Silicone overmolded products made by LSR injection molding process, firmly bonded to metal, plastic and other substrates, with excellent wear resistance, tear resistance, waterproof sealing, shock absorption performance, not easy to fall off or age, can meet the needs of different industrial scenarios, support multi-dimensional customization.
Material
Industrial LSR
Hardness
Shore A 30-80
Temperature
-40°C ~ +220°C
Colors
Black, White, Gray, Customizable
Certifications
Applications
# Liquid Silicone Rubber Overmolded Metal Plastic Parts Wear-resistant Waterproof Industrial Accessories
Liquid Silicone Rubber (LSR) overmolded industrial accessories, referred to as 硅胶包胶 products in domestic supply chains, are high-performance composite components formed by injecting and curing food-grade or industrial-grade liquid silicone rubber onto pre-treated metal (stainless steel, aluminum alloy, brass) or engineering plastic (PA66, PPS, PC) substrates. This integration combines the structural rigidity of the base substrate with the unique functional properties of LSR, delivering wear resistance, waterproof sealing, chemical corrosion resistance, and extreme temperature stability that single-material parts cannot achieve.
Our proprietary overmolding process eliminates the need for additional adhesives, achieving a bonding strength of up to 12 N/mm between LSR and the substrate under standard test conditions, which prevents delamination even after 10,000+ cycles of bending, impact, or temperature shock. The finished parts have a seamless, burr-free surface, with customizable textures (matte, glossy, patterned) and colors to meet application-specific aesthetic and functional requirements. Core selling points include IP68 ingress protection rating, -60°C to 220°C operating temperature range, 10x longer wear life than uncoated metal/plastic parts, and compliance with RoHS, REACH, FDA, and UL94 V0 flame retardant standards for use in regulated industrial environments.
The LSR outer layer has a low coefficient of friction (0.2 ~ 0.3) and excellent elastic recovery, reducing surface wear during repeated friction, insertion, or mechanical movement. Compared to uncoated metal parts, the wear life is extended by 10~15 times, and compared to rubber-coated parts, it avoids cracking and hardening after long-term use. The elastic LSR layer also absorbs 60%+ of impact energy, protecting the internal metal/plastic structure from damage under sudden impact or vibration conditions.
The seamless overmolding structure eliminates gaps between the LSR layer and substrate, avoiding water ingress that occurs with assembled gaskets or adhesive-bonded coatings. IP68-rated variants can be permanently submerged in 10m deep water for 72 hours without leakage, making them suitable for underwater equipment and outdoor applications exposed to rain, snow, or high humidity. The LSR layer also maintains stable elasticity across the full operating temperature range, preventing seal failure caused by thermal expansion and contraction.
We use proprietary substrate surface treatment processes (plasma activation for plastics, micro-etching and primer coating for metals) to form a molecular-level bond between LSR and the substrate, rather than a simple physical coating. The bonding strength far exceeds industry standards, with no delamination or peeling after 1000 cycles of temperature shock (-40°C to 150°C, 30min dwell time per cycle) and 500 hours of salt spray testing (5% NaCl concentration, 35°C).
The LSR layer is inherently resistant to most industrial chemicals, including automotive oils, hydraulic fluids, cleaning agents, and salt solutions, and does not produce harmful precipitates even after long-term immersion. Unlike traditional TPE or rubber coatings, it does not age, discolor, or become brittle under long-term UV exposure and ozone conditions, with a service life of 10+ years in outdoor environments.
Used as gripper jaws for robotic end effectors, where the LSR layer provides non-slip, scratch-resistant contact with workpieces, while the internal metal substrate maintains sufficient clamping rigidity. Also applied as buffer pads for conveyor systems, sealing rings for pneumatic/hydraulic actuators, and vibration damping mounts for precision sensors, reducing equipment noise and extending component service life.
Suitable for high-voltage connector sealing plugs, battery pack waterproof vent valve components, and charging interface protective covers. The products provide IP68 waterproof protection, 15kV+ dielectric insulation, and resistance to automotive oils and electrolytes, maintaining stable performance in the -40°C to 180°C operating environment of new energy vehicle power systems. Flame-retardant UL94 V0 variants meet automotive safety standards.
Food-grade and medical-grade overmolded parts are used as sealing components for surgical instruments, non-slip handles for medical devices, and fluid transfer connector seals for diagnostic equipment. They comply with ISO 10993 biocompatibility standards, can be repeatedly sterilized by autoclaving (121°C, 15psi) or ethylene oxide without performance degradation, and avoid the risk of particle shedding common in assembled parts.
Applied as waterproof connectors for offshore monitoring equipment, anti-corrosion handles for marine operation tools, and sealing gaskets for outdoor communication base station housings. The UV-resistant and salt-spray-resistant formula ensures no performance degradation after 10 years of exposure to harsh marine and outdoor environments, reducing maintenance frequency for remote installed equipment.
Used as non-slip bases for kitchen appliances, waterproof sealing rings for electric coffee makers, and impact-resistant protective shells for smart wearable devices. Food-grade variants meet FDA contact standards, with customizable colors and surface textures to match product aesthetic requirements.
We support fully customized sizes based on customer drawings or samples. For small precision parts (≤50mm overall size), we recommend a minimum LSR layer thickness of 0.3mm to ensure uniform molding. For large structural parts (>300mm), the LSR layer thickness should be no less than 1mm to avoid shrinkage or warpage during curing. When submitting design files, please specify dimensional tolerance requirements for critical mating surfaces to ensure assembly compatibility.
All LSR overmolded parts are manufactured in our ISO 9001:2015 and IATF 16949 certified production facilities, with a strict three-stage quality control process:
We provide a 12-month warranty for all standard products against manufacturing defects, including delamination, abnormal wear, and seal failure under normal use conditions. Custom parts can be provided with pre-shipment test reports according to customer-specified standards. All products comply with RoHS 2.0, REACH SVHC, and relevant industry certification requirements, with certification documents available upon request.
