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Melt Spinning , Dry spinning and Wet Spinning Method | Textile Study Center
Home Wet Processing Eng. Man-Made Fiber Introduction to man made fibre Melt Spinning , Dry spinning and Wet Spinning Method

Melt Spinning , Dry spinning and Wet Spinning Method

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Md Sohanur Rahman Sobuj

Md Sohanur Rahman Sobuj

Co-founder , Admin & Author at Textile Study Center
Student of Bangladesh University of Textiles (BUTEX) Department: Apparel Engineering
Md Sohanur Rahman Sobuj
Md Sohanur Rahman Sobuj
Md Sohanur Rahman Sobuj

Latest posts by Md Sohanur Rahman Sobuj (see all)

Melt Spinning, Dry spinning and Wet Spinning Method :

Man-made fibers are manufactured by spinning the polymer. There are three major types of spinning process. They are-

 Melt Spinning (It is used for polymers that can be melted easily.)

❷ Dry Spinning (It involves dissolving the polymer into a solution that can be evaporated.)

 Wet Spinning (It is used when the solvent can’t be evaporated and must be removed by chemical means.)

Melt Spinning:

Melt spinning uses heat to melt the polymer to a viscosity suitable for extrusion. This type of spinning is used for polymers that are not decomposed or degraded by the temperatures necessary for extrusion. This method is used by 70% of the fibers.

Vedio: Melt Spinning


Melt spinning process1



Spinning process:

❶ In melt spinning, polymer is heated and it melts to form a liquid spinning solution or dope.

 Chips of polymers are fed to a hopper which is heated. There is a grid (sieve) at the base which permits only molten liquid to pass through.

 Then the solution is purified by filter.

❹ The molten polymer is extruded at high pressure and constant rate through a spinneret into a relatively cooler air stream that solidifies the filaments.

❺ Finally the filament yarn either is immediately wound onto bobbins or is further treated for certain desired characteristics or end use.

Example: Melt spinning is used for the production of polyester, nylon, olefin, saran and glass fibers.

Advantages: 

 High speed (275 to 1500 yds/min); (4000 yds/min spin draw)

 No solvents

 No purification problems

Disadvantages:

 Separate drawing step (unless spin draw)


Dry spinning:

Dry spinning is used for polymers that need to be dissolved in a solvent. Solvent spinning (dry spinning and wet spinning) are used by 30% of the fibers.

Dry spinning process



Spinning process:

 In dry spinning, a volatile solvent is used to dissolve the raw materials and form a salutation.

❷ Then the solution is purified by filter.

❸ The solution is extruded through a spinneret into a warm air chamber where the solvent evaporates, solidifying the fine filaments.

❹ Finally the filament yarn either is immediately wound onto bobbins or is further treated for certain desired characteristics or end use.

Example: Dry spinning is used in the production of acetate, triacetate, and some acrylic, modacrylic, spandex, and vinyon (PVC,PVA) fibers.

Advantages:

Yarn does not require purification

Disadvantages:

Flammable solvent hazards

Solvent recovery

Slow (200-400 yds/min)

 Wet Spinning:

This is the oldest, most complex and also the most expensive method of man-made yarn manufacture. This type of spinning is applied to polymers which do not melt and dissolve only in non-volatile or thermal unstable solvents.

Video: Wet spinning


 

Wet spinning process Melt Spinning | textile study center

Spinning process:

 In wet spinning, a non-volatile solvent is used to convert the raw material into a solution.

 The solvent is extruded through the spinneret either by simply washing it out or by a chemical reaction between the polymer solution and a reagent in the spinning bath.

❸ After extrusion, the solvent is removed in a liquid coagulation medium.

❹ Finally the filament yarn either is immediately wound onto bobbins or is further treated for certain desired characteristics or end use.

Example: Wet spinning is used in the production of aramid, Lyocell, PVC, Vinyon (PVA), viscose rayon, spandex, acrylic and modacrylic fibers.

Advantages:

Large tows can be handled

Disadvantages:

Slow (70-150 yds/min)

Washing to remove impurities

Solvent and chemical recovery


General process diagram of melt, dry and wet spinning process

General process diagrum of melt, dey & wet spun synthetic fibers Wet spinning process Melt Spinning | textile study center

Difference between Melt spinning, Dry spinning & Wet spinning

Difference between Melt spinning, Dry spinning & Wet spinning Wet spinning process Melt Spinning | textile study center


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Md Sohanur Rahman Sobuj

Md Sohanur Rahman Sobuj

Co-founder , Admin & Author at Textile Study Center
Student of Bangladesh University of Textiles (BUTEX) Department: Apparel Engineering
Md Sohanur Rahman Sobuj
Md Sohanur Rahman Sobuj
Md Sohanur Rahman Sobuj

Latest posts by Md Sohanur Rahman Sobuj (see all)

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