PC Prototypes vs. Acrylic Prototypes: Key Differences and How to Choose

If you’re working on a product that requires transparency, you’ve probably asked yourself: “Should I use PC or acrylic for my prototype?” It’s a common dilemma—both materials offer clarity, but their unique properties make them better suited for different applications. In this guide, we’ll break down the critical differences between PC (polycarbonate) prototypes and acrylic (PMMA) prototypes, helping you choose the right material for your specific project needs.

Understanding PC and Acrylic as Prototype Materials

Before diving into comparisons, let’s establish what makes these materials unique. Both PC and acrylic are thermoplastic polymers used extensively in transparent prototype manufacturing, but they were developed with different priorities in mind.

Polycarbonate (PC) is known for its exceptional strength and impact resistance, making it a favorite for applications where durability matters most. It’s a versatile material that balances transparency with ruggedness, which is why you’ll find it in everything from safety glasses to electronic device housings.

Acrylic (PMMA, or polymethyl methacrylate), often called “plexiglass,” prioritizes optical clarity above all else. It offers some of the best light transmission properties among plastic materials, making it ideal for applications where visual appeal and transparency are critical.

While they may look similar at first glance, their performance characteristics differ significantly—differences that can make or break your prototype’s success.

Core Property Comparison: PC vs. Acrylic Prototypes

Let’s start with the fundamental properties that distinguish these two materials. Understanding these differences will help you align your material choice with your prototype’s requirements.

Transparency and Optical Performance

When it comes to clarity, acrylic is the clear winner:

• Acrylic (PMMA) boasts an impressive 92% visible light transmittance, which is actually higher than standard glass (typically around 90%). After proper polishing, acrylic prototypes can achieve “complete transparency” that industry professionals often describe as unmatched by other plastics.
• PC offers good transparency at approximately 89% light transmittance, but it doesn’t quite reach the crystal-clear quality of acrylic. While PC is certainly transparent, its optical performance is noticeably less impressive compared to acrylic’s pristine clarity.

This difference makes acrylic the go-to choice for prototypes where visual perfection is essential, such as display cases, light fixtures, or cosmetic product containers. PC, while transparent enough for many applications, is better suited when functionality takes priority over absolute clarity.

Impact Resistance and Toughness

Here’s where the tables turn dramatically in PC’s favor:

• PC is renowned for its exceptional toughness and impact resistance. It can withstand significant force without shattering, which is why it’s used in safety equipment and protective barriers. This durability makes PC prototypes much less likely to break during testing or handling.
• Acrylic has poor toughness by comparison. Like glass, it’s relatively brittle and can crack or shatter if dropped or subjected to impact. This fragility is a critical consideration during prototype manufacturing, as acrylic parts require careful handling to avoid damage.

In practical terms, this means an acrylic prototype might break if accidentally knocked off a workbench, while a PC prototype would likely survive the same impact intact.

Temperature Resistance

For prototypes that will encounter heat, temperature resistance is a key factor:

• PC handles high temperatures well, typically withstanding temperatures between 120°C and 150°C (248°F to 302°F). This makes it suitable for prototypes that need to perform in warm environments or undergo heat testing.
• Acrylic has much less impressive high-temperature performance. Its heat resistance is not significant, and it can start to soften or deform at temperatures above 80°C (176°F). This limits its use in applications involving heat exposure.

If your prototype will be tested near heat sources or in warm environments, PC’s superior temperature resistance becomes a crucial advantage.

Chemical Resistance

Different applications expose prototypes to various chemicals, so resistance to substances like oils and acids matters:

• PC offers good resistance to neutral oils and strong acids, though it’s not resistant to alkalis. This makes it suitable for prototypes that might encounter certain industrial fluids or cleaning agents.
• Acrylic (PMMA) has excellent chemical stability overall, with strong resistance to many common chemicals. This property, combined with its non-toxic nature, makes it suitable for prototypes used in food contact applications, such as beverage cups or kitchenware components.

Practical Performance in Prototype Manufacturing

Beyond theoretical properties, how do these materials perform in real-world CNC machining and prototype production?

