Introduction
Imagine you are developing a transparent enclosure for a prototype device. The material needs to be clear, easy to fabricate, and durable enough to withstand testing. Two common options quickly emerge: acrylic and polycarbonate.
At first glance, they may appear similar, but their differences in strength, cost, and machinability can make one a better choice than the other depending on the prototype’s requirements. This guide compares acrylic and polycarbonate, highlighting the key characteristics of each material and when they are best suited for rapid prototyping.
What is Acrylic?
Also known as polymethyl methacrylate (PMMA), acrylic is a transparent thermoplastic widely used as a lightweight alternative to glass. It is valued for its clarity, durability, and ease of fabrication.
Acrylic is available in several forms, including pellets, small granules, and sheets. It can be processed using various manufacturing methods such as injection moulding, casting, extrusion, and thermoforming. These processing options make it a versatile material for prototyping and product development.
What is Polycarbonate?
Polycarbonate is a strong, transparent thermoplastic commonly used when durability and impact resistance are required. It is valued for its toughness and ability to withstand higher temperatures compared to many other plastics.
Polycarbonate is known for its ability to bend rather than shatter under high impact. In fact, polycarbonate sheets can be up to 250 times more impact-resistant than glass, making them suitable for applications that require durability and safety.
Characteristics of Acrylic for Prototyping
Advantages of Acrylic
- Easy to machine and shape
Acrylic cuts, drills, laser cuts, and CNC machines cleanly. It can also be thermoformed, meaning it can be heated and bent into curves or complex shapes without losing clarity.
- Great clarity and aesthetics
Acrylic is highly transparent and can be polished to a smooth, glass-like finish, making it ideal for visually appealing prototypes.
- Lightweight yet impact resistant
Acrylic weighs about half as much as glass while offering around 10 times the impact resistance.
- Wide colour and finish options
Acrylic sheets are available in a wide range of colours and finishes, including diffused, mirrored, and textured surfaces, making them useful for visual prototypes and branding mock-ups.
- Cost-effective
Acrylic is generally more affordable than polycarbonate, helping to reduce material costs during multiple prototype iterations.
- Recyclable thermoplastic
Acrylic softens around 80°C and can be heated, cooled, and reheated without significant degradation, allowing it to be reused or recycled.
- UV-resistant
Acrylic has strong natural resistance to UV light, allowing it to maintain its clarity and colour even after long exposure to sunlight.
- Better optical clarity
Acrylic has better optical clarity than polycarbonate, with light transmission of up to 92% compared to about 88% for polycarbonate.
Limitations of Acrylic
- Lower impact resistance than polycarbonate
While stronger than glass, acrylic is still more brittle than polycarbonate and may crack under heavy impact.
- Prone to scratching
Acrylic surfaces can scratch more easily than polycarbonate, especially in environments with frequent handling.
- Lower impact resistance
Acrylic can crack under heavy impact or repeated stress, so it may not be suitable for prototypes that need to withstand drops or strong forces.
- More brittle than polycarbonate
Acrylic is less flexible and may fracture under stress, especially in thin sections, whereas polycarbonate is more likely to bend rather than break.
- Lower heat resistance
Acrylic softens at relatively low temperatures (around 80–100 °C), making it less suitable for high-heat environments compared to polycarbonate.
Characteristics of Polycarbonate for Prototyping
Advantages of Polycarbonate
- Flexible fabrication
It can be cold-bent or thermoformed into customised curves and angles without cracking or losing strength.
- Extremely impact‑resistant
It is much stronger than glass and acrylic, often described as “virtually unbreakable,” which makes it ideal for protective barriers and safety‑critical parts.
- Good clarity and light transmission
It allows most light to pass through, so it can replace glass in windows, skylights, and enclosures.
- Wide temperature tolerance
Polycarbonate can withstand higher temperatures and retains its shape above 130 °C, whereas acrylic begins to soften at around 80°C.
- Fire-Resistant Properties
It is naturally flame-retardant, meaning it can self-extinguish and does not easily sustain combustion.
Limitations of Polycarbonate
- More expensive than acrylic and some other plastics
It usually costs more than acrylic or basic plastics, which can add up on large‑area projects.
- Scratches more easily
Despite its strength, the surface is relatively soft and prone to scratching.
- Sensitive to certain chemicalss
Some solvents and aggressive cleaners can damage polycarbonate, so it needs compatible cleaning and adhesives.
- Prone to UV yellowing
Compared to acrylic, untreated polycarbonate may yellow or lose clarity after prolonged exposure to UV light.
- Harder to machine than acrylic
It can be more difficult to cut or drill without chipping or melting if tools and speeds are not optimised.
