Liquid Silicone Leak-proof Seals for New Energy Vehicles

# Liquid Silicone Leak-proof Seals for New Energy Vehicles

Product Overview

Our Liquid Silicone Rubber (LSR) Leak-proof Seals for New Energy Vehicles are high-performance custom-engineered sealing solutions specifically designed to address the extreme operating requirements of modern electric vehicle (EV) and hybrid electric vehicle (HEV) systems. Manufactured via precision injection molding of medical and industrial-grade liquid silicone rubber, these seals deliver exceptional long-term reliability in high-voltage, wide-temperature, and chemically exposed environments, outperforming traditional EPDM, nitrile rubber, and thermoplastic elastomer (TPE) alternatives.

Core features include 95%+ leak-proof reliability under 15-year service life testing, IP67/IP6K9K ingress protection compliance, and compatibility with high-voltage EV component operating conditions. Unlike solid rubber seals, our LSR seals feature low compression set, consistent dimensional tolerance of ±0.02mm for high-precision mating surfaces, and customizable conductive or non-conductive formulations to meet electromagnetic shielding (EMI) and electrical insulation requirements. This product line is optimized to eliminate fluid leaks, corrosion, and electrical failure risks associated with substandard seals, reducing warranty costs for NEV manufacturers and improving end-user vehicle safety.

Technical Specifications

Material Properties

All seals are formulated from high-purity two-part addition-cure liquid silicone rubber, with optional functional modifications to meet application-specific needs:

Physical Performance

The seals undergo rigorous performance validation to meet NEV industry durability requirements:

Process Parameters

Our LSR seals are manufactured with high-precision injection molding processes to ensure consistent quality across mass production runs:

Product Advantages

1. Industry-Leading 95%+ Long-Term Leak-Proof Reliability

Our LSR seals are engineered to maintain a perfect sealing interface even after 15 years or 300,000 km of NEV operation. Unlike traditional rubber seals that degrade and lose elasticity over time, our LSR formulation has a <5% compression set after 72 hours of high-temperature exposure, ensuring consistent contact pressure against mating surfaces. Independent third-party testing shows a 95.2% leak-free pass rate after 1000 thermal shock cycles, 3x higher than EPDM seal alternatives, eliminating costly field failures and warranty claims for NEV manufacturers.

2. Wide Compatibility with Harsh NEV Operating Environments

These seals withstand the full spectrum of NEV operating conditions, from extreme cold in northern winter climates to high heat generated by fast-charging battery packs and electric motors. They are inherently resistant to common NEV fluids, including ethylene glycol coolants, lithium-ion battery electrolyte (dilute), road deicing salt, and lubricating oils for e-axle systems, with no swelling, cracking, or material degradation after 1000 hours of immersion testing.

3. Customizable Electrical and EMI Performance

We offer tailored material formulations to meet the unique electrical requirements of different NEV systems: non-conductive grades with 22kV/mm dielectric strength for high-voltage battery pack and motor sealing to prevent short circuits, and carbon-filled or silver-plated aluminum conductive grades with surface resistance as low as 0.05 Ω/sq for EMI shielding in on-board charger (OBC) and power control unit (PCU) applications, eliminating electromagnetic interference with vehicle communication systems.

4. High-Precision Molding for Complex Sealing Geometries

Our precision LSR injection molding process supports the production of custom seals with complex undercuts, micro-grooves, and integrated multi-component designs (e.g., seals with integrated plastic mounting brackets) to match your component housing design. Tight dimensional tolerances of ±0.02mm eliminate gaps between mating surfaces, ensuring consistent sealing performance even for high-pressure cooling systems and vacuum-insulated battery pack enclosures.

5. Low Total Cost of Ownership

While initial material costs are slightly higher than EPDM alternatives, our LSR seals reduce total lifecycle costs by 40% on average: they require no periodic replacement, reduce warranty repair costs related to sealing failures, and support automated high-speed assembly with zero defect rates across mass production runs.

