Polyamides, better known as nylons, are a class of polymers that have found their way into countless products and industries. Their versatility makes them an invaluable engineering plastic.
One of the most common types of nylon is 6/6 nylon (also written as nylon 6-6). It’s made from two monomers: hexamethylenediamine and adipic acid.
This article offers a comprehensive look at 6/6 nylon: its properties, advantages, and common applications. We’ll also compare it to another popular type of nylon, nylon 6, to help you understand which one might be better suited for your needs.
Understanding the Chemistry and Structure of Nylon 66
To really understand what 6/6 nylon is, it helps to understand the chemical structures that make it what it is.
Chemical Composition and Polymerization
Nylon 66 is created through a process called condensation polymerization. The monomers, or building blocks, used in this process are hexamethylenediamine and adipic acid.
As these monomers combine, water molecules are released, and long polymer chains are formed.
Molecular Structure and Properties
The arrangement of these polymer chains gives 6/6 nylon its semi-crystalline structure. That structure is what gives 6/6 nylon its strength, heat resistance, and resistance to various chemicals.
Key Material Properties of Nylon 66
Nylon 66 is a popular choice for many applications because of its robust physical, mechanical, and chemical properties. Here’s a quick rundown:
Physical Properties
- Density: Nylon 66 has a density of 1.14 to 1.15 grams per cubic centimeter (g/cm³).
- Melting point: It melts at a temperature between 255 and 265 degrees Celsius (491 to 509 degrees Fahrenheit).
Mechanical Properties
- Tensile strength: Nylon 66 is known for its excellent tensile strength, meaning it can withstand significant pulling forces. This makes it useful in applications where it needs to bear a load.
- Abrasion resistance: It also has high abrasion resistance, which means it can withstand friction and wear. In fact, it can withstand more than 60,000 abrasion cycles. This quality translates to a longer product life.
Chemical Properties
- Chemical resistance: Nylon 66 offers good resistance to many chemicals, oils, and solvents, making it a reliable material in harsh environments.
- Moisture absorption: Nylon 66 does absorb moisture, which can affect its dimensional stability. Its moisture regain is around 4 to 4.5%.
Why use nylon 6/6?
Nylon 6/6 is a popular choice in manufacturing and engineering for several reasons:
- It’s strong and durable. Nylon 6/6 can withstand significant stress and wear, making it suitable for high-demand applications.
- It resists heat. With a high melting point, nylon 6/6 performs well in high-temperature environments.
- It’s chemical-resistant. Nylon 6/6 resists degradation from many common chemicals, which contributes to its longevity.
- It’s easy to mold. Manufacturers can use nylon 6/6 in various molding processes, including injection, extrusion, and blow molding.
What is nylon 6/6 used for?
Nylon 6/6 is a versatile material used in a wide array of industries and consumer products. Its strength, durability, and resistance to heat and chemicals make it a favorite choice in demanding applications.
Automotive industry
Because it stands up to heat and chemicals, nylon 6/6 is used in high-tech auto parts, such as radiator grills, airbags, and battery modules.
Textiles and apparel
Nylon 6/6’s high tensile strength and resistance to heat make it a great choice for reinforcing tires. You’ll also find it in micro denier apparel like industrial workwear and sports gear, as well as in seatbelts and parachutes, where strength and reliability are critical.
Industrial and consumer goods
The wear resistance and thermal stability of nylon 6/6 make it an excellent choice for friction bearings. You’ll also find it in carpets and conveyor belts, where durability and resistance to abrasion are important.
Electrical and electronics
Because nylon 6/6 doesn’t conduct electricity, it’s often used in circuit insulation boards and switchgear.
Nylon 6 vs. Nylon 66: A Detailed Comparison
While both nylon 6 and nylon 66 are strong and durable materials, they do have some key differences.
Key Differences in Properties
- Melting point: Nylon 66 has a higher melting point (250° – 265°C) than nylon 6 (215° – 220°C).
- Heat deflection temperature: Nylon 66 also has a higher heat deflection temperature than nylon 6.
- Moisture absorption: Nylon 6 absorbs more water than nylon 66.
Performance Characteristics
- Abrasion resistance: Nylon 66 is more resistant to abrasion. In abrasion resistance tests, nylon 66 can withstand roughly 60,000 cycles, compared to nylon 6’s 40,000 cycles.
- Impact resistance: Nylon 6 is more flexible and has better elastic recovery, making it a better choice for applications where impact is a concern.
Application Suitability
So, which one should you choose?
- Choose nylon 66 for high-temperature, high-performance applications like tire cord and friction bearings.
- Choose nylon 6 for lighter applications where impact resistance is important, such as stadium seats and hosiery.
EuroPlas PA66 Engineering Plastic Compound
EuroPlas offers PA66 compounds that contain additives and reinforcements. This gives the plastic enhanced characteristics that you can’t get from standard nylon 6/6.
EuroPlas PA66 compounds have great mechanical strength, can withstand high temperatures, and resist a wide range of chemicals.
These properties make EuroPlas PA66 compounds useful in many different industries and applications. To learn more about how nylon 6/6 compounds can improve your products, contact EuroPlas directly.
Key Takeaways
Nylon 66 is a workhorse engineering plastic. It’s valued for its strength, its high heat resistance, and its resistance to many chemicals.
When you’re deciding between Nylon 6 and Nylon 66, keep in mind the specific needs of your application. What temperatures will it be exposed to? How important is impact resistance? Will it come into contact with harsh chemicals?
Nylon 66 continues to be an essential material across many industries because it offers a compelling mix of performance properties and ease of processing. Its versatility ensures its ongoing relevance in demanding applications.