Table of Comparison for Acrylic vs. Polycarbonate
To help compare acrylic and polycarbonate more easily, the table below highlights their key differences.
| Category | Acrylic (PMMA) | Polycarbonate |
| Machining & Fabrication | Easy to cut, drill, laser cut, and CNC machine. Can be thermoformed into curves and shapes while staying clear. | Can be bent or thermoformed into curves and angles, but machining requires more care. |
| Impact Resistance | About 10× stronger than glass, but it can crack under strong impact. | Extremely impact-resistant and much stronger than both glass and acrylic. |
| Optical Clarity | Very clear, transmitting up to 92% of visible light. | Good clarity with about 88% light transmission. |
| Weight | Lightweight, about half the weight of glass. | Also lightweight and durable. |
| Heat Resistance | Softens at around 80°C. | Handles higher temperatures and keeps its shape above 130 °C. |
| UV Resistance | Naturally resistant to UV, so it stays clear longer outdoors. | Untreated polycarbonate may yellow after long UV exposure. |
| Surface Durability | Can scratch, but it is harder than polycarbonate. | Softer surface and scratches more easily. |
| Flexibility | More rigid and may crack under stress. | More flexible and tends to bend rather than break. |
| Cost | Usually more affordable. | Usually more expensive than acrylic. |
| Reprocessing | Can be reheated and reshaped because it is a thermoplastic. | Also a thermoplastic and can be reheated for processing. |
| Chemical Resistance | Some solvents may damage the material. | Certain chemicals and cleaners may damage it. |
| Fire Behaviour | Combustible plastic. | Naturally flame-retardant and can self-extinguish. |
When to Choose Acrylic for Prototypes
Acrylic is best suited for prototypes that prioritise visual clarity, aesthetics, and ease of fabrication.
Best Suited For:
- Visual or presentation prototypes
- Transparent product enclosures
- Lighting components and LED diffusers
- Retail displays and signage prototypes
- Design mock-ups requiring polished, glass-like finishes
Because acrylic is easy to machine, laser cut, and thermoform, it allows designers to quickly produce visually accurate prototypes while keeping material and production costs relatively low.
When to Choose Acrylic for Prototypes
Polycarbonate is best suited for prototypes that prioritise impact resistance, durability, and heat tolerance, especially in applications where safety and structural strength are important.
Best Suited For:
- Safety and protective components
- Automotive and transportation parts, including headlight covers, instrument panels, and motorcycle windshields
- Construction and agricultural panels, such as skylights, roofing sheets, greenhouse panels, and canopies
- Durable product housings for electronics and industrial devices
- Medical and laboratory components that require strong, transparent materials
Because polycarbonate is highly impact-resistant and more heat-tolerant than acrylic, it is often chosen for prototypes that need to withstand physical stress, safety testing, or demanding environments.
How to Choose the Right Material for Your Prototype
- Define the purpose of your prototype
If the main goal of a prototype is its visual factor or for outdoor use, acrylic is sufficient. If the prototype is for functional testing, polycarbonate may be more suitable.
- Evaluate impact and durability requirements
Consider whether the prototype needs to withstand drops, shocks, or heavy use. Acrylic works well for display or low-stress applications, while polycarbonate is better for high-impact or safety-critical parts.
- Assess clarity and visual requirements
If optical clarity is important, acrylic is often the better choice because it offers higher light transmission and a glass-like finish.
- Consider temperature needs
Think about the temperatures and conditions the prototype will experience. Acrylic softens at lower temperatures, while polycarbonate performs better in higher heat environments.
- Account for fabrication and machining needs
If the design involves complex shapes or rapid machining, acrylic is generally easier to cut, drill, and polish. Polycarbonate can also be shaped, but may require more careful machining.
- Review cost and iteration needs
For early-stage prototypes where multiple design revisits are expected, acrylic will help keep costs lower. Polycarbonate is worth the additional cost if higher durability is required from the get-go.
Conclusion
Plastic materials such as acrylic and polycarbonate continue to play an important role in prototyping and product development. While some associate plastic with more simplistic applications, its versatility, clarity, and ease of fabrication prove this belief to be untrue.
Ultimately, selecting the right material comes down to which one best suits the function and appearance of the prototype. Need further guidance on material selection? ARRK Asia’s expertise in prototyping and low-volume product (LVP) development can help you find the right solution. Reach out to us today to learn more.
Frequently Asked Questions (FAQs) about Acrylic vs. Polycarbonate
- How does polycarbonate compare to acrylic in terms of flammability?
Polycarbonate has natural flame-retardant properties and can self-extinguish when the flame source is removed. Acrylic, on the other hand, is combustible and will continue to burn once ignited.
- How does acrylic perform when exposed to UV light?
Acrylic has strong natural resistance to UV radiation. It generally maintains its clarity and colour even after prolonged exposure to sunlight, making it suitable for outdoor use.
- Can acrylic be used for outdoor applications?
Yes. Acrylic has good weather and UV resistance and does not yellow easily. Because of this, it is commonly used for outdoor signs, skylights, windows, and display panels.
- What level of load or stress can acrylic handle?
Acrylic offers moderate strength and is significantly more impact-resistant than glass. However, it is more brittle than polycarbonate and may crack under heavy loads or repeated stress.
- How does the chemical resistance of acrylic compare to polycarbonate?
Both materials can be affected by certain chemicals and solvents. However, polycarbonate is generally more sensitive to aggressive cleaners and solvents, while acrylic tends to have slightly better resistance to some chemicals.
- Can polycarbonate be used in high-precision applications?
Yes. Polycarbonate can be used in precision parts when proper machining techniques are applied. Its strength and dimensional stability make it suitable for components that require durability and tight tolerances.
- What should be considered when choosing acrylic for CNC machining?
Use sharp cutting tools to reduce friction and heat buildup, as acrylic has relatively low heat resistance.
Cast acrylic (made by pouring resin into moulds) is generally preferred because it cuts cleanly, while extruded acrylic (formed by pushing molten resin through rollers) can be softer and more prone to melting during machining
