TEXTILE SCIENCE
| Site: | Wambua e-learning site |
| Course: | Wambua e-learning site |
| Book: | TEXTILE SCIENCE |
| Printed by: | |
| Date: | Thursday, 21 November 2024, 4:42 PM |
1. introduction to textiles
INTRODUCTION:
The learner should demonstrate an understanding of textile fiber production processes, fiber identification, yarn formation, fabric formation, fabric processing, batik and tie and dye processes. The learner is also expected to acquire theoretical and practical skills necessary to work in the textile processing industry as textile quality controllers, textile supervisors and designers.
GENERAL OBJECTIVES
By the end of the course unit the learner should be able to:
1) Acquire general knowledge of textile fibers and fabrics
2) Understand the production process of natural fibers and fabrics
3) Understand the properties of natural fibers and the finishes applied to them
4) Acquire general knowledge of yarn formation and the weaving process
INTRODUCTION TO TEXTILES
Food, shelter, and clothing are the basic necessities for the survival of human civilization. Textiles play important role in making of clothing and making the shelters more comfortable and attractive. They are also used in the production or processing of many items used in day-to-day living, such as food and manufactured goods. An ideal starting place to gain an understanding for textiles is given by definitions of several basic terms.
1. Fiber
- A unit of matter characterized by flexibility, fineness and a high length to width ratio.
- It is defined as thin, fine and hair like substance, natural or manufactured, with a high length to width ratio and with appropriate properties for being processed into a fabric.
2. Yarn
- An assemblage of fibers twisted or laid together so as to form a continuous strand that can be made into textile fabrics.
- It is defined as a linear form of fibers, twisted as a continuous strand that can be made into a fabric.
3. Fabric
- A piece of material that have been twisted together to form strands that are suitable for garment construction.
- A fabric is produced from a yarn by performing mechanical operations as interlacing or interloping or intermeshing process. At this stage the fabric is referred as a grey cloth.
4. Dying
- It is a coloration of textile substrates for the purpose of improving the aesthetic features. It is a chemical process of applying color to textile substrates like fiber, yarn, fabric or garment by using natural or synthetic dyes.
5. Printing
- It is a chemical process of applying design to the fabrics for further enhancement of aesthetic features by using various techniques.
6. Filament
- A fiber of indefinite length
7. Staple fibers
- Short fibers or fibers of discrete length
8. Filament fibers
- long fibers or fibers of indefinite length
Importance of studying textiles to a fashion Designer
· Acts as a professional career
· Helps designers to make a sensible choice of choosing fabrics that complement their design
· Enables designers to make different type of fabrics under fabric construction methods
· Designers acquire knowledge on how to care for different textile products
· Designers are able to improve the aesthetic value of different fabrics
Classification of textile fibers
Textile fibers are classified into two main classes
i. Natural fibers
ii. Manmade fibers
NATURAL FIBERS
They occur naturally and are extracted from natural resources/raw materials. They are further grouped into three classes;
i. Vegetable/plant / cellulosic
Plant fibers are composed of cellulose i.e. the structural material that gives strength to plants and therefore are classified as natural cellulosic fibers. Vegetable fibers are obtained from the following
a. Leaves – sisal, manila, abaca
b. Seeds – cotton, kapok
c. Stem bast – flax, hemp, jute
d. Fruits – coir
e. Husk – coconut
The strands of cellulose fibers in the plants are associated with other natural materials such as lignin, wax, gum and pectin.
The cellulose fibers therefore have to be separated from other materials for it to be useful raw materials for textiles.
ii. Animal / protein fibers
Natural protein fibers are obtained from animal sources like hair and other secretion. Fibers include
a. Covering from such animals as sheep, mohair goat, Cashmere goat, horse, rabbit and camel.
b. Secretions are obtained from the larva, or worm stage, of the silkworm, which spins the cocoon from which silk fibers are obtained and from the spider which spins fine fibers in making its web.
There are some properties of hair fibers and secretions which are quite similar and on the other hand there are properties which are totally different.
There are two types of animal fibers
a. Filament length – a continuous length from silk worm
b. Stable length – short length e.g. Wool & hair obtained from the process of sheering
iii. Mineral fibers
Fibers obtained from minerals e.g. Asbestos, they are of little significance but are used in specialized materials e.g. fine resistance fabrics.
MAN-MADE FIBERS / MACHINE MADE FIBERS
This are fibers that are made by chemical reactions. Classified into two groups;
i. Synthetic
These are textile fibers that are wholly produced from chemical substances. Synthesis (to build up). They are made by combining a chain of smaller molecule to five a larger molecule.
The large molecule is known as polymer and the process is known as polymerization e.g.
AIR + WATER + COAL + PETROLEUM = POLYMER
Example of synthetic fibers; polyester, nylon, acrylic, mod acrylic
ii. Regenerated fibers
This are reborn fibers gotten from natural materials, treated with chemicals to give filament fibers e.g. cotton linters & wood pulp treated with chemicals.
Examples of regenerated fibers.
a. Viscos rayon
b. Acetate rayon
c. Tri-acetate
1.1. properties of fibres
GENERAL PROPERTIES OF FIBERS
i. Tenacity
They must possess sufficient strength to be worked on and processed by machine.
ii. Abrasion resistance
Ability of a fiber to withstand the rubbing in everyday use
iii. Flexibility /Pliability
ü Ability of the fibers to bend without breaking.
ü Fibers must be pliable in order to form yarns, fabrics that can be creased and have quality of draperbility and ability to move with the body.
iv. Elastic recovery
Ability of fibers to recover from strain, coming back to its original shape i.e. Ability of the fiber to return to original length after tension that produced elongation and after the fiber has been released.
v. Elongation
The ability to be stretched or lengthened.
Benefits of stretch in fabric during wear
- Comfort
- Greater freedom of motion
- Ductility i.e. material can change shape without breaking
- Durability
- Stretch fabrics give best fit
vi. Stiffness / rigidity
Opposite of flexibility is the resistance to bending or creasing.
vii. Cohesiveness/Spinning quality
Ability of the fiber to stick together in the yarn manufacturing processes
viii. Uniformity
The fibers must be similar in length and width in the spinning quality and flexibility
ix. Lustre
Refer to the gloss / shine, that fiber possess
Determines the fiber’s brightness/dullness
x. Color
ü Natural color of fibers varies from pure white to grey and black
ü Natural fibers exhibit the greatest color differences
ü Man-made fibers are usually white or off- white as they are manufactured
xi. Moisture regain and absorption
This is the ability of a fiber to take in moisture from air given the standard condition or temperature and moisture. Sometimes called hydrophilic or hygroscopic.
ü Fibers have a certain amount of water as an integral part of their structure
ü Fibers with good moisture regain will accept dyes and finishes more readily than those with low moisture regain
xii. Dye ability
Ability of fibers to readily accept dyes.
xiii. Resiliency
Ability of a fiber to return to shape following compression, bending or similar deformation
xiv. Flammability and thermal reactions
The burning characteristics of fibers are important in determining care and use of textile products.
xv. Thermo-plasticity
Ability of fibers to soften and be molded under application of heat.
xvi. Versatility
Ability of a fiber to produce a wide range of products.