Which is Better: Polycarbonate or Acrylic?

When it comes to choosing transparent plastic materials for your project, two top contenders often come to mind: polycarbonate and acrylic. Both materials are excellent substitutes for glass due to their lightweight nature, clarity, and impact resistance. However, while they might seem interchangeable at first glance, they have distinct characteristics that make one more suitable than the other depending on the specific application.

To determine which is better — polycarbonate or acrylic — we need to evaluate them based on several important factors, including impact resistance, optical clarity, durability, temperature tolerance, ease of fabrication, cost, and typical use cases. This comprehensive guide will help you make an informed decision based on your project needs.

What is Polycarbonate?

Polycarbonate is a type of thermoplastic polymer known for its remarkable impact strength and toughness. It’s virtually unbreakable under normal conditions and is often used in high-performance applications like bulletproof glass, riot shields, machine guards, and safety goggles. Polycarbonate is flexible, easy to mold at room temperature, and offers moderate UV resistance when treated. Brand names for polycarbonate include Lexan and Makrolon.

What is Acrylic?

Acrylic, also known as polymethyl methacrylate (PMMA), is a transparent thermoplastic that offers excellent optical clarity and a glass-like appearance. It is frequently used in signage, aquariums, display cases, and decorative panels. Acrylic is more rigid than polycarbonate and is easier to machine, cut, and polish. Popular brand names include Plexiglas, Lucite, and Perspex.

Impact Resistance and Strength

Polycarbonate is the undisputed champion in impact resistance. It is about 250 times stronger than glass and roughly 10 times stronger than acrylic. This strength makes polycarbonate the preferred material in safety-critical environments. It can absorb significant force without cracking, making it ideal for protective barriers, enclosures, and even ballistic panels.

Acrylic, while still much stronger than glass, is more brittle than polycarbonate. It is more likely to crack or shatter under high impact or stress. However, in lower-risk environments, such as displays or light covers, acrylic’s strength is more than sufficient.

Optical Clarity and Appearance

If visual clarity is the priority, acrylic is typically the better choice. Acrylic transmits more light than glass — up to 92% — giving it exceptional clarity and brightness. It also resists yellowing over time, making it ideal for applications where long-term transparency is critical, such as display windows or museum enclosures.

Polycarbonate is also transparent but allows slightly less light to pass through, around 88%. It may have a slight tint and, without UV stabilization, can yellow or become hazy over time. However, UV-protected polycarbonate is available and performs well in outdoor applications.

Weight and Flexibility

Both polycarbonate and acrylic are significantly lighter than glass, about half the weight for the same thickness. However, polycarbonate is more flexible and less likely to crack under stress. It can be cold-bent without heating, which adds versatility in design applications.

Acrylic is more rigid and can snap if bent beyond its limit. This stiffness gives it a more glass-like feel but also means it needs careful handling during fabrication and installation.

Temperature Resistance

Polycarbonate offers better performance at elevated temperatures. It has a higher heat deflection temperature and can withstand temperatures up to 115°C (239°F). It does not soften or deform easily, making it suitable for environments with heat exposure or thermal cycling.

Acrylic begins to soften at around 85°C (185°F), which limits its use in high-temperature environments. For most indoor applications, this is not an issue, but for lighting covers or engine housings, polycarbonate would be the more durable option.

Weather and UV Resistance

Acrylic naturally resists UV radiation and weathering, maintaining its clarity and structural integrity even after years of exposure to the sun. It performs exceptionally well in outdoor signage, skylights, and architectural features without requiring special coatings.

Polycarbonate, unless treated with a UV-resistant layer, may degrade under long-term UV exposure. Yellowing and surface crazing can occur. However, with proper UV stabilization, polycarbonate can perform well outdoors, especially when impact resistance is also needed.

Ease of Fabrication

Acrylic is easier to cut, drill, polish, and glue than polycarbonate. It can be laser-cut with clean edges and polished to a high-gloss finish. These qualities make it ideal for projects requiring precision and aesthetics, such as display units and artistic installations.

Polycarbonate, being softer and more elastic, can be difficult to machine cleanly. It tends to gum up or melt if processed too quickly, and its surface is more prone to scratching unless coated. However, it can be cold-formed and is easier to mold into complex shapes without heating.

Scratch Resistance

Acrylic is more scratch-resistant than polycarbonate. It maintains a smooth surface even with regular cleaning and handling. Polycarbonate, unless it has a scratch-resistant coating, can become visibly marred over time, especially in high-traffic or frequently touched applications.

Cost Considerations

Acrylic is generally less expensive than polycarbonate. For budget-sensitive projects that do not require high impact strength, acrylic offers excellent value. It is commonly used in decorative or low-impact products where visual appeal is more important than rugged durability.

Polycarbonate’s higher price reflects its superior strength and performance characteristics. When safety, long-term durability, or impact resistance are essential, the added cost of polycarbonate is justified. However, for projects with limited stress and exposure, acrylic may be the more economical and practical choice.

Common Applications

Acrylic is often used in:

• Point-of-sale displays and retail fixtures
• Signage and light diffusers
• Aquariums and tanks
• Picture frames and decorative panels
• Museum cases and trophies

Polycarbonate is preferred for:

• Safety shields and protective barriers
• Machine enclosures and industrial guards
• Riot gear and helmet visors
• Glazing for transportation and construction
• Lighting covers and outdoor fixtures

Environmental and Recycling Impact

Both acrylic and polycarbonate are recyclable, although polycarbonate is more challenging to recycle due to its complex polymer structure. Acrylic is more commonly reused in industries and can be repurposed into other plastic products more easily. Choosing long-lasting materials like these reduces the frequency of replacement and supports sustainability over time.

Conclusion: Which is Better?

Choosing between polycarbonate and acrylic depends entirely on your project requirements. There is no one-size-fits-all answer. Instead, each material excels in different scenarios:

Choose polycarbonate if:

• You need extreme impact resistance
• The application involves high stress or safety concerns
• It will be used in high-temperature or rugged environments
• Flexibility or cold bending is important

Choose acrylic if:

• Optical clarity and aesthetics are top priorities
• The project is indoors or protected from high impacts
• You want a cost-effective solution with easy fabrication
• Long-term UV exposure is expected without additional coatings

In summary, acrylic is best for visual, lightweight, and decorative applications, while polycarbonate shines in tough, demanding, and safety-focused environments. Knowing the strengths and weaknesses of each material will help you select the ideal option and ensure the success of your design or product.