This ppt is made by S.Y.T.S.A.D. students for their class presentation in the subject of Textile Science.

1. P R E S E N T E D B Y : S H A I M A S H A I K H - 2 3
S H A I K H TAYA B A - 2 4
S H A H E E N S I D D I Q U E - 2 5
S U M A N S I N G H - 2 6
R O S H N I V I S H WA K A R M A - 2 8
S . Y. B . S C ( T E XT I L E S C I E N C E A N D A P PA R E L D E S I G N )
2016-17
VISCOSE RAYON

2. CONTENTS
 Introduction
 History
 Manufacturing Process
 Flowchart
 Properties
 Uses

3. INTRODUCTION
 By TFPIA, viscose rayon is a manufactured fiber, composed of
regenerated cellulose in which the substituent have replaced not
more than 15% of the hydrogen from the hydroxyl group.
 Viscose is both a semi-synthetic fiber, formerly called viscose
rayon, or rayon and a solution of cellulose xanthate.
 Viscose rayon fiber is a soft fiber commonly used in dresses,
linings, shirts, shorts, coats, jackets, and other outerwear. It is also
used in industrial yarns (tire cord), upholstery and carpets, and in
the casting of Cellophane.

4.  The latter is produced by treating dissolving pulp with aqueous
sodium hydroxide and carbon disulfide which is used to spin the
viscose rayon fiber.
 Byproducts of the
production process
include sodium
thiocarbonate, sodium
carbonate, and sodium
sulfide.

7. HISTORY
 French scientist and industrialist HD Chardon net (1838–1924)
who invented the first artificial textile fiber, artificial silk-created
viscose. British scientists CF Cross and EJ Bevan took out British
patent no. 8,700, "Improvements in Dissolving Cellulose and
Allied Compounds" in May, 1892.
 In 1893 they formed the
Viscose Syndicate to grant
licenses, and in 1896 formed
the British Viscoid Co. Ltd. to
exploit the process.

8. MANUFACTURING PROCESS
Preparation of raw material
Conditioning of wood pulp
Steeping and pressing
Shredding/cutting process
Ageing
Churning

9. MANUFACTURING PROCESS(conti…)
Mixing and dissolving
Ripening
Filtering and vacuum treating
Spinning
Stretching/drawing

10. MANUFACTURING PROCESS
1. PREPARATION OF RAW MATERIAL
 Raw material for viscose rayon are cotton linter or wood
pulp derived from linter to spruce,encalyptus tree and
transported to factories, cut into small chips and cooked
with calcium bisulphate and alkali under steam and
pressure for 14 hours.
 Lignin and non-cellulosic is dissolved and converted to
cellulose sulphate waste liquor.

11. MANUFACTURING PROCESS
 On addition of water to the cellulose pulp,cellulose
floats and is squeezed and bleached with NaOCI.
 It is finally converted to paper board which are then
purchased by viscose rayon manufacturer.

12. MANUFACTURING PROCESS
2. CONDITIONING OF WOOL PULP:
 It is done by storing the sheet under controlled
condition of humidity and temperature to acquires
a pre-determined moisture content.

13. MANUFACTURING PROCESS
3. STEEPING AND PRESSING:
• The sheet of cellulose contain about 90-94% of
cellulose.
• They are steeped in 17.5% caustic soda until the
cellulose is converted to soda cellulose.
• The cellulose become brown in colour.
• The alkali is then pressed out by hydraulic ran.
The pressure leave a moist mass of soda cellulose
which is 5-6 time heavier then its original weight

14. MANUFACTURING PROCESS
4. STRESSING/CUTTINGS PROCESS:
 This soda cellulose is passed between a shredding wheel
to make it into small fluffy masses of alkali cellulose.
 This take about 2-3 hours to make crumbs of about
100kgs

15. MANUFACTURING PROCESS
5 AGEING:
 It is the storage of alkali cellulose crumbs in
galvanized steel drums for about 48hrs at 23°C. This
helps to improve the spinning quality of the solution.
 The degree of polymerization decreases from 1000
to 300 by O2 present in air.

16. MANUFACTURING PROCESS
6. CHURNING(Xanthation or sulphidizing
process):
• The soda cellulose crumbs are moved into rotating air-
right hexagonal churness and10% of their weight, CS2
is added.
• They are mixed for about 3 hrs very gradually.
• The soda cellulose gets converted to sodium cellulose
xanthate.

