Man Made Fibers:

Filament fibers are spun from spinnerets with 3500 or less holes. The no. of holes in spinnerets equals to no. of filaments. There are two types of filaments- a) Mono-filament where the final filament is made of only a single filament. b) Multi-filament; where the final filament is made of more than one filament.

Staple Man Made Fibers:

Staple fibers are of limited and relatively short length. It is unit of material which is usually at least 100 times longer than thickness. Filaments are specifically made to get the staple form.

Filament Tow:

The product of 100 or more spinnerets is collected into a large rope of fibers, which is called filament tow. It is then crimped and made into staple by cutting or breaking.

Advantages of Man Made Fibers in Textile:

MMF is durable: Man made fiber is made by following a technical process and this is why this kind of textile fiber is comparatively durable.Crease Resistance: Crease resistance is good.Dimensionally stable: Natural fiber is not stable like the man made fiber. So commercially, the demand of man made fiber is huge.Higher Strength: This fiber is more stable and strengthy than the natural fiber.Better Elongation Properties.Can be made according to expectation.More regular properties.Lower cost. As the entire chemical and raw available all time in any season; the ultimate cost of mmf is less.Production does not depend on the climate. You can produce mmf in any season.The raw materials that are used to produce man made fibers are specific.

Polyester fibre

Polyester fibre is a widely used synthetic fibre. Basic raw materials for polyester fibre production are petroleum, coal, air & water. From those basic raw materials the Glycol monomer dihydric alcohol dn Terephthalic acid are produced. Which are polymerized into an autoclave at high temperature and polyester chips are produced, which are melt spun.

General Properties of Polyester Textile:

1. Length: Polyester fibre could be produced n filament form or staple form i.e. as we desire. Fibre length is controllable.

2. Fineness of polyester textile: Fineness of polyester fibre is also controllable.

3. X-Sectional shape: Normal cross sectional shape is round but it is also made triangular, elliptical or pentagonal. Normally it is white but could be of any color if color is added during spinning.

4. Strength: Normally tenacity varies from 4.5 to 5.0 gram per denier for the polyester textile. In case of high tenacity fibre it may be up t 8.0 gram per denier.

5. Extensibility: Extension at break varies from 20% to 30 %. Good recovery from extension. Due to good extension, strength and functional property polyester is widely used as sewing thread in the garment industries.

6. Resiliency: Polyester textile shows good resiliency property. It does not crease easily and any undue crease can be recovered easily.

7. Dimensional Stability: Polyester fibre is dimensionally stable. It could be heat-set at around 200 degree C. heat set pol7yester fibre does not shrink or extended.

8. Moisture Regain: Very low moisture ranges from 0 – 0.4%. Due to low moisture regain polyester fiber feels worm, easily cleaned, soils less.

9. Action of bleaching agents: It is not damaged by the action of bleaching agents.

10. Action of acid and alkali: It is unaffected by the action of acid and alkali.

11. Action of organic solvent: Polyester textile is unaffected by organic solvent, hence polyester fibre could be dry-cleaned.

12. Action of Sunlight & Heat: Polyester is unaffected by normal sunlight but prolong exposure to sunlight cab reduce strength of polyester. Polyester fibre melts at 227 degree C to 242 Degree C. hence during ironing care should be taken to reduce the risk of damage. In contact to flame the polyester burns and melt when cold, the molten polymer forms hard bids.

13. Dye ability: Polyester fibre shows good dye ability at high temperature. Color fastness to washing and sunlight is also good. Disperse dyes are widely used for dyeing polyester fibre.

14. Biological Properties: Resistance to attack of mildew, moths and insects are good.

15. End use of Polyester textiles: Polyester fibre is widely used for apparels both 100% form and blended form with cotton, nylon, wool, rayon, acetate, etc fibres. Polyester textiles also used for making thermal underwear.

Cotton Fiber

Textile Fiber in Textile Industry. Due to it’s versatile uses; people feel comfort to use Cotton fiber to make fabric. Here is the basic things about Cotton Fiber.

Cotton Fiber:

Cotton is a natural vegetable fibre produced in the cotton plant in many countries of the world even in Bangladesh also. Some important properties of cotton fibres are discussed very briefly below:

Properties of Cotton Fibres:

Length of cotton fiber:

Physically the individual cotton fibres consist of a single long tubular cell. Its length is about 1200-1500 times than its breadth. Length of cotton fibre varies from 16mm to 52 mm depending upon the type of cotton.
Indian cotton- 16-25 mm
American cotton- 20-30 mm
Sea Island- 38-52 mm
Egyptian cotton- 30-38 mm

Fineness of cotton fiber:
Longer the fibre, finer the fibre in case of cotton fibre. It is expressed in term of decitex and it varies from 1.1 to2.3 decitex.
Indian= 2.2-2.3dtex
American= 2.1-2.2 dtex
Egyptian= 1.2-1.8 dtex
Sea Island= 1.0-1.1 dtex
Fineness may be more in case of immature fibre. So it is necessary to express maturity with fineness.

Strength and extension of cotton fiber:
Cotton fibre is fairly among natural fibres in relation to tenacity which is 3-3.5g/dtex. Its tensile strength is between wool and silk fibre but disadvantage is low extension at break which is 5-7%.

Elastic properties of cotton:
Recovery from deformation of cotton fibre, yarn or fabric from applied load is very low. By applying heat it can’t be achieved. This property can be achieved by -1.Chemical treatment to improve crease recovery, but the problem is the materials become harsher due to chemical treatment 2. blending or mixing of cotton with elastic fibre, e.g. polyester, blend ratio depends on the end use of the fabric. The initial modulus is fairly high=0
5 g/dtex (wool=0.25 g/dtex)

Cross-section:
Cross-section of cotton fibre is some what ribbon like. The cell wall is rather thin and the lumen occupies about two-third of the entire breadth and shows up very prominent in polarized light. Fibre cross-section becomes round when mercerized.

Appearance:

Cotton fibre is fairly short, fine and creamy white color. Color of the fibre depends on soil of growth. By adding chemicals in the soil, color of the cotton fibre may be varied.

Crimp:

Cotton fibre is more or less twisted on its longitudinal axis which cab not be seen from out side is called convolution. The twist in the fibre does not to be continuous in one direction i.e. if at first right direction, then left direction. This property of cotton fibre helps in spinning.