Liquid Silicone Rubber Precision Seals for New Energy Vehicles

# Liquid Silicone Rubber (LSR) Precision Seals for New Energy Vehicles

*91 Series High-Performance Sealing Solutions for NEV Critical Systems*

Product Overview

Our 91 Series Liquid Silicone Rubber Precision Seals are custom-engineered sealing components designed exclusively for the extreme operating conditions of new energy vehicle (NEV) powertrain, battery, and electronic control systems. Manufactured via high-precision injection molding with medical and automotive-grade liquid silicone rubber raw materials, these seals deliver consistent, long-term performance across a wide temperature range, while resisting degradation from automotive fluids, high voltage, and mechanical vibration.

As a critical component for NEV safety and reliability, this product line addresses the core pain points of traditional sealing materials (EPDM, nitrile rubber) in electrified vehicle applications: premature aging under high heat, poor insulation performance at high voltages, and limited compatibility with EV-specific coolants and electrolytes. Each seal is precision-machined to tolerance levels as tight as ±0.02mm, ensuring a perfect fit even in complex, space-constrained NEV assemblies. The 91 Series is available in custom geometries including O-rings, gaskets, frame seals, and custom profiled seals, all optimized to prevent leakage of fluids, dust, and moisture while maintaining electrical insulation for high-voltage NEV systems.

Technical Specifications

Material Properties

All 91 Series seals are formulated with automotive-grade LSR compliant with IATF 16949 material requirements, with customizable formulations for application-specific performance:

Physical Performance

Engineered to withstand the dynamic operating environment of NEVs, the 91 Series seals deliver consistent mechanical performance over their 15-year/300,000km design lifespan:

Process Parameters

The 91 Series is manufactured via closed-loop LSR injection molding to ensure consistency across high-volume production runs:

Product Advantages

1. Superior Long-Term Reliability in Extreme NEV Operating Conditions

Unlike EPDM or nitrile rubber seals that degrade after 1000h of exposure to 150°C heat and EV coolants, the 91 Series LSR seals retain 90% of their original mechanical properties after 3000h of continuous use. Their low compression set (<10% at 150°C) eliminates permanent deformation after repeated thermal cycling and pressure changes, preventing leakage over the entire vehicle lifespan and reducing warranty claims for NEV manufacturers.

2. Optimized Electrical Performance for High-Voltage NEV Systems

With a standard dielectric strength of 22kV/mm (upgradable to 35kV/mm), the 91 Series provides reliable insulation for 800V and higher NEV powertrain systems, reducing the risk of arcing and electrical failure. Custom semi-conductive formulations are also available for electromagnetic shielding (EMI) applications in motor controllers and BMS enclosures, eliminating the need for separate shielding components and reducing assembly complexity.

3. Unmatched Material Compatibility with NEV-Specific Fluids

The 91 Series is fully compatible with all common NEV fluids, including ethylene glycol coolants, dielectric thermal management fluids, and lithium-ion battery electrolytes. Immersion testing shows less than 5% volume swell after 1000h of exposure to these fluids, compared to 20–30% swell for traditional rubber seals, which prevents seal extrusion and system blockage.

4. Precision Molding for Complex, Space-Constrained NEV Assemblies

Our advanced LSR injection molding process achieves tolerance levels as tight as ±0.02mm, enabling the production of custom profiled seals that fit the compact, irregular geometries of NEV battery packs, e-axles, and on-board chargers. The low viscosity of uncured LSR allows for the molding of thin-walled (as low as 0.5mm) seals with complex cross-sections, reducing overall component weight and supporting NEV lightweighting goals.

