Some micro projects require specialty micro injection molding processes, such as overmolding. Overmolding involves two or more materials molded together to become one part. Examples include molding plastic over plastic or molding plastic over a preformed part, such as a metal insert. (See examples of common polymers and substrates below.)
MTD specializes in two types of overmolding:
Overmolded Catheter Tip
Made from Ultem, this surgical device measures .005″ wall thickness at overmolded section over the steel ring, and features +/- .001″ tolerances.
Overmolded Suturing Assembly
The overmolded assembly design has a spring OD of 0.11″ (0.28mm). The Ultem wall thickness is 0.012″ (0.30mm).
Carbon-Filled PEEK Device
The PEEK component is overmolded over a .031″ diameter stainless steel rod for a sports medicine device.
Benefits of MTD’s Overmolding Process
- High part precision achieved by leading edge molding equipment, capable tooling, and robust validation procedures
- Shot-to-shot consistency guaranteed by instrumented molds
- Improved part functionality (i.e. creating a water-resistant seal)
- Cost-effective high volume production achieved through robotics and automation
- Ultra-precise positioning of overmolding tool inserts enabled by in-line camera systems
- Avoidance of foreign materials such as glues and adhesives into the final medical device
- Significant reduction or elimination of costly and cumbersome assembly operations that can lead to failure modes and high fall-out rates