Nylon, otherwise commonly known as polyamide, is one of the most versatile synthetic materials with huge applications across various industries. The versatility it has regarding properties and applicability extends the usability in manufacturing, textiles, and even prototype development. The article explores the characteristics of nylon, its properties, types, and applications, with an insight into the selection of the appropriate type of nylon for your intentions.
What Is Nylon?
Nylon, also known as polyamide fiber in chemical terminology or “锦纶” in Chinese, is the world’s first synthetic fiber. Nylon is a generic term for thermoplastic resins whose molecular backbone contains repeating amide groups. Therefore, nylon includes all kinds of types and is not a specific substance. It includes aliphatic polyamides, aliphatic-aromatic polyamides, and aromatic polyamides. Of these, aliphatic polyamides are most varied, of the highest production volume, and find the widest application. Their names depend on how many carbon atoms are present in the synthetic monomers.
Basic research of the synthesis of polyamides began in 1928. In 1935, American scientist Carothers and his colleagues, in the process of working on the theory of condensation polymerization, first successfully synthesized a high molecular weight linear condensation polymer called polyhexamethylene adipamide (polyamide 66) from adipic acid and hexamethylenediamine in the laboratory. In the United States, from 1936 to 1937, DuPont developed polyamide 66 fibers with the melt spinning method based on Carothers’ research and named the fiber product “nylon.” It was the first type of polyamide and realized industrial production in 1939. In 1938, Germany’s Schlack invented a method to synthesize polycaprolactam (polyamide 6) using caprolactam along with its fiber production technology, realizing industrial production in 1941.
Hundreds of polyamide products have been brought in over the development of more than fifty-plus years. Aliphatic polyamides include many types, such as PA-6, PA-610, PA-612, PA-1010, PA-11, PA-12, and PA-46. Aromatic polyamides contain the fibers of poly(p-phenylene terephthalamide), whose usual name in China is aramid 1414, and the fibers of poly(m-phenylene isophthalamide), whose usual name in China is aramid 1313. Mixed polyamides include poly(m-xylylene adipamide) (MXD16) and poly(hexamethylene terephthalamide) (polyamide 6T), among others.
How Is Nylon Made?
Nylon is a synthetic material produced through a process called polymerization, where small monomers react to form long chains of repeating units. The monomers used in the production of nylon usually come from petrochemical sources such as coal, natural gas, or petroleum. During the process, the monomers are heated in the presence of a catalyst within a reaction vessel. This heating breaks the chemical bonds between the monomers, producing free radicals. These free radicals then couple in a series of reactions to form new chemical bonds, building up the polymer chains. After polymerization is complete, the chains of polymer are cooled and solidified into nylon.
Nylon can also be made into various forms, such as fibers, films, and molded products. Their properties depend on the specific manufacturing form and process used. For example, nylon fibers are strong, durable, and thus can be used in the manufacturing of clothes and other garments, while nylon films are transparent and hence can find application in packaging. Versatility in form and functionality is what makes nylon as a synthetic polymer useful in a wide range of applications.
What Are The Properties Of Nylon (Polyamide) Material?
What does nylon stand out for? Indeed, not one specific feature but a combination of impressing physical and chemical characteristics. From water-resistant features to such unbelievable stretch, nylon seems a real powerhouse. You just have to explore further, and you’ll really discover all the details that turn it into a popular variety among industries.
Physical Properties
Whenever we think about nylon, its strength and elasticity often come to mind. Did you know it’s also lightweight and smooth to the touch? Let’s examine the physical properties that make nylon the go-to material for products ranging from clothes to industrial parts.
- Due to the big amount of —CH₂— groups in the molecular structure, nylon possesses good elasticity; it is easy to bend. The molecular chains in the amorphous region have a tendency to take an irregularly curled state, giving excellent tensile and rebound properties, good softness, and high elasticity.
- Nylon has excellent dry strength, and its wet strength is also fairly high.
- Nylon has moderate moisture absorption, about 10 times that of polyester.
- Nylon fabrics have a very high abrasion resistance, about 10 times higher than that of cotton fibers.
- Nylon fabrics have good resistance to heat. Since nylon is a thermoplastic fiber, it softens at a certain temperature and melts at higher temperatures. Hence, special care during dyeing and finishing processes is required.
- Nylon also naturally resists moths and mildew, hence making it a good material for decorative fabrics.
