Published: September 1987
Nylon 66 is made by polycondensation of hexamethylene diammonium adipate, commercially known as nylon salt. Nylon salt, made from hexamethylenediamine and adipic acid, is produced as an aqueous solution if it is to be used captively or as a solid if it is to be transferred. The polycondensation starts from an aqueous solution, and produces a nylon melt. The reaction is conducted in three-stages: first in a tank or in a heat-exchanger/column, second in a tubular reactor, and finally in a vessel under a slight vacuum. Nylon melt can be pelletized to form nylon resin, or spinning chips. Nylon resin may be further treated for use in extrusions.
Nylon 66 fiber can be melt-spun from chips, or it can be spun directly from the melt. Processes for making representative grades of carpet staple, carpet yarn, tire cord, textile yam, and hosiery monofilament are described and evaluated in this report.