CNC acrylic: how to achieve the fit between the two
Acrylic sheet is a specially treated organic glass with pure color and rich colors. It has the characteristics of good plasticity, good transparency, strong impact resistance and high recyclability. It is widely used in lighting, construction and advertising industries. This article will talk about the characteristics of acrylic, the methods and advantages of CNC processing acrylic, how to process it, and how to achieve the best processing.
1.The concept of acrylic
Acrylic is a hard and transparent thermoplastic material, commonly known as polymethyl methacrylate (PMMA). It can be melted and changed without losing its basic properties. Unlike other transparent plastics, acrylic is a UV-stable, optically transparent, lightweight, durable and hard plastic that will not fade even if exposed to sunlight for a long time. These reasons make acrylic an ideal substitute for glass in various applications, and acrylic processing is often used in the automotive and test and measurement fields.
2.The characteristics of acrylic
Acrylic is a material with properties similar to glass. Its characteristics include transparency, clarity, firmness and translucency. It is considered one of the most durable materials used in manufacturing and is less likely to suffer damage. Some of the unique properties of acrylic are as follows:
(1) Light Transmittance
Acrylic polymer has a refractive index of 1.49, allowing it to transmit up to 92% of light. This light transmittance is greater than glass and other plastics. Therefore, custom acrylic plastics can be produced while maintaining optical clarity. In addition, due to its environmental stability, it is well suited for use in most outdoor applications.
(2) Resistance to UV Radiation
Most CNC acrylic designs ensure UV stability. Therefore, they can withstand prolonged sunlight exposure. This property also makes acrylic an excellent choice for outdoor applications, especially for more open air exposure.
(3) Chemical Resistance
Acrylic has strong chemical resistance. It is not susceptible to most aqueous laboratory chemicals. You can safely apply cleaners, alkalis, detergents, diluted inorganic acids, and other substances to acrylic resin.
(4) High Harness
Acrylic is a tough, lightweight and durable thermoplastic with a density that varies between 1.17 g/cm3 and 1.20 g/cm3. In comparison, it has excellent scratch resistance. In addition, acrylic has excellent dimensional stability, which makes it less able to absorb water or moisture.
3.Concept of CNC Processing Acrylic
CNC processing acrylic is a precision manufacturing technology that can accurately cut acrylic plastic with minimal force, thereby quickly and efficiently producing precisely shaped acrylic parts. The development of CNC processing acrylic technology can help achieve better target dimensional tolerances for better long-term performance.
Best way to CNC process acrylic sheets:
Both CNC milling machines and lathes can be used to cut acrylic. Lathes are usually used for softer materials such as aluminum, plastic, wood, and foam. CNC milling machines can effectively cut acrylic at multiple points, and their cutting tools and angle range are conducive to improving accuracy. Therefore, CNC milling has become the best processing method for processing acrylic sheets.
4.How CNC milling machines cut acrylic sheets
The router bit rotates at high speed to cut the acrylic material. The cutting speed of the router head depends on the cutting depth of the acrylic sheet.
CNC routers use computer-controlled router heads to cut acrylic materials into the desired shape and size. The router bit is mounted on a spindle, which drives the drill bit to rotate at high speed. The router head is then moved along the X, Y, and Z axes via a gantry. This allows the router bit to cut the acrylic material very accurately.
5.Advantages of CNC cutting acrylic sheets
High-precision cutting CNC plastic cutting machines can achieve very high precision, which is very important for many applications. For example, they can be used to make precision parts or make complex designs.
(1) Fast cutting speed
Cutting acrylic materials quickly saves time and money. This is especially beneficial for businesses that need to cut materials regularly.
(2) Precision cutting
CNC machines can ensure processing accuracy and meet various requirements for complex shapes and sizes of acrylic sheet materials.
(3) Repeatable cutting
Repeated cutting with the same effect is very important for applications that require consistency.
(4) Easy to use
Relatively simple to use, computer-controlled, and easy to use even without cutting experience.
(5) High efficiency
It is very cost-effective. When producing in large quantities, acrylic materials can be cut quickly and accurately, saving time and money.
(6) Wide processing range
Wide processing range: CNC machines are suitable for processing a variety of materials, including acrylic sheets. Whether it is cutting, punching or engraving, CNC machines can easily cope with different processing needs.
(7) Environmental protection
It does not produce a lot of waste like traditional plastic cutting methods, so it is relatively environmentally friendly.
6.Precautions for CNC machine processing acrylic sheets
(1) Choose the right tool
To avoid acrylic melting during the cutting process, which has a negative impact on appearance and function. Therefore, choosing a tool with a sharp and strong edge is the key to successfully cutting acrylic with a CNC machine.
(2) Controlling the processing speed
During the processing process, how to control the correct processing speed requires certain skills. To avoid melting of acrylic, a faster feed rate is required, but too fast a speed will cause the acrylic sheet to crack or deform. Conversely, a slower feed rate may produce incorrectly sized or unfinished parts, as well as rough surface finishes. Therefore, the setting of the optimal feed rate depends on the type of acrylic material selected and the geometry of the component.
(3) Timely chip cleaning
During the processing process, chips need to be cleaned in time to avoid affecting processing accuracy and tool life.
We can discuss here whether the choice of tool will have an impact on chip cleaning. Special tools usually have a single groove to maximize chip removal. A single groove can also be used to prevent heat accumulation in the material. However, when chips are trapped, fewer grooves can help reduce the risk of catastrophic failure.
(4) Cutting direction is important
Set the direction in which the CNC tool will rotate or spin in advance, including whether it rotates left or right, clockwise or counterclockwise. Setting these is critical to achieving precise design features.
(5) Set the correct revolutions per minute (RPM)
The RPM you use must be associated with the feed rate. Different acrylic types will dictate different settings. Faster RPMs will require you to increase the feed rate to avoid the risk of material melting. The correct relationship between these settings will help create the best results.
(6) Pay attention to ramp features
When using CNC acrylic, it is recommended to use a ramp. Move your drill bit gradually downward in a smooth ramping motion rather than inserting it directly. This technique can reduce damage and achieve better precision finishing. Using a smooth ramp between 1 and 3 inches will achieve the best results.
7.Summary
Acrylic, as a special material that is widely used in various industries today, can effectively match CNC technology and provide the industry with precise CNC acrylic parts. After reading this article, I hope you can understand the potential advantages and broad application scenarios of CNC acrylic, which will be helpful to you.