Computer numerical control (CNC) plastic machining has rapidly emerged as a preferred technique for producing plastic components with tight tolerances. While there are many manufacturing methods for processing plastics — from commodity resins to high-performance thermoplastics — CNC plastic machining has carved out a niche due to the specific benefits it can provide.
But before you can understand what advantages CNC plastic machining can unlock, you have to go back to the basics and dive deeper into what CNC plastic machining is all about.
What Is CNC Plastic Machining?
CNC plastic machining is known as a subtractive manufacturing process that involves cutting a solid block of plastic and creating parts out of it. To understand the process of CNC plastic machining, let’s take a look at some of the most commonly used methods below.
Methods of CNC Plastic Machining
CNC machining uses a computer-generated and controlled machine to remove parts of the plastic polymer to create a specific product. Because of this, it ensures uniformity, accuracy, and high tolerance. The methods involved in making an end-product include:.
- CNC Turning: This is a specific technique that holds the workpiece on a lathe and rotates it against a cutting tool by turning or spinning the plastic around. Under this method, there are two types of turning: cylindrical or straight CNC turning, which is suitable for considerably larger cuts, and taper CNC turning, which is best used for cone-line shapes. Depending on what you’re working with, the type of CNC turning method may vary.
- CNC Milling: Another method of CNC machining is known as milling. This method utilizes a milling cutter to shave off specific parts of the workpiece to produce a desired outcome. Much like CNC turning, there are also different types of milling methods to choose from, which can be divided into two mills: three-axis mills and multi-axis mills.
As the name implies, the three-axis milling machine can move in three axes, mainly left to right, up and down, and back and forth. As a result, it’s best for projects with simple designs. The multi-axis milling machine, on the other hand, can move more dynamically, making it a great solution for more complicated geometries.
- CNC Drilling: Plastic drilling uses a drill to make a hole in a workpiece. The size and shape of the hole will depend on the type of drill bit used.
- CNC Broaching: In relation to drilling, if you don’t have the right drill bit but want to enlarge the hole you’ve created, you can explore a method known as broaching. This can effectively widen the diameter of a hole while improving the overall quality of the plastic’s finish.
Experience plastic manufacturing excellence: Connect with our team today to learn about Ensinger’s capabilities.
Different Plastics Used in CNC Machining
One of the reasons why CNC machining is so popular across various industries is that it’s compatible with a wide selection of plastics. Because of this, many enterprises can manufacture plastics at a more convenient rate as opposed to other alternatives.
Take a look at some of the most common plastic materials used to accomplish this process.
- Polyetheretherketone (PEEK): PEEK is a high-performance thermoplastic that’s popular for its unique combination of mechanical and chemical properties. This type of plastic can resist chemicals, fatigue, liquids, and wear. What’s more, it can withstand temperatures up to 480°F. On top of this, PEEK is lightweight, durable, insoluble to common solvents, and strong enough to endure harsh conditions. Overall, PEEK is a desirable material to work with in terms of CNC machining.
- Acrylonitrile Butadiene Styrene (ABS): ABS is another popular thermoplastic in engineering known for its heat resistance, impact resistance, and impeccable machinability. It’s a good insulator, and it remains mechanically stable over long periods, which makes it a great option for electrical applications.
Much like PEEK, this kind of plastic is also strong and lightweight, but it’s not resistant to wear, solvents, or alcohol. Unless treated with heat stabilizers, ABS is susceptible to burning. It’s important to keep this information in mind when choosing the best material for your project.
- Polyamide (PA): More commonly known as nylon, this material is a low-friction thermoplastic that has high impact strength, chemical resistance, and abrasion. It also has excellent mechanical properties. Because of this, it’s well-suited for a wide range of applications across industries, such as medical and automotive.
- Polyacetal Polyoxymethylene (POM): Commercially known as Delrin, POM is considered to be one of the most machinable CNC plastics, especially when businesses need a plastic with incredible wear, weather, heat, fuel, and chemical resistance; high strength; and high stiffness. In addition, POM is also a great option for product teams to create precise parts because it features outstanding dimensional stability.
