Choose the Right Polymer for CNC Machining

Discover the price, material properties, and key applications of the most popular polymers used in CNC machining.

When CNC machining with polymers, how can you select the most suitable material?

A wide array of polymers, from Acryl to PVC, present unique attributes such as strength, flexibility, heat, and chemical resistance. These properties make them perfect for specific applications, so we’ve prepared this guide.

You’ll find a comprehensive overview of the most frequently used polymer materials in CNC machining, including their composition, significant benefits, and typical uses.

What Is a Polymer?

A polymer is a large molecule composed of many repeated subunits, known as monomers. These monomers are chemically bonded to form long chains, known as polymer chains. Polymers can be found naturally, such as in cellulose, proteins, and DNA, or they can be synthesized in a laboratory.

Synthetic polymers are created through a chemical process that combines monomers into a long chain. This process can be repeated multiple times to create a polymer chain with specific properties, tailored for various applications.

Price Overview

The polymer you choose affects the price you’ll pay for your component. In addition to the raw material cost, some polymers may involve additional machining expenses. This table shows the differences.

Material Overview

ABS

Overview: ABS is a common thermoplastic polymer typically used for injection molding applications. It’s composed of Acrylonitrile, Butadiene, and Styrene.

Benefits:

• High impact resistance

• Good machinability

• Excellent dimensional stability

Key Applications: Commonly used in automotive components, consumer electronics, and protective equipment.

Acryl (PMMA – Methyl Methacrylate)

Acryl, often known as PMMA or Acrylic, is a transparent thermoplastic primarily composed of polymethyl methacrylate (methyl methacrylate) with exceptional optical clarity.

Benefits:

• Excellent optical clarity

• Good weather resistance

• High light transmission

Key Applications: Used frequently in signage, lighting fixtures, and optical devices.

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High Density Polyethylene (HDPE)

High-Density Polyethylene (HDPE) is a thermoplastic polymer made from petroleum. It is well known for its high strength-to-density ratio.

Benefits:

• High strength-to-density ratio

• Good impact resistance

• Excellent chemical resistance

Key Applications: Often used in producing corrosion-resistant piping, and plastic lumber.

Nylon 6

Nylon 6 or Polyamide 6 (PA6) is a semi-crystalline polyamide with excellent wear resistance. Nylon 6, a polyamide, is related to amino acids, which are organic chemical building blocks contributing to the formation of complex structures in biological systems.

Benefits:

• High mechanical strength

• Good fatigue resistance

• Excellent wear resistance

Key Applications: Frequently used in the automotive industry, gears, and sports equipment.

Nylon 6 30GF 

Nylon 6 30GF is a 30% glass-fiber-reinforced nylon 6. It offers improved strength, stiffness, and temperature resistance.

Benefits:

• High strength and stiffness

• Good dimensional stability

• Excellent temperature resistance

Key Applications: Widely used in automotive under-hood applications and electrical and electronic parts.

PC

Polycarbonate (PC) is a thermoplastic polymer known for its transparency and high-impact strength.

Benefits:

• High impact strength

• Good electrical insulation

• Excellent optical clarity

Key Applications: Commonly used for bulletproof glass, eyewear, and compact discs.

PEEK

Polyether Ether Ketone (PEEK) is a semi-crystalline thermoplastic with excellent mechanical and chemical resistance properties.

Benefits:

• High chemical resistance

• Good mechanical properties

• Excellent thermal stability

Key Applications: Often used in the aerospace, automotive, and medical industries.

POM

Polyoxymethylene (POM), also known as Acetal, is a semi-crystalline thermoplastic known for its high stiffness and excellent dimensional stability.

Benefits:

• High stiffness

• Good dimensional stability

• Excellent wear resistance

Key Applications: Frequently used for precision parts requiring high stiffness, low friction, and excellent dimensional stability.

PP

Polypropylene (PP) is a thermoplastic polymer used in various applications. It is known for its toughness and resistance to chemicals.

