Dr. BMN College _Manufacture of Viscose rayon

31
PRESENTED BY : SHAIMA SHAIKH - 23 SHAIKH TAYABA - 24 SHAHEEN SIDDIQUE - 25 SUMAN SINGH - 26 ROSHNI VISHWAKARMA - 28 S.Y.B.SC (TEXTILE SCIENCE AND APPAREL DESIGN) 2016-17 VISCOSE RAYON

Transcript of Dr. BMN College _Manufacture of Viscose rayon

Page 1: Dr. BMN College _Manufacture of Viscose rayon

PRESENTED BY : 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 X T 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

Page 2: Dr. BMN College _Manufacture of Viscose rayon

CONTENTS

IntroductionHistoryManufacturing ProcessFlowchartPropertiesUses

Page 3: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 4: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 5: Dr. BMN College _Manufacture of Viscose rayon
Page 6: Dr. BMN College _Manufacture of Viscose rayon
Page 7: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 8: Dr. BMN College _Manufacture of Viscose rayon

MANUFACTURING PROCESS

Preparation of raw materialConditioning of wood pulpSteeping and pressingShredding/cutting processAgeingChurning

Page 9: Dr. BMN College _Manufacture of Viscose rayon

MANUFACTURING PROCESS(conti…)

Mixing and dissolvingRipeningFiltering and vacuum treatingSpinningStretching/drawing

Page 10: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 11: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 12: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 13: Dr. BMN College _Manufacture of Viscose rayon

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

Page 14: Dr. BMN College _Manufacture of Viscose rayon

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

Page 15: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 16: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 17: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 18: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 19: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 20: Dr. BMN College _Manufacture of Viscose rayon

MANUFACTURING PROCESS

9.FILTERING AND VACUUM TREATING: The solutions is filtered and vacuum treated

to remove air bubbles, As they cause filament breakage.

Page 21: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 22: Dr. BMN College _Manufacture of Viscose rayon

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

Page 23: Dr. BMN College _Manufacture of Viscose rayon

FLOWCHART

Page 24: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 25: Dr. BMN College _Manufacture of Viscose rayon

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 300F and looses strength .Above 350F it start decomposing.

Page 26: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 27: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 28: Dr. BMN College _Manufacture of Viscose rayon

USES

Apparels

Page 29: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 30: Dr. BMN College _Manufacture of Viscose rayon

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.

Page 31: Dr. BMN College _Manufacture of Viscose rayon