Transparent Plastic Parts: PC vs. PMMA & Alternatives

Transparent plastic parts are used in a wide variety of applications, from eyeglasses and medical devices to building materials and signage. Two of the most common transparent plastics are polycarbonate (PC) and polymethyl methacrylate (PMMA), also known as acrylic. Each material has its own unique properties and advantages, making it suitable for different applications.

In this blog post, we’ll compare polycarbonate (PC) and polymethyl methacrylate (PMMA), also known as acrylic. We’ll discuss the unique properties and advantages of each material, as well as some specific application recommendations. We will also look at some alternative materials and their properties.

Introducing 2 of the most common plastic types for transparent plastic parts: PC vs PMMA

PC vs PMMA, which to choose? Both are extremely common plastics used for making transparent plastic parts. But which is better for your needs? Here’s an introduction and some common uses for each:

Polycarbonate (PC)

Polycarbonate is a strong and durable thermoplastic material known for its impact resistance, optical clarity, and weatherability. It is also lightweight and easy to fabricate. PC is commonly used in a variety of applications, including:

• Safety equipment, such as helmets, face shields, and safety glasses
• Medical devices, such as incubators, MRI machines, and surgical instruments
• Building materials, such as skylights, greenhouses, and sound barriers
• Signage and displays
• Consumer products, such as electronics, appliances, and sporting goods

Polymethyl Methacrylate (PMMA)

Polymethyl methacrylate, also known as acrylic, is a transparent thermoplastic material known for its optical clarity, scratch resistance, and weatherability. It is also lightweight and easy to fabricate. PMMA is commonly used in a variety of applications, including:

• Optical devices, such as lenses, mirrors, and prisms
• Signs and displays
• Architectural features, such as skylights, windows, and doors
• Furniture and fixtures
• Consumer products, such as eyeglasses, toys, and cosmetics

Summary of the key differences between PC vs PMMA

PMMA is more transparent and scratch-resistant than PC, but is also more brittle and less expensive. PC is stronger and more impact-resistant than PMMA, but is also more expensive and more likely to get scratched easily. Below, we compare some of the key features of the two materials:

• Transparency: PMMA is more transparent than PC.
• Brittleness: PMMA is more brittle than PC, meaning it is more likely to break under impact.
• Scratch resistance: PC is more scratch-resistant than PMMA.
• Cost: PC is more expensive than PMMA.

Application Recommendations

Polycarbonate (PC)

• Safety equipment: PC is ideal for safety equipment that needs to be both strong and lightweight, such as helmets, face shields, and safety glasses. It is also resistant to chemicals and abrasion, making it a good choice for safety gear used in industrial and hazardous environments.
• Medical devices: PC is used in a wide range of medical devices, from incubators and MRI machines to surgical instruments and implants. It is chosen for its biocompatibility, transparency, and durability.
• Building materials: PC is a popular choice for building materials such as skylights, greenhouses, and sound barriers. It is strong, lightweight, and weather-resistant. It also has good insulation properties, making it ideal for energy-efficient buildings.
• Signage and displays: PC is used in a variety of signage and displays, from store signs and billboards to digital displays and trade show booths. It is chosen for its optical clarity, impact resistance, and durability.
• Consumer products: PC is used in a wide range of consumer products, from electronics and appliances to sporting goods and luggage. It is chosen for its strength, lightweight, and durability.

Polymethyl Methacrylate (PMMA)

• Optical devices: PMMA is the ideal material for optical devices such as lenses, mirrors, and prisms. It is transparent, scratch-resistant, and has excellent optical clarity. PMMA is also used in eyeglasses and other optical products.
• Signs and displays: PMMA is a popular choice for signs and displays that require high optical clarity and scratch resistance, such as point-of-purchase displays, trade show booths, and backlit signs. It is also used in LED signs and displays.
• Architectural features: PMMA is used in a variety of architectural features, such as skylights, windows, doors, and balustrades. It is chosen for its transparency, weather resistance, and durability. PMMA is also used in decorative and signage applications in buildings.
• Furniture and fixtures: PMMA is used in a variety of furniture and fixtures, such as tabletops, chairs, shelves, and cabinets. It is chosen for its high-quality finish, optical clarity, and resistance to scratching and staining.
• Consumer products: PMMA is used in a wide range of consumer products, such as eyeglasses, toys, and cosmetics. It is chosen for its high optical clarity, scratch resistance, and durability.

In addition to the specific applications listed above, PC and PMMA can be used in a variety of other ways. For example, PC can be used in automotive parts, electrical components, and aerospace applications. PMMA can be used in medical devices, food packaging, and laboratory equipment.

When choosing between PC and PMMA, it is important to consider the specific requirements of the application. PC is a good choice for applications that require high impact resistance, optical clarity, and weatherability. PMMA is a good choice for applications that require superior optical clarity and scratch resistance, as well as a high-quality finish.

Alternative plastics

In addition to PC and PMMA, there are several other transparent plastic materials that can be used for different engineering applications. Some of these alternatives include:

• Polyethylene terephthalate glycol (PETG): a good alternative to PC when impact resistance is needed, but at a lower cost.
• Cellulose acetate butyrate (CAB): a good alternative to PMMA when scratch resistance is needed, but at a lower cost.
• Styrene acrylonitrile (SAN): a good alternative to PC and PMMA when optical clarity and chemical resistance are needed.
• Polyvinyl chloride (PVC): a good alternative to PC and PMMA when low cost and easy fabrication are needed.

Sourcing tips and tricks for PMMA and PC

• Check prices from a number of different sellers. The prices of PC and PMMA can change a lot from one supplier to the next. Before you buy anything, make sure you look at prices from more than one seller.
• Think about the material’s grade. There are different types of PMMA and PC, and each has its own special qualities. Make sure you choose the type of material that works best for your application.
• Ask the provider how they ensure the quality of their work. Finding PMMA and PC from a provider with a good quality control system is important. This will make it more likely that you will get good grade product.
• Talk to the seller about getting samples. Make sure you get samples of the PMMA or PC from the supplier before you place a big order. You can look at the material and make sure it fits your needs this way.
• Check the lead times of the provider. Based on the supplier and the grade of the material, wait times for PMMA and PC can be very long. Check the lead times of the seller before you place an order.
• When sourcing PMMA, be sure to be clear about the color and thickness you want. Since PMMA comes in many sizes and colors, it’s important to be clear about what you want.
• When sourcing PC, be sure to be clear about the grade and effect strength you want. There are different types of PC, and each has a different impact strength. Make sure you choose the type of material that works best for what you need it for.
• Make sure you get a proof of analysis from the supplier of PMMA or PC if you need it for a very important project. This will give you confidence that the stuff meets your needs.
• Make sure that you store PC and PMMA the right way. Heat and UV light can damage both PMMA and PC. Keep them in a cool, dark place to keep them from breaking down.

Summary

PC and PMMA are two of the most common transparent plastics used in a wide variety of applications. Each material has its own unique properties and advantages, making it suitable for different applications. When selecting a transparent plastic for a particular application, it is important to consider the required properties, such as impact resistance, optical clarity, weatherability, and cost.

P.S.

If you have found this useful then you should definitely take a look at our page all about different kinds of thermoplastics, as this will give you tons of help to choose the right plastic for your needs and understand their properties, testing, and more.

You may also like to read this post about Mechanical Parts Inspections: Checkpoints & Defects if your transparent plastic parts are mechanical, too.