PROCESS OF 100% MANUFACTURING

COTTON

CULTIVATIONOF

COTTON

HARVESTING COTTON

COLLECTING RAW

COTTON

YARN PROCESSING

SPINING

GINNING

SCOURING,BLEACHING

SIZING

WARPING&

WEAVING

DESIZING&

DYEING

Stage of Dyeing: First stage (Dissolving of the dye): In this first stage, the dye, in solid form, is equilibrated according to the dye dissolved in molecular form , or in form of dispersed micro powder.Second stage (Adsorption): During this stage, by the effect of the dye-fibre affinity, the dye is adsorbed at the surface of the fibre, thus forming chemical bonds with it. A quick adsorption of the dye on the surface of the fabric reduces the dye concentration near the fibre, thus reducing the adsorption speed. A correct speed of the liquor change in contact with the fibre allows the maximum concentration of the dyeing solution near the fibre, and consequently the correct speed.

At the same time, the liquor flow in contact with the material is spread homogeneously and allows a good distribution of the dye in all the areas of the textile surface; this enhances the dye consistency with the same operating times

Third stage (Diffusion): During this stage the dye, adsorbed in molecular form by the surface, by breaking and restoring the bonds many times tends to penetrate into the bulk of the fibre through amorphous areas, to spread homogeneously and fix steadily.

Fourth stage (Migration): Stages 2 and 3 are reversed in this fourth migration stage; the dye must diffuse toward the external layers of the fibre, and then come back always in solution and migrate in areas of the fibre where there is a lower concentration of dye, thus enhancing the colour consistency.

METHODS OF DYEING COTTON YARN

PROCESS OF MANUFACTURING 100% POLYESTER

PROCESS OF MANUFACTURING POLYESTER FILAMENT YARN

Polymerization To form polyester, dimethyl terephthalate is first reacted with ethylene

glycol in the presence of a catalyst at a temperature of 302-410°F (150-210°C).

The resulting chemical, a monomer (single, non-repeating molecule) alcohol, is combined with terephthalic acid and raised to a temperature of 472°F (280°C). Newly-formed polyester, which is clear and molten, is extruded through a slot to form long ribbons.

Drying After the polyester emerges from polymerization, the long molten

ribbons are allowed to cool until they become brittle. The material is cut into tiny chips and completely dried to prevent irregularities in consistency.

Melt spinning Polymer chips are melted at 500-518°F (260-270°C) to form a syrup-like

solution. The solution is put in a metal container called a spinneret and forced through its tiny holes, which are usually round, but may be pentagonal or any other shape to produce special fibers. The number of holes in the spinneret determines the size of the yarn, as the emerging fibers are brought together to form a single strand.

At the spinning stage, other chemicals may be added to the solution to make the resulting material flame retardant, antistatic, or easier to dye.

Drawing the fiber When polyester emerges from the spinneret, it is soft and easily elongated up

to five times its original length. The stretching forces the random polyester molecules to align in a parallel formation. This increases the strength, tenacity, and resilience of the fiber. This time, when the filaments dry, the fibers become solid and strong instead of brittle.

Drawn fibers may vary greatly in diameter and length, depending on the characteristics desired of the finished material. Also, as the fibers are drawn, they may be textured or twisted to create softer or duller fabrics.

Winding After the polyester yarn is drawn, it is wound on large bobbins or flat-wound

packages, ready to be woven into material

Manufacturing Staple FibreIn making polyester staple fibre, polymerization, drying, and melt spinning (steps 1-4 above) are much the same as in the manufacture of filament yarn. However, in the melt spinning process, the spinneret has many more holes when the product is staple fibre. The rope-like bundles of polyester that emerge are called tow.

• Drawing tow• 1 Newly-formed tow is quickly cooled in cans that gather the thick fibers. Several lengths of

tow are gathered and then drawn on heated rollers to three or four times their original length.

• Crimping• 2 Drawn tow is then fed into compression boxes, which force the fibers to fold like an

accordion, at a rate of 9-15 crimps per inch (3-6 per cm). This process helps the fiber hold together during the later manufacturing stages.

• Setting• 3 After the tow is crimped, it is heated at 212-302°F (100-150°C) to completely dry the fibers

and set the crimp. Some of the crimp will unavoidably be pulled out of the fibers during the following processes.

• Cutting• 4 Following heat setting, tow is cut into shorter lengths. Polyester that will be blended with

cotton is cut in 1.25-1.50 inch (3.2-3.8 cm) pieces; for rayon blends, 2 inch (5 cm) lengths are cut. For heavier fabrics, such as carpet, polyester filaments are cut into 6 inch (15 cm) lengths

DYEING PROCESS OF POLYESTERPolyester is the most commonly used synthetic fiber in the world. Polyester fiber is dyed with disperse dyes. It can also be dyed during extruding the fiber but we can dye after yarn preparation.

The process involves dye transfer from liquid (water) to a solid organic fibre and it takes as following:

Dispersion of the dye in the solid phase into water by breaking up into molecules( dissolution of the Dye)

Adsorption of the dissolved dye from the solution onto the fibre surface

Diffusion of the dye molecules from the fibre surface into the interior of the fibre

SUSTAINABLE WAY OF MANUFACTURING POLYESTER

PROCESS OF MANUFACTURING

50%COTTON&

50%POLYESTER

Poly CottonPoly Cotton fabric is made of a combination of cotton and polyester. It combines the benefits of cotton, such as its absorbency and breathing qualities, with the toughness and lack of wrinkling that polyester possesses.

In order to weave a poly cotton blend, yarn of both cotton and polyester are put on a loom. The loom is then used to weave a single fabric out of both the cotton and the polyester yarn, creating a new fabric that is sometimes called poly cotton. Most common types of poly cotton fabric boast slightly more cotton content than polyester content in the end.

Dying of Polyester/Cotton Blends Goods(One bath one stage dyeing with disperse/ direct dyes at atmospheric pressure)

In this method the PC or CVC goods can be dyed at one single bath with disperse and selected direct dyes (stable in high temperature and compatible with polyester dyeing)- disperse for polyester and direct for cotton. Some direct dyes , for example , C.I. Direct Black 22 – the pH may be adjusted to 8-9 with soda ash.

Dyeing Procedure:1. Set the dyebath with substrate at 50 temperature and add dispersing agent, leveller, acetic acid , carrier and other auxiliaries , then urn the dyebath for 5-10 minutes. 2. Add both dyes and raise the temperatur4e to 90- 100 @ 1-2 C/min 3. Add glauber salt and run the bath for one to two hours at the same temperature . 4. Lower down the bath temperature to 70 – 80 over 10-15 minutes. 5. Drip the dyebath and carry on the after treatment process.

After Treatment Process:1. Rinse twice with hot and cold water. 2. Treat the fabric with suitable fixing agent for improving the wet fastness properties of dyed goods . 3. Soap wash according to vender recommendation. 4. Rinse twice with hot and cold water and then 5. Neutralize with acetic acid.