Overmolding Services
- 20+ years of overmolding expertise
- ISO 9001:2015 certified facility
- Multi-material compatibility
- Tooling and production-ready in as fast as 2 weeks
What is Overmolding?
Think about your power tool handle. It has a rigid structural core that’s overmolded with soft-grip TPE for enhanced control and comfort. Overmolding is an advanced multi-material injection molding process that bonds thermoplastic elastomers to rigid substrates in a single molding cycle.
- Enhanced product durability and performance
- Improved grip and ergonomics
- Cost-effective multi-material solutions
- Reduced assembly time and labor costs
- Superior chemical and environmental resistance
Overmolding Capabilities
Capability | Specification |
|---|---|
Maximum Part Dimensions | Up to 250 × 350 × 120 mm (9.84 × 13.78 × 4.72 in.) |
Minimum Part Dimensions | As small as 1.5 × 1.5 × 1.5 mm (0.06 × 0.06 × 0.06 in.) |
Wall Thickness Range | Typically 0.5 mm to 4 mm (0.02 to 0.16 in.), depending on material combination |
Dimensional Tolerance | ± 0.02 mm (± 0.0008 in.) achievable for critical features |
Minimum Radii | Down to 0.2 mm (0.0079 in.) |
Cavity Depth from Parting Line | Up to 120 mm (4.72 in.) |
Tooling & Validation | T0–T2 sample trials before production approval |
Inspection & Compliance | FAI, ISO 9001, ISO 13485, RoHS-compliant upon request |
Supported Molding Types | Insert molding, two-shot overmolding, vertical and horizontal mold configurations |
Production Lead Time | 15–45 business days from tooling to sample delivery (depending on complexity) |
Comprehensive Overmolding Solutions
Pre-formed rigid components are placed into specialized molds, then overmolded with thermoplastic materials through injection molding. This molding process creates a tight bond between hard and soft materials, producing more durable and functional products.
Applications: Automotive connectors, medical devices, tool handles, electronic product housings
Two-Shot Molding
No pre-formed inserts required. Two different materials are injected sequentially into the same mold. The first shot forms the rigid base structure, while the second shot adds the soft layer. Two-shot molding enables more complex material distribution and precise interface control.
Applications: Automotive dashboard buttons, smartphone cases, toothbrush handles, tool switches
Soft over Hard
Soft thermoplastic elastomer (TPE) is directly injected over a rigid plastic substrate to create a comfortable tactile layer. This process maintains structural strength while providing excellent grip feel and anti-slip performance.
Applications: Tool handles, sports equipment grips, electronic device housings, automotive interior switches
Rigid Plastic over Metal
Metal components serve as the structural foundation, with rigid plastic materials molded around them. The metal provides strength and conductivity, while the plastic layer offers insulation protection and aesthetic enhancement.
Applications: Electrical connectors, precision instrument housings, automotive electronic components, industrial equipment assemblies
Overmolding Materials
Common Substrate Materials
Material | Key Properties | Typical Applications |
|---|---|---|
ABS (Acrylonitrile Butadiene Styrene) | Good rigidity, easy to mold, and cost-effective | Electronic housings, tool handles |
Polycarbonate (PC) | High impact resistance, heat-resistant, available in transparent grades | Protective components, industrial parts |
PC/ABS Alloy | Combines PC toughness with ABS processability | Balanced performance, ideal for consumer electronics |
Nylon (PA6, PA66) | High strength, wear, and chemical resistance | Mechanical components, gears |
Polypropylene (PP) | Lightweight, excellent chemical resistance, low cost | Automotive parts, consumer products |
PBT (Polybutylene Terephthalate) | High stiffness, good dimensional stability | Industrial electronics, electrical connectors |
Common Overmold Materials
Material | Key Properties | Typical Applications |
|---|---|---|
TPE (Thermoplastic Elastomer) | Soft, flexible, recyclable, and available in various hardness levels | Soft-touch grips, consumer products, and seals |
TPU (Thermoplastic Polyurethane) | High abrasion resistance, good elasticity, and chemical resistance | Protective cases, automotive components |
Silicone Rubber | Excellent flexibility, high/low temperature resistance, biocompatible | Medical devices, waterproof seals, and food-grade products |
SEBS (Styrene-Ethylene-Butylene-Styrene) | Soft, good weather resistance, good adhesion to PP/PE | Toothbrush grips, tool handles |
Santoprene® (TPV – Thermoplastic Vulcanizate) | Rubber-like feel, durable, good chemical resistance | Automotive seals, appliance parts |
Our Injection Molding Process
Material Selection
Choosing the appropriate plastic material is the initial step. This involves consideration of factors such as the product's intended use, environmental conditions, durability, and cost. The selected material impacts the performance, lifespan, and functionality of the final product.
