How to choose the right composite material – A practical guide for developers and OEMs

Selecting the right composite material is one of the key decisions in product development. Different combinations of resin systems and reinforcing fibers result in very specific properties regarding strength, temperature resistance, electrical insulation, and chemical resistance.

For developers and OEMs, this means: A well-founded material selection is crucial for the performance, lifespan and cost-effectiveness of a component.

Why choosing the right material is crucial

Composite materials offer properties that are often unattainable with conventional metals or standard plastics. At the same time, the individual material systems differ considerably in their behavior under:

• mechanical stress
• thermal stress
• electrical voltage
• chemical exposure

An incorrect choice can lead to:

• premature component failure
• increased production costs
• elaborate redesigns
• Limitations in series production

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A structured selection of materials prevents both over- and under-dimensioning and ensures that the component meets the requirements in the long term.

Key selection criteria for composite materials

1. Mechanical requirements

First, it must be clarified what stresses the component is exposed to.

Key performance indicators include:

• Tensile strength
• flexural strength
• elastic modulus
• Fatigue behavior

The following are particularly suitable for structurally stressed components:

• glass fiber reinforced thermosets (e.g. epoxy or polyester resins)
• fiber-oriented systems (e.g., wound or woven structures)

These offer high stiffness and excellent dimensional stability.

2. Temperature resistance

In addition to the continuous operating temperature, short-term temperature peaks must also be taken into account.

Thermosetting composites are particularly suitable for:

• high continuous temperatures (> 120 °C to significantly higher depending on the system)
• strong temperature changes
• Applications with high demands on dimensional stability

In contrast, thermoplastic materials tend to deteriorate under prolonged heat exposure. Creep or deformation.

3. Electrical and thermal insulation

In many applications – especially in electrical engineering – electrical insulation is a crucial criterion.

Thermoset composite materials offer:

• high dielectric strength
• good tracking resistance
• stable dielectric properties
• low thermal conductivity

Typical applications are:

• electrical insulation components
• Carrier for printed circuit boards
• High-voltage insulators

4. Wear, friction and chemical resistance

For moving components or aggressive environments, additional requirements must be taken into account:

• Resistance to oils, solvents or acids
• low wear and tear
• optimized friction properties

Reinforced composite materials can be adapted here through special resin systems or additives.

5. Manufacturability

A common mistake in development is selecting a material without considering the manufacturing process.

Please note:

• Component geometry and wall thicknesses
• Manufacturing processes (e.g. pressing, winding, CNC machining)
• numbers
• Tolerances and post-processing

Early coordination between design and manufacturing can significantly reduce costs.

Thermosets vs. thermoplastics – When is which system suitable?

Thermosetting composite materials

Ideal for:

• high temperatures
• high mechanical loads
• electrical insulation applications
• chemically aggressive environments
• low creep tendency

Typical applications:

• Laminated materials (e.g. epoxy resin or phenolic resin systems)
• coiled tubes and cylinders
• High-temperature insulation components

Thermoplastic composites

Suitable for:

• high quantities
• cost-sensitive applications
• flexible or impact-resistant components
• Recycling requirements

Limitations:

• lower temperature resistance
• higher creep tendency
• Limited electrical performance in demanding applications

Frequently underestimated material trade-offs

In practice, problems often arise not from obvious wrong decisions, but from overlooked details:

• Creep behavior: Material deforms under continuous load
• Temperature cycles: lead to cracking or delamination
• Moisture absorption: affects electrical properties
• Machinability: limited geometries and tolerances
• chemical interactions: lead to material degradation

An early technical assessment helps to minimize these risks.

Checklist for material selection

For structured decision-making, the following points should be examined:

• mechanical stress
• Temperature range
• electrical requirements
• chemical and environmental influences
• expected lifespan
• manufacturing processes
• Quantity and budget
• Tolerance requirements

Support provided by Dr. Dietrich Müller GmbH

The Dr. Dietrich Mueller GmbH supports companies in the selection and processing of suitable composite materials – from the concept phase to series production.

The range of services includes:

• technical materials consulting for electrical and mechanical applications
• Support with design and material selection
• Manufacturing of prototypes and series components
• Processing of laminated materials, technical films and composite materials

By combining materials expertise and manufacturing experience, solutions can be developed that are both technically and economically convincing.

Summary: Key takeaways about intuitive eating

Selecting the right composite material is a complex process that goes far beyond simply considering strength values.

Only through a holistic assessment of:

• mechanical requirements
• thermal taxes
• electrical properties
• manufacturing processes

An optimal solution can be achieved.

Companies that consider these factors early on reduce risks, shorten development times, and ensure the long-term performance of their products. Dr. Dietrich Müller GmbH is happy to support you in your decision-making processes with our technical consulting services.

You can find more information on this topic in the article. Thermosets vs. Thermoplastics.