Nylon 6 is polymerized from caprolactam as monomer raw material, while nylon 66 is polymerized from hexamethylenediamine and adipic acid as monomer raw material.
2.In terms of molecular structure, nylon 6 and nylon 66 have the same atomic ratio of carbon, hydrogen, oxygen, and nitrogen, but nylon 6 is polymerized into polyamide via ring-opening polymerization arranged in a head-to-tail manner, while nylon 66 is made from hexamethylenediamine and adipic acid. Due to different monomer raw materials, they have different polymer structures and physical properties:
Nylon is a semi-crystalline polymer. The hydrogen bond arrangement of nylon 66 is different from that of nylon 6 that the regularity of the atomic arrangement of nylon 66 is better than that of nylon 6. The tighter the hydrogen bonds, the higher the crystallinity. Nylon 6 hydrogen bonds have two types of arrangements: about 50% have longer and weaker oblique hydrogen bonds. Nylon 66 has only one type of hydrogen bond arrangement, which form a robust and dense polymer structure in a straight line.
3.Different performances
The structure determines their performances. Due to the different molecular chain arrangement structures, they have different properties. Because nylon 66 has better crystallinity and more orderly arrangement than nylon 6 under similar process conditions, nylon 66 has a higher melting point (40℃ above that of nylon 6), slower permeability, and stronger deformation resistance.
（1）High melting point - resistant against high temperature
Unlike polypropylene, both nylons do not melt by frictional heat. The melting point of nylon 66 is higher than that of nylon 6, which significantly improves the safety in recovery after contact with high-temperature objects and brings friction resistance.
（2）Dimensional stability - maintaining quality performance
Both nylons have superior elastic recovery as carpet fibers compared to polypropylene and polyester. However, nylon 66 performs better than nylon 6 when used in carpets with the same structure because it has a more orderly arrangement and stronger hydrogen bonding.
（3）Tight and orderly structure - resistant against stain penetration
With a more tight and orderly polymer structure, nylon 66 has a good resistance against stain penetration, which means dirt seeps into nylon 66 more slowly.
The company has 11 modified plastics production lines with a daily production capacity of 80 tons, which has a rapid producing speed.
The flame retardant grade of plastic increases from HB, V-2, V-1 to V-0:
HB: The lowest flame retardant UL94 rating. It is required that HB burn on a 3-13mm thick specimen with a burning rate of less than 40mm/min, burn on a less than 3 mm thick specimen with a burning rate of less than 70mm/min, or stop burning before the 100mm mark.
V-2: Burning stops within 60 seconds after two applications of ten seconds each of a burning test. Flaming drips are allowed.
V-1: Burning stops within 60 seconds after two applications of ten seconds each of a burning test. NO flaming drips are allowed.
V-0: Burning stops within 30 seconds after two applications of ten seconds each of a burning test. NO flaming drips are allowed.
