Speeding Up Your Development: A DFM Handbook

By Chamfr Team
August 8, 2024

In this sponsored content post, Bioana CEO Andrea Siller shares helpful information for engineers regarding Design for Manufacturability (DFM): Speeding Up Your Development: A DFM Handbook. In the fast-paced world of medical device development, speed to market is crucial. Companies and R&D teams are constantly racing against competitors, budgets, and evolving technologies. Bioana’s DFM Handbook is designed to help you navigate this race efficiently. By integrating DFM principles early in the process, you can reduce iterations, cut development time, and ensure a smoother path to market success. Discover practical tips and insights for various manufacturing processes to accelerate your development.

Speed. Fast. Now. That’s all we want to hear when developing a medical device, right? Speed to market is a huge deal for medical device companies and R&D teams, and a major challenge.

Developing a medical device often feels that you are in a race, a race against competitors, against burn rate or against new technology taking over. And when talking about medical devices, we really want to speed up, Usain Bolt style. I often compare the product development process to one of my favorite shows “The Amazing Race”, the goal to be the first to cross the finish line by successfully overcoming all the challenges on the road, all those speed bumps, detours, U-turns, while enjoying the ride at the same time. Developing a new medical device, truly is an Amazing Race, and we definitely want to go as fast as we can without risking a “road-block” from FDA or a “U-turn” from the customers. 

So how do we balance that? How can R&D teams speed up while assuring success on the market?

The Key to Speed: A DFM mindset

DFM is all about bridging the gap between design and manufacturing. Embedding DFM principles as early as in your Concept Phase is your one and only “Fast Forward” card.

Why?

  • 50% fewer prototypes and iterations – faster and more cost-effective development cycles
  • 30 – 50% of reduction in time to market
  • 70% of manufacturing costs are derived from design choices

As a designer and engineer of new medical products we are often in need of designing for several different processes that have their own process tolerances and considerations.

So, considering an injection molding process, here are some insights to help you streamline your design:

  1. Wall Thickness: Aim for consistent wall thickness to avoid warping and sink marks during cooling. For ABS keep it in the range of 1.2 mm – 3.5 mm. For PP between 0.8 mm – 3.8 mm. For PC between 1.0 mm – 3.8 mm. When wall thickness changes are necessary, use gradual transitions with a taper angle of 1º to 3º to avoid abrupt changes that can cause stress concentrations.
  2. Draft Angle: Incorporate draft angles, typically of 1º to 2º, to facilitate the ease ejection of parts from the mold without damage. Apply a draft angle of 0.5º to 1º per side for external surfaces. Use a draft angle of 1.5º to 2º per side for internal surfaces, as they can be more prone to sticking.
  3. Rib-to-Wall Ratio: Use ribs to add strength to thin-walled sections without significantly increasing material usage or weight. Ribs should be less than 60% of the adjacent wall thickness to avoid sink marks.
  4. Radii and Fillets: Use fillets with a radius of at least 0.5 times the wall thickness to improve flow and reduce stress concentrations at internal corners. Use larger radii where possible to maintain material flow and strength.
  5. Tolerances: Consider the following tolerance for each dimension:
    • 0.5 to 6 mm = +/- 0.1 mm
    • 6.1 to 30 mm = +/- 0.2 mm
    • 30.1 to 120 mm = +/- 0.3 mm
    • above 120 mm = +/- 0.5 mm
  6. Gate Design: Place gates at the thickest section of the part to promote even filling and reduce voids. Optimize gate size to control the follow rate and minimize pressure drop. Typically around 60% to 80% of wall thickness.

We have prepared a DFM Handbook, as a guide to design for manufacturing success, that includes insights for additional processes such as: Catheter Extrusion, Casting, CNC Machining, 3D Printing, and Electronics Assembly.

Get your Handbook in 10 seconds or schedule a call with Bioana.

Bioana is part of Chamfr’s Supplier Directory. They are a product development company and contract manufacturer (nearshoring – Monterrey, Mexico, a 3-hour drive from Texas), we can help you streamline design and production with strong DFM practices for a fast and successful Design Transfer and market entry. Bioana has 14,000 sq. ft. facility, with ISO 7, ISO 8, and ISO 9 cleanroom assembly, FDA registered and ISO 13485 certified.