1. There is not much difference between the two varieties in civilian use, and their uses are the same. This is one reason why some countries such as the United States have long been dominated by nylon 66, while other countries such as Japan have been dominated by nylon 6 for a long time. However, in industrial applications, especially tire cord nylon 66 will receive greater development due to its temperature resistance.
2. From the perspective of the monomer production process, both nylon 66 and nylon 6 use cyclohexane and ammonia as raw materials. However, because nylon 6 is based on sulfuric acid, and ammonium sulfate, a by-product of sulfuric acid, does not sell well in the world powder market, it will have a certain impact on the expansion of nylon 6 production.
From the perspective of the polymerization process, the polymerization of caprolactam increases the monomer extraction and recovery and vacuum drying processes, and the polymerization time is long and the infrastructure investment is large; while the polymerization of nylon 66 salt consumes large monomers.
Although nylon 66 has its advantages, it has disadvantages due to the long monomer production process and high infrastructure investment.
3. In terms of equipment interchangeability, nylon 66 production has its advantages. Generally, the spinning machine that produces nylon 66 can be used to produce nylon 6, but the spinning machine that produces nylon 6 cannot be used to produce nylon 66.
4. The development of nylon 66 and nylon 6 should be comprehensively considered from the rational utilization of resources. When the resources of sulfuric acid are sufficient, the application of ammonium sulfate has its market, and nylon 6 has its own advantages of priority development. It is more suitable to develop nylon 66 in areas where sulfuric acid resources are relatively scarce.
Judging from foreign trends, the two varieties of nylon 66 and nylon 6 will also develop in parallel, rather than being partial.
