Nylon was invented in New York and London at the same time and hence it was named by taking “NY” from New York and “LON” from London. Nylon is the common name of linear polyamides which all have in common the carbonamide group –CO—NH-recurring in a chain of methylene groups.
Why Nylon is important in fiber optics? This is a natural doubt anybody who is not associated with the manufacturing of optical fiber cables may raise. Nylon along with other many polymer compounds are important in the fiber optic industry.
Polymer compounds are used to protect the fiber optic cables from environmental and mechanical stresses. Let us limit this discussion to the use of Nylon in the fiber optic industry.
The nomenclature of nylons is derived from the number of carbon atoms in the monomer. For example, in the case of Nylon 6.6, –[HN—(CH2)6—NHCO—(CH2)4—CO]n–, one of the most common nylon, that is a polycondensation product of hexamethylenediamine H2N—(CH2)6—NH2 and adipic acid HOOC—(CH2)4 –COOH, the first digit is derived from the number of carbon atoms in the diamine and the second digit from the number of carbon atoms in the dibasic acid.
Some of the deployment conditions of optical fiber cables demand the outer sheathing material to withstand attack from termites and other vermin present in the soil. Polyethylene sheathing material added with the anti-termite chemicals will do to some extent the job of protecting the cable from damage due to termite attack. But it is not a foolproof method to secure the cable. Even though there are anti-termite chemicals added to the polyethylene material, fiber optic cable can not be secured from severe termite attack. Tropical soil is ideally suitable for termites and the fiber optic cables laid in tropical countries must be protected against termites.
Nylon provides a solution against termite attack. If used as an outer jacketing material on fiber optic cables, Nylon will prevent termites attack on fiber optic cable. Nylon 6 is a cheaper material compared to Nylon 12, but we strongly recommend fiber optic cables to use Nylon 12 though the cost is approximately two times higher than that of Nylon 6.
The use of Nylon 12 is costly. Of course, but one thing we need to remember is the quality comes with a price. Service providers and fiber optic cable installers should not compromise on the quality of fiber optic cable they buy from the fiber optic cable manufacturers. And thus it becomes the responsibility of the fiber optic cable buyer or the third inspection party to ensure that they get the fiber optic cable with all the properties to perform in the field. Profit shall not be made by compromising on the quality of the product.
The synthesis of Nylon 12 and Nylon 6 is similar but more expensive and more difficult with Nylon 12. If the fiber optic cable manufacturer uses Nylon 6 instead of Nylon 12, there are some tests to find out. One of the tests is to find out the melting point of the material. Nylon 12 has a melting point in the region of 180 to 190 degrees C while Nylon 6 will show a result of 210 to 220. The density or specific gravity of both the materials are also different. Nylon 12 has a specific gravity that varies from 1.01 to 1.05 while Nylon 6 specific gravity is around 1.09 to 1.12.
Nylon 12 is superior in characteristics to Nylon 6. Nylon 6 may crack when exposed to the environment for a long time. Nylon 12 is resistant to cracking if processed with the right temperature settings.
There are some polymers that imitate Nylon 12 in appearance especially when it is mixed with color masterbatch. One such material is Polybutylene terephthalate. The reason for all these kinds of manipulation in the industry is due to the severe competition and pressure to reduce the price. It is the duty of the inspection personnel to ensure that the end customer gets the value and original product for the money he pays.
There are many Nylon 6 manufacturers in many countries, but making Nylon 12 needs special technology and process knowledge. Thus it is costly and has high quality. Some of the reputed Nylon 12 manufacturers are;
EMS Chemie
UBE
Evonik/Degussa/Huels
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