CNC plastic machining is a versatile manufacturing process known for its high precision and accuracy. Another draw of using CNC plastic machining is that it is compatible with a broad range of plastic materials like ABS and Nylon.
Parts made with plastic CNC machining can fulfill a wide range of applications in the automotive, consumer electronics, and consumer goods sectors, to name but a few. In addition, their various properties—which we’ll look at in more depth below—offer strengths for particular material applications. For example, an impact-resistant material such as ABS is a popular choice for producing car parts or protective casings. This next section will explain factors that can help in picking the best CNC materials.
Factors to Consider When Choosing CNC Machining Plastics
Plastic machining has quite a few materials that machinists utilize. As a client, having to choose the best CNC material for a project yourself might be a tiring process. However, with experts such as RapidDirect, you can easily make a shortlist of the properties you need your material to possess.
To come up with this shortlist, you have to be able to answer some questions about the part satisfactorily. This will help clarify which properties are quite important and the ones that you can sacrifice. Examples of such questions include:
What Will You Use the Part For?
The structure of a part is always a result of its function. Hence, the function of your part will ultimately determine the material you should utilize for the plastic CNC machining process. The environment where you will use the CNC plastic part will have the most significant impact on material selection. For example, POM is the best choice if your plastic part will function in an environment that requires little or no friction in its operation. This is because the material is known to possess low friction, hence, making it suitable for the process.
Also, the specifications for the part design have a role to play in the selection of CNC plastic. For example, ABS or PMM will be suitable for parts that require a high level of tolerance. This is because both are two of the best machinable plastics. Hence this property makes them suitable for plastic machining of this nature.
How Strong and Temperature-Resistant must the Plastic Be?
There are different ways by which machinists measure the strength of plastic materials. They include wear resistance, tensile strength, and material hardness. Each of these terms has different meanings in plastic materials. Determining whichever suits your part will help in the selection of the best material for your CNC plastic machining.
Also, the temperature of the environment where you will use the part will be a quite important factor when choosing plastics. This is because making a wrong choice could lead to warping of the part or a loss of shape. This will definitely lead to a loss of function. Hence, choosing a material with high-temperature resistance when making a part for use in high-temperature areas is important.
This rule will also apply to environments where there is a high degree of fluctuation in temperature. Using materials with high-temperature resistance will help to ensure the materials expands and contracts minimally, leading to minimal changes in its dimensions over time.
The Cost of the Plastic
The cost of CNC plastic is just as important as any of the factors above. This is because the costlier the plastic, the higher the cost of production. This will also affect the cost of the finished part, which lead to low sales of the finished part. Hence, you should always consider your production budget before choosing any material.
Does the Part Require Post-Processing Treatments?
Some parts might require some post-processing treatments after machining to increase their aesthetic value. However, not all plastics are readily compatible with all types of finishes. Hence, you should also consider this when picking the plastic for CNC machining.
Various Plastics for CNC Machining
At RapidDirect, we offer a comprehensive portfolio of plastic materials for CNC machining, which we’ve evaluated based on their cost-effectiveness. (Note that the price of raw material can fluctuate depending on the market.) See our offering below:
Acrylonitrile Butadiene Styrene, or ABS, is a widely used CNC plastic, which meets the needs of many industries because of its material properties and accessible cost. ABS is one of the best machinable plastics with a low raw material cost. Both of these factors have led to the use of the material for many prototyping applications, as well as certain end-use applications.
In terms of properties, ABS has excellent impact resistance, as well as good temperature and chemical resistance. The high machinability of ABS leads to parts with high-quality surface finishes. Machined ABS parts can also undergo a number of post-processing treatments, including surface metallization, electroplating, bonding, and more.
POM, also known under the names Acetal and Delrin, is one of the easiest plastic materials for CNC machines. While easier to machine than ABS, the high-strength engineering plastic is slightly more expensive as a raw material, which influences its overall machining cost.
POM is known for its excellent wear resistance, low friction, strength, and dimensional stability. These material properties have led to the adoption of POM for various end-use plastic CNC machining applications, such as the production of gear bearings, automotive parts, consumer electronics, pipe components, and much more.
PMMA, also known as Acrylic, is a transparent CNC plastic material with good strength and stiffness properties. The plastic boasts good machinability and a low raw material cost, which makes it an appealing option for many manufacturers.
As one of the most commonly used plastics, you can see PMMA almost anywhere. Because of its transparency, machinists often use it as an alternative to glass in the construction, interior design, and chemical sectors. Machinists use this weather-resistant material in the construction of billboards and other signage.
PA, also known as Nylon, is a broadly used synthetic polymer with good mechanical strength, shock absorption, and wear resistance—among other properties. Though the cost of raw PA material is relatively low, the material’s medium machinability rate can affect the cost of certain projects—especially those that require tight tolerances and fine features.
It has widespread use for producing all kinds of structural parts and as a cheaper alternative to metal components. The material’s good electrical insulation and chemical resistance also make it appealing to plastic machining manufacturers across many industries.
PC, or Polycarbonate, is a transparent thermoplastic material with high strength and stiffness. PC’s most sought-after material property is usually its outstanding impact resistance. PC also has good machinability—meaning the cost of CNC machining the material is relatively low. However, the cost of raw PC—available in rod or plate format—is the highest of the CNC machining plastics.
In terms of applications, PC has widespread use in plastic machining for the automotive industry. They use it in the production of various car parts, like instrument panels, pumps, and valves. In other sectors, they also utilize this plastic material for producing protective gear, internal mechanical parts, medical devices, and more.
CNC Machining Plastics
Overall, the price of CNC machining plastic materials is significantly lower than metals because of the lower raw material cost. For this reason, CNC machining plastics are often a go-to for prototyping. Still, within the range of CNC machining plastics available at RapidDirect, some are more cost-effective than others.
If cost is your main priority when producing a prototype or end-use part, you should also consider how design can influence the cost of CNC machining. Find some useful design tips to keep your machining costs down here.
RapidDirect CNC Machining Services
Choosing the material to use for your plastic CNC machining process could be such a cumbersome task. This is especially true if you have to do it on your own.
However, if you need the opinion of experts on choosing the best plastic for CNC machining processes, there’s no better option than RapidDirect. We have a team of CNC machining specialists comprising designers, machinists, DFM specialists, and the likes. They work on different CNC projects to ensure they bring out the best results for your plastic machining processes.
At RapidDirect, we offer you only the best of CNC machining services. Contact us today to get the best CNC plastic parts.