Man-Made

Textile Man Made Fiber’s Physical Forms & Advantages

Physical Forms of Man Made Fibers (MMF):

Man Made Fibers is produced in three forms. These are 1. Filaments 2. Staple 3. Filament Tow.

• Filament 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:

1. 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.
2. Crease Resistance: Crease resistance is good.
3. Dimensionally stable: Natural fiber is not stable like the man made fiber. So commercially, the demand of man made fiber is huge.
4. Higher Strength: This fiber is more stable and strengthy than the natural fiber.
5. Better Elongation Properties.
6. Can be made according to expectation.
7. More regular properties.
8. Lower cost. As the entire chemical and raw available all time in any season; the ultimate cost of mmf is less.
9. Production does not depend on the climate. You can produce mmf in any season.
10. The raw materials that are used to produce man made fibers are specific.

How To Spin Man Made Fiber?

The man made fibers spinning are accomplished from polymer solutions basically by the following three methods. Which are:-
1. Dry spinning
2. Wet spinning
3. Melt Spinning
A brief description about the above mentioned three spinning methods for man made fibre spinning are discussed below:

Dry Spinning:

One of the three spinning methods for spinning man made fibre is dry spinning method. Fibres produced by this techniques are acetate rayon, acrylic fibres etc. In this technique fibre forming materials are dissolved in volatile solvent. Each spinning unit consists of a pump and spinneret at the top pf a tall shaft about 9 to 15 feet high. There is an air outlet at the top of the tall shift and air in let at the bottom. The fibre spinning solution is forced under pressure from the storage tank to the spinning pump and then through the spinneret.
The number of holes, dia of holes and shape of holes varies according to requirements of a spinneret. The fineness of the filament is determined partly by the diameter of the holes but primarily by the relation between the rate at which solution is forced through the spinneret and rate at which the yarn is wind up. When the fibre spinning solution emerging from spinneret meet the worm air, volatile solvent evaporates leaving the filaments, hence coagulation takes place and becomes dried before leaving the chamber.

Wet Spinning:

In this method the common man made fibres spun are viscose rayon, alginate, acrylic fibres etc. the fibre forming polymer solution first de aerated and then pumped under pressure through metering pump unit, them through the filter and finally through the spinneret. The spinnerets are immersed in a spin bath containing coagulating fluid at a reasonable temperature, as the polymer solution emerges from the spinneret and travel through the bath it becomes coagulated by the chemicals of the spin bath.
Dia of holes, rate of solution feeding and rate of holes per spinneret may be 100000 numbers per squa4e inch diameter and space of holes in the spinneret could be varied.

Melt- Spinning:

In this technique, the common man made fibres spun are Nylon, polypropylene etc. the fibre forming polymer chips are fed through a hopper into a spinning vessel. In spinning vessel, melts by the heated grid and passes through the grid mesh and collected on the pool. The n the melt is metered by a pump through a filter and finallyu through the spinneret.
The melt solidifies immediately it issues from the jets and so form filaments passes through a cooling chamber in which cold air current swept across the filaments. The spinning speed is approximately 1200 meters per minute.
Melt spinning has two big advantages over dry spinning. It avoids the need for a solvent recovery plant and loss of solvent during recover. The high fibre spinning speeds that are possible here.