenerated fibers and natural cotton is same that is ‘’Cellulose’’ but only difference is in the morphology of the fobers.The modification in the morphology is done based on the requirments which suits contemporary fashion trends as well as considering the need of comfort.

Density: Every earthly particle of this world have their own density. Without density no material will appear on this earth. Density is the mass of the material weighs per unit area.All chemical elements found on this earth have their own density. The density is influenced by gravity when the material is on earth. Though the textile fiber is small in size and weight must have density. The density of the textile fiber influence the factors like dye fiber affinity, weight of the finished fabric and comfort of the fabric wearer. And main understanding of this fibe density lies in giving functional performance to the sportswear , active wear and outer wear fabrics.The unit of measurement of fiber density is ‘’Grams per Cubic Centi Meter’’. Natural fibers like Cotton has 1.54 to 1.56 ,Wool has 1.30 to 1.32,Silk has 1.25 to 1.34 while manmde fibers like Polyester has 1.23 to 1.38,Nylon has 1.14 and Spandex has 1.20 to 1.25.

Luster:The word Luster indicate the shininess of the material that is in this case Its Luster of Fiber.The shininess ,semi dullness and dullness in appearance of fiber will directly influence the appearance of the finished fabric. Natural fibers have their own surface appearance and its depends on the surrounding environments where they have been grown or cultivated. But The shininess can be incorporate in man-made synthetic filament fiber based on the requirement. Fabrics need luster level depends on end use used specially for outerwear, casual wear, party wear, etc

Color: The luster defines the shininess of the fiber, whereas color defines the fiber’s visual outcome belongs to which VIBGYOR line..that is Red,Blue,Green,.etc,. Natural cotton fibers possess their own natural colors like off white cotton, bluish cotton and yellowish cotton.Wool has its own shades depends on its origin. Silk has its own shades based on silk work and sericulture done. But color of the synthetics are not decided while manufacturing, instead will be preferred to finish in white only by keep in view of dyed it in required colors.Though the visual shades of the fibers are natural or white but spun grey yarn or woven grey fabric from those fibers are subjected to wet process to bring them to the status of ‘’Prepared for Dyeing’’ before the spun yarn or woven fabric taken for dye to the required colors.But in some natural fibers cases like Jutes,Hemp,Flex,Linen,Wool etc, their natural shades are dominated though they spun into yarn or woven into fabric.

Moisture Regain and Moisture Absorption: One of the important property required for textile fiber is characteristics of absorbing moisture and its regain. This property will help the textile fiber to cooperate in wet processing. If fiber does not have absorbing character, no liquid chemical penetrate into the surface of the fiber and dye fiber affinity will be not there. For Dyeing of the yarn or fabric involves many stages of wet processing. Wet processing needs the core fiber to absorb wet particles. Particle may be any chemical or it may be color. The absorbency of fiber in turn depends on its morphology that is its internal chemistry.The whole wet processing of textiles depends on morphology of fibers.We will discuss about fiber morphology later in dyeing technology. Here we can say the percentage of air space available inside the fiber chemistry will decide the dyeability of the fiber.This available air space will be taken into consideration to judge the absorption capability of the fiber.

            Moisture absorption is the ability of the fiber to absorb surrounding moist during particular time.  Moisture regain is the ability of the fiber to have required moist.Here the moist is water particle. Both Moisture absorption and moisture regain are measured in terms of percentage of oven dry weight of the fiber.The lab will calculate the percentage by measuring weight of the fiber at oven dry condition and by measuring the fiber weight after 48 hours of lab conditioning that is with 23’C Temp and +/-65% Relative humidity. The percentage resulted with the initial weight from the difference between oven dry weight & conditioned weight will indicate the ability of the fiber to absorb.[ give % of different fibers].The testing of moisture absorbency will help in deciding the dye ability of the fibers.

Elastic Recovery and Elongation: Textile fibers are flexible in nature and should have property of elongate and recover when subjected to stress and strain. The fibers and yarns in the garment are subjected to stress and strain while body is in movement. Due to this the chances of fibers gets elongate to its capable extent when strain is caused and attaint its original state when strain is released. If the fiber does not have this quality of elongation and attaining back, then fiber rupture can takes place.  Such fibers cannot be used for production of cloth for garment end use.

            Fibers getting elongate from its original size to its capable extent when applied tension is measured in terms of ‘’Percentage of Elongation’’ .Like that, the ability of fibers attaining back to its original state is expressed as Elastic recovery and measured in terms of ‘’Percentage of Recovery’’ [ give % of different fibers].Elastic recovery and elongation also influence the strength characteristics of the yarns and fabrics. That is the tear strength and tensile strength of the fabric. This will be discussed in textile testing part.

Resiliency: This is the state of the fiber attained its complete rest position when tension is removed and cannot recover further or elongate further.All textile fibers should have this character and its part of property of elongation and recovery. Dimensional stability of the fabric is measured based on this resilience character. Fibers, yarns and fabrics are subjected to many stress and strains from spinning to wet processing of fabrics. When fabric reached its finishing stage,the fabric is  passed through Sanforization treatment in the mill. That is making the fabric dimensionally stable.Making the fabric stretch and shrunk will makes the fibers attain their rest position as well as reduce the yarns elongation.This will result in controlled shrinkage rate.

            Why natural fiber fabrics shrunk more compared to man-made fiber fabrics ?.The reason is the morphology of the man-made fibers are controlled manually ,so the fabrics are stable, as the morphology of natural fibers are varying and need additional applications.

Flammability: Flammability is also the essential property for the garments, especially for the end uses which are need to wear by workmen who work in the industries at floor, who involved in extinguishing of fire and areas where chances of fire expected. Flammability of the textile fibers  or fabrics is an risk factor while considering for end use.The behaviour of fibers when comes in contact with the fire as well as the duration of withstanding the fire are varying from fiber to fiber. Some fibers catch fire immediately, some fibers takes time to burn, some fibers melt & lose the shape.Some fibers gets fire even at higher surrounding temperature.If fibers are flammable but need for end use, then its required to apply the finish’’Fire Proof’’ or ‘Fire Retardant’’ to the fabrics. Complete fire proof is difficult but fire retardant is feasible to increase the fire resisting time.This fire resisting time of fabric will help victim to come out from the risk.  So this flammability test is made mandatory by many global brands.

Classification of textile fibers - Natural fibers

Natural Fibers

                Natural textile fibers are as title says these fibers are originated from nature. The sources of nature are Vegetable, Animal and Mineral.

The fibers comes under Vegetable fibers are grouped as Cellulose Fibers, Protein Fibers, Mineral fibers .

Cellulosic Fibers: The fibers belongs to this class are regrouped as Seed Hairs, Bast Fibers , Leaf fibers and Nut husk fibers.

Cotton belongs to seed hair category.

Flax, Hemp, Ramie and Jute belongs to bast fibers.

Abaca, Pineapple, New Zealand Flax belongs to leaf fibers.

 Coir( Coconut ) belongs to Nut husk Fibers.

Protein Fibers: The fiber belongs to this class are regrouped as Animal-Hair Fibers and Animal Secretion

                Wool (from Sheep) and special fibers like Cashmere and Mohair (Angora goat) belongs to Animal hair.

               Fur fiber Angora rabbit also falls to animal hair category.

                Silk (Cultivated, Dupion, Tussah ) and Spider Silk belongs to animal secretion class of fibers.

Mineral Fibers: Asbestos (rock source) falls to this mineral fiber category.

Note: This article will be updated as and when required.