EVA (foam)

Physical properties

Laser processing

Combustion of EVA releases vinyl acetate and other volatile organic compounds irritating to the respiratory tract. Fumes are of moderate intensity and have a characteristic burnt plastic odor. Requires standard extraction with activated carbon filter.

CO₂: Excellent CO2 laser cutting. EVA foam responds very well to laser: clean, deep cuts with moderate power (15–30 W). Engraving produces crisp reliefs with 3D effects highly appreciated in cosplay and decorations. Use high speed to avoid excessive melting at the edges.

Diode: Good results on dark-colored EVA. Light colors may require multiple passes. The surface tends to melt slightly, creating a thin glossy film at the edge.

Fiber: Not applicable.

CNC / milling processing

EVA foam can be milled with single-flute cutters at high feed rates, but tends to crumble if density is too low. Best results on high-density EVA (>100 kg/m³). No coolant required.

Plotter and thermoforming

Excellent plotter workability up to 6 mm thickness. Standard sharp blades are sufficient. The softness of the material requires optimizing pressure to prevent the blade from sinking deeper than necessary.

Post-processing

Sanding: Sandable with medium-fine grit abrasive paper to bevel edges or level surfaces. Produces plastic dust: wear a mask.

Primer: To obtain a smooth, paintable surface without a spongy effect, apply Plasti-Dip or a thin layer of epoxy resin before the final paint.

Gluing: Excellent bonding with contact glue (neoprene), low-temperature hot glue (EVA-compatible stick gun) or specific double-sided tapes. Conventional high-temperature hot glue can melt the foam.

Over time: EVA is stable over time under normal indoor use conditions. The foam may degrade from prolonged exposure to solvents, oils or high temperatures. Over the years it may slightly lose shape under constant compression.

Common defects

• Surface melting on laser cut edges if speed is too low
• Permanent thermal deformation if exposed to temperatures above 60–70°C even briefly
• Absorption of solvent-based paints without adequate primer, resulting in a gummy, sticky finish

Safety

Low-hazard material in ordinary processing. Laser combustion fumes are irritating: standard extraction sufficient. Avoid heating EVA beyond thermoforming temperature without ventilation.

Availability and formats

Commercial formats: sheets 2–10mm in A4/A3 format, rolls 1–2mm, large panels for stage sets

Sources

• Schede tecniche fornitori EVA foam per cosplay e modellismo
• Manuali operativi FabLab su schiume polimeriche