Mold Creation
The next step involves designing and creating the mold based on the product specifications. High-quality stainless steel is often used due to its durability and resistance to wear. The mold's design is guided by the SPI-SPE standards, ensuring precision and consistency in the produced parts.
Injection Process
The selected plastic material is heated and injected into the mold under high pressure. This stage requires careful control of conditions like temperature, pressure, and injection speed to ensure the material fills the mold uniformly and solidifies correctly, maintaining the design's integrity.
Cooling and Ejection
After injection, the mold is cooled to allow the plastic to harden into the desired shape. Once adequately cooled, the final product is ejected from the mold. This step includes any necessary post-processing services such as trimming, surface finishing, and assembly to ensure the product meets all specifications and quality standards.
Why Choose TDL Mould for Overmolding?
Advanced Material Bonding Expertise
We have extensive experience with complex substrate-overmold combinations such as TPE over ABS, TPU over Nylon, and silicone over PC. Our team supports primer selection, bonding tests, and long-term durability verification to ensure reliable adhesion under real-world use.
High-Precision Manufacturing
Our in-house production follows tight dimensional control, achieving tolerances down to ±0.02 mm. Whether it’s a dual-shot housing or a fine-sealed interface, we ensure consistent part quality, even in high-cavity tools or intricate geometries.
Fast & Flexible Delivery
TDL offers rapid mold fabrication (7–15 days for sampling), streamlined sampling (T0–T2), and scalable output—from small prototyping runs to 100,000+ unit series production. You get fast development without compromising quality.
In-House Tooling & DFM Support
All molds are designed and built in-house, allowing full control over lead times, revisions, and tool performance. Our engineers collaborate on DFM, gate/vent placement, and mold flow optimization from the earliest design phase.
Certified Quality Assurance
We are ISO 9001 and ISO 13485 certified, with in-process inspections, dimensional validation, and First Article Inspection (FAI) available. Every batch follows strict quality protocols to ensure repeatability and compliance.
Collaborative Engineering Team
Our technical staff brings 10+ years of injection and overmolding experience, offering end-to-end support from concept development through tooling and mass production. You benefit from expert input at every critical decision point.
Overmolding Service Process
Consultation & Feasibility Review
Our engineering team evaluates your design, materials, and bonding requirements to confirm technical feasibility and recommend optimized solutions.
DFM Analysis & Quotation
We conduct Design for Manufacturability (DFM) analysis and provide a detailed quotation covering tooling, materials, unit cost, and lead time.
Mold Design & Fabrication
Upon approval, we design and build the overmolding tool in-house, incorporating features like undercuts, ejector layout, and dual-material flow control.
T0–T2 Sampling & Validation
We produce initial samples (T0, T1, T2) for dimensional verification, bonding strength testing, and customer review. Adjustments are made as needed.
Mass Production
Once samples are approved, we move to full-scale production. Quality control is enforced through in-process inspections and final verification.
Packaging & Global Delivery
Parts are packed according to your shipping and labeling requirements. We coordinate global logistics, customs documentation, and on-time delivery.
After-Sales Support
Offer after-sales support, clients can request technical assistance.
We support CAD, STL, STEP, and IGES formats. Contact us if you encounter any upload issues.
Choose us for overmolding services and get up to 100% mould cost refund!
Our Equipment
CMM
Inspection
High Speed CNC Machines
Double-Head EDM Machines
EDM
Workshop
CNC machining Workshop
Plastic Injection Molding Room
Mirror EDM Machining
Mould Spotting Machine
Plastic Injection Team
Meet Our Expert Team: The Driving Force Behind TDL Mold’s Innovative Solutions.
