EVA is the go-to base material for custom orthotics. Medium density grades are the most widely used because they balance cushioning with support.

Aortha A50 Medium Density EVA (approx. 1000 × 1000mm sheets) is designed for consistent performance in Australian clinics and workshops- reliable to heat-mould, easy to finish, and durable in daily wear.

Why A50 Medium Density?

• Clinic-standard feel: A50 delivers a supportive, resilient platform without feeling overly firm.
• Predictable fabrication: Heat-moulds cleanly, grinds smoothly, and sands to fine feather-edges.
• Hygienic & skin-friendly: Closed-cell EVA is toxic-free and washable.
• Stable in use: Retains shape well and provides dependable shock absorption.

Key Features

• Medium Density EVA (Shore A50): The most commonly used grade for custom orthotic bases.
• Heat Mouldable: Custom-fit to individual foot contours with standard clinic ovens/heat sources.
• Workable Finish: Grindable and fine-sandable for precise adjustments.
• Closed-Cell Structure: Wipe-clean surface; resists moisture ingress.

Typical Applications

• Custom orthotic bases and shells
• Posting elements and mid-layers (when combined with higher/low density layers as needed)
• Footwear modifications and in-shoe supports
• General orthopaedic builds where medium firmness is preferred

Technical Details

Thermo-Moulding Guidance

Exact times depend on thickness, oven type, and heat source. Use staged testing.

• General range for EVA: 120–160 °C with a guide of ~2 minutes per mm thickness.
• Shore A25–A35 (15 mm): 100–130 °C for ~30–90 seconds.
• Shore A50 (15 mm): 110–140 °C for ~30–120 seconds.
• Shore A65 (15 mm): 120–150 °C for ~30–140 seconds.

Adjustments: Thinner materials generally need lower temperatures or shorter exposure. Direct IR heating is more aggressive than circulating hot air—reduce temperature/time accordingly. Avoid temperatures near or above 200 °C to prevent EVA degradation (which can release acetic acid, producing a vinegar-like odour and potential corrosion risk).

Benefits at a Glance

• Support + comfort for day-to-day clinical prescriptions
• Efficient workflow thanks to predictable heating and finishing
• Durable with reliable shape retention under load

Frequently Asked Questions (FAQ)

1) Is A50 suitable as the main orthotic base?

Yes—A50 is the most commonly used EVA hardness for custom orthotic bases in Australia, balancing support with comfort for everyday use.

2) When would I choose a different density?

Use A25–A35 for softer top covers/linings and A65 (or higher-density materials) for firmer posting or higher load-bearing elements.

3) What adhesives work best with EVA?

Most EVA/PU contact cements perform well. Lightly abrade, clean, apply adhesive to both surfaces, respect open time, and press firmly.

4) How do I avoid overheating or scorching?

Start at the low end of the range, heat in short stages, and check flexibility frequently—especially with direct IR heaters. Keep well below 200 °C.

5) Can I clean the finished device?

Yes. Wipe surfaces with mild detergent and water. Avoid harsh solvents that can affect adhesive bonds or the EVA surface.