Everything you need to know about Nylon
Wallace Carothers first invented Nylon in 1935. He worked for DuPont then, and Nylon quickly became a popular product for the company. Nylon is used in various applications, including clothing, textiles, carpets, and articles of thing.
What is Nylon?
Nylon is a synthetic fabrics formally known as Polyamide; Polyamide is a synthetic polymer made from two monomers: diamine and dicarboxylic acid. It is produced by the reaction of these monomers in the presence of a catalyst, typically zinc chloride. It is often used in producing textiles, engineering plastics, and coatings. Polyamide has many desirable properties, including high strength, low weight, and resistance to wear and tear.
The plastic properties of nylon
“Nylon” material has “strong” physical properties, the main reason is from the chemical formula “-CONH,” take PA6 for example, because of its -CONH chemical formula, so it has considerable stability and heat resistance. Still, because the amide group has good hydrophilicity, So the hygroscopic property of nylon fabric is very high, which also gives many manufacturers who want to use Nylon to mold the production of goods caused some trouble, but now can use drying equipment before production to pre-bake nylon fabrics (moisture content below 0.2%, Some PA plastics even require water content below 0.05%) to overcome the problem of water brittleness when Nylon is heated.
In addition, even after injection molding, NYLON continues to absorb moisture from the air until it is saturated. Miraculously, when water is added to the NYLON’s molecular chains, it “toughens.” Also, because Nylon fibers still will continue absorbing water swelling after injection molding, so that cause the size of the nylon injection products after controlled not easily, even bending deformation caused by the wait for a phenomenon, which is very rare in other plastic materials to the phenomenon, so the evaluation using the Nylon for injection at the beginning of the finished product development will advance simulation after injection of water absorption and swelling of the problem, Even before the development of plastic mold to reserve the mold can be modified space.
Some people call this phenomenon of plastic absorption and swelling as it is ejected “water absorption.” Still, it is the first time “Gavin Leo” has heard it, as the definition of backwater is like a water trunk or a whirlpool of rivers that flow back after passing through obstacles.
Nylon will inevitably absorb water and grow in size after being ejected; if you want to accelerate the ejected Nylon to a saturated and stable size, you may want to consider boiling the ejected Nylon in hot water for 2 hours or placing it in hot steam for an hour to achieve this.
What are the different types of Nylon and their applications?
There are various types of Nylon, each with its properties. The most common types of nylon are: Nylon PA6,Nylon PA66,Nylon PA610,Nylon PA1010.
Discirption: Fatigue strength of steel, heat resistance is lower than nylon 66, but good elasticity, vibration, and noise reduction ability. The appearance is generally white.
Application: Mainly used in light load, medium temperature (80-100), no lubrication or little lubrication, low noise requirements of the working conditions of wear-resistant force transmission parts. For Example, Nylon textiles, Nylon stockings, Automotive parts, gears, bearings, and rollers.
Discirption: This is the most widely used type of Nylon, thanks to its combination of properties. Nylon PA66 is strong, elastic, and resistant to abrasion. It can also be easily molded and extruded. High fatigue strength and stiffness, good heat resistance, low friction coefficient, and good wear resistance, but high moisture absorption and dimensional stability are not enough.
Application: Mainly used for medium load, operating temperature & LT; 100-120 degree wear-resistant force transmission parts working without or with little lubrication. Examples: Automotive parts, electronic equipment parts, gears, hair combs, bearings, fishing nets, sleeping bags.
Discirption: Rigid heat resistance is lower than nylon 66, moisture absorption is lower than nylon 610, good molding process, and good wear resistance.
Application: It is used for the production of light load, the temperature is not high, working in a dry or wet environment under the condition of no lubrication or less lubrication of the parts.
Discirption: Rigid heat resistance is lower than nylon 66, moisture absorption is lower than nylon 610, good molding process. and low cost, good economic effect, excellent self-lubrication and wear resistance, good oil resistance, low brittle conversion temperature (about -60℃), high mechanical strength.
Application: Mainly used for the production of light load, the temperature is not high, humidity changes, under the conditions of no lubrication or less lubrication under the condition of the work of the parts. Widely used in mechanical parts and chemical and electrical parts.
All Type of Polyamide material:
- Nylon PA6
- Nylon PA66
- Nylon PA11
- Nylon PA12
- Nylon PA46
- Nylon PA610
- Nylon PA612
- Nylon PA1010 ect.…
Application of Nylon Production
Nylon is used in various applications thanks to its combination of properties. Here are some of the most common uses for Nylon:
– Clothing: Nylon is often used in clothing, especially sportswear. Thanks to its strength, water resistant, elasticity, and abrasion resistance, Nylon is the perfect material for activewear.
– Car parts: Nylon is commonly used in car parts, thanks to its strength and heat resistance. Nylon is often used in engine covers, fuel lines, and dashboard components.
