When it comes to high precision, excellent processing accuracy, and reliable machining option, then predominantly CNC machining serves this purpose most effectively and comprehensively. Computer numerical control machining comes amongst the most efficient and errorless machining processes. Along with its numerous characteristics, it offers a large category of materials to be machined such as plastic.
If you are looking for in-depth knowledge about plastic CNC machining then it’s a must-read piece of writing for you. And it is highly recommended that you read till the end. In this article, you will be thoroughly elaborated on the role of plastic in CNC machining, and its applications in different industries. Also, the advantages and limitations of plastic CNC machining will be discussed. In the end, numerous different plastic types and their prominent attributes will also be discussed.
Plastic CNC machining offers manufacturing of small quantities to mass production. For low-volume plastic parts manufacturing, the production process is often faster and more efficient as compared to the other rapid prototyping technologies, and is considered more preferable when the manufacturing quantity between 1 and 10 parts and sizes greater than 600 mm.
What is Plastic Machining
Plastic CNC machining is a machining process that uses computer numerical controlled tools to remove material from plastic parts, it can be used to create complex shapes and geometries including those with complex curves and angles.
Plastic CNC machining is a versatile manufacturing process that can be used to produce parts for a wide range of applications. The most common plastics that are machined are acrylic, polycarbonate, nylon, delrin, and PEEK.
Common Types of Plastics in Use
There are many types of plastics that machinists utilize in plastic CNC machining. The selection of a particular material depends on the requirements, qualities, and properties of the part to be manufactured. Below we discuss a few of them that have excellent qualities in plastic prototype machining.
Nylon, which is called polyamide too, is a general-purpose machining material. It comes in many different grades. Its characteristics include good elasticity, its washable and dyeable, and can also to bear against high levels of heat. Nylon finds its applications in the manufacturing of parts like automotive parts, parachute canopies, etc.
ABS stands for Acrylonitrile Butadiene Styrene. It’s a favorable choice when it comes to good toughness and strength because of its excellent chemical and thermal stability. ABS is a terpolymer being manufactured by applying a polymerization process to styrene and acrylonitrile in the presence of polybutadiene. Its general properties include high rigidity, good insulating properties, high dimensional stability, and high surface brightness. ABS finds its applications in the making of parts like refrigeration components, control panels, keyboard keys, etc.
POM stands for Polyoxymethylene (that is known as Delrin, polyacetal, or acetal too). It is an engineering thermoplastic and its properties include low moisture sensitivity, good electrical conductivity, high strength, and toughness, etc. POM finds its applications in the manufacturing of parts such as automotive clips, seatbelt adjuster, etc.
PC stands for polycarbonate. This material also finds very helpful in making excellent plastic prototyping. Generally, polycarbonates are strong, stiff, hard, and tough engineering thermoplastics. It is used in plastic CNC machining for making different parts like Blu Ray discs, swimming goggles, etc.
- PP Machining
PP stands for polypropylene (also known as polypropene) is a hydrocarbon polymer. PP is one of the most commonly produced plastics in the world. Polypropylene is such a thermoplastic that offers an excellent blend of physical, chemical, mechanical, thermal, and electrical properties. Its properties include excellent chemical and electrical resistance, low cost, lightweight, good fatigue resistance, recyclable, and excellent weldability. As PP offers outstanding adaptability therefore it is usually referred to as ‘steel of the plastic industry’. PP finds its applications in plastic parts for various industries like the automotive industry, special devices like living hinges, and textiles, etc. • PEEK PEEK stands for polyether ether ketone, is a semi-crystalline engineering thermoplastic, and is preferred in high-performance part productions. During machining, PEEK has a high tendency to break due to high temperature and high internal stress. Therefore, a seasoned worker needs to deal with it. Its properties include excellent chemical resistance, low moisture absorption, excellent strength, and wear resistance. During machining, it shows high accuracy, tight tolerances, and high repeatability.
Plastic Machining Processes
CNC Turning
Plastic CNC turning process begins with a block of plastic, which is mounted on a lathe. The lathe is then operated using a computer program to cut the desired shape out of the block of plastic.
Plastic CNC turning is a great way to create parts with a high degree of accuracy and repeatability. The process is also relatively fast, making it an efficient method for mass production.
CNC Milling
Plastic CNC milling is a process where computer numeric controlled mills are used to remove material from a workpiece. Plastic CNC milling is a versatile manufacturing process and can be used to create intricate designs or to mass produce parts.
