Overmolding Injection Molding

 

Overmolding is a specialized injection molding process that layers two or more materials—typically a rigid substrate and a soft, elastomeric outer layer—to create a single, integrated, multi-material part. This process is an efficient operation when two engineered materials are desired within a component, to accomplish two distinct functions. We perform the overholding process with a number of different [materials] and inserts to achieve the desired performance results for the engineered product. Used to enhance ergonomics, add grips, dampen vibration, or improve aesthetics, this method reduces assembly time by creating chemical or mechanical bonds between materials in one or two steps.

 

Core Capabilities

 

Multi‑Material Molding Expertise

- Ability to mold two or more materials together (e.g., rigid plastic + soft elastomer).

- Knowledge of material compatibility, bonding behavior, and shrink rates.

- Experience with both insert molding and two‑shot molding.

 

Design for Manufacturability (DFM) Support

- Guidance on part geometry, wall thickness, bonding surfaces, and gating.

- Optimization to reduce defects like delamination or warping.

- Collaboration on CAD models and prototyping.

 

Tooling and Mold Fabrication

- Design and manufacture of multi‑cavity, multi‑shot, or rotating‑core molds.

- Precision machining for tight tolerances.

- Maintenance and lifecycle management of molds.

 

Production Capabilities

- High‑volume automated production.

 

 What Overmolding Enables For You

 

Enhanced Product Functionality

- Soft‑touch grips on tools, toothbrushes, medical devices.

- Seals and gaskets integrated directly into housings.

- Shock‑absorbing layers for electronics.

 

Improved Durability

- Stronger bonding than adhesives or mechanical fasteners.

- Better resistance to wear, moisture, and chemicals.

 

Aesthetic and Ergonomic Benefits

- Color accents without painting.

- Comfortable textures and improved handling.

 

Cost and Assembly Reduction

- Eliminates secondary assembly steps.

- Reduces part count.

- Improves production efficiency.