– Gear wheels: Nylon synthetic material is often used to make gear wheels, thanks to its low friction coefficient and resistance to wear.
– Bearings: Nylon bearings are common in various applications, thanks to their low friction and resistance to wear.
– Fixtures: Nylon fixtures are common in manufacturing and assembly operations, thanks to their durability and resistance to scratches and bumps.
– Engineering plastics: Nylon is a synthetic materials, it is often used in engineering plastics, thanks to its strength, flexibility, heat resistant, and ease of processing.
What are the benefits of Nylon?
Nylon has a wide range of benefits, thanks to its properties. Here are some of the most notable benefits of Nylon:
– Strength: Nylon has high strength and elasticity. It is also tough and resistant to abrasion. It is one of the strongest synthetic fibers.
– Elasticity: Nylon is also very elastic, making it ideal for clothing and other applications where flexibility is important.
– Abrasion resistance: Nylon is resistant to abrasion, making it ideal for activewear and other applications where durability is important.
– Heat resistance: Nylon has a good balance of thermal stability and heat resistance. It can be used at temperatures up to 200°C (392°F), making it ideal for car parts and other applications where heat resistance is important.
– Chemical Properties: Nylon is resistant to many chemicals, including oils and greases.
– Low friction: Nylon has a low friction coefficient, making it ideal for gear wheels and other applications where low friction is important.
– Wear resistance: Nylon is resistant to wear, making it ideal for bearings and other applications where wear resistance is important.
– Dimensional stability: Nylon is dimensionally stable, meaning it retains its shape and size under stress. It makes nylon ideal for a wide range of applications.
– Ease of processing: Nylon is easy to process, making it ideal for engineering plastics and other applications where ease of processing is important.
Nylon is often used as fixtures in manufacturing and assembly operations, especially for fixtures that require motion or where fixtures need protection from scratches and bumps when they come into contact with the product.
What are the drawbacks of Nylon?
Nylon has a few drawbacks, depending on the application. Here are some of the most notable drawbacks of Nylon:
– Moisture absorption: Nylon absorbs moisture from the atmosphere, which can cause it to swell and degrade over time. It is a problem in applications where Nylon is exposed to high humidity or repeated wetting and drying cycles.
– UV sensitivity: Nylon is sensitive to UV light, meaning it can degrade and become brittle when exposed to sunlight. It is a particular problem in outdoor applications.
– Chemical sensitivity: Nylon is also sensitive to some chemicals, which can degrade when exposed to certain solvents or cleaning agents. It is a particular problem in applications where Nylon is exposed to harsh chemicals.
What is the difference between Polyamide and POM?
Polyamide is a generic designation for a family of related nylons. POM is an acronym (polyoxymethylene) that stands for one specific type of Polyamide, also known as acetal. Its strength and rigidity characterize POM, low friction, wear resistance, and good chemical resistance. It is often used in gears, bearings, and other mechanical parts. Polyamide is a generic term that covers all nylons, while POM refers to one specific type of Nylon. Both materials are thermoplastic polymers with a wide range of applications.
Nylon and POM look similar in appearance and touch. Still, the friction coefficient of POM is smaller, the size is more stable than Nylon, and the mechanical strength, toughness, tensile and compressive strength of Nylon is better, so if you need a relatively good size and mechanical strength requirements are not high, the POM material will generally be used.
How do we improve the dimensional stability of nylon products?
If you want to improve the size of Nylon after injection, swelling is not easy to control; so far, it seems that the only way to do plastic modification is to add Glass Fiber, also known as “nylon + Fiber.” Since Nylon is a semi-crystalline thermoplastic material, its physical properties and shrinkage rate will change significantly after adding glass fiber. Basically, after adding glass fiber modification, better mechanical strength and hardness can be obtained, higher thermal deformation temperature will be achieved, and shrinkage rate will also decrease.
But nylon toughness declines after adding glass fiber modification will get a higher melting point; obvious shortcomings also produce this change, is the injection operation “（fusion line, welding line)” will be more obvious, and the fusion of bonding strength will become worse, once the product is under stress rupture is easy to start from the position of the fusion line.
Secondly, if the alignment of glass fiber is not well done, it will lead to uneven stress distribution and may cause warping and deformation of the ejecting product. Although it can be improved by moving the position of the glue injection port, it is better to consider the service characteristics of the product before evaluating whether to add glass fiber modification. In addition, before opening the mold, we must do a good job in advance of the glass fiber alignment evaluation and reserve the possibility of glue mouth change.
Gavin Leo is a technical writer at Aria with 8 years of experience in Engineering, He proficient in machining characteristics and surface finish process of various materials. and participated in the development of more than 100complex injection molding and CNC machining projects. He is passionate about sharing his knowledge and experience.