The first step in plastic CNC milling is creating a computer model of the desired part or product. This can be done using computer aided design (CAD) software. Once the CAD model is complete, it is converted into a format that can be read by the CNC milling machine. The next step is to setup the CNC milling machine. This includes loading the appropriate cutting tools and selecting the correct milling parameters.
After the machine is set up, the actual milling process can begin. The cutting tools are controlled by the CNC milling machine and remove material from the workpiece according to the computer model.
CNC Drilling
Plastic CNC drilling is a process where computer numerical controlled (CNC) machines are used to drill holes into plastic, it is an efficient and versatile way to create a variety of hole sizes and shapes in plastic materials.
Drilling will generate more heat than most other machining processes, so it’ll bring a problem for those heat-sensitive materials like plastics. There are a few ways to reduce heat when drilling plastics with CNC machines. One method is using coolant, which helps to dissipate heat and keeps the drill bit and workpiece cool. Another option is to use a lower feed rate, which will generate less friction and heat. Additionally, drilling holes in plastic is best done with spur-point drill bits, they have a cutting edge on both the periphery and on the end, so they can be used for both drilling and counterboring applications. The main advantage of spur-point bits is that they create a very clean, round hole with little to no chipping on the exit side. These bits can also be used in handheld power drills and drill presses. The point and angle in front of these bits guarantee smooth cutting and reduce the stress in front.
Despite the challenges, plastic CNC drilling is still a widely used and effective way to create holes in plastic materials. This process can be used for a variety of applications, including creating ventilation holes, mounting hardware, and more.
Threading
Plastic CNC threading tapping is a process that can be used to create internal threads in plastic parts. This process is typically used for creating small, precise threaded holes. A CNC machine is used to create the threads, and a tapping tool is used to create the actual threading. The tapping tool is inserted into the hole and then rotated. The rotation of the tool cuts the threads into the plastic.
This process can be used to create both functional and decorative threads in plastic parts. It is often used for creating electrical connections or for attaching two plastic parts together. Plastic CNC threading tapping is a relatively quick and easy process, and it can be used to create very precise threads.
How Plastic CNC Machining is Used in Different Industries
Many different industries use plastic CNC machining services because of their efficiency and durability, and the industries are as follows
- Aerospace Industry
The crucial industries like aerospace where the tiniest mistake may lead to catastrophic outcomes. That will not only cause losing a great amount of money but precious human lives too. Therefore, after finalizing a part and rather directly fixing it into hefty airplanes, it is preferred to pre-judge the durability of the part. To do so, a prototype of the part is manufactured using plastic CNC machining.
This advanced prototyping technology offers a great deal to check the durability of the parts. So, any disastrous happening can be avoided due to an error in the parts. Apart from manufacturing plastic prototypes, different aircraft parts like fuselages, rudders, ventilation ducts, etc., are also manufactured using the plastic CNC process.
- Military and Defense Industry
Military and defense industries rely on plastic CNC machining for the production of their numerous important plastic parts. These plastic parts offer great durability and serve as prototypes for the testing of complex designs. From the manufacturing of the parts to be used in their communication devices to parts fixing in their vehicles, plastic CNC machining plays a vital role in the military and defense industry.
- Medical Industry
The medical industry requires the production of some specialized equipment to be used to carry out some critical processes and in the manufacturing of different medicines. Some categories of plastic offer these special properties required in the manufacturing of this equipment and machines.
As the medical field is evolving expeditiously and the demand for new equipment is also rising. But some equipment requires a high level of purity, safety, and sterilization. This means the equipment will be exposed to extreme levels of sterilization regularly. So, to meet this demand, certain plastic types are found highly suitable. Other than this, medical equipment like sterilization trays, surgical equipment, imaging equipment, etc. is made using plastic CNC process.
- Electronic Industry
Plastic CNC machining is extensively used in the manufacturing of many electronic devices. These devices require efficient plastic components that comprise a complex electronic product. Electronic devices such as circuit breakers, switchgear, lighting fixtures, electrical components, telephone handsets, keyboards, monitors, computer housings, etc. are manufactured using the plastic CNC process.
