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How Are EPS Foam Liners Made for Motorcycle Helmets?

Jul 10, 2024

Discover the precise manufacturing process of EPS foam liners and their role in helmet safety.

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The inner shell of motorcycle helmets, known as EPS foam liners, undergoes a precise manufacturing process to ensure safety and performance. Here’s how it’s done:


EPS foam liners are typically created through injection molding. The process begins with raw polystyrene particles placed in a heated cylindrical tank. Internal blades and hot air soften the material uniformly during the pre-expansion stage. Then, a vacuum removes pentane gas, allowing the material to expand to the desired density.


Once pre-expanded, the material moves to a mold where it’s shaped using a blowing agent like hot air or superheated steam. This forces the foam beads to conform to the mold’s shape and bond together. The mold is cooled to stabilize the EPS foam. After cooling, the EPS helmet liner is separated from the mold core, aided by a release agent like Teflon to ensure smooth removal.


The advantages of EPS foam liners include lightweight construction and excellent impact resistance, making them ideal for motorcycle helmets produced in large quantities at low cost. However, manufacturing constraints limit helmets to a maximum of 180° hemispherical shape, and complex molds can increase costs and reduce impact resistance. Additionally, integrating ventilation holes in EPS can be challenging.


For more content or illustrations, head to our website, or check out our FAQ. To reference our article to your friends, or family, in the Motorcycling/Motorsport community, click the link below or simply copy this URL or bookmark the page for future referencing: Otherwise read our next article about Helmet Laser Scanning Shines the Green Light Significantly Enhancing Your Safety, titled “Helmet Safety: Vital for Motorcycling”


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