Nylon

A Comprehensive Guide to CNC Machining with Nylon

About Nylon

Nylon, a synthetic thermoplastic material, has gained recognition for its exceptional mechanical characteristics, including high strength, stiffness, and toughness. Moreover, nylon exhibits resistance to wear, abrasion, and chemicals, positioning it as an optimal choice for demanding, high-performance applications.

One of the remarkable advantages of nylon lies in its versatility. It is available in various grades, each offering distinct properties suited for specific applications. For instance, nylon 6 and nylon 6/6 are commonly utilized grades, each with its own set of strengths and weaknesses.

Nylon has gained significant popularity due to its ease of machining and cost-effectiveness when compared to other engineering materials. Machining nylon can be accomplished with standard cutting tools, making it accessible for numerous manufacturers. It finds frequent application in the production of gears, bearings, and other mechanical components.

Nylon emerges as a versatile material boasting excellent mechanical properties, making it a sought-after option for a wide range of applications.

Subtypes

Nylon 66

Nylon 66, also known as polyamide 66, is a type of nylon material that is commonly used in various industries. It is a synthetic thermoplastic polymer made by combining hexamethylenediamine and adipic acid through a process called polycondensation. Nylon 66 is known for its excellent mechanical properties, including high strength, stiffness, and heat resistance.

One of the most significant advantages of nylon 66 is its ability to withstand high temperatures without losing its mechanical properties. This makes it suitable for use in high-temperature applications such as automotive parts, electrical components, and industrial machinery.

Nylon 66 is also known for its good chemical resistance, making it resistant to oils, solvents, and most chemicals. It is also resistant to abrasion, making it ideal for use in applications that require high wear resistance.

In CNC machining, nylon 66 is a popular choice due to its ease of machining and low cost compared to other engineering materials. Machining nylon 66 can be done with standard cutting tools, making it an accessible material for many manufacturers. It is commonly used in applications such as gears, bearings, and other mechanical components.

Overall, nylon 66 is a high-performance material with excellent mechanical properties, making it a popular choice in various industries. Its ability to withstand high temperatures and good chemical resistance make it suitable for use in harsh environments. As an expert in CNC machining, I recommend considering nylon 66 for your next project if you are looking for a material that is strong, durable, and easy to work with.

Surface Finishes

When it comes to surface finishes for nylon parts, two common options are bead blasting and dying. Both of these methods can enhance the appearance and functionality of nylon parts, but they have their own advantages and disadvantages.

Bead blasting is a process where small glass beads or other abrasive media are blasted onto the surface of the nylon part at high pressure. This process can create a uniform, matte finish that can hide any imperfections or blemishes on the surface of the part. Bead blasting can also improve the adhesion of paints and coatings to the surface of the nylon part.

One of the disadvantages of bead blasting is that it can weaken the surface of the nylon part by creating small surface defects, such as pits or cracks. Additionally, if the bead blasting process is not done properly, it can leave behind abrasive media on the surface of the part, which can cause problems during assembly or use.

Dying is a process where a dye is applied to the surface of the nylon part to change its color. This process can be used to create parts in a wide range of colors and shades, and it can also be used to create parts with custom logos or designs. Dying does not affect the surface of the nylon part, so it does not weaken the part or create surface defects.

One of the disadvantages of dying is that it can be difficult to achieve consistent color across a batch of parts, especially if the parts are different sizes or shapes. Additionally, the color of the dye may fade over time due to exposure to UV light or other environmental factors.

Overall, both bead blasting and dying are viable options for enhancing the appearance and functionality of nylon parts. Bead blasting can create a uniform, matte finish that can improve the adhesion of paints and coatings, but it can weaken the surface of the part. Dying can create parts in a wide range of colors and shades, but it may be difficult to achieve consistent color across a batch of parts and the color may fade over time. As an expert in CNC machining, I recommend considering the pros and cons of each option before selecting a surface finish for your nylon parts.

Design Tips

Design for manufacturability: Keep in mind the limitations of the CNC machining process and design parts that are easy to manufacture. This includes avoiding sharp corners and edges, designing with uniform wall thickness, and minimizing undercuts or complex geometries.
Account for shrinkage: Nylon has a relatively high coefficient of thermal expansion, which means that it will shrink as it cools after being molded or machined. To account for this, it’s important to design parts with enough clearance and tolerances to ensure proper fit and function.
Consider reinforcement: Depending on the specific application, it may be beneficial to reinforce the nylon part with additives such as glass fiber or carbon fiber. This can increase the part’s strength and stiffness, making it more suitable for high-stress applications.
Choose the right grade: Nylon is available in a range of different grades, each with its own specific properties and characteristics. Consider the requirements of your application and choose the nylon grade that is best suited for your needs.
Design for assembly: If your nylon part will be assembled with other components, it’s important to design it in a way that facilitates easy and reliable assembly. This includes features such as snap fits, mating surfaces, and threaded inserts.

FAQ

Can nylon be machined?

Yes, nylon can be machined using CNC machining or other machining processes. Nylon is a relatively soft material, which makes it easy to machine compared to other engineering plastics.

Which nylon is best for machining?

Nylon 6/6 is one of the most common and best types of nylon for machining due to its excellent mechanical properties and ease of machining. It has good dimensional stability, chemical resistance, and is relatively easy to machine using standard cutting tools.

Is nylon better than Delrin?

The choice between nylon and Delrin (also known as POM or acetal) will depend on the specific application requirements. Both materials have excellent mechanical properties, with nylon being slightly more flexible and impact-resistant, while Delrin is more rigid and has better dimensional stability. Nylon also has better chemical resistance than Delrin. Ultimately, the choice between the two materials will depend on the specific application requirements and performance needs.

What are the three types of nylon?

There are many different types of nylon, but three common types include:

Nylon 6: This type of nylon is known for its toughness, stiffness, and resistance to wear and abrasion. It is commonly used in applications such as gears, bearings, and bushings.
Nylon 6/6: This type of nylon has excellent mechanical properties, including high strength, stiffness, and heat resistance. It is commonly used in applications such as automotive parts, electrical components, and industrial machinery.
Nylon 12: This type of nylon is known for its flexibility and resistance to impact. It is commonly used in applications such as tubing, hoses, and cable insulation.