🧩 EMA – Ethylene Methyl Acrylate
(Flexible and weldable material, impact and oil resistant, used in gaskets, caps, electrical housings, and elastic automotive components with sealing and chemical resistance requirements.)
🔹 What is EMA
EMA (Ethylene Methyl Acrylate) is a thermoplastic copolymer obtained by combining ethylene (PE) with methyl acrylate (MA). The result is a soft, elastic, and thermally stable material with superior adhesion to metals and other olefinic plastics. Compared to EVA, it has better resistance to oils, fuels, and UV radiation, being frequently used in the engine compartment and for automotive gaskets. EMA is considered a “technical” variant between EVA and TPE, offering an optimal combination of elasticity and durability.
🔧 Composition
- Ethylene (PE) – 60–80 %
- Methyl Acrylate (MA) – 10–40 %
- Additives – UV stabilizers, antioxidants, anti-cracking agents.
- Density: 0.93–0.96 g/cm³
- Melting Point: ≈ 90–110 °C.
- Elongation at break: up to 500 %.
🚗 Where EMA is used in the automotive industry
| Component | Example parts | Observations |
| Gaskets & Caps | Seals, sleeves, corners | Elastic, adherent, oil resistant |
| Engine Compartment | Protections, insulation, sleeves | Stable under heat and chemicals |
| Car Interior | Pads, trays, dampers | Soft and vibration resistant |
| Wiring / Electrical | Housings, insulation, supports | Very good dielectric properties |
🔧 Welding Temperature and Methods
| Method | Optimal Temperature | Observations |
| Hot Air | 230 – 250 °C | Uniform melting, slightly sticky when hot |
| Heat Plate (Mirror) | 220 – 240 °C | For straight and smooth joints |
| Manual Extrusion | 210 – 230 °C | Suitable for thicker areas |
🔩 What to Weld EMA With (Material Compatibility)
The question “what to weld EMA with” often arises for flexible and watertight components. EMA is compatible with all soft olefinic materials, especially PE, EVA, and TPO.
✅ Compatible:
- EMA ↔ EMA – ideal combination.
- EMA ↔ EVA / PE-LD / PE-MD / PE-HD – very good compatibility.
- EMA ↔ TPO / POE / PP+EVA – good compatibility.
❌ Incompatible:
- ABS, ASA, PC, PA, PVC – no thermal adhesion.
💡 ReplastMD Recommendation: Use EMA, EVA, or PE rods at a temperature of 240–250 °C. Heat slowly to avoid excessive melting of the soft layer. Apply constant pressure with a rubberized spatula for a clean and watertight finish.
🏭 Manufacturers and Trade Names
- Arkema: Lotryl® EMA
- ExxonMobil: Optema™ EMA
- Dow: Primacor™ EMA
- SABIC: EMA Copolymer
🧠 How to Identify EMA
- Engraved marking: >EMA<, >PE-MA<, >ETHYLENE-MA<.
- Soft, rubbery surface, slightly glossy.
- Yellow-blue flame, faint sweet (acrylic) smell.
- Softens completely at ≈ 240 °C, without black smoke.
- High elasticity, does not crack when bent.
🛠️ EMA Welding at ReplastMD: At our service center in Chisinau (Ciocana sector), ReplastMD performs professional EMA welding for:
- gaskets, caps, and flexible housings;
- sealing and thermal protections;
- reconstructing corners, supports, and deformed areas;
- smooth, soft, watertight, and durable finish.