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| Cotton fibers. |
Fibers
A fiber is a hairlike unit of raw material of which cloths are made. For example, cotton linen, rayon, silk, wool, nylon, and polyesters. Fibers that are used in textiles can be classified under two main categories: Natural fibers and Man-made fibers.
Natural Fibers
The 'natural' classification is subdivided into fibers of vegetable, mineral, and animal origins.
Vegetable Fibers
Vegetable fibers are found in the cellulosic structure of many plants. Some are on the coverings of seeds, such as cotton, kapok, and coir. Others are in the outer layer of stalks, such as linen, ramie, jute, and hemp. Some are in the leaves, such as sisal, and some are grasses and reeds.
Seed Fibers
Cotton
Cotton is a vegetable fiber that grows from the surface of the seed. Each fiber is essentially a long thin tube of cellulose with a central feed channel, called a lumen, which runs almost the whole length of the fiber. In modern production, cotton is cultivated as an annual plant rather than letting it grow into a tree. Harvesting is easier working in this way and fiber properties are better controlled; also, cotton plants left in the ground after harvesting are subject to attack by pests.
Kapok
A vegetable fiber that comes from a plant or tree grown chiefly in Java, the West Indies, Central America, India, Africa, South Asia, and Brazil, kapok is a silky fiber, finer than cotton but not as adaptable to spinning; hence, it is not used in woven cloth. Mattresses and pillows are filled with kapok. Kapok dries quickly and is serviceable for life preservers because it is buoyant and light in weight. After a season's use the kapok filling can become heavy and nonbuoyant.
Coir
This is a hard, reddish-brown fiber obtained from the outer shell of the coconut. Coir is prepared by hand or by machines with fluted iron rollers that crush the husks. Broken fibers are dried in the sun, then cleaned, and are used for mattresses. The finer grades of mattress fiber can be made into rope and cocoa matting. The stronger, coarser fibers are made into hanks and sold for brushes, primarily to the European market. From strips of leaves of the coconut palm, a thread can be made that is elastic, lightweight, and waterproof. It is used in mats, bags, hats, and slippers.
The Bast Fibers
Flax
Flax (Linum usitatissimum) is an annual, herbaceous plant grown in temperate and subtropical areas. After flowering, the bolls or capsules contain up to ten seeds. The fibers occur in the bark of the stem and it is the long stemmed varieties that are used for linen. Bast stems contain bundles of fibers that act as hawsers in the fibrous layers lying beneath the bark of dicotyledenous plants. (A dicotyledon is a plant having two seed leaves.) They help hold the plant erect. The Soviet Union was the largest producer before the collapse of communism but is no longer. Some satellite countries of the former USSR, such as Slovakia, produced large quantities of flax and linen yarns, some of which were directed to the manufacture of tarpaulins and other industrial uses.
Jute
Jute fibers are obtained from two species of Corchorus, namely C capsularis and C. olitorius. There are also a number of jute substitutes such as Bimli (from Hibiscus cannabinus) and China jute (from Abutilon theophrasti). Jute fabrics formed the sackcloth of Biblical times and are now used for wrappings, bindings, etc.
Hemp
The botanical name for hemp is Cannabis sativa. Sisal and manila hemps are hemp substitutes. Cultivation is not unlike that of other bast fibers and, again, the time for harvesting has to be judged carefully. The fibers are soft and fine if they are harvested as the pollen begins to shed, but they are weaker than those obtained from later harvesting. Hemp made its mark because of the strength of the fiber. The cells vary from about 0.5 to 1 inch long, and, like flax, they are thick-walled tubes, although the lumen has blunt ends. The fibers may be up to 6 ft long and are roughly cylindrical with cracks, swellings, and other irregularities.
Ramie
Ramie comes from plants with the botanical name Boehmeria niva or B. tenacissema. Fibers are removed by decortication, which is a process whereby the fibers are removed from soaked stalks by scraping or beating. Gums are then removed by soaking in caustic soda followed by neutralization in an acid bath. The fiber is then washed and oiled. The thick- walled cells often reach 18 inches long. Normally the fiber is rather stiff but mercerized ramie has some qualities that allow it to approach the performance of cotton. »»Ramie photo
The Leaves Fibers
Sisal
Sisal, from the leaves of a tropical plant, is often called sisal hemp. This is a hard fiber larger and stiffer than the bast fibers, flax, hemp, jute, and ramie. Sisal grows on large planatations in Java, Haiti, Kenya in East Africa, West Africa, and Central America. Principal uses are for cordage, ropes, and binder twine.
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Cellulose fibers are fibers made with ether or esters of cellulose, which can be obtained from the bark, wood or leaves of plants, or from a plant-based material. Besides cellulose, these fibers are compound of hemicellulose and lignin, and different percentages of these components are responsible for different mechanical properties observed.
The main applications of cellulose fibers are in textile industry, as chemical filter, and fiber-reinforcement composite, due to their similar properties to engineered fibers, being another option for biocomposites and polymer composites. Cellulose fibers market has been witnessing strong growth over the past few years on account of increasing demand from textile industry.
Natural cellulose fibers are fibers that are still recognizable as being from a part of the original plant because they are only processed as much as needed to clean the fibers for use. For example, cotton fibers look like the soft fluffy cotton balls that they come from. Linen fibers look like the strong fibrous strands of the flax plant. All "natural" fibers go through a process where they are separated from the parts of the plant that are not used for the end product, usually through harvesting, separating from chaff, scouring, etc. The presence of linear chains of thousands of glucose units linked together allows a great deal of hydrogen bonding between OH groups on adjacent chains, causing them to pack closely into cellulose fibers. As a result, cellulose exhibits little interaction with water or any other solvent. Cotton and wood, for example, are completely insoluble in water and have considerable mechanical strength. Since cellulose does not have a helical structure like amylose, it does not bind to iodine to form a colored product.
Manufactured cellulose fibers come from plants that are processed into a pulp and then extruded in the same ways that synthetic fibers like polyester or nylon are made. Rayon or viscose is one of the most common "manufactured" cellulose fibers, and it can be made from wood pulp.
Natural fibers are compose by microfibrils of cellulose in a matrix of hemicellulose and lignin. This type of structure, and the chemical composition of them is responsible for the mechanical properties that can be observed. Because the natural fibers make hydrogen bonds between the long chains, they have the necessary stiffness and strength.
Which alternative fabrics are eco-friendly
Bamboo, once the darling of eco-designers who prized its silky hand feel and drape, has largely been discredited as an alternative source. While bamboo is among the fastest-growing plants on the planet and grows without irrigation, processing its fiber into textiles requires heavy-duty chemical solvents such as sodium hydroxide and carbon disulfide that can harm human health and the environment. The use of bamboo has dropped dramatically.
Lyocell, more commonly known by its brand name Tencel, is soft and absorbent, strong, takes dyes nicely, drapes well, and is resistant to wrinkles and shrinkage. The process for manufacturing Lyocell requires very little water and produces little air pollution, which makes it more environmentally friendly than other cellulosics. It can also be given a variety of textures during the manufacturing process to make it resemble suede, leather, and even silk.
What are plant-based fibers?
Unlike keratin fibers which are made from animal products (usually wool), plant based fibers are just that – a vegan friendly, all natural alternative. Plant based hair fibers are made from cotton and they offer some specific benefits, including:
They are hypoallergenic and will not cause adverse reactions with your skin and scalp. Based on the scientific law of attraction, they form a stronger bond with your existing hair than keratin fibers. They stay in place, even with wind, rain and sweat. They look natural and give you fullness and coverage.
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