Organic glass (PMMA) is widely used in a variety of industries, but processing organic glass requires special attention to operating skills to ensure accuracy and surface quality. This article will take you through every key step of CNC plexiglass processing, from tool selection to cutting technology, to ensure that you master all the key points before cutting.
What Is Plexiglas？
PMMA (polymethyl methacrylate) is a transparent plastic widely used as an alternative to glass. Compared with glass, it offers lighter weight, better impact resistance, and greater design flexibility, making it well suited for CNC machining manufacturing. PMMA is commonly applied in construction, automotive, medical, and advertising industries where clarity and machinability are required.
What Are the Processing Methods for Acrylic?
When CNC machining PMMA, different processing methods are selected to meet specific requirements. Widely used in advertising, construction, automotive, medical, and electronics industries, PMMA offers high transparency and good machinability. Choosing the right method helps ensure machining accuracy and surface quality for both complex and simple parts.
Next, I will introduce several common CNC processing methods for plexiglass in detail, and analyze the advantages and applicable scenarios of each method :
CNC Milling
CNC milling is widely used for machining plexiglass parts with complex geometries, flat surfaces, and curved features. It supports plane, contour, and angled surface machining with high flexibility. Typical accuracy can reach ±0.05 mm, making it suitable for parts requiring good surface finish, such as advertising signs and lamp housings. Proper control of feed rate and spindle speed helps prevent overheating and chip adhesion.
CNC Turning
CNC turning is ideal for machining round or cylindrical plexiglass parts. The workpiece rotates while the cutting tool machines outer diameters or inner holes with high consistency. Tolerances can typically reach ±0.01 mm, making it suitable for shafts, tubes, and symmetrical components that require precise diameter control and stable efficiency.
Laser Engraving
Laser engraving is mainly used for detailed surface processing on plexiglass, such as text, patterns, and logos. It is a non-contact process that avoids mechanical stress and surface damage. With accuracy up to ±0.001 mm, laser engraving is well suited for medical devices, signage, and decorative plexiglass parts requiring fine surface details.
CNC Drilling
CNC drilling is used to create precise holes and channels in plexiglass parts. By selecting appropriate drill geometry and cutting parameters, smooth hole quality can be achieved without cracking or melting. Typical drilling accuracy reaches ±0.01 mm, and the process is often combined with milling or turning for more complex parts.
CNC Grinding
CNC grinding is applied to improve surface quality and flatness of plexiglass components. It removes burrs, scratches, and minor surface defects, producing smooth and uniform finishes. Grinding accuracy can reach ±0.002 mm, making it suitable for optical components, display parts, and applications with high surface requirements.
CNC EDM
CNC EDM is used for machining complex or fine plexiglass features that are difficult to achieve with conventional cutting. It enables thin walls, small holes, and intricate contours without mechanical force. With accuracy up to ±0.002 mm, EDM is suitable for high-precision applications in medical, aerospace, and electronic components.
Waterjet Cutting
Waterjet cutting uses high-pressure water mixed with abrasives to cut plexiglass without heat generation. It is especially suitable for thick sheets and complex shapes, avoiding thermal deformation or melting. Typical accuracy is around ±0.1 mm, making it ideal for architectural, automotive, and custom-designed plexiglass parts.
Laser Cutting
Laser cutting is commonly used for fast and precise cutting of thin plexiglass sheets. It provides clean edges, high cutting speed, and good repeatability. With accuracy up to ±0.01 mm, laser cutting is well suited for mass production and parts with intricate outlines or irregular shapes.
How To CNC Process Plexiglas
Organic glass (PMMA) is a widely used transparent plastic with good machinability. During CNC machining, proper selection of tools, feed rates, and spindle speeds is essential to avoid surface damage and overheating, ensuring stable accuracy and surface quality.
Step 1: Fix The Workpiece
In CNC machining, it is crucial to ensure that the workpiece is stably fixed. If the workpiece is not firmly fixed, it may move during the machining process, resulting in reduced cutting accuracy. Common fixing methods include using special fixtures or suction cups to prevent the workpiece from moving during the machining process and maintain machining accuracy.
Step 2: Choose A Tool
It is very important to choose the right tool for processing plexiglass. Carbide milling cutters and two-edge milling cutters are common choices for processing plexiglass. They can effectively reduce surface damage and extend tool life. For thinner plexiglass, using a small diameter tool can ensure a finer cutting effect , while thicker plexiglass requires a larger diameter tool to improve processing efficiency.