Chemical Properties
Chemically resistant and able to withstand heat-nylon thrives on what would break down other materials. Still, it too has weaknesses. Interested in how nylon resists chemicals and heat or what causes limitations in doing so? Okay then, let’s go figure it out.
- Nylon has excellent stability to alkalis. In a 50% NaOH solution at room temperature, it retains its strength almost invariable. Above 60°C, damage to the fiber has been observed.
- Nylon fibers are sensitive to acids, especially inorganic acids and strong organic acids. Concentrated hydrochloric acid and concentrated sulfuric acid will decompose or fully dissolve nylon.
- Strong oxidizing agents also degrade nylon. Hydrogen peroxide, potassium permanganate, and sodium hypochlorite can cause the breaking of its molecular chains hence degradation. On the other hand, it has shown good resistance to sodium chlorite.
- Nylon is insoluble in normal solvents like gasoline, benzene, and ketones but dissolves in phenolic compounds.
Different Types Of Nylon Material Introduction
Not all nylons are created equal. From Nylon 6 to Nylon 66 and beyond, each type serves specific purposes. Have you ever wondered which type of nylon suits your needs best? Let’s explore the diverse options and their unique advantages.
PA46
PA46 is an aliphatic polyamide obtained by the polycondensation of tetramethylene diamine and adipic acid. Compared with PA6 and PA66, PA46 has more amide groups per given chain length and a more symmetrical chain structure, hence its crystallinity is as high as 70% and the crystallization rate is very fast.
PA46 has a melting point of 295°C. The HDT of unreinforced PA46 is 160°C, while glass fiber reinforcement can increase the HDT as high as 290°C, with a long-term service temperature of 163°C. This special structure gives PA46 extraordinary properties that no other material can match. As the only owner of PA46 intellectual property, DSM is industrializing its excellent properties step by step through continuous modification. While maintaining its high-temperature resistance, DSM has developed a number of special applications such as ultra-wear resistance, ultra-high rigidity, and ultra-high flowability.
In the field of high-temperature resistance, DSM introduced its new high-performance STANYL Diablo at Chinaplas 2008. This material features long-term heat stability, is able to work at 230°C for over 3000 hours, and keeps mechanical property degradation to less than 15%.
PA6T
Semi-aromatic nylons PA6T are synthesized by polycondensation of hexamethylene diamine with terephthalic acid. The melting point of pure PA6T reaches a value as high as 370°C, whereby at this temperature the degradation of nylon starts and makes the thermoplastic molding impossible. Thus, all commercial PA6T consists either of copolymers or composites modified by other monomers that decrease the melting point.
With a great amount of benzene rings incorporated into its aliphatic chain, PA6T has a higher Tg, lower moisture absorption, superior dimensional stability, and excellent heat resistance than traditional PA6 and PA66. Since PA6T has to copolymerize with other monomers in order to reduce its melt processing temperature, different ratios of the monomers become the keys for the modification of PA6T, which offers great potential in the development of the high-temperature-resistant modification of PA6T.
Wang Peigang of China has conducted research on the copolymerization process and heat resistance of PA6T/66 copolymers with different aromatic contents. Shanghai Jesa Company has successfully developed and commercialized PA6T-based high-temperature-resistant nylons; the products are already in production.
PA9T
PA9T, independently developed by Japan’s Kuraray Co. is synthesized by the polycondensation of nonanediamine and terephthalic acid. Though it is also semi-aromatic nylon, its melting point does not have to be lowered by copolymer modification before processing, as with PA6T. Pure PA9T has a melting point of 306°C. Its high glass transition temperature (125°C) along with its high crystallinity gives excellent toughness in a high-temperature environment.
In addition, compared with other PA materials, the chemical resistance of PA9T is very strong, second only to PPS, and the moisture absorption rate is as low as 0.17%, ranking first among all polyamides. The comprehensive performance is superior, and it is one of the best traditional heat-resistant nylons. In the future, with larger and larger scales of production, its cost will be close to that of standard PA materials. PA9T is a kind with very great development potential.
PA4T
With its position as the world’s leading producer of high-temperature nylon, PA46, DSM possesses the only industrialized process for producing tetramethylene diamine, a key raw material for synthesizing PA46. This technological edge has now enabled DSM to become the first company to develop PA4T, also based on this raw material.
It is also PA4T that represents a highly dimensionally stable, lead-free solder-compatible, high melting point, extremely hard, and mechanically strong at high temperature-first new polymer of the 21st century. These products feature ultra-low moisture absorption compared to DSM’s existing PA46 products and even PA9T.
