Nylon 6-6

Nylon 6-6, also referred to as nylon 6,6, is a type of nylon. Nylon comes in two types: nylon 6 and nylon 6,6.

Composition
Nylon 6,6 is made of hexamethylene diamine and adipic acid, which give nylon 6,6 a total of 12 carbon atoms, and its name.

Properties
1. Nylon 6,6 has the highest melting point (256° C) of all synthetic fibers: - making it the the most resistant to heat and friction - enabling it to withstand excellent heatsetting for twist retention

2. Its long molecular chain results in more sites for hydrogen bonds, creating chemical “springs” and making it very resilient

3. It has a dense structure with small, evenly spaced pores: - making nylon 6,6 harder to dye, but also providing superior colorfastness - making it less susceptible to fading from sunlight and ozone and to yellowing from nitrous oxide

Manufacture
1. Hexamethylene diamine and adipic acid are combined with water in a reactor. This produces nylon salt. The nylon salt is then sent to an evaporator where excess water is removed.

2. The nylon salt goes into a reaction vessel where a continuous polymerization process takes place. This chemical process makes molten nylon 6,6.

3. The molten nylon 6,6 undergoes a spinning process, where the nylon 6,6 is extruded and sent through a spinnerette, which is a small metal plate with fine holes. The nylon is then air-cooled to form filaments.

Applications
1. Carpet fiber 2. Apparel 3. Airbags 4. Tires 5. Ropes 6. Conveyor Belts 7. Hoses

Nylon 6,6's longer molecular chain and denser structure qualifies it as a premium nylon fiber, specified most often by professional architects and designers for use in commercial settings like offices, airports, and other places that get a lot of wear and tear. It is also an excellent choice for residential carpet applications where it is available under the Wear-Dated carpet fiber brand name, as well as StainMaster.