BAST FIBERS

1. BAST FIBERS • Botanical name is “Dicotyle Denous”. • Bundles of strands that over lap each other. • Fibers made up of long thick cell walls which overlap one another , cemented by non cellulosic material to form continous strands.

2. QUEEN OF BAST FIBERS • It grows in hot as well as in cold areas. • Growth of flax is in the areas where rain fall is in greater amount. • Flax fibers come from the stem of an annual plant “LINUM USITATISSIMUM” which grows in sub-tropical regions. • Firstly it was known as Linen. With growth of cotton industry interest was lost for flax industry.

3. FLAX • Probably the 1st plant which was used by man. • In Egypt and Switzerland its cloth was prepared and dyed. • Now a days it is cultivated in Europe, England, France, Germany etc. • As a source of oil, the flax plant is grown in USA, Canada, Argentina but the output of fiber from these countries is relatively insignificant. • Soviet Russia grows fiber and oil. • 1,875,018 world production

4. PROCESSING • Natural, Cellulosic, Bast fiber is annual plant grown once in a year. • 3-4 months for harvesting. • 3-4 feet height of plant. • Plants are planted closely to avoid branches. • Flowers appear, mature plant is pulled out from the roots manually or mechanically. • After this flax is allowed to dried. • 1/3rd of stem consist of fibers.

5. RETTING • Decomposition of outer core • “ A fermentation process in which binding flax fibers are seperated from non-cellulosic gummy material”. • Dam Retting (10 days) • Dew Retting • Tank Retting • Chemical Retting

6. Processing • Breaking and Scutching: scutching rollers break & separate woody portion. • Hackling: straightening and cleaning fibers by comb. Coarse fibers removed. Long fibers LINE and short fibers TOW. • Carding: • Drawing: 4 to 8 slivers • Spinning: For coarse yarn dry spinning, Finer wet spinning. • Dyeing:

7. Fibre morphology Macro-structure • Flax is a thick, regular fibre with subdued luster. • Length is from 10 – 100 cm; average length is 50 cm • 3-6 cells constitute fibre cross-section. Fibre cells are about 25mm long and 10 µm thick. Average fibre thickness ranges from 40 µm – 80 µm. • Flax fibre length is of considerable significance. For longer flex it is about 15000:1 and for short fibres the length to breath ratio is 1500:1 or less. • The colour of flax changes from light blond to grey blond. • The subdued luster is due to its longer fibre surface which is coated with a film of wax.

8. Microscopic appearance • Cross marking know as nodes give them characteristic microscopic appearance. There may be 800 nodes in a single flex fibre.

9. Fiber Properties • Tanacity Flax is a strong fiber because its very crystalline polymer system forms more hydrogen bonding than cotton polymer. Its tenacity also increases in wet condition same as cotton. • Elastic nature The very inelastic nature is due to its crystalline polymer system. Being a stiff fiber it resists bending and flexing. The crispiness of its handle is due to its ability to absorb moisture rapidly. The wrinkling and creasing which in linen fabrics is due the stiffness of fibers; when fibers are bent, the hydrogen bonding between the polymer chains breaks and reformed at the new positions due to which fiber is unable to come back to its original position. • Hygroscopic nature like cotton it has a good moisture absorption capability

10. Fiber properties • Density Fiber density is 1.5 g/cm cube and is considered as heavy fiber. • Thermal properties flax has the best heat resistance and conductivity of the all common used textile fibers. • Moisture regain: It is 12%. • Elongation: dry state 1.8% and wet state 2.2% • Heat Action: It is good conductor of heat.

11. Chemical properties • Action of acids: 80%dissolved in H2SO4. strength reduces. • Effects of alkalies: • Effect of organic Solvents: • Insects: • Micro organisms:

12. USES • Sail and tent cloth • Shoe threads • Sweing thread • Book binder threads • Table cloth • Handkerchiefs • Waste flax