7/28/2019 Requirement for Fiber Forming Polymer

1/4

Requirement for fiber forming polymerThe requirement for the fiber forming polymer are as follows:-

1. Hydrophilic2. Chemical resistant3. Linear4. Long5. Capable of being oriented6. Able to form high melting point polymer system

The polymer system of the different fiber should have all the above

requirements. Acetates, acrylics, cotton, flax, nylon, polyester, silk, viscose and

wool consist of polymers which meet the above requirements in a large extent.

Natural cellulosic fibers such as abaca, coir, hemp, jute, kenaf, ramie and sisal

have very restricted apparel use because they are very stiff. On the other hand

man-made fibers such as chloro-fibers, polyethylene and polypropylene fibers do

not meet satisfactorily the fifth and sixth requirements listed above.

Hydrophilic propertiesFiber polymer should be hydrophilic. This means that the polymer should be

polar, enabling them to attract water molecules. A fiber is comfortable to wear if

its polymer system consists of hydrophilic polymers and the system itself permits

the entry of water molecules. The fibers whose polymers are not hydrophilic

mean hydrophobic and yet these fibers are used for apparel. For this purpose the

fibers are have to make more absorbent and more or less comfortable,

hydrophilic polymer fibers need to blend with the hydrophobic polymer fibers.Hydrophobic polymer fibers are often blended with cotton, viscose or wool (e.g.

two-third polyester and one third cotton blend. Such blending improves the

absorbency and comfort of the apparel.

7/28/2019 Requirement for Fiber Forming Polymer

2/4

A fiber consisting of hydrophilic polymers attracts water molecules which prevent

or enable the discharge of any static electricity accumulating. The static electricity

is discharged by the water molecules, because of their polarity to the surrounding

atmosphere. The generation of the static electricity on a fiber is undesirable

because it will cause the fiber to attract the dirt particles more readily and soil

more quickly. This causes the fiber to cling together and creates discomfort during

wear.

Chemical resistanceFiber polymer should be chemically resistant for a reasonable period of time

against the common degrading agents such as sunlight and weather, common

types of soiling, body exudations, laundry liquors and dry cleaning solvents.

Chemically resistant polymer should also not be toxic or hazardous to wear

against human skin.

Fiber polymer should be chemically resistant they should not be inert means

totally unreactive.

LinearityFiber polymer should be linear means it should not be branched. Only linear

polymers allow adequate polymer alignment to bring into effect there should be

sufficient inter polymer force of attraction to give a cohesive polymer system. In

made fiber manufacture it is important to have the right stereo-polymer for the

extrusion of useful filaments. They are of three types and are explained below:-

The atactic polymer -This is a stereo-irregular polymer. Its side group groups are

arranged at random above and below the plain of the polymer backbone.-

7/28/2019 Requirement for Fiber Forming Polymer

3/4

Atactic polymers are usually not found in the polymer systems of the fibres. This

gives insufficient cohesive polymer system and si indicated by the wax like

substance formed. Due to this it does not allows enough alingment or orientation

of plymers for the effective inter polymer force of attraction.

The syndyotatic polymer- this is a stereo regular polymer and its side groups are

arrranged in a regular manner above and below the polymer backbone.

These structure permits close enough alignment or the orientation of polymers to

form a effective inter-polymer force of attraction which gives a cohesive to

polymer system and are useful to form a fiber.

The isotactic polymer- it is also a stereo-regular and all its side groups are

arranged on the same side of the back bone.

These polymers orient themselves very closely and permits effective inter

polymer force of attraction and give better cohesive polymer system for useful

fiber.

LengthFiber polymers should be long. The length of the polymer should be more than

100 nanometers so that it can be easily oriented. This orientation give rise to

sufficiently effective inter polymer force of attraction to form a cohesive polymer

and used as fiber. The longer polymer gives more the cohesive and stronger the

fiber. For the maximum force of attraction the orientation should be well and

aligned closely.

7/28/2019 Requirement for Fiber Forming Polymer

4/4

Capable of being orientedThe polymer should be arranged well and orientation should be more or less

parallel to the longitudinal axis of the fiber. In natural fiber orientation occurs

during growth. While on the man-made fiber operation called DRAWING whichstretches the extruded and coagulated filaments and cause the polymers to orient

themselves longitudinally more or less parallel order. The orientation can depend

upon the amount of amorphous and crystalline region present on the fiber and

affect the properties.

Formation of high melting-point polymer systemsA fiber consisting of high melting point polymer system tends to have adequate

heat resistance to enable it to withstand the various heat treatments of textile

finishing, laundering and ironing. The fibers melting point should be above 225oC.

The longer polymer system and better the orientation gives more the cohesive

with a stronger melting point. Which means that more heat or kinetic energy is

required to break the inter polymer force of attraction and free the polymer from

each other. The ability of a fiber to conduct heat depends upon its degree of

polarity of its polymers. The inter polymer force of attraction can be broken at

one time under controlled temperature due to this they become more or lessfree to0 each other and assume a new position in the polymer system of the fiber.

When they are cooled the inter polymer force of attraction reform and the fiber

gets heat set. The lost their plasticity and become stiff and even brittle, after heat

set.