Updated on 09.25, Published on 09.25

How to Choose the Right Plastic Material for Injection Molded Parts

Choosing the right plastic material is one of the most important decisions when developing a custom plastic part. Material selection affects strength, durability, temperature resistance, chemical resistance, appearance, dimensional stability, manufacturability, and overall cost.

There is no single plastic material that is suitable for every application. The right choice depends on the product's function, operating environment, design requirements, production process, and target cost.

At Akinotek, material selection is considered together with product design, DFM, mold development, injection molding, and final application requirements.

1. Understand the Part's Application

The first step is to understand how the plastic part will be used.

Consider questions such as:

Will the part carry a mechanical load?
Will it experience impact or vibration?
What temperature will it operate at?
Will it contact chemicals, oils, or cleaning agents?
Will it be exposed to sunlight or outdoor conditions?
Does it need to be flexible or rigid?
Is electrical insulation required?
Is the appearance important?

For example, a decorative electronics housing may prioritize appearance and dimensional stability, while an automotive component may require higher heat resistance and mechanical strength.

2. Consider Mechanical Requirements

Different plastics provide different combinations of strength, stiffness, impact resistance, hardness, and flexibility.

Common material options include:

ABS

ABS is widely used for housings, covers, consumer electronics, home appliances, and other products requiring a good balance of strength, impact resistance, appearance, and cost.

PC

Polycarbonate offers high impact resistance and good dimensional performance. It is often considered for protective covers, transparent components, electronic housings, and products requiring greater toughness.

PP

Polypropylene is lightweight and provides good chemical resistance and fatigue performance. It is commonly used for containers, interior components, household products, and living hinges.

PA / Nylon

Nylon provides good mechanical strength and wear resistance. It can be used for gears, structural components, mechanical parts, and other applications requiring engineering performance.

POM

POM, also known as acetal, offers good dimensional stability, low friction, and wear resistance. It is commonly used for gears, bushings, slides, and precision mechanical components.

TPE

TPE is a flexible material family that can provide rubber-like characteristics. It is commonly used for grips, seals, soft-touch components, and overmolded parts.

3. Check Temperature Requirements

Operating temperature is another important consideration.

A plastic part used near a heat source may require a material with higher temperature resistance than a standard consumer product. Temperature changes can also affect dimensional stability and mechanical performance.

When selecting a material, consider both the continuous operating temperature and short-term temperature exposure.

For electronic products, automotive components, appliances, and industrial equipment, this factor should be evaluated during the early design stage.

4. Consider Chemical and Environmental Resistance

Plastic parts may come into contact with:

Oils and lubricants
Cleaning chemicals
Detergents
Water and moisture
Solvents
Outdoor weather conditions

A material that performs well in a laboratory environment may not be suitable for a specific chemical or environmental condition.

For products exposed to chemicals or moisture, material compatibility should therefore be evaluated before finalizing the design.

5. Appearance and Surface Finish

For visible plastic parts, material selection also affects the final appearance.

The required appearance may include:

Glossy surface
Matte texture
Transparent or translucent appearance
Custom color
Painted surface
Plated surface
Soft-touch finish
Mold texture

For example, ABS is commonly selected for products requiring attractive molded surfaces and can also support various post-processing options.

The material should be considered together with the mold surface finish, texture, wall thickness, gate location, and injection molding process.

6. Consider Moldability and Part Design

A material may meet the functional requirements but still require design adjustments for successful injection molding.

Material selection can affect:

Shrinkage
Warpage
Flow behavior
Cooling requirements
Wall thickness
Rib design
Draft angle
Gate design
Mold structure

This is why material selection should not be treated as an isolated purchasing decision.

A DFM review can identify potential manufacturing issues before tooling begins.

7. Balance Performance and Cost

Higher-performance engineering plastics are not always necessary.

Using an expensive material when a standard material already meets the product requirements can increase the overall part cost without providing meaningful benefits.

On the other hand, selecting a low-cost material that cannot withstand the actual operating environment may lead to premature failure and higher costs later.

A practical material selection process should balance:

Performance + Manufacturability + Availability + Appearance + Cost

Plastic Material Selection Guide

Material	Main Characteristics	Common Applications
ABS	Good impact resistance, appearance, cost balance	Electronics housings, appliances, covers
PC	High impact resistance, toughness	Protective covers, electronics, transparent parts
PP	Lightweight, chemical resistance, fatigue resistance	Containers, appliances, automotive parts
PA/Nylon	Strength, wear resistance	Gears, mechanical parts, structural components
POM	Low friction, wear resistance, dimensional stability	Gears, bushings, precision components
TPE	Flexible, rubber-like feel	Seals, grips, soft-touch parts

Material Selection Should Start Before Tooling

Choosing the plastic material after the mold design has already been finalized can create unnecessary engineering changes.

Ideally, material selection should be reviewed during the product development and DFM stage. The engineering team can evaluate the application, part geometry, expected production volume, appearance, material properties, and molding requirements before the tooling design is finalized.

At Akinotek, we support customers from product design and DFM through mold development, injection molding, assembly, and mass production. This allows material selection to be considered as part of the complete manufacturing process.

Custom Plastic Parts and Material Selection from Akinotek

If you are developing a new plastic product, selecting the right material is an important step before moving into injection mold manufacturing.

Akinotek can help evaluate your CAD files, drawings, application requirements, material preferences, surface finish, production quantity, and target cost to determine a suitable manufacturing approach.

Send us your product drawings or 3D CAD files, and our engineering team can review the project and provide recommendations for plastic material selection, DFM, tooling, and injection molding production.

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