Common Engineering Plastics for Electronic Components

Choosing the right plastic material is an important part of electronic product development and injection molding.

For electronic housings, connectors, gears, brackets, covers, cable components, and internal structural parts, the material needs to satisfy more than basic strength requirements. Operating temperature, electrical insulation, dimensional stability, chemical resistance, impact resistance, wear resistance, flame retardancy, and molding behavior may all affect the final product.

As an injection mold manufacturer and plastic injection molding company in China, we help customers evaluate engineering plastics from both the product design and manufacturing perspective.

The most suitable material is not necessarily the strongest or most expensive resin. It is the material that provides the required performance while remaining suitable for the intended injection molding process and production cost.

What Are Engineering Plastics?

Engineering plastics are thermoplastic materials used for components that require higher mechanical, thermal, electrical, or chemical performance than conventional commodity plastics.

Compared with general-purpose plastics, engineering plastics can provide advantages such as:

• Higher mechanical strength
• Better dimensional stability
• Higher temperature resistance
• Better wear resistance
• Improved chemical resistance
• Good electrical insulation
• Better impact performance for selected grades

However, engineering plastics also have different processing characteristics.

Some materials absorb moisture, some require careful drying, some are sensitive to molding temperature, and some have relatively high shrinkage or warpage tendencies.

For injection molded electronic components, material selection and mold design should therefore be considered together.

Common Engineering Plastics for Electronics

1. PA — Nylon

PA, commonly known as nylon, provides good mechanical strength, toughness, wear resistance, and fatigue resistance.

It is widely used for functional components that require mechanical performance rather than purely cosmetic appearance.

Typical applications

PA can be used for:

• Gears
• Bushings
• Cable components
• Connectors
• Structural brackets
• Coil formers
• Mechanical supports
• Small appliance components
• Moving components

Engineering considerations

The main issue with PA is moisture absorption.

Moisture can affect dimensional stability, mechanical properties, and the molding process. For precision electronic components, the material condition needs to be controlled before injection molding.

PA grades can also have significantly different properties depending on whether they are unfilled, glass-fiber reinforced, flame-retardant, or modified for specific applications.

When glass-filled PA is used, fiber orientation can also affect shrinkage and warpage.

For precision parts, the material grade should therefore be confirmed before finalizing critical mold dimensions.

2. PC — Polycarbonate

PC is known for its high impact strength, good dimensional stability, and transparency.

It is commonly used when an electronic component requires a combination of impact resistance, appearance, and dimensional performance.

Typical applications

PC can be used for:

• Transparent covers
• Display windows
• Electrical enclosures
• Protective panels
• Instrument housings
• Lighting components
• Electronic device housings

Engineering considerations

PC has good impact resistance, but it can be sensitive to certain chemicals and solvents. Molded PC components may also develop stress cracking if the material, design, processing conditions, and chemical environment are not properly controlled.

For transparent parts, mold surface quality and processing stability are particularly important.

Gate location, weld lines, ejector marks, flow marks, and internal stress can all affect the appearance of a transparent PC component.

For these applications, mold design cannot be separated from material selection.

3. PC/ABS

PC/ABS is a commonly used engineering plastic that combines characteristics of polycarbonate and ABS.

It provides a useful balance of:

• Impact resistance
• Rigidity
• Surface appearance
• Dimensional stability
• Processability

PC/ABS is widely used for electronic and electrical housings where appearance and mechanical performance are both important.

Typical applications

• Electrical enclosures
• Electronic device housings
• Display housings
• Battery housings
• Charger housings
• Cable connectors
• Control panels
• Office equipment
• Small appliance housings

Engineering considerations

PC/ABS is available in different grades with different impact, heat, flame-retardant, and processing characteristics.

For an electronic enclosure, the material grade should be selected according to the actual operating environment rather than simply specifying “PC/ABS.”

If the product requires flame retardancy or a specific regulatory approval, the exact resin grade must be confirmed before mold design and production.

4. POM — Acetal

POM, also called acetal or polyacetal, is widely used for precision mechanical components.

Its key characteristics include:

• High stiffness
• Good wear resistance
• Low friction
• Good dimensional stability
• Good fatigue resistance
• Good chemical resistance

POM is particularly suitable for components that move or contact other components.

Typical applications

• Gears
• Cams
• Rollers
• Shafts
• Bushings
• Mechanical drive components
• Precision mechanisms
• Switch components

Engineering considerations

POM is different from PC and PC/ABS because it is usually selected for mechanical performance rather than housing appearance.

The mold design must take into account material shrinkage, cooling, ejection, and dimensional requirements.

For precision POM components, consistent molding conditions are important because dimensional variation can directly affect assembly and mechanical movement.

Engineering Plastic Selection for Electronic Components

There is no single “best” engineering plastic for all electronic products.

Material selection should start with the actual requirements of the component.