With a performance that is balanced and super, PA4T will indeed have a very important impact in high-temperature service situations such as electronics, electrical equipment, and car-making industries. The market tendency of miniaturization and higher integration in an electronic product has driven invention for high-performance materials: that is, the appearance of PA4T.
PA10T
Chinese scholars like Cao Ming and Zhang Mingqiu have conducted systematic studies on the synthesis and copolymer modification of PA10T. Their results show that the pure PA10T has a high melting point of 319.1°C, and its excellent heat resistance gives it significant commercial potential. Domestic plastic modification leader Kingfa Sci. & Tech. Co., Ltd. has commercialized this technology.
In the 2009 Rubber & Plastics Exhibition, Kingfa launched a PA10T product with a brand name of Vicnyl. The material possesses excellent heat resistance, ultra-low moisture absorption, superior dimensional stability, and a lead-free soldering temperature resistance as high as 280°C. In addition, the chemical resistance and injection molding performance are superior.
Notably, nearly half of the raw materials for PA10T resin are derived from the castor plant, which makes this material bio-based and friendly to the environment, featuring excellent overall performance and high market competitiveness. The commercialization of PA10T filled the gap in China’s independent development of high-temperature nylon material. With this, Kingfa became the second domestic company after Shanghai Jesa to possess industrialized technology for high-temperature nylon.
Pros And Cons Of Nylon (Polyamide) Material
Like everything else in this world, everything has its positive and negative sides; nylon is no exception. What makes it a superstar, and where does it fall short? Join us as we weigh the benefits and drawbacks of this popular synthetic material.
Pros Of Nylon Or Polyamide Material
Nylon, or polyamide, is one of the more versatile and commonly used synthetic materials across a wide range of industries. The unique combination of properties in this material makes it ideal for applications ranging from textiles to engineering plastics. Below are some of the key advantages that make nylon a preferred material for manufacturers and designers alike.
- High mechanical strength, toughness, and excellent tensile and compressive strength: Nylon has a strong ability to absorb impact energy.
- Good fatigue resistance: Parts made from nylon can undergo repeated bending while maintaining their original mechanical properties.
- High softening point and heat resistance: Similar to Nylon 46, high-crystallinity nylons have a high heat deflection temperature and can be used long-term at 150°C. Glass fiber-reinforced PA66 can achieve a heat deflection temperature exceeding 250°C.
- Smooth surface with low friction and excellent wear resistance: When used in moving mechanical parts, nylon offers self-lubrication, operates quietly, and can be used without additional lubrication if friction is not excessive.
- Corrosion resistance: Nylon is highly resistant to alkalis and most salt solutions, weak acids, engine oil, gasoline, aromatic hydrocarbons, and common solvents. It is chemically inert to aromatic hydrocarbons and exhibits excellent aging resistance.
- Self-extinguishing, odorless, non-toxic, weather-resistant, and biocorrosion-resistant: Nylon also has superior antibacterial and antifungal properties.
- Excellent electrical properties: Due to its high volume resistivity, nylon does not easily break down under high voltage. It can be used as an engineering insulation material in dry environments and retains good electrical insulation even in high humidity.
- Lightweight, easy to dye, and easy to mold: With low melt viscosity, fast flow, high solidification point, and rapid injection molding capability, nylon supports short molding cycles and high production efficiency.
Cons Of Nylon (Polyamide) Material
hile nylon, or polyamide, has many of the reasons that make it popular in so many areas, there are still areas in which it does have its drawbacks. These limitations must be learned to know which material fits better for what. The following are some major disadvantages of nylon, which could result in it not performing correctly or serving well in particular situations.
- High moisture absorption: the absorption of water by nylon has a great impact on dimensions and accuracy for moulded parts, especially for thin wall parts. The mechanical strength of the plastic also decreases a lot. In material selection, the operating environment concerning temperature and required precision with other components should be considered together.
- Poor resistance to light: When exposed to high temperature, nylon, by reacting with oxygen present in air, undergoes oxidation. It first causes discoloration (browning) and finally results in cracking and disintegration.
- Injection molding has rigid requirements: Even a small amount of moisture can drastically affect the quality of molded products. Thermal expansion easily leads to a loss of dimensional stability. Sharp corners of molded parts can easily develop stress concentration and lower mechanical strength. Uneven wall thickness can easily lead to warping and deformation. Besides, the precision required by equipment in post-processing is very high.
- Not resistant to strong acids and oxidizing agents: Nylon is unsuitable in application involving resistance to acids.
