Nylon 6 is made from one component namely Caprolactum, which has six carbon atom. Nylon 6 fibers are tough, possessing high tensile strength, as well as elasticity and luster. They are wrinkle-proof and highly resistant to abrasion and chemicals such as acids and alkalis. The fibers can absorb up to 2.4% of water, although this lowers tensile strength. The glass transition temperature of Nylon 6 is 47 °C. Nylon 6 Manufacturing Process is as follows:
Flow Chart of Nylon-6 Manufacturing Process
Nylon 6 is produced by ring-opening chain-growth polymerization. In presence of water vapor and an acid catalyst at the melt. After removal of water and acid, the nylon 6 is melt-spun at 250°–260°C into fibers. Nylon 6,6 is prepared by step-growth polymerization of hexamethylene diamine and adipic acid. After drying, the nylon 6,6 is melt-spun at 280°–290°C into fibers.
- Density: 1.14 g/cc
- Tenacity: Dry= 4.2-5.8 gpd, Wet=4.0-5.3 gpd
- Elongation at Break: Dry = 24-40, Wet= 28-43
- Elastic Recovery at 4% extension= 100%
- Moisture Regain= 4%
- Because of low MR, wet nylon dries quickly.
- Melting Point= 215 deg ºC ( Nylon 66-250 deg º C)
- It is weakened by prolonged exposure to sunlight.
- It is resistant to most organic acids such as benzene, chloroform, acetone, esters ethers, etc.
- It dissolves in phenol, cresol, and strong mineral acids.
- good resistance towards alkalies.
- Resistant to inorganic acids
These fibers are cylindrical in shape, with smooth surfaces, and without having any markings. The fibers are uniform in diameter and appear round in cross-section.
Application of Nylon 6:
a. Tyre Cord Manufacturing
b. Fishing Lines
c. Luxury Yachts
d. Stockings with good fit, sheerness, quick washing, and drying properties.
Nylon 6 has certain advantages over Nylon 6,6. The synthesis of caprolactam is easier than that of Hexamethylene Diamine and Adipic Acid. Therefore it is cheaper to make Nylon 6 than Nylon6,6. Furthermore, nylon 6 has a greater affinity for acid dyes than Nylon6,6.
Author of this Article: Muhammad Ibrahim Khalilullah Department of Textile Engineering Daffodil International University Email: [email protected]