Overmolding

Custom Overmolding Service

In the past decades, low-volume production of overmolded parts has resulted from the separate production of the substrate and the molded part. But more advanced methods in manufacturing processes have allowed for the production of the substrate in the same material as the overmolded part. Read on to learn more about our overmolding process for manufacturing prototypes and production types.

What Is Overmolding?

Overmolding is a process in which a single part or product is created by combining two or more different materials. The substrate can be anything ranging from metal, an existing product, or a screw. Examples of common overmolded products include screwdrivers and toothbrushes.

What Is Overmolding Used For?

Enhancing a device’s aesthetics and improving color and texture contrast are the major reasons why overmolding is highly preferred over similar methods like insert molding. Depending on the particular project, overmolding has several applications:

Surgical Instruments and Devices

In hospital operating rooms, devices are expected to operate at peak performance. Overmolded surgical tools have improved precision and comfort with their smooth, ergonomic grips.

Electrical Applications

Electrical elements must be weatherproof in situations that require them to withstand harsh climates. Thermoplastic Elastomer (TPE) is an overmolding material that expands to create a seal restricting moisture from electrical appliances, preventing injury and device malfunction from shock or extreme heat.

Communication and Navigation Tools

Overmolded materials are perfect candidates for the manufacturing of delicate communication or navigation devices used in environments with rain, vibration, and dust particles. Overmolded materials are extremely reliable and protect internal components.

Automated External Defibrillators

AEDs are portable life-saving devices that require overmolding to protect them from UV resistance, shock, and temperature changes.

Overmolding Materials

Using a substrate that is not compatible with an overmolding material results in deformed products and subsequent resource wastage. Fortunately, Rapid Axis has all of the most commonly used materials in stock, including:

  • High-Density Polyethylene (HDPE)
  • PMMA (Acrylic)
  • POM (Polyoxymethylene)
  • PP (Polypropylene)
  • SI (Silicone)
  • TPE (Thermoplastic Elastomers)
  • TPU (Thermoplastic Polyurethane)
  • TPR (Thermoplastic Rubber)
  • Polyetheretherketone (PEEK)
  • Polyetherimide (PEI)
  • Acrylonitrile Butadiene Styrene (ABS)

The Overmolding Process

Overmolding is a two-shot process that first requires molding a substrate and allowing it to cure. On top of it, a second layer is directly molded to create a single solid piece. It is a simple process that takes less time than most other manufacturing methods.

Is Overmolding Right for Your Project

Overmolding is a multifaceted and cost-effective manufacturing method that combines speed with sleek design. Before choosing this method, you must compare the compatibility of available materials. The nature of overmolding material determines how rigid the product will be. Custom overmolded products have a wide range of use as the process critically compares the nature of plastic resin, peel strength, and assembly cost. We recommend that you choose overmolding if:

  • Your project requires that you manufacture both the substrate and the overmolding material.
  • The completed part does not need to be disassembled
  • The finished product can be made of rubber or thermoplastics
  • The finished product will consist of multiple layers and colors

Advancements in manufacturing are allowing innovators to prototype using overmolding, insert molding, and 3D printing. At Rapid Axis, we can provide all of these services quickly, affordably, and with a quality prototype or mass-produced product. Send us your design and we’ll have your quote ready in one business day.