Engineer Education Series #8: Co-Extrusion vs Single Material Extrusion

Plastic extrusion allows engineers to create continuous profiles with consistent geometry, but not all extrusion is limited to a single material. Co-extrusion expands design possibilities by combining multiple materials into a single profile.

Understanding when to use co-extrusion versus single material extrusion helps engineers optimize performance, durability, and cost.

What is Co-Extrusion?

Co-extrusion is a process where two or more materials are extruded simultaneously through the same die to form a single, unified profile.

Each material maintains its own properties while bonding together during the extrusion process.

This allows engineers to combine different material characteristics into one component.

Benefits of Co-Extrusion

Co-extrusion enables enhanced performance by leveraging multiple materials within a single profile.

Common advantages include:

• combining rigid and flexible materials
• improving impact resistance
• adding UV-resistant outer layers
• enhancing surface durability
• reducing overall material cost

For example, a rigid structural core can be paired with a softer outer layer to improve grip or impact protection.

Common Co-Extrusion Applications

Co-extrusion is often used in applications where multiple performance characteristics are required.

Examples include:

• sealing profiles with flexible edges
• protective covers with durable outer layers
• profiles with UV-resistant exterior surfaces
• multi-functional industrial components

These designs allow engineers to achieve performance that would not be possible with a single material.

When to Use Single Material Extrusion

Single material extrusion remains the best choice for many applications.

It is typically preferred when:

• the design is simple
• only one material property is required
• cost needs to be minimized
• production efficiency is a priority

Single material profiles are generally easier to manufacture and require less complex tooling.

Tooling and Process Considerations

Co-extrusion requires more advanced tooling and process control compared to single material extrusion.

Considerations include:

• multiple material feed systems
• precise control of material flow
• bonding between materials
• increased tooling complexity

Because of this, co-extrusion typically involves:

• higher tooling costs
• longer development timelines
• more process optimization

Designing for Co-Extrusion Success

Engineers designing for co-extrusion should consider:

• compatibility between materials
• bonding characteristics
• relative material flow rates
• thermal behavior during cooling

Early collaboration with the extrusion manufacturer is especially important to ensure the design is feasible.

Choosing the Right Approach

The decision between co-extrusion and single material extrusion depends on:

• performance requirements
• environmental conditions
• cost constraints
• design complexity

If multiple material properties are required in one profile, co-extrusion may provide significant advantages.

Working with OEM Engineers

Lincoln Plastics works with OEM manufacturers to develop both single material and co-extruded plastic profiles for applications including:

• agricultural equipment
• industrial machinery
• infrastructure protection systems
• cord management products

If you're evaluating whether co-extrusion is right for your application, our team can help review your design and material options.

Engineer Education Series

Explore the full series:

Engineer Education Series #1:
Designing Plastic Extrusion Profiles – Key Engineering Considerations

Engineer Education Series #2:
Plastic Extrusion Tolerances – What Engineers Should Expect

Engineer Education Series #3:
Common Design Mistakes Engineers Make with Plastic Extrusion

Engineer Education Series #4:
How Plastic Extrusion Tooling Works

Engineer Education Series #5:
Plastic Extrusion vs Injection Molding – When to Use Each

Engineer Education Series #6:
Plastic vs Metal Components in Equipment Design

Engineer Education Series #7:
Designing Plastic Components for Outdoor Equipment

Engineer Education Series #8: Co-Extrusion vs Single Material Extrusion
Engineer Education Series #9: How Engineers Collaborate with Extrusion Manufacturers
Engineer Education Series #10: Material Selection for Extruded Plastic Parts

Additional Engineering Resources

Society of Plastics Engineers (SPE)
https://www.4spe.org

Plastics Technology – Co-Extrusion Overview
https://www.ptonline.com

Polymer Processing Society
https://www.ppsociety.org

‍