Our Related Services & Capabilities
At TDL, we design molds with a clear focus on manufacturability, durability, and efficiency. Our team combines advanced CAD/CAM tools, mold-flow simulation, and hands-on production experience to anticipate issues before cutting steel. Through flow analysis and DFM reviews, we identify risks such as short shots or warpage early, saving you from costly rework and ensuring the mold runs reliably from the start.
TDL builds molds that hold up in real production. We use high-grade steel, precision machining, and strict QC to make sure every tool matches the design intent. From prototype molds to multi-cavity production tools, we control tolerances, surface finish, and cooling layouts so parts come out consistent and cycle times stay efficient. Each mold is tested before shipment, giving you tools that are ready to run and reliable over the long term.
TDL runs 75+ injection molding machines from 50 to 3,700 tons, giving you flexibility from small prototype runs to full-scale production. We support single-cavity, multi-cavity, and family molds, with part-to-part repeatability down to ±0.004 mm. You can get T1 samples in as fast as 2 weeks, with no MOQ required. Our ISO-certified facilities, including cleanroom molding, ensure consistent quality for industries such as medical, automotive, and consumer electronics.
At TDL, we offer a full range of surface finishing options, from polishing and texturing to painting, plating, and laser marking. These processes improve function, durability, or aesthetics, depending on your application. Whether you need a high-gloss surface for consumer products or a textured finish for better grip, we deliver consistent, production-ready results directly from our shop floor.
FAQ's
Overmolding is compatible with a wide variety of thermoplastics and elastomers. Typically, a rigid substrate is combined with a softer overmold material to improve grip, protection, or sealing.
Common Substrate Materials (Base Layer):
- ABS – Strong and easy to mold; commonly used in consumer products.
- Polycarbonate (PC) – High impact resistance and heat stability.
- Nylon (PA6, PA66) – Excellent for mechanical parts with wear resistance.
- PBT – Good dimensional stability and chemical resistance.
- Polypropylene (PP) – Lightweight and cost-effective.
- PC/ABS Alloy – Balances strength and processability.
Common Overmold Materials (Top Layer):
- TPE (Thermoplastic Elastomer) – Soft-touch, flexible, and available in various hardness levels.
- TPU (Thermoplastic Polyurethane) – Offers durability, elasticity, and abrasion resistance.
- Silicone Rubber – Ideal for medical or high-temperature applications.
- SEBS – Soft and weather-resistant, adheres well to PP.
- TPV (e.g., Santoprene®) – Rubber-like feel, great for seals and grips.
Important: Material compatibility depends on chemical bonding, molding temperature, and functional requirements. Some combinations may require primers or mechanical interlocks to ensure strong adhesion.
There is no minimum order quantity (MOQ) at TDL Mould.
We support projects at any stage — from early prototyping to full-scale production. Whether you need just a few samples or thousands of parts, we’re ready to deliver with the same level of precision and care.
Tooling development typically takes 2 to 5 weeks, depending on part complexity, mold structure, and project requirements.
- Simple overmold tools: ~2–3 weeks
- Complex multi-cavity or 2-shot tools: ~4–5 weeks
- Tool modifications or replications: ~1–2 weeks, based on existing design
We provide clear timelines during the quoting phase and offer T0–T2 sample validation to accelerate your product launch.
Need fast turnaround? We also offer expedited tooling options for urgent projects.
Yes, we offer full design support throughout your overmolding project.
Our engineering team works closely with you to optimize part geometry, material selection, and moldability, ensuring strong bonding, efficient tooling, and reliable production.
Our design assistance includes:
- DFM (Design for Manufacturability) analysis
- Material pairing & bonding recommendations
- Undercut, gate, and vent optimization
- Support for 2D/3D files, revisions, and prototyping feedback
Not sure if your part is suitable for overmolding? Send us your design files — we’ll evaluate and suggest improvements at no cost.
At TDL Mould, we maintain strict quality standards to ensure consistent and reliable production.
We are certified to:
- ISO 9001 – Quality Management System
- ISO 13485 – Medical Device Manufacturing Quality (available upon request)
We also support:
- FAI (First Article Inspection)
- PPAP (Production Part Approval Process)
- RoHS & REACH compliance (upon customer request)
- Full traceability of materials and processes