- Polytetrafluoroethylene (PTFE): PTFE is a high-performing polymer that’s a versatile chemical-, light-, temperature-, water-, weather-, fatigue-, corrosion-, and UV-resistant type of plastic. It’s also known for its exceptional anti-adhesion properties. Because of this, it’s most commonly found in kitchen appliances, as well as many other semiconductor parts. While Ensinger PC does not work with pure PTFE, some of our materials are made with a percentage of PTFE.
The Benefits of CNC Plastic Machining
Aside from being compatible with a wide variety of plastics, CNC machining also offers many user benefits.
Precision and Accuracy
One of the advantages of this manufacturing process is its ability to create plastic products with great precision and accuracy. Since the machine depends on a computer-generated design, it only follows a specific flow. What’s more, it has tight tolerances, leaving almost zero room for mistakes.
Support for Prototyping
Another advantage is that CNC machining supports prototyping. With its accuracy and precision, you will be able to produce and reproduce identical products at a high volume. Even if your design has complex shapes, CNC machining can generate large quantities of the same shape and size with the same high quality.
Cost-effectiveness and Speed
Whether you plan to produce small or big batches, CNC machining is one of the most cost-effective solutions you can explore. Unlike other traditional methods that may require a series of manufacturing processes and take a lot of time, CNC machining can accomplish everything you need in one go. What’s more, it’s fast and efficient.
Applications for CNC Plastic Machining
As a versatile plastic manufacturing process, CNC machining is an excellent option for businesses in different sectors. Below are some of the most common industries that utilize this solution.
Manufacturing aerospace parts requires high accuracy, precision, and tight tolerances. Because of this, the industry relies heavily on CNC machining to design, test, and build various aerospace products.
On top of its ability to guarantee precision in every production, CNC machining also works with lightweight, heat-resistant, chemical-resistant, and durable materials that are essential for this particular sector.
CNC plastic machining is also applicable in the medical field. The process is often utilized to create medical devices such as artificial hearts and prosthetic limbs. The repeatability and high degree of accuracy of CNC machining meet the strict safety standards of the industry. Moreover, its plethora of material options and ability to produce complex shapes make it a beneficial method for the medical field.
Engineers and car designers use CNC machining to make prototypes of different automotive components in real-time. It enables them to customize each part and see how every component fits into place. With its lightweight materials and heat-resistant features, CNC plastic machining can help car designers build efficient and practical parts.
The electronics sector also favors CNC machining primarily because of its repeatability and high precision. The sector’s specialists can develop plastic electronic components like device keypads, LCD screens, and wire enclosures with so much ease.
While CNC plastic machining is an effective approach to accommodate a wide range of applications across various sectors, there are also other alternatives you can explore, such as injection molding.
As opposed to CNC machining, injection molding is the process of shaping or reshaping plastic particles by injecting a heated substance into a mold. It applies to a wide range of plastic materials and industries, making it an excellent alternative to CNC machining.
Do you need injection molding? Find the right custom injection molding partner to tackle complex designs that focus on versatility, functionality, and durability.
Experience Ensinger Excellence in CNC Plastic Machining
Ensinger Precision Components specializes in advanced manufacturing services, including CNC machining and injection molding. We are a leader in the industry, engineering thermoplastic components, molding high-performing materials, and offering essential finishing capabilities to add value to your operations.
Recently, we have acquired assets of Poly-Tech Industrial, Inc., which is known for offering technically-oriented solutions that combine their expertise in high-performing materials and practical applications.
Much like us, Poly-Tech has had experience with CNC machining and fabricating parts. That’s why we believe that our acquisition will enable us to expand our services into prototyping and product design, which will ultimately increase customer value.
Connect with our team today to achieve more in plastic manufacturing with essential CNC machining services.