Step 3: Feed Speed
Feed speed is an important parameter to ensure smooth cutting. If the feed speed is too fast, it is easy to cause melting and adhesion on the cutting surface . If it is too slow, it will cause the tool to overheat and increase the processing time. For most organic glasses, the recommended feed speed range is 1000-1500mm/min. The specific speed should be adjusted according to the tool, material thickness and spindle speed to achieve the best cutting effect.
Step 4: Spindle Speed
The choice of spindle speed directly affects the cutting effect. A higher spindle speed can help form continuous chips, reduce cutting resistance, and improve processing efficiency. Generally speaking, the spindle speed should be set between 12,000 and 18,000 RPM. For thinner plexiglass, using a higher speed can improve cutting efficiency, while for thicker plexiglass, the speed can be appropriately reduced to avoid overheating and damage.
Step 5: Cutting Depth
The cutting depth should be avoided to be too large. Cutting too deep at one time will increase the burden on the tool, causing tool overheating or workpiece deformation. It is usually recommended to control the cutting depth between 1-2mm each time and make multiple shallow cuts to ensure surface quality. For thicker workpieces, using the layered cutting method can improve the stability and effect of processing.
Step 6: Bevel Cut
Bevel cutting is an effective way to improve cutting results, especially for processing thicker plexiglass. By gradually inserting the tool deeper into the workpiece instead of cutting directly vertically, the tool load can be reduced, avoiding surface damage or workpiece fragmentation caused by excessive cutting force. Using bevel cutting can distribute cutting force more evenly, improve processing efficiency, and extend tool life.
Through reasonable parameter settings and techniques, CNC processing of organic glass can improve production efficiency while ensuring processing accuracy. Each step needs to be adjusted according to specific processing requirements to ensure cutting quality and surface effect. This can not only help reduce problems in processing, but also extend the service life of tools and equipment.
What Surface Treatments Does Organic Glass Have
Surface treatment of organic glass (PMMA) improves both appearance and performance. Common methods include standard finishing, pearl blasting, and polishing, selected based on design requirements and application needs. Proper surface treatment also helps enhance durability and visual consistency of the final product.
The following are several common methods for surface treatment of plexiglass, each of which has its own unique effects and application scenarios :
Standard Processing
Standard processing refers to the surface condition after basic CNC cutting, without additional finishing. It provides a clean and smooth surface and is suitable for functional plexiglass parts where appearance is not the primary focus, such as display racks, simple signage, and electronic housings.
Pearlescent Sandblasting
Pearlescent sandblasting creates a uniform matte surface on plexiglass by blasting fine media. It reduces glare and light reflection while maintaining translucency, making it suitable for signage, light boxes, and automotive interior panels.
Custom Polishing
Custom polishing produces a high-gloss, mirror-like surface on plexiglass. It is used for applications requiring excellent transparency and visual quality, such as optical components, decorative parts, and display covers.
Advantages Of Plexiglass
Organic glass (PMMA) is a transparent material widely used in various fields. With its advantages of light weight, impact resistance and high transparency, it has become an indispensable material in modern manufacturing and daily life. Compared with glass, it is easier to process and has stronger impact resistance, and can replace traditional glass materials in many fields.
Next, I will introduce the advantages of plexiglass and its applications in various industries :
| Advantages | Describe |
| Easy to process | Organic glass can be processed into various complex shapes by cutting, milling, drilling, etc. |
| Lightweight and impact-resistant | It is 50% lighter than glass and has high impact resistance, making it suitable for replacing fragile materials. |
| High transparency | It has a transparency close to that of glass, with a light transmittance of up to 92%, and is widely used in places that require high light transmittance. |
| UV resistance | Excellent UV resistance, suitable for long-term exposure to outdoor environments while maintaining unchanged transparency. |
Disadvantages Of Plexiglass
Although organic glass (PMMA) offers many advantages, it also has certain limitations that should be considered during material selection. Compared with traditional glass and some engineering plastics, plexiglass may not be suitable for all working conditions, especially in applications involving high temperature, heavy load, or strong chemical exposure.
