Wuhan Custom Liquid Silicone Rubber Overmolding

# Wuhan Custom Liquid Silicone Rubber Overmolding

Product Overview

Wuhan Custom Liquid Silicone Rubber (LSR) Overmolding is a precision manufacturing service that bonds liquid silicone rubber to rigid substrates (including plastics, metals, and engineered composites) during the injection molding process to produce integrated, high-performance multi-material components. Based in Wuhan, China's advanced manufacturing hub for medical devices and automotive components, our service combines local automated production infrastructure with international material standards to deliver custom overmolded solutions for low-volume prototyping and high-volume mass production.

Our core value lies in tight process control that ensures consistent, void-free bonding between LSR and rigid substrates, eliminating the need for secondary adhesive bonding and reducing long-term component failure risk. We support fully custom design from initial prototyping to mass production, with flexible order quantities ranging from 10-unit prototype runs to 1,000,000+ unit annual mass production, matching the diverse requirements of startups, mid-sized enterprises, and global OEMs. Our local Wuhan production base also enables shorter lead times for Asian clients and optimized logistics for global distribution, with full design for manufacturing (DFM) support to help clients optimize part performance and reduce production costs.

Technical Specifications

Material Properties

All LSR materials used in our overmolding process comply with international industry standards, and we offer a full range of material grades to match application requirements:

Physical Performance

Our controlled injection process delivers consistent physical properties for finished overmolded components:

Process Parameters

Our LSR injection overmolding process follows standardized control parameters to ensure consistent quality:

• Injection pressure: 50–150 bar, adjusted based on part geometry and wall thickness
• Mold temperature: 160°C – 190°C, controlled within ±2°C to ensure complete curing
• Curing time: 30–120 seconds, depending on LSR thickness and part complexity
• Molding method: Two-step overmolding (insert molding) or two-shot injection overmolding, selected based on production volume and design requirements
• Surface treatment: Plasma treatment, primer coating, or mechanical texturing available to improve bond strength for hard-to-bond substrates

Product Advantages

1. Void-Free, High-Strength Integrated Bonding: Unlike post-assembly bonding or cold-cast overmolding, our high-temperature injection overmolding process forms a chemical and mechanical bond between LSR and the substrate, eliminating adhesive failure, delamination, and voids that commonly occur in secondary bonding processes. This improves long-term component durability and reduces maintenance requirements for end products.

1. Full-Spectrum Customization Capability: We support custom part sizes ranging from tiny 2 mm medical components to 500 mm automotive sealing gaskets, with custom colors, surface finishes (matte, glossy, textured), and hardness to match exact application requirements. Our in-house tooling workshop in Wuhan can produce custom aluminum or steel molds in 3–7 working days, enabling fast prototyping and rapid design iterations.

1. **Regulatory Compliance for High-Requirement Industries: All our material batches are traceable, and we offer material grades that meet the strict regulatory requirements of medical, food contact, automotive, and aerospace industries. We provide full material test reports, process documentation, and compliance certificates to support clients' product registration and audit requirements.

1. **Cost-Effective Production with Local Wuhan Advantages: Our Wuhan-based production facility combines low local manufacturing costs with advanced automated injection molding equipment, enabling us to deliver high-quality overmolded components at 15–30% lower cost than Western manufacturers for comparable quality. We also offer flexible pricing for low-volume prototyping and tiered pricing for high-volume mass production to match different project budgets.

1. **End-to-End Engineering Support: Our team includes experienced material and process engineers that provide free DFM analysis to help clients optimize part design for overmolding, reducing potential issues such as LSR flash, poor bonding, and incomplete filling before tooling production. We also support functional testing of prototype components to validate performance before mass production.

Applications

Wuhan Custom LSR Overmolding serves a wide range of industrial and commercial applications, with core use cases including:

• Medical Devices: Overmolded handles for surgical instruments, gaskets for diagnostic equipment, catheter hubs, sealing components for wearable insulin pumps, and soft grip overmolds for orthopedic devices. Our medical-grade LSR meets biocompatibility requirements per ISO 10993-5 and ISO 10993-11.
• Consumer Products: Soft non-slip grips for kitchen utensils, electric toothbrush handles, waterproof sealing gaskets for smart watches and wearable electronics, baby bottle nipples, and pacifiers. Food-grade LSR options comply with FDA and EU 10/2011 food contact standards.
• **Automotive Industry: Sealing gaskets for automotive lighting systems, engine sensors, and door handles, soft touch overmolds for steering wheel buttons and gear shift knobs, and vibration damping components for electronic control units. Our materials meet automotive industry requirements for aging resistance and low VOC emission.
• **Industrial Equipment: Waterproof sealing components for outdoor electronics, vibration damping mounts for industrial motors, protective overmolds for hand tools, and chemical-resistant gaskets for fluid handling equipment.
• **Aerospace and Electronics: Insulating overmolds for high-voltage connectors, sealing gaskets for avionics enclosures, and anti-slip components for aircraft cabin interiors.

Selection Guide

Hardness Selection

Select the LSR hardness based on functional requirements:

• 10–20 Shore A: For soft sealing applications, skin-contacting wearable components, and low-force gaskets that require high elasticity
• 20–50 Shore A: For soft grip overmolds, general purpose sealing gaskets, and ergonomic handles
• 50–80 Shore A: For high-wear components, structural sealing, and applications that require high rigidity and tear resistance

Size Specifications

We support custom part sizes across a wide range:

• Maximum substrate size for insert overmolding: 500 mm × 300 mm × 100 mm
• Maximum LSR overmold thickness: 12 mm (thicker sections available upon special request)
• Minimum LSR overmold thickness: 0.5 mm for precision sealing applications

Material Grade

Select the appropriate material grade based on your application's regulatory requirements:

• Industrial Grade: For general industrial applications with no food contact or medical requirements, cost-effective
• Food Contact Grade: Complies with FDA 21 CFR 177.2600 and EU 10/2011, suitable for kitchenware and food processing equipment
• Medical Grade: Complies with ISO 10993 biocompatibility requirements, suitable for implantable and disposable medical devices
• High-Temperature Grade: Formulated for continuous operation above 180°C, suitable for automotive under-hood and aerospace applications

Quality Assurance

Our Wuhan production facility operates under an ISO 9001:2015 certified quality management system, with full traceability from raw material incoming inspection to finished product outgoing inspection. Every production batch undergoes 100% visual inspection for surface defects, and we conduct regular testing of bond strength, dimensional accuracy, and material properties to ensure compliance with specification.

We provide full documentation for every order, including material test reports (MTR), dimensional inspection reports, and compliance certificates for relevant industry standards. For medical and automotive clients, we support process validation (PPAP) documentation to meet their quality system requirements. All our tools and finished components undergo final inspection before delivery, and we offer a 12-month quality guarantee for mass-produced components, with free replacement for any products that do not meet agreed specifications.