17. MANUFACTURING PROCESS
• The colour change from white to light yellow to deep
yellow and finally to Reddish orange.
• Lump formation should be avoided as they are difficult
to dissolve in subsequent and at the end CS2 vapours
process should be removed by applying vacuum.

18. MANUFACTURING PROCESS
7 MIXING AND DISSOLVING:
 Sodium cellulose xanthate balls are mixed with dilute
NaOH for 4-5hrs in a resolver.
 Dissolution takes place and clear brown thick viscose
solution is formed(like honey).
 The solutions from different batches are mixed together
to get uniform viscosity and kept for ripening.

19. MANUFACTURING PROCESS
8. RIPENING:
 The solution is stored for 2-5 days at 10-18°C.
 The viscosity first decreases and then rises to the
original viscosity.
 The solutions become more spinable of delusion have to
be added TiO2 is added at this stage.

20. MANUFACTURING PROCESS
9.FILTERING AND VACUUM TREATING:
 The solutions is filtered and vacuum treated to
remove air bubbles, As they cause filament breakage.

21. MANUFACTURING PROCESS
10. SPINNING:
 The solution is forced through the holes of spinneret with
the help of a pump into an acid bath containing 10%
H2SO4 for conversion of xanthate to cellulose; 18% of
sodium sulphate for precipitation or coagulation of the
sodium cellulose xanthate; 2% glucose which makes the
fiber safer and more pliable; 1% zinc which gives added
strenght;69%H2O.
 The temperature of the bath is at 40- 45°C.
 Viscose Rayon is spun in the wet spinning method.

22. MANUFACTURING PROCESS
 STRETCHING / DRAWING:
 After spinning 30% stretch is given to the filament with
the help of rollers.
 Finally it is washed desulphurised in sodium sulphide,
bleached and washed.
 Cellulose + Caustic soda Soda Cellulose + Water
(C6H10O5)n NaOH (C6H9O5Na)n H2O
 Soda Cellulose Carbondisulphide Sodium Cellulose Xanthate
(C6H9O5Na)n CS2 C6H9O4OCS2Na

23. FLOWCHART

24. PROPERTIES
 Strength: It is about half strong than silk. It is weaker than cotton
and linen but stronger than wool. When rayon is wet it loses 40%
to 70% of its strength. It completely regains its strength when it is
dry.
 Microscopic View: It has a uniform diameter with striations.
Cross- Section the shape is variable, usually it has serrated edges
and sometimes smooth round.
 Luster: Can be controlled from bright to semi-dull depending
upon the delusturing agent added to the solution.

25.  Resilience: It does not have natural resilience like wool or silk
therefore wrinkles easily.
 Drapability : It is a heavy weight fiber it has good drape.
 Absorbency: It has good moisture absorbency. It is more than
cotton and linen, but less than wool and silk. Thus it takes up
dye easily and contributes to comfort in apparel.
 Thermal properties: It is a pure cellulose fiber it behaves
similarly to cotton. It burns at 300F and looses strength .Above
350F it start decomposing.

26.  Effect of light: Good resistance to sunlight but prolonged
exposure results in faster deterioration and yellowing.
 Heat and electrical conductivity: It is a good conductor of heat;
electrical conductivity is enough to prevent static charge buildup.
 Resistance to acid and alkali: Similar to cotton, strong alkali
cause swelling and loss in strength. Dilute alkalis do not harm it.
Not diluted and cold concentrated acid disintegrate the fiber. It
has some resistance to dilute and cold acids. Other organic
solvents stain removing agents and other organic compounds do
not affect viscose rayon.

27.  Biological properties: They are resistance to moth, but they attract
fungus/ mildew like cotton if stored in damp condition for a long-
time.
 Resistance to perspiration: Not affected by perspiration however
colour may fade.
 Elasticity: It has greater elasticity than cotton and linen but lesser
than wool and silk.

28. USES
 Apparels

29.  Home furnishings like blankets, sheets and curtains all be made
from rayon.
 The fabrics is used to create clothing such as blouses, jackets,
sportswear, and dresses.

30.  Industrial application includes medical surgical products.
 Some rayon fabrics are for filling in zippo lighters, furnishing
including bedspreads, bed sheets, blankets, window covers and
slipcover.