DfM focuses on material changes, modifications based on mated assemblies, or geometries to achieve a better result and increased scalability in serial production.

September 28, 2022

4 Min Read
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Image courtesy of RTimages / Alamy Stock Photo

Chris Tellers

Design for Manufacturability (DfM) is a proactive process to design parts, components, or products for ease of manufacturing with an end goal of making a better product at a lower overall cost. It is important in all industries but particularly so in the healthcare and medical industry due to the high level of cleanliness required and the potential life-saving nature of components. DfM focuses on material changes, modifications based on mated assemblies, or geometries to achieve a better result and increased scalability in serial production.


When Original Equipment Manufacturers (OEMs) engage with component suppliers on DfM early in the design process, they can lower costs, cut lead times, and reduce quality risk. Carefully considering these three aspects in DfM means OEMs can take their products to market faster, see increased profits, and provide customers with a product that is higher in quality and performance. Additionally, by incorporating changes to produce a better yield during the production process, DfM can contribute to sustainability through scrap avoidance and less waste.

Conducting DfM
The DfM process often starts with a conversation between the OEM and the component manufacturer. A partner like Trelleborg, builds relationships with OEM engineers and manufacturing teams to help make a better product. They collaborate on design solutions by modifying 3D models or marking up drawings and working to understand how a part will be used and how changes can be made in manufacturing without compromising product functionality.

Since 80% to 90% of costs are designed into a product, component suppliers can work with OEMs to help reduce these costs upfront. When examining a part model or drawing, they look at several specific design features and focus on the following questions, depending on if the part will be molded or extruded:

  • Are there sharp corners?

  • How will the part fill?

  • How will the part demold?

  • What are the gate location options?

  • Where could air become trapped or knit lines form?

  • What thickness do walls need to be?

  • What are the part finish requirements?

  • What are the critical to function surfaces or features?

  • What will the part mate with?

They will also consider splitting the part, this determines how to build the component tool and what is realistically possible.

Tools for DfM
3D modeling and screenshot tools help when communicating with the customer, while mold flow simulation helps engineers understand how a mold will fill during injection. Trelleborg, for instance, offers all these capabilities at a rapid development center, which has dedicated tooling equipment and experts with decades of experience. The combination of the right tools and an experienced team help OEMs achieve the best results from DfM. Thorough DfM also enables component manufacturers to test several tooling iterations in a short amount of time.

The consequences of forgoing DfM
OEMs that do not engage with their part suppliers in a conversation about DfM can run into issues that result in expensive tooling and part costs. During manufacturing, there could also be problems with air traps, short shots, or tear outs, as well as other quality problems, delays in delivery, and added costs. Sometimes it can be challenging for component manufacturers to have OEMs on board with their recommendations, and compromises are necessary because of the OEMs design constraints.
 

 DfM in the past and present
As already discussed, parts suppliers and engineers today have tools and technology that enable them to approach DfM in a calculated and sophisticated way. However, in the past, performing DfM looked different. aPriori, a company that creates intelligent software for manufacturing, notes that historically DfM relied on trial and error due to the limited resources manufacturers had for modeling production. DfM was also based heavily on past experiences as the only reliable source of data and was limited to ad hoc calculations that could not analyze complex interrelationships between design, manufacturing, and cost. DfM often operated independently without input from production engineers leading to problems due to the related nature of design and production.

 DfM calls for changing course  
By asking the right questions and understanding a customer’s project, Trelleborg was able to make recommendations that improved the part design for a customer working on a Class III medical device component. The customer was having issues sealing the fluid path for their part and made multiple attempts at developing a functional component that used an extruded seal.

Trelleborg engineers asked questions about the long-term volume of the product line and the criticality of the seal retaining patient fluids. The Trelleborg team recommended injection molding the part using silicone instead of extruding it. Molding the part allowed for repeatability and design leverage compared to the previous extrusion attempts.

Once the customer is satisfied with the molded part, conversations about commercialization can begin and Trelleborg experts can help prepare for production volumes and validation processes.

Conclusion
The practice of DfM is not new, but it has evolved and yields increased benefits to OEMs thanks to early conversations with their component manufacturers. When OEMs proactively engage their component partners about DfM, they benefit from cost reduction, speed in development and production, and reduced quality risk. All of this means products reach the market faster and help OEMs be more profitable.

 

 

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