Home | Flax (Linen) - Plant Fibers : History, Growth, Production, Preparation of fiber, Properties

Chapter: 11th 12th std standard Political Science History goverment rule laws life Higher secondary school College Notes

Flax (Linen) - Plant Fibers : History, Growth, Production, Preparation of fiber, Properties

Flax (Linen) - Plant Fibers : History, Growth, Production, Preparation of fiber, Properties
Principal Origin : Natural Chemical Type : Cellulosic Generic Name : Bast fiber Common Name : Flax.

The source of Natural fibers are from plants, animals and mineral. Since these are available naturally, it is called as natural fibers.

Plant Fibers

Plant fibers are composed of cellulose and therefore are classified as natural cellulosic fibers. The important raw material to produce fabrics are fibers especially cotton and silk.


Flax (Linen):

 

The word flax is derived from Old English 'flax'. Linen is the term applied to the yarn spun from flax fibres and to the cloth or fabric woven from this yarn, flax fibers are held together under the stem's bark principally by a gummy substance (pectin) from the body of flax plant. It is composed basically of substance cellulose. It is a natural, cellulosic, bast, multicellular fiber.


Principal Origin : Natural

Chemical Type  : Cellulosic

Generic Name : Bast fiber

Common Name : Flax.


a. History:

Linen has been known in civilised societies for thousands of years. Flax was already being cultivated systematically by ancient Egyptians, Babylonians and other civilisation. The rich people of Greece used only linen material. The priests used linen material for their dress while performing holy and custom deeds.

Linen was specially popular in middle ages. A common fabric of that period was a combination of linen and wool, called 'linsey-woolsey'.

In India from the time of Buddha Linen material was considered to be expensive. Before 2500 BC, the carving in the graveyard, show the preparation of Linen fibre from the flax plant was pictographically depicted and it was found in the year 1887 by archeological expects.

 

Fine quality linens still retain the reputation of luxuriousness and expensiveness. Manufacture of fiber into fabric requires unusual care throughout each process to retain the strength and beauty of the fiber.

 

b. Growth and Production:

1. Cultivation:

 

The flax plant requires deep, rich, well plowed soil and a cool, damp climate. Prematurely warm weather affects the growth and the quality of the fiber. As soil in which flax is grown must be enriched for six years before it will yield a good harvest, only one crop in seven years can be raised on specified portion of land. The flax seeds are sown by hand in April or May. In three months the plants become straight, slender stalks from 2 to 4 feet in height, with tapering leaves with small blue, purple or white flowers. The plant with the blue flower yields the fine fiber. The others produce coarse but strong fiber. After flowering mature plant develops seed capsules in the size of peas. The seeds are about 2 mm long and are very rich in oil.

 

2. Harvesting:

 

By the end of August, the flax turns a brownish color, which indicates that the plant is about to mature, it is ready for harvesting. There must be no delay at this stage; otherwise the fiber will lose its prized luster and soft texture. The plants are pulled out of the ground either by hand or efficiently by machine. If the stalk is cut, the sap is lost; this loss affects the quality of the fiber, the stalk must be kept intact and the tapered ends of the fiber must be preserved so that a smooth yarn may be spun. The stalks are tied in bundles, called beets in preparation for extraction of the fiber.

 

3. Preparation of fiber:

 

(a) Rippling:

 

The seeds and the leaves are removed from the stems of the flax plant by passing the stalk through coarse combs. This process is called 'Rippling'.

 

(b) Retting:

 

The bundles of plants are then steeped in water so that the tissue or woody bark surrounding the hairlike flax fiber will decompose, thus loosening the gum that binds the fiber to the stem. The decomposition is called retting.

 

Retting only loosens the woody bark. If flax is not retted enough, the removal of the stalk without injury to the delicate fiber is difficult. If flax is over-retted the fiber is weakened. The retting operation, as well as other processes for producing linen fabric, therefore, requires great care. Retting can be done via different methods.

1. Dew retting:

 

The flax straw is spread on the grass and is exposed to the atmosphere for 3 to 4 weeks. This method produces strong dark flax gray in color.

 

2. Pool or damp retting:

 

It takes less time than dew retting (10-15 days). As stagnant pools of water are used this method sometimes causes over-retting, which is responsible for brittle and weak flax fibers. Pool retting darkens the flax giving it a bluish grey colour.

 

3. Stream retting:

 

This method for producing high quality flax fiber was used before but now is outmoded.

 

4. Tank or VAT retting:

 

The flax is immersed in wooden vats of warm water at temperature. Ranging from

 

25-30 o c which hastens the decomposition of the woody bark. The flax is removed from the vats and passed between rollers to crush the decomposed bark as clean water flushes away the pectin or gum and other impurities. Linen produced by this method is more susceptible to mildew.

 

5. Chemical retting:

 

Chemical retting can shorten the retting process but chemicals will affect the strength and color of the flax fiber. Soda ash, oxalic acid are the chemicals used.

 

(c) Drying:

 

These fibers (flax stalks) are then dried by means of warm air ovens.

 

(d) Breaking:

 

The stalk becomes partially separated from the fiber when the wet plants are placed in the fields to dry. When the decomposed woody tissue is dry, it is crushed by being passed through fluted iron rollers. This breaking operation reduces the stalk to small pieces of bark called sheaves.

 

(e) Scutching:

 

The removal of woody parts from fibers is scutching. The scutching machine removes the broken sheaves by means of rotating wooden paddles, thus finally releasing the flax fiber from the stalk.

 

(f) Hackling (combing):

 

The simple combing process known as hackling straightens the flax fibers, separates tows from lines and arrange lines in parallel form.


(g) Processing:

 

The line tow is spun into yarns using the linen process.


c. Properties of Linen:

Shape : Width varies. Diameter is varies from a few inches to 22 inches or more; average length after processing is 10 to 15 inches

Luster : Medium to high

Elastic Recovery : Low elongation

Resiliency : Poor

Density : 1.5

Moisture absorption : Good

Dimensional Stability : Good

Acids : Good to cool, dilute. acids; low or poor to hot dilute. Poor to concentrated either hot or cold

Alkalies : High resistance.

Sunlight : Good

Insects : Good

To Flame : Burns readily


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11th 12th std standard Political Science History goverment rule laws life Higher secondary school College Notes : Flax (Linen) - Plant Fibers : History, Growth, Production, Preparation of fiber, Properties |


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