How to deliver high

August 21, 2020 By Nancy Crotti

Medical device manufacturers can produce high-performing, complex geometric parts and components for surgical instruments at high volumes cost-effectively using a metal injection molding (MIM) process. This flexible, hybrid technology can deliver high-quality parts consistently using a single manufacturing process.

Steve Santoro, Micro

(Image courtesy of Micro)

Demand for lightweight, disposable surgical devices has been increasing as hospitals see a distinct cost advantage for off-the-shelf, single-use products that don’t require sterilization. Disposable sterile devices can also help minimize risk of infection.

CMOs and their original equipment manufacturer partners (OEMs) can work together to address changing market needs with innovative technology, and MIM can help manufacturers meet the increased demand.

MIM doesn’t replace machining, but it offers distinct advantages for certain high-volume, high-precision projects in which parts may be smaller and require more maneuverability along with having strong mechanical properties.

MIM integrates the shaping capability of plastic injection molding and the materials flexibility of conventional powder metallurgy to efficiently produce small, complex parts at high volumes, using high temperature and pressure. The process uses combinations of metal powder and plastic binders that are blended and compounded so that an injection-moldable feedstock can be produced to fabricate the green part.

Using an injection molding machine, the parts produced are then subjected to a binder-removal process. Depending upon the type of binder used, either thermal or solvent, thermal debinding is applied. After debinding, the parts go through a sintering process to ensure densification, alloying, optimal mechanical properties and correct geometry. Newly molded parts are the shape of the final part but larger. The sintering process allows controlled shrinkage, usually in the range of 15%, to achieve full density. The end result is a net shape part. Post-processing may be needed to arrive at the final part.

MIM and traditional machining each have advantages and disadvantages depending on each project scope and requirements. MIM allows components to be produced in a single manufacturing process, but a mold is needed to make the green part. Machining and other technologies typically require lower tooling cost and lower lead time upfront but incur higher piece-part prices due to processing times. MIM may have several advantages when considering the following:

An experienced CMO partner can help OEMs select materials, optimize designs and ensure uniform parts with dimensional repeatability. Collaboration early in the development cycle can ensure a component produced through metal injection molding meets the form-fit-function requirements.

Engineers with expertise in both MIM and machining processes can suggest design modifications and provide input to get the best performance out of a product, no matter what technique is ultimately used. An experienced CMO partner can work with their OEM customers to factor in design considerations upfront that can save time and costs.

Steve Santoro is EVP of Micro, directing corporate technical and commercial teams. He previously held high-level operations, sales, engineering and general management positions, and is a charter board member of the School of Applied and Engineering Technology at the New Jersey Institute of Technology.

The opinions expressed in this blog post are the author’s only and do not necessarily reflect those of Medical Design and Outsourcing or its employees.