Download - Viscose Rayon (Cotton Modification)
Viscose Rayon
Presented By: Kazi Sazed Salman
ID No: 111-23-130
Rayon:Rayon is a manufactured regenerated cellulose fiber.
Type of rayon differs in manufacturing process and properties of the finished product.
The types of rayon:
Viscose Modal Lyocell
Viscose RayonViscose is a solution of cellulose xanthenes made by treating a cellulose compound with Sodium hydroxide (NaOH) & Carbon disulfide (CS2). The viscose solution is used to spin the fiber viscose rayon. It is soft man-made fiber commonly used in dresses, shirts, shorts, coats, jackets and other outer wear. It is also used as industrial yarns like tire cord, upholstery and carpets.
Chemical reaction for Viscose Rayon production The cellulose is treated with 17.5% solution of NaOH which converts it into Soda-cellulose.
cell-OH + NaOH => cell-ONa + H2O Soda-cellulose reacts with CS2 to form Na-
cellulose Xanthate.
cell-ONa + CS2 => cell-O-CS-SNa Na-cellulose Xanthate remains desolved in
a dilute solution of cauctic soda. It is extruded into H2SO4 which regenerates the cellulose. Then it forms in the long fillaments (Viscose Rayon).
cell-O-CS-SNa + H2SO4 => cell-OH + Na2SO4
Steps of Viscose Rayon manufacturing processPulp PreparationStipping &
PressingShreddingAgeing
ChurningMixing(Solution)
RipeningSpinning
Purification
Physical Properties of Viscose RayonMoisture
Absorption13% Tensile
StrengthDry:
1.5-2.4 g/dWet:
0.7-1.2 g/dElasticity 2-3% Elongation at
Break15-30%
Density 1.5 g/cc Specific Gravity
1.5
Melting Temperature
176-240* C Abrasion Resistance
Low
Dimensional Stability
High Flammability Burns like cotton
CHEMICAL Properties of VISCOSE RAYON
Acid: Hot acids may cause damage but have resistance among cold weak acids.
Alkali: Concentrated Alkalis cause swelling & reduce strength.
Solvent: Resistant to organic solvents
Bleach: Attacks by strong oxidizing bleaches.
Biological agents: Attacks by moulds & mildew.
Light: UV light may reduce the strength.
Dye ability: Better affinity with vat, direct & sulphure dye.
Comparison of different fibers
Types of Viscose Rayon
Regular RayonHigh Wet ModulusHigh Tenacity RayonCupramonium
RayonTrade names of Viscose Rayon
Zantral (USA)Avril (USA)Fibro HSO (USA)Grasim (India)
Viscose Rayon made Yarns & Fabrics
Thank YouWish you have enjoyed the presentation.