Applications Of Nylon
Due to its superior properties, high-temperature-resistant nylon has been applied in more and more downstream areas in recent years. Along with increased market demand, it has found wide application in industries such as electronics, automotive manufacturing, and LED technology.
Electronics And Electrical Sector
Along with miniaturization, integration, and efficiency in the electronic and electrical industry, requirements related to properties such as the heat resistance of materials also became high. New SMT applications have started increasing the required temperature for heat resistance from 183°C to 215°C where the material has to tolerate 270–280°C. Traditional materials cannot satisfy this requirement. With excellent intrinsic properties like a heat distortion temperature higher than 265°C, superior toughness, and good flowability, high-temperature-resistant nylon can just meet the high-temperature resistance requirements for components in the SMT process. Some of the application fields, markets, and uses that high-temperature-resistant nylon sees are: connectors in 3C products, USB ports, power connectors, circuit breakers, motor parts, and many more.
Automotive Sector
With the improvement in consumer standards, the trends of lightweighting, energy efficiency, environmental friendliness, and comfort have become the target of the automotive industry. The advantages of vehicle weight reduction are saving energy, extending driving range, less wear of brakes and tires, extended lifespan, and most importantly, reduction in vehicle exhaust emissions.
In the automotive field, some traditional engineering plastics and some metal materials are being replaced with heat-resistant materials. Examples include chain tensioners manufactured with high-temperature-resistant nylon for engine areas, showing a lower wear rate than PA66 and better cost performance. Components made of high-temperature nylon also show a longer service life under corrosive environments at high temperatures.
In automotive control systems, high-temperature nylon is widely applied to such exhaust control components as housings, sensors, connectors, and switches due to its good heat resistance. Besides that, it is used in recyclable oil filter houses withstanding high temperatures from the engine, road impacts, and harsh weather conditions.In automotive generator systems, high-temperature polyamides can be applied to generators, starters, and micro-motors, further enhancing their performance and durability.
LED Industry
The LED industry is an emerging and rapidly developing sector. With advantages in energy efficiency, environmental friendliness, long lifespan, and shock resistance, LEDs have gained widespread market attention and acclaim. In the past decade, China’s LED lighting industry achieved an average annual compound growth rate of over 30% percent.
The high local heat from the packaging and manufacturing of LED products is highly demanding for the heat resistance of plastics. Currently, only high-temperature-resistant nylon materials are generally adopted by lower-power LED reflector brackets. PA10T and PA9T have become the staple material that supports large-scale production.
Other Fields
The advantages of heat-resistant nylon materials are excellent resistance to heat, low absorption of water, and a good dimensional stability that enables assurance of high strength and rigidity for the materials even under continuous service in humid conditions. They can replace metals in certain applications.
At present, using high glass-fiber-reinforced high-temperature nylon materials to replace metal is a growing trend for structural frames in products such as tablets, mobile phones, and remote controls. Materials such as Dupont Zytel HTN53, EMS Grivory GV, and Solvay IXEF high glass-fiber-reinforced series have already been adopted in this industry.
In fact, the low water absorption and good hydrolysis resistance make the PA10T materials even better suited than other high-temperature nylon materials to replace metal in the applications of water meter and water pump components. For example, the EMS Grivory CV series materials have already been extensively applied in this sector.
Choose The Right Nylon For Prototype Development
Are you designing a prototype and considering nylon? With the many types and properties, it can be very overwhelming to choose. Don’t worry, let’s walk through the key considerations to make your decision easier and more informed.
CNC Machining
At Ultirapid, we offer prototype nylon parts produced with CNC machining for customers. A project we did some time ago was to create plastic hook prototypes that are used with cords. We assisted our customers by first validating the size, structure, shape, appearance, aesthetics, and functionality with ABS prototypes made through FDM technology. After confirmation, we did the machining of the hook from nylon using our CNC equipment to test the strength. Finally, injection molding was used to produce the final parts.
3D Printing
Natural nylon raw materials have an off-white appearance in general, but are also easily available in black and white. Put it in another way, nylons are dyeable into any color. Easily filament form of the material is available, which would suit this material for 3D printing. The filament heats up to melting point, and while it is melted, it shapes 3D using a 3D printer.