Machinability and Processing

Both materials are machinable, but they behave differently during the manufacturing process:

• Acrylic machines cleanly but requires careful handling due to its brittleness. Machinists must use sharp tools and appropriate feed rates to avoid cracking or chipping the material. The upside is that acrylic polishes beautifully, allowing machinists to achieve that signature glass-like finish.
• PC is more forgiving during machining thanks to its toughness. It’s less likely to crack during processing, which can reduce waste and rework. However, PC doesn’t polish to the same level of clarity as acrylic, so its final optical finish is naturally slightly inferior.

Post-Processing Requirements

The need for post-processing is another key difference:

• Acrylic prototypes require thorough polishing to achieve their maximum transparency. This additional step is essential because machining marks can significantly reduce light transmission. With proper polishing (using progressive grits from 400 to 2000), acrylic reaches its full optical potential.
• PC prototypes benefit from polishing but don’t require the same level of effort to look good. Their natural transparency, while lower than acrylic’s, is more consistent straight from the machine. PC also often requires a UV coating to prevent yellowing over time—a step not needed for acrylic.

Durability During Testing

Prototype testing can be demanding, and material choice affects how well your prototype holds up:

• PC prototypes excel in durability testing. Their impact resistance means they can withstand repeated handling, assembly/disassembly cycles, and functional testing without damage. This makes PC ideal for prototypes that need to undergo rigorous testing regimens.
• Acrylic prototypes require more careful handling during testing. Their brittleness makes them susceptible to cracking under stress, which can limit the types of tests they can endure. However, for visual testing or static display prototypes, this fragility is less of a concern.

Application Guide: When to Choose PC vs. Acrylic Prototypes

The best way to decide between PC and acrylic is to match the material to your prototype’s intended use. Here’s a practical guide to help you choose:

Ideal Applications for Acrylic Prototypes

Acrylic shines in these scenarios:

• Visual prototypes where transparency and aesthetics are the top priorities, such as display models or consumer product concept demos.
• Lighting components like lamp covers or light diffusers, where maximum light transmission is essential.
• Non-impact consumer goods prototypes, including cosmetic containers, beverageware, or stationary items.
• Infrared applications requiring specific light filtering—special colored acrylic variants can block visible light while allowing specific infrared wavelengths to pass, making them useful for remote control prototypes or thermal sensors.
• Medical or food contact prototypes where acrylic’s chemical stability and non-toxic nature are required.

Ideal Applications for PC Prototypes

PC is the better choice for:

• Functional prototypes that need to demonstrate durability and impact resistance, such as electronic device housings or protective covers.
• High-temperature environments including automotive components, industrial machine parts, or lighting fixtures near heat sources.
• Safety-critical prototypes where shatter resistance is essential, like protective goggles or face shields.
• Outdoor application prototypes that need to withstand weathering (when properly UV-coated) and temperature fluctuations.
• Structural transparent components that need both clarity and strength, such as display cases with security requirements.

Side-by-Side Comparison Table

To summarize the key differences:

Cost Considerations

While material costs shouldn’t be the only factor, they do play a role in prototype budgeting:

• Acrylic is generally more economical than PC, making it a better choice for early-stage prototypes or projects with tight budgets.
• PC has a slightly higher material cost, but its durability can reduce overall costs by minimizing rework and replacement due to damage.
• Post-processing costs can tip the balance: acrylic requires more polishing time, while PC needs UV coating. Depending on your prototype’s size and complexity, these additional steps can affect the total cost.

For most prototype projects, the performance requirements should outweigh minor cost differences—choosing the wrong material can lead to inaccurate testing results or failed presentations, which are far more costly than the material itself.

Yigu Technology’s Perspective

At Yigu Technology, we guide clients to match PC or acrylic to their prototype goals. Acrylic delivers unmatched clarity for visual demos, while PC provides rugged durability for functional testing. Our precision machining and polishing expertise ensures both materials reach their full potential, helping clients validate designs with confidence and accuracy.

Frequently Asked Questions (FAQ)

1. Can acrylic prototypes be used for functional testing?

They can, but with limitations. Acrylic’s brittleness makes it unsuitable for impact or stress testing, but it works well for static functional prototypes where visual clarity is more important than durability.

2. Do PC prototypes yellow over time?

Yes, uncoated PC can yellow when exposed to UV light. This is why PC prototypes often require a UV protective coating, especially for outdoor applications or long-term display prototypes.

3. Is one material easier to machine than the other?

PC is generally more forgiving during machining due to its toughness, while acrylic requires more careful handling to prevent cracking. However, acrylic polishes to a higher clarity finish than PC.