Home
About Us
Courses
Admission
Syllabus
Photo Gallery
Apply Now
Contact Us

Wool and Rayon

wool

Wool

Different kinds of animals have been used for textile fibres. Wool is a hair fibre made up of fibrous protein called 'Keratin' and comes from fleece of sheep and also some other animals such as Angora, Cashmore, Camel, Alpaca.
Wool Processing
Shearing
Sheeps are sheared to remove the fleece in the spring season. Expert shearers move from place to place removing fleece. A section is kept seperate for fleece from sides of the sheep. This is done because the fleece from undersection and legs tend to be inferior in quality to that of the sides because it contains more vegetable matters and is tangled with thorn. Fleece is sheared from sheep at 8 months of age or younger. Younger is called lamb's wool because it is the first growth of hair with tapered ends it tends to be softer and finer. Wool removed from animals that have been slotted for meat is reffered as pulled wool. Pulled wool is inferior in quality to fleece or clipped wool because it is less elastic.
Grading
Grading of wool is done at the time of shearing. In grading, the fleece is judged for its overall fibre fineness and length. An alternative to grading is found in sorting in which the fleece is divided into section of different quality. The best fibre comes from the sides and shoulders, the poorest from the lower legs.
Preparation of spinning
The first step taken to prepare the fleece for use is scouring, which removes oil, greece and other impurities from the fleece. The fleece is washed a number of times in a warm soapy solution, A fleece about 8 pounds will be reduced by scouring to about 3 to 4 pounds. Much of weight loss results from te removal of a natural oil covered by it. After that all the fibres are carded and then spinning is given.

Properties of Wool

1. Color
Wool fibres vary in nature. Color being white to cream to light yellow, brown and black. Wool may be dyed easily however it is difficult to keep it white. Bleaching is not given to wool because it is harmful for fibres or that itself may cause for yellowing.
2. Shape
The length of the fibre depends on the breed of the sheep from which it comes. The length ranges from 1 - 15 inches or more. The outer layer consists of small overlapping scales. The scales on the surface of fibre overlap like the tiles on a roof.
3. Lustre
The lustre of the wool is low because of the scaly rough surface. Lustre varies amoung different breeds of sheep, different section of fleece.
Environmental Properties
Fabric should be put away only after they are completely dry. One of the major problems in the case of wool is its possibility of damage from insects. Care in the storage of wool is required. Mildew wil not form on wool unless the fabric has been stored in a damped condition for an extended period of time.
Mohair
Mohair is a silky cloth made from the hair of Angora goats.

Rayon

rayon
Rayon is the first manmade fibre. It has been called "The laboratory's first gift to the loom". Rayon is considered to be one of the most versatile and economical manmade fibres available. It is a regenerated fibre derived from wood pulp, cotton linters or other vegetables matters. Because of its lustre and softhand feel, it resembles silk thus it is also known as artificial silk or art silk.
Manufacturing Process of Rayon
1. Cellulose
Production begans with processed wood pulp.
2. Steeping
The cellulose is dissolved in canstic soda (Sodium hydroxide - NaOH)
3. Pressing
The solution is then pressed between rollers to remove excess liquid.
4. Shredding
The pressed sheets are crumbled or shredded to produce what is known as white crumb.
5. Aging / Ageing
The white crumb is allowed to stand in contact with oxygen in the air.
6. Xanthation
The aged white crumb is mixed with carbon disuphide in a process known as Xanthation. The aged Alkali cellulose crumbs are placed in vats and are allowed to react with carbon disulphide under controlled temperature to from cellulose Xanthate. Xanthation changes the chemical makeup of the cellulose mixture and the resulting product is called yellow crumb.
7. Dissolving
The yellow crumb is dissolved in caustic solution to form viscose.
8. Ripening
The viscose is allowed to stand for a period of time to ripen.
9. Filtering
After ripening the viscose is filterd to remove any undissolved materials that might disrupt the spinning process or cause defects in the rayon filament.
10. Degrassing
Bubbles of air are removed from the viscose is a degrassing process.
11. Spinning
The viscose solution is extreded through a spinneret (It resembles a shower head with many holes). As the viscose exits the spinneret it lands in an acid bath (Sulfuric acid, sodium sulphate and zinc) resulting in formation of rayon filament.
12. Drawing
Rayon filaments are stretched known as drawing, to straighten the fibres.
13. Washing
The fibre are then washed to remove any chemicals(impurities).
14. Cutting
If filament fibres are desired the process ends here. The filaments are cut down when producing staples fibres.
washing rayon
Properties of Rayon
1. Color and Lustre
The rayon fibres are normally white in color. Their lustre can be modified by adding titanium dioxide delusterting agent to the solution before the fibres are extruded.
2. Shape
Manmade fibres can be manufactored in any length and diameters. In cross section the viscose rayon fibres appears as irregular circles with srerated (having a toothed edge) edges.
3. Strength
Strength of viscose rayon is low when compared with cotton or linen.
Rayon Fibre Characterstics

Most Viewed Articles, Check them out!
Getting started with Sewing Equipments
Getting started with Sewing Equipments
What is fashion?
What is fashion?
History of Fashion
History of Fashion
Ritu Beri, most popular Indian female designer
Ritu Beri, most popular Indian female designer
Admission Open
" I dont approach fashion, Fashion approaches me " ~ Daphne Guinness
The Institution
Home
About Us
Online Admission Form
Contact Us
FAQ
Admission
Related Links
Fashion Designing
Dress Designing
Courses
Career at WIFD
Articles / Blog
Sitemap
Reach Us
Waves Institute of Fashion Designing,
3rd Floor, Chavara Cultural Centre,
St. Thomas Church, Amalapuri,
Near 4th Gate, P T Usha Road,
Kozhikode (Calicut) - 673001, Kerala, India
info@wifd.in
+91 9747375599
© Waves Institute of Fashion Designing 2018. All Rights Reserved   |   Privacy policy   |   Terms and Conditions