Injection Molding
To enhance its tensile strength, nylon is often blended with a percentage of glass fibers in the process of injection molding; the percentage can be in the range between 10% and 40%. For hooks, the glass fiber content is even higher than 40%. The addition of glass fibers does increase strength up to a certain extent, but it also makes the material fail differently. Pure nylon tends to bend and yield before breaking, whereas nylon with a high glass fiber content fails suddenly and brittly, with minimal bending. Nylon reinforced with glass fibers is often labeled to indicate its composition, as for example “30% GF Nylon.”
Conclusion
Nylon is a revolutionary synthetic material that includes strength, flexibility, and versatility in its structure. Because of their varied properties and applications-from textile to industrial prototypes-they have become indispensable in modern manufacturing. Whether it’s a stretchable fabric, strong components, or lightweight solution, nylon has it. Understanding its characteristics and hence choosing the right type of nylon for your needs unlocks all of its potential for innovative designs and practical applications.
Final Thoughts
As a professional with over 15 years of CNC machining service experience, I’ve seen firsthand how crucial materials like nylon are in various manufacturing processes. Nylon, with its excellent strength, durability, and versatility, is a favorite for producing precision parts in industries ranging from automotive to aerospace. In our company, we often work with nylon, particularly for creating custom components that require flexibility, resistance to wear, and low friction. One of our successful projects involved machining complex nylon gears for a client in the robotics industry. The durability and lightweight nature of nylon allowed us to meet the high-performance standards required, ensuring longevity and precision.
At Ultirapid, we understand the unique properties of nylon, and we’re equipped to machine it to exact specifications. If you’re looking for reliable CNC machining services for nylon or other materials, our team can provide tailored solutions that meet your specific needs, ensuring both quality and cost-effectiveness.
Faqs
Is Nylon Waterproof?
Nylon is water-resistant but not completely waterproof. It has excellent moisture resistance, making it ideal for outdoor equipment, clothing, and other applications that come into contact with water. However, prolonged exposure to water or immersion can cause nylon to absorb moisture, which reduces its durability. To make nylon more waterproof, it is often treated with a waterproof coating or pressed with a waterproof layer.
Is Nylon A natural Or Synthetic Material?
Nylon is a synthetic material, not a natural one. It is a man-made polymer produced from petrochemical products, first developed by DuPont in 1935. Nylon is widely used in many applications due to its strength, durability, and versatility, including clothing, footwear, outdoor equipment, and industrial products. Unlike natural fibers such as cotton or wool, nylon does not come from plants or animals and does not naturally exist in the environment.
Can Nylon Be Injection Molded?
Yes, nylon can be injection molded. Nylon is well-suited for injection molding because it can easily melt under high pressure and form strong, durable parts with accurate dimensional precision. Nylon also has other beneficial properties, such as high strength and hardness, excellent wear resistance, and good chemical resistance, making it a popular choice for many applications, including automotive parts, gears, bearings, and electrical components.
Does Nylon Conduct Electricity?
Nylon is an insulating material. It is a synthetic polymer made up of long-chain molecules that do not easily allow charges to pass through them. Modifications to nylon can make it conductive, such as adding conductive fillers or incorporating conductive fibers. These modified nylons can be used in applications that require both conductivity and mechanical strength, such as electrostatic shielding or electromagnetic interference (EMI). However, in its standard form, nylon is not considered a good conductor of electricity and is typically used as an insulator in applications where conductivity is not required.
Is Nylon UV Resistant?
Nylon can resist UV to some extent, but its resistance to ultraviolet (UV) light depends on various factors, such as the specific form of nylon, the presence of additives, and the processing conditions. In general, untreated nylon is prone to UV degradation, which can cause it to become brittle, fade, and lose strength. To improve nylon’s UV resistance, manufacturers can add UV stabilizers during production, which help slow down the effects of UV degradation. The type and amount of UV stabilizer used can affect nylon’s UV resistance as well as other properties such as color fastness and durability.
Can Nylon Be Recycled?
Technically, nylon is recyclable, but the recycling process can be difficult, and not all forms of nylon are equally recyclable. Nylon is a synthetic polymer material that can be melted and remolded into new products, but the recycling process can be complex and is not as widespread as other materials like aluminum or paper. The recyclability of nylon may also depend on the specific form of nylon and the presence of other materials or additives. For example, Nylon 6,6 is easier to recycle than other forms of nylon, while nylon mixed with other materials, such as cotton, may be more difficult to recycle. Despite the challenges, efforts are being made to increase nylon recycling and reduce its environmental impact. This may include efforts to improve recycling processes, increase the availability of recycling programs, and encourage consumers to recycle nylon products.