Applications

Our LSR leak-proof seals are widely used across core NEV systems:

1. Power Battery Systems: Sealing for battery pack upper/lower housing covers, battery module end plates, coolant pipe interfaces, pressure relief valve mounting points, and charging port gaskets. The seals prevent water and dust ingress that could cause battery short circuits, and contain coolant leaks that could lead to thermal runaway, meeting GB 38031 and UN 38.3 battery safety standards.
2. Electric Drive Systems: Seals for e-motor housing end covers, gearbox oil circuit interfaces, inverter power module mounting surfaces, and high-voltage wiring harness feedthroughs. They withstand continuous high temperatures up to 220°C generated by motor operation, and resist lubricating oil degradation to maintain leak-proof performance for the 15-year service life of the drive system.
3. Power Electronics Components: Seals for on-board chargers (OBC), DC-DC converters, power distribution units (PDU), and motor controllers. Conductive EMI-shielding variants prevent high-frequency electromagnetic interference from affecting vehicle ADAS and infotainment systems, while non-conductive variants provide electrical insulation for high-voltage busbars.
4. Thermal Management Systems: Seals for coolant pipe connectors, chiller interfaces, heat pump system valve seats, and radiator mounting gaskets. They maintain leak-proof performance under 10 bar of coolant pressure, preventing fluid loss that could lead to battery overheating during fast charging.
5. Body and Auxiliary Systems: Seals for panoramic sunroof drain interfaces, hydrogen fuel cell stack manifold gaskets (for FCEV applications), and high-voltage charging cable connectors, with low-VOC formulations available for interior cabin applications to meet EU REACH and China VOC emission standards.

Selection Guide

Hardness Selection

• 20-30 Shore A: Recommended for uneven mating surfaces, low-pressure sealing applications, and applications requiring high elasticity to absorb vibration, such as battery module gap seals and wiring harness feedthrough gaskets.
• 40-50 Shore A: General-purpose grade for most NEV sealing applications, including battery pack housing seals, coolant pipe connectors, and e-motor housing gaskets, balancing compression resistance and elasticity.
• 60-70 Shore A: Recommended for high-pressure applications (≥8 bar) and seals requiring high structural rigidity, such as heat pump system valve seats and high-flow coolant manifold gaskets.

Size Specifications

We support fully custom seal dimensions to match your component design:

• Radial O-rings: Inner diameter range 2mm to 500mm, cross-section range 1mm to 10mm
• Gaskets: Maximum size 1500mm x 1000mm, thickness range 0.5mm to 20mm
• Custom profiles: Complex extruded or molded profiles with grooves, mounting holes, and integrated fasteners available upon request

For existing designs, we offer 50+ standard seal sizes for common NEV battery pack and e-axle models, with sample delivery within 3 working days.

Material Grade

• Industrial Grade (Standard): Compliant with RoHS and ELV standards, suitable for under-hood and battery pack applications with no food contact or medical requirements, the most cost-effective option for mass production.
• Low-VOC Grade: VOC emission <5 μg/g, compliant with GB/T 27630 and EU VOC standards, recommended for interior cabin applications and seals used in passenger compartment adjacent components.
• High-Temperature Grade: Operating temperature up to 260°C, suitable for fuel cell system seals and high-power e-motor applications exposed to continuous high heat.
• EMI Shielding Grade: Conductive formulation with surface resistance 0.05-100 Ω/sq, recommended for power electronics component seals requiring electromagnetic interference suppression.

Quality Assurance

We implement a strict end-to-end quality control system to ensure every seal meets NEV industry requirements:

1. Incoming Material Inspection: All LSR raw materials are tested for hardness, viscosity, and purity upon arrival, with traceability records maintained for every production batch. We only source raw materials from ISO 9001 and IATF 16949 certified suppliers, including Dow Silicones, Wacker Chemie, and Momentive.
2. In-Process Quality Control: Every production run undergoes first-piece inspection (dimensional tolerance, hardness, visual defect check) before mass production, with in-line sampling every 2 hours to verify dimensional consistency and flash control.
3. Final Performance Testing: 100% of finished seals undergo visual inspection for defects, with 3% of each batch randomly selected for performance testing, including compression set, ingress protection, and tensile strength testing. We also offer optional 100% leak testing for high-risk applications such as battery pack seals, with test reports provided for every batch.
4. Certifications: Our entire LSR seal product line is IATF 16949 automotive quality management system certified, with compliance to EU RoHS 2.0, REACH, ELV, and UL 94 flammability standards. We can provide third-party test reports from CNAS, SGS, or TÜV upon request, as well as PPAP level 3 documentation for NEV manufacturer approval.

We offer a 5-year warranty against material defects and sealing failure under normal operating conditions, with dedicated technical support teams to assist with material selection, design optimization, and failure analysis for custom projects.