Requirement	Materials to Consider
High impact resistance	PC, PC/ABS
Good mechanical strength	PA, PC, POM
Wear and low friction	POM, PA
Dimensional stability	PC, POM, selected PA grades
Transparent components	PC
Electronic housings	PC/ABS, PC, selected ABS/engineering grades
Mechanical gears	POM, PA
Electrical insulation	PA, PC, PC/ABS and other suitable grades
Flame-retardant requirements	Specific FR grades of PA, PC, PC/ABS, etc.

This table is only a starting point. The final material should be selected according to the exact resin grade and application requirements.

What Engineers Should Consider Before Selecting the Material

Operating Temperature

The material must maintain its required mechanical and electrical properties at the actual operating temperature.

A component exposed to continuous heat may require a different resin than a component operating at room temperature.

Electrical Requirements

For electronic components, electrical insulation, dielectric performance, and flame-retardant requirements may be important.

The required properties depend on the product and applicable standards.

Chemical Exposure

Consider whether the part will contact:

• Cleaning agents
• Oils
• Fuels
• Solvents
• Adhesives
• Other chemicals

A material that performs well mechanically may not be suitable for a particular chemical environment.

Dimensional Requirements

If the component is used for precision assembly, connector positioning, gears, clips, or moving mechanisms, dimensional stability becomes more important.

Material shrinkage and molding conditions should be considered during mold design.

Surface Appearance

For visible electronic housings, the material needs to provide the required:

• Color
• Gloss
• Texture
• Transparency
• Surface durability

The mold surface finish also has a direct effect on the final appearance.

Material Selection Also Affects Injection Mold Design

One of the most common mistakes in new product development is selecting the material after the mold has already been designed.

Material properties can affect:

• Mold shrinkage
• Gate design
• Runner dimensions
• Cooling requirements
• Ejection
• Warpage
• Cycle time
• Mold steel dimensions
• Part tolerances

For example, PA and POM can have different shrinkage behavior from PC or PC/ABS. Glass-fiber reinforced materials can introduce additional directional shrinkage and warpage considerations.

For this reason, the plastic material grade should be confirmed before finalizing critical mold dimensions.

Engineering Plastics and Injection Molding

Selecting the correct resin is only part of the process.

The material must also be processed within an appropriate molding window.

Our engineers consider factors such as:

• Resin drying requirements
• Melt temperature
• Mold temperature
• Injection speed
• Injection pressure
• Holding pressure
• Cooling time
• Venting
• Gate design
• Runner design
• Mold cooling

For moisture-sensitive materials such as PA, proper material drying is particularly important.

For transparent PC parts, processing and mold surface quality can directly affect cosmetic performance.

For POM precision components, molding stability and dimensional control are critical.

The injection molding process therefore needs to be developed together with the material and mold design.

Common Problems When Choosing the Wrong Plastic

An unsuitable material can create problems even when the mold itself is correctly manufactured.

Typical problems include:

Warpage

Uneven shrinkage or fiber orientation can cause deformation.

Sink Marks

Thick sections, bosses, and ribs can create localized shrinkage and visible sink marks.

Dimensional Variation

Moisture absorption, material shrinkage, processing conditions, and cooling can all affect dimensions.

Stress Cracking

Some plastics, particularly PC, can be sensitive to certain chemicals or excessive internal stress.

Poor Wear Performance

A housing material may not be suitable for gears or moving components where friction and wear are important.

Insufficient Flame Retardancy

For some electronic and electrical applications, a standard resin may not meet the required flame-retardant specification.

These issues should be identified during product development rather than after mass production has started.

Plastic Injection Molding for Electronic Components

We provide plastic injection mold manufacturing and injection molding services for electronic and electrical components.

Our manufacturing process can include:

Material Review → DFM Analysis → Mold Design → Mold Manufacturing → Mold Trial → Sample Inspection → Process Optimization → Mass Production

During DFM, our engineers review the part geometry and material together.

We look at:

• Wall thickness
• Draft angles
• Ribs and bosses
• Undercuts
• Gate location
• Parting line
• Ejection
• Cooling
• Shrinkage
• Dimensional tolerances
• Cosmetic requirements

This approach helps identify potential molding problems before the injection mold is manufactured.

Why Work With an Injection Mold and Molding Manufacturer?

For engineering plastic components, mold design and injection molding are closely connected.

A mold can produce the correct geometry during sampling but still have problems with cycle time, warpage, dimensional consistency, or long-term production stability.

Because we provide both injection mold manufacturing and plastic injection molding, our engineers can evaluate the tooling and production process together.

Our goal is not simply to manufacture an injection mold.

The goal is to produce a mold that can run reliably and produce consistent plastic parts during mass production.

Custom Engineering Plastic Injection Molding

If you are developing an electronic component and are unsure which engineering plastic or molding process to use, send us your 3D CAD model, 2D drawing, material specification, or existing sample.

We can review the part from a manufacturing perspective and provide recommendations regarding:

• Material selection
• Mold structure
• Gate location
• Shrinkage
• Draft angle
• Wall thickness
• Cooling
• Ejection
• Potential molding defects
• Injection molding process

We manufacture custom injection molds and molded plastic components in China, helping customers move from product development to stable production.