Benefits:

• High toughness

• Good chemical resistance

• Excellent electrical insulation

Key Applications: Commonly used in packaging, textiles, and automotive components.

PTFE

Polytetrafluoroethylene (PTFE) is a high-performance fluoropolymer known for its non-reactivity, high-temperature resistance, and low friction.

Benefits:

• High-temperature resistance

• Low friction

• Excellent non-reactivity

Key Applications: Often used in non-stick cookware, electrical insulation, and seals.

PVC

Polyvinyl Chloride (PVC) is a widely used synthetic plastic polymer, produced through the polymerization of vinyl chloride. It’s known for its durability and cost-effectiveness.

Benefits:

• High strength

• Good flame resistance

• Excellent chemical resistance

Key Applications: Frequently found in pipes, electrical cable insulation, and signs.

Applications of Polymers in CNC Machining

Polymers are widely used in CNC machining due to their unique properties. Some common applications include:

  • Creating Prototypes: Polymers can be used to create prototypes quickly and inexpensively, allowing for rapid iteration and testing.

  • Producing End-Use Parts: Polymers can be used to produce end-use parts that require specific properties, such as chemical resistance or high strength.

  • Creating Molds: Polymers can be used to create molds for casting metals or other materials, providing a cost-effective solution for small to medium production runs.

  • Producing Composite Materials: Polymers can be combined with other materials, such as fibers or metals, to produce composite materials with enhanced properties.

Advantages of Using Polymers for CNC Machining

There are several advantages to using polymers for CNC machining, including:

  • Low Cost: Polymers are often less expensive than metals or other materials, making them a cost-effective choice for many applications.

  • Easy to Machine: Polymers are relatively easy to machine, which reduces production time and costs.

  • High Accuracy: Polymers can be machined to high accuracy, making them suitable for creating complex parts with tight tolerances.

  • Chemical Resistance: Many polymers are resistant to chemicals, making them ideal for use in environments where they will be exposed to harsh substances.

  • High Strength-to-Weight Ratio: Polymers can have a high strength-to-weight ratio, making them useful in applications where weight is a concern, such as in aerospace and automotive industries.

Challenges of Working with Polymers

While polymers have many advantages, there are also some challenges to working with them. These include:

  • Limited Thermal Stability: Some polymers can degrade at high temperatures, which can limit their use in certain applications.

  • Limited Chemical Resistance: Not all polymers are resistant to all chemicals, which can restrict their use in specific environments.

  • Difficulty in Bonding: Polymers can be difficult to bond to other materials, which can complicate assembly processes.

  • Limited Recyclability: Some polymers can be difficult to recycle, which can pose environmental challenges and limit their use in sustainable applications.

Overall, polymers are a versatile material that can be used in a wide range of applications, including CNC machining. While they have many advantages, there are also some challenges to working with them. By understanding the properties and challenges of polymers, manufacturers can choose the best material for their specific application.

Properties of Polymers

Polymers exhibit a wide range of properties that make them indispensable in numerous applications. Some of the key properties include:

  • High Molecular Weight: Polymers have a high molecular weight, which is the total weight of all the atoms in the molecule. This contributes to their strength and durability.

  • Chemical Stability: Polymers are resistant to chemical reactions, making them ideal for use in environments where they will be exposed to various chemicals.

  • Thermal Stability: Many polymers can withstand high temperatures without breaking down, which is crucial for applications involving heat.

  • Mechanical Strength: Polymers can be incredibly strong and resistant to deformation, making them suitable for structural applications.

  • Optical Properties: Depending on their composition, polymers can be transparent, opaque, or colored, which is useful for applications requiring specific visual characteristics.

Choosing the Right Thermoplastic Polymers

One of the key advantages of CNC machining is the extensive range of materials available. At MakerVerse, we can provide materials beyond our standard offerings. With our global supply chain, we’re ready to deliver your needed parts, including those made from natural rubber for specific applications.

If you require further assistance in choosing the right polymer for your CNC machining project, we’re here to help. Upload your part and specify your request in the comments when requesting a quote. Our team of experts is eager to assist.