RAYON PROCESSING

MANUFACTURING PROCESS OF RAYON PRESENTED BY FES 16TH BATCH, SUST. VISCOUSE RAYON PROCESS, CHARACTER OF RAYON. USE OF RAYON . THE FUTURE OF RAYON

1. WELCOME To the presentation

2. Presented By : 2013631032 2013631035 2013631037 2013631038 2013631039 2013631042 2013631043 2013631044 2013631045 2013631046 20136310

3. Rayon Manufacture & Uses

4. Introduction Definition : Rayon is a manufactured regenerated cellulose fiber. “Man made textile fibers and filament composed of regenerated cellulose” --------The US trade commission

5. History Oldest artificial fibers Pioneered by Robert Hooke Rayon, or viscose, was patented in 1884. commercial production of viscose rayon began in 1910 in the US.

6. Rayon Production Process

7. Viscose-rayon process Viscose is the most widely produced form of rayon Made from purified cellulose, primarily from wood pulp, which is chemically converted into a soluble compound. viscose process is a batch operation.

8. Raw materials Cellulose Wood pulp Cotton linters

9. Steps in viscose-Rayon process: 1.Steeping 2.Shredding 3.Aging 4.Xanthation 5.Dissolving 6.Filtration 7. Ripenning 8.Spinning 9.Washing 10.Bleaching Drying-coning-shipping VISCOUSE RAYON

10. Manufacture Steeping : Cellulose pulp is immersed in 17-30% aqueous sodium hydroxide ( NaOH ) at a temperature in the range of 18 to 35°C in order to swell the cellulose fibers and to convert cellulose to alkali cellulose. 2. Shredding: The pressed alkali cellulose is shredded mechanically to yield finely divided, fluffy particles called “crumbs”. This step provides increased surface area of the alkali cellulose, thereby increasing its ability to react in the steps that follow. 3. Ageing : The alkali cellulose is discharged in cans with loosely fitted cover and kept in a temperature controlled ageing room. 4. Xanthation: In this step the aged alkali cellulose is converted into cellulose xanthate by treating it with carbon disulphide for 2-3 hours in Churn at 20-35 C degree.

11. 5. Dissolving: The cellulose xanthate is dissolved in dilute caustic soda solution in a mixture tank forming into viscose. 6. Filtration: The viscose is filtered to remove undissolved materials. 7. Ripening: To make the viscose fit for spinning and casting, it is stored in a controlled condition of time and temperature to permit ripening. 8. Spinning ( convertion of viscose into rayon filament): The viscose solution is metered through a spinneret into a spin bath containing sulphuric acid(8-10%), sodium sulphate (13-31%) and zinc sulphate (4-10%). Once the cellulose xanthate is neutralized and acidified, rapid coagulation of the rayon filaments occurs which is followed by simultaneous stretching and decomposition of cellulose xanthate to regenerated cellulose.

12. 9. Washing: The yarn is the washed, dried and desulphurized . 10. Bleaching: To obtain pure, white color the yarn is bleached with hypochlorite solution and dried again.

13. Properties of Rayon Highly absorbent Soft and comfortable durable Easy to dye Drapes well Wrinkles easily Resist insect damages

14. Uses Jackets Linings Millinery Slacks Sportswear Suits Ties Bedspreads Blanket Curtain Slip covers Table cloth

15. THE FUTURE The future of rayon is bright. Not only is there a growing demand for rayon worldwide, but there are many new technologies that promise to make rayon even better and cheaper. For a while in the 1970s there was a trend in the clothing industry toward purely synthetic materials like polyester. However, since purely synthetic material does not "breath" like natural material, these products were not well received by the consumer. Today there is a strong trend toward blended fabrics. Blends offer the best of both worlds.

16. Thank You