Advantages of Plastic CNC Machining
There are several reasons why you should prefer plastic for your part manufacturing. It depends on your product requirements when to choose this technology. But if your requirements are fulfilled using other technologies than the plastic CNC process, but why you still rely on this technology? So, numerous advantages make using plastic a wise choice for your product manufacturing and are discussed below
- Faster Prototype Turnaround
Creating prototypes to test the efficiency and durability of your part design before going into mass production. It saves a lot of time, and money, and helps in maintaining project schedules. But when it comes to a faster and more economical prototyping process, then plastic CNC machining is the best choice. The reason is, creating a prototype using this technology does not require any mold-making. That offers faster prototype turnarounds.
- Offer Higher Tolerances
When it comes to manufacturing high-precision parts, then such machining technologies and materials are preferred that offer higher tolerances. Because higher tolerances are one of the key factors that ensure high-precision part productions. So, the plastic CNC machining process offers outstanding higher tolerances. And is used in many crucial industries for the production of high-precision parts.
- Offers Economical Process
The plastic CNC machining process is comparatively economical. Because it does not require any extra money and time to be wasted on making the molds for the products to be manufactured. For example, if you choose injection molding for your part production then be ready to spend more resources than the plastic CNC process on mold generation.
- Offer Greater Resistance to Corrosion and Chemicals
The parts manufactured using plastic than the ones that are made of metal materials have the advantage of not being rusted. Because plastic material generally offers greater resistance to corrosion and chemicals.
Preferred Use of Plastic CNC Machining
Sometimes, it becomes hard to decide whether plastic CNC machining will work out efficiently for what it is intended to fulfill. Now, the question arises, how will you come to know? So, don’t worry! If your production requirements meet the following criteria then it’s good to go with plastic CNC technology.
- When you have a limited budget for your project.
- When you require the production of parts for visual and functional tests.
- When you require faster product or prototype turnaround.
- When you have to ensure mechanical, aesthetic, and thermal material validation.
- When you require low part production.
- When you have to test the efficiency and durability of your part design.
If you think that you fall in any of the above-mentioned statuses or are confused about making the right decision then don’t worry. You can CONTACT US. We can guide you in the best possible way to maximize your productivity.
Plastic Machining Tips
this section we’ll explore some useful tips when manufacturing machined plastic parts, follow them to achieve better results.
Stress-relieving of plastic materials
stress-relieving is necessary to ensure dimensional stability of the final product. Heat-treating or annealing the stock prior to machining can help reduce the amount of internal stress.
Control thermal expansion
Thermal expansion must be considered when machining plastics. The amount of expansion or contraction can vary depending on the plastic material and the temperature changes that it will experience in its intended application.
To avoid dimensional issues, machine the part at the temperature that it will be used in. If this is not possible, take measurements of the part at different temperatures and account for the expansion in your machining process.
Adequate cooling and the feeding of machine tools
Excessive force or speed while machining can cause the material to deform, so it is important to use the correct tooling and operating speeds. When drilling, reaming, or tapping blind holes, it is necessary to break through the surface film to avoid tear out. A safe way to do this is by using a small diameter drill bit followed by the larger tool. When threading, it is important to use a oil-based lubricant to prevent the material from galling. Chamfering the edges of the workpiece can also help prevent tearing.
Plastic materials tend to be very sensitive to heat build-up, so it is important to use lower cutting speeds and provide adequate cooling. lighter cuts with frequent chip removal will help to prevent heat build-up and tool failure. When using a CNC router, it is important to use sharp tools and smaller stepover values to avoid tool marks on the surface of the workpiece.
Personal protective equipment
Plastics release harmful decomposition when heated. When machining plastics, always use proper ventilation and personal protective equipment, such as a dust mask or respirator, safety glasses or goggles and gloves.
In conclusion, following these tips will help you successfully machine plastic materials. By stress-relieving the material, controlling thermal expansion, and using the proper tooling and operating speeds, you can produce high quality parts with little to no dimensional issues. Always remember to use proper ventilation and personal protective equipment when working with these materials.
Conclusion
If you are looking for any plastic prototyping or customized parts manufacturing then you are at the right place. We offer advanced plastic CNC machining and prototyping services with high-temperature and high-strength plastic materials. We are amongst China’s leading state-of-the-art CNC machining workshops. We guarantee excellent accuracy and durability. Our team consists of seasoned and well-reputed engineers and technicians and these are amongst the greatest minds in the industry.
If you need our services, JUST CONTACT US. Our team will take care of the rest. We assure excellent quality and we are ISO9001 certified. In wherever part of the world, you are, don’t worry. We ship globally. We have earned the trust of more than 600 clients globally. Most of them are repeatedly ordering from us.
