Plastic Materials in EV Charging Stations: Material Selection & Grade Recommendations

The charger housing is the first line of defense, directly exposed to outdoor environments — enduring UV radiation, rain, temperature cycling, and potential mechanical impact.

**Core Material Requirements:** • Flame Rating: UL94 V-0 (at minimum V-2) • Weatherability: No significant yellowing or property degradation after prolonged outdoor use • Impact Resistance: Withstand potential collisions and vandalism • Electrical Insulation: High CTI value to prevent leakage risk • Processability: Suitable for large housing injection molding

**Recommended Material: PC (Polycarbonate)** PC combines high transparency/colorability, ultra-high impact strength (Izod ≥60 kJ/m²), and good weatherability (UV-stabilized grades can achieve 10+ year service life) — making it the material of choice for charger housings.

**Flame-Retardant Requirement: FR-PC** For chargers requiring UL94 V-0 rating (e.g., public fast-charging stations), FR-PC is recommended. Jinsu's FR-PC product line offers both transparent and colored options, supporting V-0 (1.5mm) and V-2 (0.8mm) ratings.

**Jinsu Grade Recommendations:** • General Housing: Transparent PC — Light transmission ≥88%, excellent impact resistance • FR Housing: FR-PC — UL94 V-0 (1.5mm), CTI ≥250V

**Processing Note:** PC is extremely moisture-sensitive. Must use a desiccant dryer at 120°C for 4-6 hours before molding, ensuring moisture ≤0.02%, or silver streaks and bubbles will form.

The interior of an EV charger contains numerous electrical connectors, terminal blocks, relay bases, contactor housings, and other components requiring high electrical insulation and heat resistance.

**Core Material Requirements:** • Flame Rating: UL94 V-0 (0.8-1.6mm wall thickness) • High CTI: ≥250V (preferably ≥400V), tracking resistance • Heat Resistance: HDT ≥200°C (internal temperatures can be high) • Dielectric Strength: ≥20 kV/mm • Dimensional Stability: No creep under long-term use

**Recommended Material: PA66-FR (Flame Retardant Reinforced PA66)** PA66 inherently has a higher melting point (260°C vs 220°C for PA6) and better heat resistance. With glass fiber reinforcement (typically 25-30% GF), HDT can reach 240-250°C. Adding flame retardant modification to achieve UL94 V-0 makes it the ideal material for charger internal insulation components.

**Why Not PA6-FR:** PA6 has higher moisture absorption (1.5-2.0% vs 1.0-1.5%), causing significant electrical insulation degradation in humid environments — unsuitable for safety-critical charger applications.

**Jinsu Grade Recommendation:** • PA66 FR Reinforced — UL94 V-0 (0.8mm), HDT ≥240°C, CTI ≥250V (halogen-free option available, CTI up to 400V+) • Features: High CTI halogen-free FR formulation, meeting IEC 60664 insulation coordination standards

**Processing Note:** FR-PA66 has a narrow processing temperature window (260-285°C). Residence time at temperature must not exceed 5 minutes, or FR additives will degrade, causing performance loss and mold corrosion. Use corrosion-resistant screw and barrel.

EV charger cables must withstand frequent bending, stretching, crushing, and outdoor climate conditions while ensuring excellent electrical insulation. The cable sheath is the protective layer of the entire cable system.

**Core Material Requirements:** • Flexibility: Excellent bending fatigue life (>30,000 flex cycles) • Weatherability: UV, ozone, and temperature resistance (-40°C to +85°C) • Abrasion Resistance: Prevent wear from dragging and crushing • Flame Retardancy: UL94 V-0 or VW-1 • Electrical Insulation: High volume resistivity

**Recommended Materials: TPE (Thermoplastic Elastomer) / TPU (Thermoplastic Polyurethane)** TPE and TPU are the two main choices for charging cable sheaths. TPU offers better abrasion resistance; TPE provides superior flexibility and low-temperature performance. Both can pass the VW-1 vertical flame test.

**Jinsu Product Alignment:** Jinsu's current product line focuses on rigid engineering plastics (ABS, PA, PC, PMMA, etc.) and does not directly produce TPE/TPU cable compounds. However, we maintain partnerships with several high-quality TPE/TPU compounders and can provide one-stop procurement matching services.

**Alternative Approach:** Internal structural supports and insulation barriers inside the charging connector can use Jinsu's PA66-FR or PA6-FR materials. While these parts don't directly contact conductors, they still require flame retardancy and electrical insulation properties.

The charging connector (charging gun) is the component users directly handle, and the most mechanically stressed assembly in the entire charging system. It must simultaneously satisfy ergonomics, electrical safety, and mechanical durability requirements.

**Core Material Requirements:** • Ultra-High Impact Resistance: Pass 1m drop test (a fully assembled connector weighs ~2-3kg) • Flame Rating: UL94 V-0 • Heat Resistance: Connector body can reach 60-80°C during fast charging • Surface Quality: Good tactile feel, burr-free, premium appearance • Chemical Resistance: Tolerate common cleaning agents and lubricants

**Housing Option 1: PC (Polycarbonate)** PC's ultra-high impact strength (Izod ≥60 kJ/m²) makes it the classic choice for charging connector housings. It easily passes multiple drop tests and offers high surface gloss with excellent tactile quality.

**Housing Option 2: PA66-FR (Flame Retardant Reinforced PA66)** Some structurally-intensive connector designs use PA66+GF FR solutions. Compared to PC, PA66 offers higher rigidity (flexural modulus 9000-10000 MPa vs 2300-2400 MPa), providing advantages in thin-wall designs, though surface gloss is inferior to PC.

**Jinsu Grade Recommendations:** • Option 1: FR-PC — UL94 V-0, excellent impact resistance and surface quality • Option 2: PA66 FR Reinforced — UL94 V-0, HDT ≥240°C, high rigidity

**Selection Advice:** For home AC slow chargers — recommend PC (appearance and tactile feel first). For public DC fast chargers — recommend PA66-FR (heat resistance and rigidity first).