3.  The monomer is acrylonitrile. Another name for acrylonitrile is vinyl cyanide. The polymer is (PAN) POLYACRYLONITRILE. They go under addition process.

4.  In one commercial method, hydrogen cyanide is treated with acetylene: acetylene + Hydrogen cyanide --> Acrilonitrile  In second method Ethylene--Air Oxidation--> Ethylene oxide + HCN--> Ethylene cyanahydrin--Dehydration at 300 °C (catalyst)--> Acrylonitrile In a continuous polymerisation process, 95% acrylonitrile and 6% methyl acrylate, 0.25% aqueous solution of K2S2O8, 0.50 % Na2S2O5 solution and 2N sulphuric acid are fed into the reaction vessel at 52°C under nitrogen atmosphere giving a slurry with 67% polymer. The slurry is continuously withdrawn, filtered and washed till it is free from salts and dried.  Acrilonitrile is dry spun. The material is dissolved in dimethyl formamide, the solution contains 10-20 polymers. It is heated and extruded into a heated spinning cell. A heated evaporating medium such as air, nitrogen or steam moves counter current to the travel of filaments and removes the solvent to take it to a recovery unit. The filaments are hot stretched at 100 to 250 depending on the time of contact in the hot zone, to several times their original length.

7.  The spinning Solution is pumped through fine holes of a jet into a coagulating bath and drawn off as continous filaments which are collected togather to form a continous ‘toe’ or rope of fiber. The bath removes the solvent from the spinning solution leaving acrylic filaments.

8.  The fibers are drawn under heat  Washing removes excess solvent

9.  The fibers are dried in a heat chambber.  Controlled heat treatment to prevent subsequent shrinkage.

10.  Crimping imparts bulk and cover to the spun yarn and improves fiber to fiber cohesion. This crimp may not be permanent and may not withstand dyeing and finishing.

11.  Cutting the filaments into the desired staple length for spinning.

12.  An Acrylic polymer is random copolymer composed of 2 or more monomers, but by definition, at least 85% of the monomer used must be acrylonitrile.  70-80% crystalline, 30-20% amorphous, excellent alignement orientation. Dégrée of polymérisation is 1000.  The additional monomers are often included in order to confer dye ability: Vinyl acetate (opens up structure) Acrylic acid ( provides dye sites)

13.  Acid – Damaged by strong concentrate acid and Acrylic has good-to-excellent  resistance to strong mineral acids as well as organic acids.  Alkali –Acrylic has fair to good resistance to weak alkalies and to strong  alkalis at room temperature  Bleach – Resistance to oxides solvent  Organic solvent –In mildew may form on But surface, But it will have no effect on fabric. In insects acrylic is unaffected by moth.

14.  Light – Acrylic has resistance to light. Its extreme resistance to such  degradation makes it especially useful for fabrics that will be exposed to  sunlight for an  extended period of time..  Heat – Acrylic fiber gets tacky at 4550F (2350C) which is slightly above that of  nylon. At higher temperatures, it will melt.  Dye – Some times of acrylic are specific to acid dyes and some to basic dyes

15.  Handle: Acrylic has a warm and dry hand like wool.  Density: Its density is 1.17 g/cc as compared to 1.32 g/cc of wool. It is about 30% bulkier than wool. It has about 20% greater insulating power than wool.  Mositure regain: Acrylic has a moisture regain of 1.5-2% at 65% RH and 70 deg F.

16.  It has a tenacity of 5 gpd in dry state and 4-8 gpd in wet state.  Breaking elongation is 15% ( both states).  It has a elastic recovery of 85% after 4% extension when the load is released immediately.  It has a good thermal stability. When exposed to temperatures above 175 deg C for prolonged periods some discoloration takes place.  Acrylic shrinks by about 1.5% when treated with boiling water for 30 min.

17.  Sweaters  Knit garments  Faux Fur  Coats  Pants  Skirts  Shoe soles  Blankets, furniture covers,  Hosiery