Liquid Silicone Overmolding Part for New Energy Charging Gun

# Liquid Silicone Overmolding Part for New Energy Charging Gun

Product Overview

The Liquid Silicone Overmolding Part for New Energy Charging Gun is a high-performance, precision-molded component engineered to deliver long-lasting sealing, insulation, and mechanical protection for AC and DC charging interfaces of new energy vehicles (NEVs) and public charging infrastructure. As a critical safety part for high-voltage, high-frequency charging scenarios, this overmolding part adopts medical and industrial-grade liquid silicone rubber (LSR) as the base material, and is molded via a one-step co-injection process to achieve seamless bonding with charging gun shells, copper terminals, internal wiring harnesses, and signal transmission components.

Core selling points of this product include 15-year outdoor aging resistance, IP68-level dust and waterproof performance after assembly, stable dielectric insulation under 1000V DC high voltage, and compliance with global NEV charging interface standards (GB/T 20234, SAE J1772, IEC 62196, CHAdeMO). Unlike traditional thermoplastic elastomer (TPE) or rubber overmolding parts, this LSR component eliminates interface gaps, degumming, and cracking risks caused by temperature fluctuations, frequent plugging, and harsh environmental exposure, effectively reducing charging safety hazards such as current leakage, short circuits, and interface overheating. It is suitable for 7kW~350kW all-series charging guns, including home AC piles, public DC fast charging piles, and V2G (vehicle-to-grid) bidirectional charging equipment.

Technical Specifications

Material Properties

All raw materials used for this overmolding part comply with RoHS 2.0, REACH SVHC, and ELV (End-of-Life Vehicle) hazardous substance restriction requirements. The base LSR formula is customized for NEV charging scenarios, with the following material indicators:

Physical Performance

The component maintains stable performance under extreme working conditions, with key physical indicators as follows:

Process Parameters

The product is manufactured via high-precision LSR injection molding with strict process control to ensure dimensional consistency and bonding strength with base materials (PC, ABS, PA66-GF, copper, etc.):

Product Advantages

1. Superior Long-Term Environmental Adaptability

Compared with TPE overmolding parts that easily harden and crack after 3~5 years of outdoor use, this LSR component can withstand 15 years of exposure to sun, rain, acid rain, salt spray, and temperature fluctuations without performance degradation. It passes 1000-hour salt spray test (5% NaCl, 35℃) with no corrosion or interface separation, making it suitable for NEV charging infrastructure in coastal, high-altitude, and frigid regions.

2. Reliable High-Voltage Insulation & Overheat Resistance

The LSR material maintains stable dielectric insulation performance even at 200°C high temperature caused by overcurrent or short-circuit abnormal conditions, avoiding insulation failure and electric shock risks. Its UL94 V-0 flame retardant grade ensures that the component will self-extinguish within 10s in case of extreme overheating, and will not produce toxic smoke or dripping molten materials, effectively preventing fire hazards.

3. Seamless Overmolding Bonding & Zero Interface Risk

The one-step co-injection process eliminates secondary assembly gaps between the silicone part and the charging gun housing/terminals, avoiding water and dust ingress issues common in assembled sealing rings. The bonding strength between LSR and base materials exceeds the tear strength of silicone itself, ensuring no degumming or separation even after 10,000 plugging cycles and long-term vibration during vehicle driving.

4. Low Temperature Flexibility & User-Friendly Operation

The component maintains excellent elasticity at -60°C extreme low temperature, avoiding the problem of hardening and difficult plugging of traditional rubber parts in frigid environments. Its low compression set ensures that the sealing interface remains tight after long-term plugging, and the customizable matte non-slip surface improves user grip comfort, effectively reducing operation fatigue for frequent charging users.

Applications

This LSR overmolding part is widely used in NEV charging industry scenarios, including but not limited to:

• Public DC Fast Charging Guns: Suitable for 120kW~350kW high-power charging piles for passenger cars, commercial vehicles, and heavy trucks, providing long-term sealing and insulation protection for high-current transmission terminals.
• Home AC Charging Guns: Used for 3.5kW~11kW portable and wall-mounted charging piles, with low VOC emission and no peculiar smell, suitable for closed garage use scenarios.
• V2G Bidirectional Charging Interfaces: Matches vehicle-to-grid bidirectional charging equipment, with stable signal transmission performance to avoid charging and discharging communication failures caused by interface aging.
• Special Scenario Charging Equipment: Applied to charging piles for new energy ships, mining trucks, and outdoor emergency charging vehicles, withstanding salt spray, dust, and high vibration harsh working conditions.
• **Charging Interface Accessories: Used as waterproof seals, terminal insulation sleeves, grip overmolding layers, and cable connection protection parts for charging gun interfaces.

Selection Guide

Hardness Selection

• 40~50 Shore A: Recommended for cable connection protection parts and grip overmolding layers, providing better flexibility and non-slip feel, suitable for portable charging guns requiring frequent bending.
• 55~65 Shore A: Suitable for terminal insulation sleeves and interface sealing parts, balancing elasticity and compression resistance, meeting 10,000+ plugging cycle requirements, and is the universal hardness choice for most charging gun models.
• 65~70 Shore A: Recommended for high-power DC fast charging gun interface sealing parts, with higher mechanical strength and wear resistance, suitable for public charging piles with high usage frequency.

Size Specifications

The product supports customized design according to customer charging gun structure and applicable standards:

• Standard size series for GB/T 20234 (Chinese standard), SAE J1772 (American standard), IEC 62196 Type 2 (European standard), and CHAdeMO (Japanese standard) interfaces are available for direct selection, with molding tolerance matching the interface fit requirements of each standard.
• For custom non-standard structures, customers only need to provide 3D drawings (STEP/IGS format) and working condition requirements, and our technical team will complete material formula adjustment, mold design, and sample production within 15 working days.
• Thickness selection: 0.5mm~5mm custom thickness is supported, with 1.5mm~2mm being the recommended thickness for sealing parts to balance insulation performance and assembly convenience.

Material Grade

• Industrial Grade: Cost-effective option, meeting RoHS and REACH requirements, suitable for general public charging pile scenarios, with 10-year service life warranty.
• Low-VOC Grade: Low volatile emission formula, passing VDA 278 test, no peculiar smell, recommended for home charging guns and indoor charging pile scenarios.
• Extreme Environment Grade: Added anti-UV and anti-salt spray components, with 15-year outdoor service life warranty, suitable for coastal, high-altitude, and alpine region charging infrastructure.

Quality Assurance

We implement a full-process quality control system from raw material incoming inspection to finished product delivery to ensure product reliability:

1. Raw Material Control: All LSR raw materials are supplied by accredited suppliers, with batch inspection reports provided for each shipment, and traceability codes are maintained for all material batches for 15 years.
2. Production Process Control: Each injection molding machine is equipped with real-time parameter monitoring system, recording injection pressure, temperature, and curing time for each product, and SPC statistical process control is implemented to ensure dimensional consistency.
3. Finished Product Testing: Each batch of products undergoes 100% appearance inspection and 5% random sampling performance testing, including plugging cycle test, high voltage withstand test (3kV AC, 1min no breakdown), IP68 sealing test, and bonding strength test. Unqualified products are completely rejected.
4. Certification System: The product has passed IATF 16949 automotive quality system certification, and has obtained CE, TÜV, and CQC product safety certifications, fully complying with global NEV industry regulatory requirements.
5. Warranty Service: We provide 5-year warranty for all standard products, and 8-year warranty for extreme environment grade products. If product quality problems such as degumming, cracking, or insulation failure occur during the warranty period under normal use conditions, we will provide free replacement or compensation.