Introduction to Polymer, Elastomer and Synthetic Fibre, Polymerisation (Part - 2) | Chemical Technology - Chemical Engineering PDF Download

Elastomer 

Rubber can be broadly classified as natural rubber and synthetic rubber. Natural rubber is a product of the tree Heveabrasiliensis while synthetic rubber is elastomer derived from petrochemical feedstock product. Table M-VIII 1.4 shows the general and special purpose of rubber. 

Table M-VIII 1.4: General Purpose and Special Purpose Rubber

Synthetic Fibre 

• First manmade fiber – natural occurring polymers from cellulose and protein – Viscose rayon first manufactured in 1986 in England
• First true synthetic in 1935 – Nylon by DuPont
• Nylon was followed by acrylic and mod acrylic fiber based on Acrylonitrile in 1950.
• Polyester Fiber in 1953 in India
• Viscose rayon in India started in 1950
• Acetate rayon in 1954 in India

World consumption of non-woven man-made fibre is mention in Table M-VIII 1.5.\

Rayon Grade Pulp : Harihar Polyfibre, Gwalior Rayon, Travancore Rayon, Baroda Rayon, Andhra Rayon, Shri Ram Rayon, Kesoram Rayon, South India Viscose Rayon

Caprolactam: Gujarat state fertilizer and chemicals vadodara, Fertilizer and chemicals travancore

DMT /PTA: Bombay Dying, BRPL, Reliance (Patal Ganga, Hazira, Vadodara), IOC Panipat

p-Xylene: BRPCL, Reliance (Patal Ganga, Hazira, Vadodara, Jamnagar), Indian oil Corporation

Projected Consumption of Fiber in India 

Table M-VIII 1.5: World Consumption of Non woven Man-made Fibers (% of total)

Raw Materials for Manmade Fibre 

• Synethetic fibre polymer production needs extremely pure raw materials and chemicals. The most important chemicals are monomers, catalysts, and solvents.
• The most common monomers dealing with large volume organic chemicals are as follows:
  • Ethylene, propylene, butadiene, isoprene, styrene
  • Vinyl chloride, vinyl esters, vinyl ethers, chloroprene
  • Acrylic and methaacrylic esters, vinyl ethers, chloroprene
  • Adipic acid, hexamethylenediamine, caprolactam
  • Terephthalic acid, ethylene glycol
  • Formaldehyde
  • Aromatics, like phenol, cresol, bisphenol A
  • Maleic anhydride, etc
• Catalysts are chemicals used to speed up or initiate the polymerization reaction. Common catalysts include Zieger catalysts (titanium chloride and aluminium alkyl compounds), chromium-containing compounds, and organic peroxides.
• Solvents are sometimes used to dissolve or dilute the monomer or reactants. The use of solvents facilitates polymer transport through the plant, increases heat dissipation in the reactor, and promotes uniform mixing in the reactor

Details of man made fibre is shown in Figure M-VIII 1.6.

 Some terms used in synthetic fibre industry 

Denier: denier is the measure of coarseness of a yarn and is defined as the  weight in grams of a length  9000meter of a yarn or filament.

Tex and Millitex: Tex is the defined as the weight in grams of 1000 meter

 Tenacity: The tenacity or strength of rayon is expressed as grams per denier. IF a load of 250 gms will just break at a denier yarn, the tenacity is said to be 2.5 gms per denier.

Elongation at break: Elongation is a important properties of a yarn.  If a length of 100cm of a yarn can be stretched 112 cm before breaks, it is said to have elongation at break of 12%

Moisture regain: Regain is of a fibre is the percentage of moisture calculated on oven dry basis.

Staple: The choped fibre is called staple .

Filament yarn:  Reeled filaments yarn

Elasticity: The elasticity of a fibre is its ability to recover from strain. 

Figure M-VIII 1.6: Manmade Fibre and Raw Material 

Overview of Indian Man-Made Textile Industry 

• Second Largest producer of cellulosic fibre/yarn
• Fifth largest producer of synthetic fibres/yarns.
• Production of synthetic fibres nearly 10 lakh MT (2009-10) 
• Production of Synthetic yarn about 15 lakh MT (2009-10)

Indian: Fibre Demand 

• Current All fibre demand is arround 80 lakh MT
• Cotton 43 lakh MT and polyester around 30 lakh MT
• All fibre demand to grow nearly 130 lakh MT by 2020 @ 5% CAGR
• PFY has grown at around 10% CAGR in last decade and is likely to sustain similar growth rates

Indian: Textile Growth Drivers 

Figure M-VIII 1.7 shows emerging trends of man made textiles

• Higher disposable income and changing life style
• Increasing fashion awareness even in tier B, C cities
• New emerging segment of non-apparel application
• Increasing urban households and working women population
• Rapid spread of organised retail sector
• Rise in exports to traditional and new markets
• Favourable govt policies like TUFS, SITP (textile Parks)

Table M-VIII 1.6 give the details of demands of man-made fibre in India. Brief details of various synthetic fibre producing units in India is given is Table M-VIII 1.7. Table M-VIII 1.8 gives the details of rising demand of polyester. Per-capita consumption of cotton and manmade fibre is mention in Table M-VIII 1.9.

Figure M-VIII 1.7: Emerging Trends in Man-made Textiles 

Table M-VIII 1.7: Various synthetic fibre producing units in India