Quick answer: EPP (expanded polypropylene) is a closed-cell foam that is lightweight yet highly resistant to repeated impact. Unlike EPS, EPP springs back after compression, tolerates higher temperatures and is easy to recycle, which is why it is used in automotive parts, helmets and reusable packaging.

What is EPP foam?

Expanded polypropylene (EPP) is a closed-cell foam made from polypropylene beads. Like EPS, the beads are expanded and fused inside a mold, but the base polymer gives EPP very different behaviour: it is tougher, more elastic and able to recover its shape after impact.

Key properties of EPP

Two properties stand out. First, EPP's multi-impact resistance: after being compressed, it returns to nearly its original shape, so it keeps protecting over repeated loads. Second, its high temperature tolerance, which is roughly 40 °C higher than EPS.

Density and performance

EPP density is usually expressed in grams per litre (g/L), which is numerically the same as kg/m³. Low densities (20–30 g/L) are soft and light for cushioning; medium densities (40–60 g/L) suit automotive and structural parts; high densities (80–200 g/L) are used where stiffness and durability matter most.

Why EPP outperforms EPS in many applications

The trade-off is cost: EPP is more expensive than EPS. For single-use protective packaging, EPS is often the economical choice; for parts that must survive repeated impact or high heat, EPP pays for itself. Our comparison of EPP and EPS covers the design implications.

Main applications of EPP

Automotive

Bumper cores, seat bases, sun visors, tool boxes and structural components use EPP to cut weight while improving crash safety. See EPP automotive parts molds.

Safety and sport

Helmet liners, protective pads and impact mats rely on EPP's ability to absorb repeated impacts. See EPP helmet molds.

Reusable packaging and logistics

EPP boxes, trays and cold-chain containers are durable and can be used hundreds of times. See EPP box molds.

Consumer and leisure

Fitness rollers, toys, furniture frames and sports equipment increasingly use EPP for its safe, skin-friendly surface.

How EPP parts are made

EPP parts are moulded in aluminium tooling on a shape moulding machine: beads are filled into the cavity, fused with steam, cooled and ejected. The tooling — an EPP mold — controls density, surface finish and dimensional accuracy.

Frequently asked questions

Is EPP foam the same as EPE foam?

No. EPP is expanded polypropylene, while EPE is expanded polyethylene. EPE is softer and cheaper and is common in packaging films and sheets; EPP is stiffer, more heat resistant and far better at repeated impact.

Is EPP foam toxic?

Moulded EPP is chemically inert and does not contain the blowing agents associated with older foam types. It is widely used in contact with skin, in children's products and in food-packaging applications.

Can EPP foam be recycled?

Yes. EPP is polypropylene and carries resin code 5. It can be recycled, and because it is so durable it is usually reused many times before that.

What is the difference between EPP density and EPP hardness?

They are related but not identical. Density is mass per unit volume; hardness also depends on the bead grade and moulding parameters. Two parts at the same density can feel different if the bead grade differs.

Related products and guides

• EPP Mold Manufacturer
• EPP Automotive Parts Molds
• EPP Raw Materials
• EPP Mold vs EPS Mold