Engineering Plastics: Properties, Types and Uses

You see plastics everywhere, but not all plastics are the same. Some are weak and soft, while others are tough and heat-resistant. The strong ones are called engineering plastics.

In this guide, you’ll learn the different types of engineering plastics available, their properties, and their uses.

What are Engineering Plastics?

Engineering plastics are high-performance polymers that can replace metals, ceramics, and glass in many applications. Unlike regular plastics, they can handle more heat, stress, and chemicals that’s why they are useful for building strong and durable parts.

Properties of Engineering Plastics

Engineering plastics have special properties that make them useful in tough environments. Here are some key properties:

• Stark und langlebig
• Transparent or translucent
• Chemical-resistant
• Shape stability
• Schwer entflammbar
• Heat-resistant
• Water-resistant
• Geringe Reibung
• Gute elektrische Isolierung

Advantages and Disadvantages of Engineering Plastics

Engineering plastics have many benefits, but they also have some drawbacks. It’s important to understand both before choosing them for a project.

Advantages of Engineering Plastics

• Engineering plastics are tougher than regular plastics. They can handle heavy loads, impacts, and stress without breaking.
• These plastics are much lighter than metals. They can reduce the weight of automotive and aerospace parts to improve fuel efficiency and performance.
• Many engineering plastics don’t react with chemicals, oils, or solvents.
• Some engineering plastics can handle extreme temperatures without melting or losing strength.
• Most engineering plastics don’t conduct electricity so they are great for electronic components and wire insulation.
• These plastics don’t shrink or warp easily, so they hold their shape even in tough conditions.
• Engineering plastics can be molded into complex shapes, allowing for custom designs that are hard to make with metal or other materials.
• Some engineering plastics are naturally slippery, reducing wear and tear on moving parts.
• Many engineering plastics are eco-friendly because they can be recycled.

Disadvantages of Engineering Plastics

• While some types handle high heat, others can weaken or change shape at extreme temperatures.
• Some engineering plastics break down when exposed to UV rays for too long. This can cause them to fade, crack, or lose strength.
• Compared to standard plastics, engineering plastics cost more to produce and buy.
• Not all types of engineering plastics are easy to find. Some specialty grades are only made by a few manufacturers so they are harder to source.
• Some engineering plastics require higher temperatures and special processing methods so they are more difficult and expensive to manufacture.
• While many engineering plastics can be recycled, some contain additives that make recycling harder or impact the environment.
• Unlike glass or some standard plastics, some engineering plastics are not fully clear.
• Even though they resist many chemicals, some engineering plastics can still react with aggressive solvents.
• Some engineering plastics lose their flexibility in freezing conditions so they might crack or break.

Different Types of Engineering Plastics

There are many types of engineering plastics, each with different properties. Below are some of the most common types of engineering plastics:

Polycarbonates (PC)

Polycarbonat is a tough and durable plastic that is easy to shape and mold. It resists impact, heat, and electricity better than regular plastics.

Some types of polycarbonates are also clear like glass. Because of these properties, it is often used to make motorcycle helmets, car bumpers, and optical discs (like CDs and DVDs).

Acrylnitril-Butadien-Styrol (ABS)

ABS is made from a mix of different chemicals to create a strong and heat-resistant plastic. It is also flame-resistant, chemical-resistant, and provides good electrical insulation.

Since ABS is easy to machine and 3D print, it is commonly used for car dashboards, wheel covers, and bumpers.

Polymethylmethacrylate (PMMA)

PMMA, also called acrylic, is known for its clear, glass-like appearance. It is strong, heat-resistant, and lightweight. You’ll find it in car taillights, protective shields, and display panels.

Polyamide (PA)

Polyamide, also called nylon, is one of the most popular and widely used plastics today. It is made by combining acid and amide molecules to form long polymer chains.

Nylon is strong, hard, and resistant to corrosion. It is also easy to shape, has a smooth and glossy surface, and is non-toxic. Plus, it can be easily mixed with other materials to improve its properties.

Polyoxymethylene (POM)

POM is a hard and wear-resistant plastic that is easy to process into high-performance parts. It is commonly used for gears, fasteners, ball bearings, and other mechanical parts that require strength and durability.

Polyethylene Terephthalate (PET)

PET is a lightweight and transparent plastic made from terephthalic acid and ethylene glycol. It is strong, impact-resistant, and resistant to heat, chemicals, and moisture.

PET also does not absorb alcohol and stays stable in different conditions. It is one of the most commonly recycled plastics today.

Polyphenylene Sulfide (PPS)

PPS is a high-performance plastic that is usually white and has a high level of crystallinity. It is known for its excellent heat and chemical resistance, working well in extreme temperatures from 240-260°C.

Even under high heat, PPS maintains its strength, hardness, and resistance to corrosion, UV light, and radiation. It is also flame-retardant and a good electrical insulator.

Polyetheretherketon (PEEK)

PEEK is a high-heat-resistant plastic made from polyetheretherketone resins. It can withstand temperatures of 260°C for long periods and up to 310°C for short times.

PEEK has great mechanical strength, corrosion resistance, friction resistance, and UV resistance. It is also flame-resistant and produces very little smoke when burned.

Engineering Plastics vs Commodity Plastics

Commodity plastics are everyday plastics used in high-volume applications where advanced performance isn’t needed. These include polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), polyurethane (PU), and polystyrene (PS).

You’ll find commodity plastics in packaging, containers, disposable products, clothing, and household items. They’re affordable, easy to manufacture, and widely available, but they don’t offer high strength, heat resistance, or durability.

On the other hand, engineering plastics like the ones discussed above are designed for high-performance applications. These materials are replacing traditional metals and ceramics in many industries because of the properties they offer.

Engineering plastics are used in automotive, aerospace, electrical, electronics, and construction. However, they cost more than commodity plastics, so they’re typically used for smaller, precision parts or low-volume applications where performance matters most.

Applications of Plastic Engineering Products

Engineering plastics are used in many industries, with each application needing specific properties. Here are some common uses:

Low-Friction Parts

These components include wear-resistant surfaces, guides, bearings, and slides. They need a low coefficient of friction so they can move smoothly without wearing down too quickly.

This helps machines and equipment last longer and require less maintenance.

Mechanical Plastic Parts

Mechanical plastic parts include gears, cams, and couplings. These parts must be strong enough to handle impact and tension without breaking.

They also need to stay stable and work well for a long time, even under high temperatures.

Electrical Plastic Components

Electrical plastic parts, such as connectors and relays, need to resist electricity while staying strong and stable. They must handle physical stress and temperature changes without failing.

Since plastic doesn’t conduct electricity like metal, it helps keep electrical systems safe.

Chemical and Heat-Resistant Plastic Parts

These parts include water pump housings, valve covers, and fuel rails. They must resist corrosion from chemicals and withstand high temperatures.

They are often used in environments where traditional materials like metal would wear out too quickly.

Schlussfolgerung

Now you know that engineering plastics are stronger and more durable than regular plastics, and they can replace metals and ceramics in some applications. They can handle heat, stress, and chemicals so they are useful for many industries.

Unter DEK, we specialize in high-quality engineering plastics for a wide range of uses. Contact our experts today and get the right material for your project.