Applications

The 91 Series LSR Precision Seals are deployed across all critical NEV systems:

• Battery Energy Storage Systems (BESS): Seals for battery pack housings, module end plates, coolant line connectors, and pressure relief valves, providing IP68 protection against moisture and dust ingress while resisting electrolyte leakage in the event of cell damage.
• High-Voltage Powertrain Components: Seals for e-motor housings, reduction gearboxes, power distribution units (PDUs), and on-board chargers (OBCs), delivering electrical insulation and resistance to the high heat generated during fast charging and high-output operation.
• Thermal Management Systems: Seals for coolant pipes, chiller assemblies, and heat pump systems, ensuring zero leakage of dielectric or water-glycol coolants across a -40°C to 120°C operating temperature range.
• Electronic Control Systems: Seals for battery management system (BMS) enclosures, domain controllers, and sensor housings, providing EMI shielding (for semi-conductive grades) and protection against road splash, salt spray, and mechanical vibration.
• Charging Infrastructure: Seals for DC fast charging ports, vehicle inlet connectors, and charging cable assemblies, resisting UV exposure, weathering, and repeated plug/unplug cycles for over 10,000 operations.

Selection Guide

Hardness Selection

• 30A–40A Softer Grades: Ideal for low-compression force applications, irregular mating surfaces, and static sealing of fragile components (e.g., ceramic battery cooling plates). Offers improved conformability but lower resistance to high pressure.
• 50A Standard Grade: Balances flexibility and mechanical strength, suitable for most static and dynamic sealing applications including battery pack housings, coolant line connectors, and e-motor gaskets.
• 60A–70A Harder Grades: Recommended for high-pressure (≥10bar) dynamic sealing applications, such as gearbox output shafts and coolant pump seals, offering enhanced extrusion resistance and wear performance.

Size Specifications

• Standard O-rings are available in AS568, JIS B 2401, and custom metric sizes, with inner diameter ranging from 1mm to 1000mm.
• Custom profiled seals and frame gaskets can be manufactured to your exact CAD specifications, with maximum dimensions of 1200mm × 800mm for full battery pack perimeter seals.
• For new product development, our engineering team provides DFM (design for manufacturing) support to optimize seal geometry for performance and cost efficiency.

Material Grade

• Standard Automotive Grade (91-A Series): Compliant with IATF 16949 and RoHS 2.0, suitable for non-cell contacting sealing applications including housing seals and coolant line connectors.
• Battery Contact Grade (91-B Series): Low-extraction formulation with ≤0.05% volatile organic compound (VOC) content, approved for direct contact with lithium-ion battery cells and electrolytes.
• High-Voltage Grade (91-E Series): Enhanced dielectric strength (≥28kV/mm) and tracking resistance (CTI ≥600V), designed for 800V and higher high-voltage system sealing applications.
• Flame-Retardant Grade (91-F Series): UL 94 V-0 rated with low smoke toxicity, recommended for sealing in enclosed battery compartments to meet FMVSS 302 fire safety requirements.

Quality Assurance

All 91 Series LSR Precision Seals are manufactured in IATF 16949 certified production facilities, with a zero-defect quality control framework tailored to NEV industry requirements:

• Incoming Material Inspection: Each batch of LSR raw material is tested for hardness, tensile strength, and dielectric performance before entering production, with full traceability from raw material to finished component.
• In-Process Control: 100% dimensional inspection of first-run parts, with real-time monitoring of injection molding parameters (temperature, pressure, cure time) to ensure consistency across production runs.
• Finished Product Testing: Every batch undergoes a 10-point performance test, including compression set testing, thermal aging testing, fluid immersion testing, and leak testing (1.5x operating pressure for 30 minutes). For critical applications, 100% of parts are inspected via automated vision systems to detect flash, dimensional deviations, and surface defects.
• Certifications: The 91 Series is compliant with RoHS 2.0, REACH, UL 94, and UN 38.3 requirements for battery transport, with custom PPAP (Production Part Approval Process) documentation available upon request to meet OEM quality requirements.
• Warranty: All 91 Series seals come with a 5-year manufacturing defect warranty, and performance guarantees of up to 15 years/300,000km for validated applications, aligned with standard NEV powertrain warranty terms.