Nylon is a generic designation for a family of synthetic polymers composed of polyamide, which are repeating units linked by amide links. Nylon is a silk-like thermoplastic, usually made from petroleum, that can be melt-processed into fibers, films, or shapes. Nylon polymers can be mixed with various additives to achieve many different property variations.
There are many types of nylon polymers, as discussed in this article. This article looks at five different types of nylon: nylon 1,6; nylon 4,6; nylon 510; nylon 6; and nylon 6,6. This article also explains where nylon fabric comes from, the environmental impact of nylon, how the quality of nylon is determined, and the safety of nylon.
1. Nylon 1,6
Nylons can be synthesized from dinitriles using acid catalysis. For example, this method is applicable for preparing nylon 1,6 from adiponitrile, formaldehyde, and water. It has a high moisture absorbance because of the polymer's significant density of amide residues. Nylon 1,6 is not typically used for fabrics.
2. Nylon 4,6
Nylon 46 was mainly developed to have a higher operating temperature than other grades of nylon. Therefore, its applications include engine components such as transmissions, brakes, and air cooling systems.
The advantages of nylon 4/6 include higher heat distortion temperature than nylon 6 or nylon 6/6, higher crystallinity that leads to better chemical resistance, particularly to acidic salts, and short cycle times. The disadvantages of nylon 4/6 are that it has similar moisture absorption to nylon 6/6, but the dimensional increase is more minor and has a high processing temperature.
3. Nylon 510
Nylon 510 is made from pentamethylene diamine and sebacic acid and was included in the Carothers patent to nylon 66. It has superior properties but is more expensive to produce. Because its production costs ultimately prohibited the mass production of this polymer for fabric purposes, the applications of nylon 510 are used in industrial and scientific applications.
Its advantages include its strength and durability. Its disadvantages include the high cost to produce.
4. Nylon 6
Nylon 6 fibers are tough, possessing high tensile strength, elasticity, and luster. The fibers can absorb up to 2.4% of water, although this lowers tensile strength. The glass transition temperature of nylon 6 is 47 °C. Nylon 6 is generally white as a synthetic fiber but can be dyed in a solution bath before production for different color results. The tenacity of nylon 6 is 6–8.5 gf/D with a density of 1.14 g/cm3. Its melting point is 215 °C and can protect heat up to 150 °C on average.
The applications of nylon 6 include construction material in many industries, including the automotive industry, electronic and electrotechnical industry, aircraft industry, clothing industry, and medicine.
The advantages of nylon 6 are that its fibers are wrinkleproof and highly resistant to abrasion and chemicals such as acids and alkalis. A disadvantage is that it is relatively difficult to process due to exceptionally low melt viscosity.
5. Nylon 6,6
Nylon 6,6, also written as nylon 6-6, nylon 66, or nylon 6/6, is a more crystalline version of nylon 6. It is also referred to as polyamide 66 or PA 66. It has improved mechanical properties due to its more ordered molecular structure. Nylon 66 for machining has improved temperature resistance and lower rates of water absorption when compared to standard nylon 6. The applications of nylon 6,6 include wear pads, guide wheels, and slide bearings.
The advantages of nylon 6,6 are that the yield strength is higher than nylon 6 and nylon 610. It has high strength, toughness, rigidity, and low coefficient of friction in a wide temperature range. In addition, it is oil resistant and resistant to chemical reagents and solvents.
The disadvantages of nylon 6,6 are its high hygroscopicity, reduced impact strength in a dry environment, the molding process is challenging to control, and good wear resistance.
Where Does Nylon Fabric Come From?
Nylon comes from diamine acid being forced to enter into a reaction with adipic acid. The nylon composition is then extruded through a spinneret with dozens of tiny holes. Nylon immediately hardens upon extrusion through the spinneret, and the resulting fibers can then be loaded onto bobbins.
Nylon fibers are then stretched to increase their strength and elasticity. Nylon is then wound onto another spool in a "drawing" process that makes the polymer molecules arrange in a parallel structure. After the drawing process, the resulting fibers are ready to be spun into garments or other forms of threads.
Nylon is sometimes spun into fabrics by itself, but it is usually combined with other fabrics to create mixed textiles. It is then dyed to produce the desired color for the end product.
What Is the Environmental Impact of Nylon?
The environmental impact of nylon is mainly negative. Nylon is energy-intensive to produce. It is an artificial polyamide. The production of nylon releases nitrous oxide, a greenhouse gas that significantly contributes to global warming. Nylon is also not biodegradable.
However, nylon is infinitely recyclable. Econyl is a certified recycled nylon textile made from used fishing lines and other post-consumer waste found in oceans. Recycled fabrics let designers access the functionality of nylon and contribute to a better environmental outcome. However, the recycling process is still energy-intensive, releases greenhouse gases, and uses more harmful chemical dyes.
How Is the Quality of Nylon Determined?
Diverse characterization methods are investigated to define a test procedure for the quality of nylon. In the pre-process, the laser sintering process, as well as the post-process, are kept constant. The quality characterization of nylon involves the examination of advanced material properties like mechanical (static and cyclic), thermal, and electrical ones. Physical properties are investigated as well to determine nylon quality.
How Much Does Nylon Fabric Cost?
Nylon fabric has a low cost compared to other materials. Its low cost to buy is because it has a relatively low cost of manufacture. Although nylon fabric was more expensive than silk when it was first developed, it rapidly dropped in price, and it is exceedingly inexpensive when mixed with other fabrics.
Is It Safe to Use Nylon Fabric?
Yes, it is safe to use nylon fabric. Nylon polymers are unreactive and are not considered particularly harmful to most people, making the fabric safe to use. However, some people who are sensitive to materials made from petroleum may react to nylon.
Which Type of Nylon Is Used for Plastic Injection Molding?
The most commonly used types of nylon for plastic injection molding are the PA 6 and PA 66 versions. Nylon has excellent strength, stiffness, heat resistance, wear resistance and lubricity, and chemical resistance to hydrocarbon. In addition, nylon has a relatively low cost compared to the performance of engineering-grade polymers and is easy to process, and can be reinforced with glass or carbon fiber to increase mechanical and thermal properties.
In plastic injection molding, nylon 6 and nylon 66 is often used in clips, electrical connection bodies, gears, wheels, bushings, firearms grips and stocks, housings for power tools, and automotive applications. Nylon also replaces metal in electrical and electronics, gears, hardware, glass, and carbon-reinforced applications.
Is Every Type of Nylon Used for Industrial Manufacturing?
Yes, every type of nylon can be used for industrial manufacturing. However, nylon 6,6 and nylon 6 are the two most often used. Nylon 510 is used infrequently in industrial manufacturing because of its high cost.
Summary
This article reviewed 5 common types of nylon and discussed their properties and applications. Xometry offers nylon sheets and rods in a range of different sizes. Visit our supplies page for all of your nylon material needs.
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