Nylon-6.6:
There are several types of “nylon” polymers. The most widely utilized polyamides in commerce are type nylon 66 and nylon 6. Nylon-6.6 fiber is spun from polyhexamethylene adipamide, a polyamide made by condensation of hexamethylene diamine and adipic acid. Flow Chart of Nylon 66 Fiber Manufacturing Process is as follows:
Nylon 66 is frequently used when high mechanical strength, rigidity, good stability under heat, and/or chemical resistance are required. It is used in fibers for textiles and carpets and molded parts. It is also used as zip ties, conveyor belts, hoses, etc. Nylon 66 is also a popular guitar nut material. The manufacturing flow chart of Nylon 66 fiber is given below.
Nylon 66 Fiber
Flowchart of Nylon-6.6 Fiber Manufacturing
Hexamethylene diamine + Adipic acid
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Mixing tank
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Evaporator
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Reactor
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Autoclave
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Melt spinning
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Drawing
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Texturization
The production process of nylon 66 fiber:
Nylon 66 could synthesize by using a polycondensation reaction. The simplest polycondensation for making nylon 66 is the reaction of a diamine and a diacid:
Polycondensation reaction: In the production of nylon 66 polymer adipic acid and hexamethylenediamine are used. During polymerization, the diamine and the diacid each donate 6 carbons to the polymer chain. Therefore the polymer formed in this reaction is called nylon 66. As with other regular copolymers like polyesters and polyurethanes, the repeating unit consists of one of each monomer.
Melt spinning: Two-step melt spinning, comprised of spinning and drawing, is considered to be the conventional method to manufacture nylon filaments. After melting, filtering, and deaerating, the molten polymer is extruded through a spinneret into a chamber where the melt solidifies into a filament form.
Drawing: When the molten polyester gets solid and gets converted into filament. It has little molecular orientation, and its slight birefringence is. The desired orientation of molecule and degree of crystallinity is improved by drawing the filaments.
Author of this Article Muhammad Ibrahim Khalilullah Department of Textile Engineering Daffodil International University Email: ibrahim23-3123@diu.edu.bd