Mastering Mold Design: A 4-Part Series for the Next Generation

An example from a virtual mold design curriculum showing DFM-driven thread lead-in modifications for improved manufacturability and grinder accessibility. Source | Virtual.Mold.Design

Our longtime industry colleague Don Smith — a past MMT Leadtime Leader, ongoing contributing author, past speaker, previous Editorial Advisory Board member and lifelong advocate for solidifying the future of moldmaking — is sharing his expertise through a new four-part series in MMT. While he may be approaching retirement, his passion for sharing his knowledge of mold design to help educate the next generation of moldmaking professionals remains stronger than ever.

Don has developed a virtual mold design curriculum he’s ready to share with our readers. This series will explore best practices in four key areas of mold design: DFM, simulation, specification development and comprehensive design reviews.

Injection mold design is vital for production success, with design issues potentially resulting in costly changes or a new mold build. To avoid these risks, shops must implement a comprehensive review process before tooling begins. Each installment of this series will take a deeper dive into one of these essential best practices:

1. Design-for-Manufacturing (DFM) Review
A proper DFM review ensures part designs adhere to standard injection molding constraints and design rules. Well-executed DFM can reduce cycle times by up to 50%, improve cosmetic appearance and enhance process yield by addressing critical dimensions, functional aspects, seam line locations and flash allowances.

2. Flow Simulation
Understanding how molten plastic behaves within the mold cavity is essential. Simulations guide decisions on gating, runner layouts and cooling designs. Key analyses include fill-pack-warp, hot runner systems and conformal cooling evaluations which optimize gate location, runner systems, cooling channels and predict warpage risks.

3. Mold Specification Development
A thorough mold specification communicates critical requirements to designers, ensuring DFM and simulation insights are properly implemented. This includes material selection, gate design, venting strategy, cooling requirements, cycle time predictions and ejection requirements.

4. Mold Design Review
The final review ensures the proposed design meets performance criteria and follows industry best practices. Key areas include structural integrity, mold splitting and alignment, gating/runner systems, venting, cooling/temperature control, demolding/ejection, material selection and finishes/coatings.

By following this structured approach, Don believes manufacturers can achieve robust, high-performing molds that meet both functional and aesthetic requirements while maintaining process capability over time.

Part 1 was featured in the May issue. Parts 2, 3 and 4 of this series will appear in MMT’s August, October and December issues, respectively. If you’re interested in taking a deeper dive into Don’s virtual mold design curriculum, reach out to him directly or email me.

We hope this series will help to develop your team’s skills. We are currently discussing related webinar content and workshops, so stay tuned!