Next, I will introduce the main disadvantages of plexiglass and the scenarios where they may affect performance:
| Disadvantages | Description |
|---|---|
| Limited heat resistance | Plexiglass softens at relatively low temperatures and may deform under high heat conditions. |
| Lower surface hardness | The surface is more prone to scratching compared with glass and some engineering plastics. |
| Chemical sensitivity | PMMA can be affected by certain solvents and chemicals, which may cause cracking or surface damage. |
| Limited structural strength | Although impact-resistant, plexiglass is not suitable for high-load or structural applications. |
Application Areas Of Plexiglass
Organic glass has been widely used in many industries. Its excellent performance makes it perform well in various complex environments, especially in areas that require lightweight, transparent and durable materials. Whether in the automotive, construction, medical or electronics industries, organic glass plays an important role.
| Industry | Application Examples |
| Automotive Industry | Used for car windows, dashboards, rearview mirrors and other parts, it is lightweight and impact-resistant. |
| Lighting and electronics | Used to make lamp covers, display screen protectors, lighting housings, etc., providing good transparency and UV resistance. |
| Architecture and decoration | Used for transparent roofs, curtain walls, advertising signs, etc., and suitable for outdoor use due to its transparency and weather resistance. |
| Medical Industry | Used in medical device housings, dialyzer housings, etc., meeting the requirements for cleanliness, transparency and impact resistance. |
FAQs
Can You CNC Plexiglass?
Yes, CNC machines can effectively cut plexiglass, also known as acrylic. CNC milling and routing are the most common methods for cutting plexiglass, allowing for high precision and smooth finishes. With the rich tools and settings, CNC machines can cut plexiglass with a tolerance of ±0.1mm , making them ideal for intricate shapes and detailed designs. It’s crucial to select the correct cutting speed, feed rate, and tooling to avoid material damage and achieve the desired result.
What Speed Do CNC Machines Cut Plexiglass?
When cutting plexiglass with a CNC machine, the recommended spindle speed ranges between 12,000 to 18,000 RPM. This speed range helps ensure that the material is cut efficiently without causing excessive heat buildup, which could result in melting or fraying edges. The optimal feed rate is usually around 1000-1500 mm/min, but it should be adjusted based on the thickness of the material and the type of cut being made to ensure a smooth finish and minimal tool wear.
What Is the Best Method of Cutting Plexiglass?
The best method of cutting plexiglass depends on the complexity and requirements of the project. CNC routing is ideal for precision and intricate shapes, while laser cutting offers excellent results for fine details and smooth edges. For larger or simpler cuts, using a table saw with a fine-toothed blade works well. For straight cuts or small projects, a glass cutter can be used effectively. The method chosen should be based on the specific application, material thickness, and desired finish.
Can You Cut Plexiglass With a Glass Cutter?
Yes, plexiglass can be cut with a glass cutter, but it’s typically suited for straight-line cuts. A glass cutter is effective for scoring the surface of the plexiglass, after which it can be snapped cleanly. This method is most effective for thinner sheets, typically less than 6mm thick. For more complex shapes or thicker sheets, CNC cutting or laser cutting methods are recommended, as they offer greater precision and smoother edges.
How to Smooth the Edges of Plexiglass?
To smooth the edges of plexiglass, several methods can be used, depending on the desired finish. A flame-polishing tool is one of the best options for achieving a glossy, smooth edge, especially for clear plexiglass. Sanding with progressively finer sandpaper (starting with 400-grit and moving to 2000-grit) is another common method for smoothing edges. After sanding, polishing with a soft cloth and acrylic polish can help achieve a high-quality finish, giving the edge a clean, professional look.
How Hard Is It to Break Plexiglass?
Plexiglass is known for its toughness and impact resistance, making it significantly harder to break than glass. However, while it’s much stronger than glass, it is still prone to cracking or breaking under excessive pressure, especially when subjected to sharp impacts. The material’s strength is measured by its impact resistance, which is approximately 10-24 times higher than glass, depending on the grade of plexiglass. Despite its strength, proper handling is necessary to avoid fractures.
Conclusion
As a transparent and powerful material, organic glass has been widely used in many industries due to its advantages in processability, impact resistance, transparency and weather resistance. It not only provides us with higher design freedom and processing flexibility, but also improves the durability and aesthetics of products in various applications. Through the correct material selection and processing methods, we can give full play to the advantages of organic glass and meet the needs of different fields.
TiRapid provides reliable CNC machining services for organic glass (PMMA), supporting custom parts with stable quality and fast turnaround. Contact TiRapid to start your project.
