Design for manufacturability (DFM) is a broadly-implemented step in today’s development process to ensure that a designed product can actually be manufactured. While the concept sounds simple, there are nuances to every supplier relationship and every new process. Three suppliers—a contract manufacturer, additive manufacturer and plastics company—will each spend 15 minutes answering the following question: With orthopaedic customers, our greatest DFM pain point is ___ and the best strategy to change that is ___. OEMs will learn best practices and ways to approach DFM with their supplier partners.

2. © 2016 Solvay Specialty Polymers1
OMTEC 2016
Design for Manufacturability (DFM) Session
Presentation by Solvay Specialty Polymers
Speaker: Jim Hicks – Technical Development Engineer

3. © 2016 Solvay Specialty Polymers2
With our Orthopedic customers,
Our greatest Design for Manufacturability (DFM) pain
point within the orthopedic community is the engineering
staff’s lack of polymer experience,
and the best design strategy for change involves forming
early partnerships with the polymer supplier and
processors.
Session Topic Statement

4. © 2016 Solvay Specialty Polymers3
The role of the Polymer supplier in the DFM process
• Understand the requirements of the
application and device.
• Provide material choice options
• Help the engineering team find the right
balance of:
- Material properties – short and long term
- Material availability – beyond just whether
we have the product in stock
- Material supply chain – direct sell, custom
compounder or stock shape convertor
- Primary processing – Injection molding,
thermoformed or machined
- Post processing – Marking, welding,
insertions and assembly
Goal: Help the customer follow the path of least resistance to bring a design to production

5. © 2016 Solvay Specialty Polymers4
Designing with plastic is not difficult, just different.
• Our orthopedic customers have great
design engineers that come up with
creative new devices.
- Many are very knowledgeable about
designing in metal but do not have much
experience with plastics.
• Remember these simple rules when
converting a traditional metal design to
plastic:
- Pick your polymer based on whether you
want toughness or strength.
- Sharp inside corners are not your friend in
plastics!
- Not every dimensional tolerance needs to
be translated from the metal design.
- Uniform wall thickness = predictable
designs
Good plastic parts are a function of the right design and the right material!

6. © 2016 Solvay Specialty Polymers5
Define what the part is expected to do and the
critical-to-quality parameters
• If you are converting a metal part to
plastic, step back and define actual use
conditions, loads and deflections.
• Simulate the current design in metal and
test.
• Translate design to plastic and begin
modifications to achieve similar
behavior, not similar properties.
• Take advantage of CAE and Moldflow
analysis to troubleshoot design and
manufacturing before production.
Many traditional metal parts have few defined performance criteria. They just work.

7. © 2016 Solvay Specialty Polymers6
Partner at the beginning of the design process
• Use the experience and knowledge of skilled
molding shops and polymer engineers to look
for potential problems early in the design
process
• Consider consolidating multiple parts into the
new design.
• Take advantage of the best attributes of
metal and plastics. Combine the ability to
have higher tolerance standardized metal
inserts with lower cost plastic structures.
• Design a plastic part as if it is to be molded
long term. Even if the part is to be machined
in the early design or as part of a limited
launch, be prepared for this option.
Do not wait until the part design is locked
to start looking for processing partners
Don’t design alone. Find partners that can help in the whole process.
SLIDE FIT
Metal Plastic

8. © 2016 Solvay Specialty Polymers7
Key takeaways for plastic part design and
manufacturing
• Define critical dimensions and allow
others to float….Do not over tolerance!
• Take advantage of plastic simulations
and Computer Modeling to predict
behavior.
• Metal – Plastic hybrid design can allow
easier manufacturing by simplifying
steps and combining parts.
• And most important, get the tool
maker, plastic processor, and the
polymer supplier involved as early as
possible!
DFM is a team effort - Make maximum use of internal and external resources!

9. © 2016 Solvay Specialty Polymers8
Design For Manufacturability (DFM)
The best design strategy involves forming the right team:
polymer experts, processors, tool builders, fabricators….
Final Thoughts

10. Safety Data Sheets (SDS) are available by emailing us or contacting your sales
representative. Always consult the appropriate SDS before using any of our products.
Neither Solvay Specialty Polymers nor any of its affiliates makes any warranty, express or
implied, including merchantability or fitness for use, or accepts any liability in connection
with this product, related information or its use. Some applications of which Solvay’s
products may be proposed to be used are regulated or restricted by applicable laws and
regulations or by national or international standards and in some cases by Solvay’s
recommendation, including applications of food/feed, water treatment, medical,
pharmaceuticals, and personal care. Only products designated as part of the Solviva®
family of biomaterials may be considered as candidates for use in implantable medical
devices. The user alone must finally determine suitability of any information or products for
any contemplated use in compliance with applicable law, the manner of use and whether
any patents are infringed. The information and the products are for use by technically
skilled persons at their own discretion and risk and does not relate to the use of this
product in combination with any other substance or any other process. This is not a license
under any patent or other proprietary right.
All trademarks and registered trademarks are property of the companies that comprise the
Solvay Group or their respective owners.
© 2016, Solvay Specialty Polymers. All rights reserved.
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11. paragonmedical.com
OMTEC 2016
DFM Rapid Fire
Mike Street
Paragon Medical
Sr. Manufacturing Engineer/Prototype Manager

12. paragonmedical.com
DFM Oversights
With orthopaedic customers, our greatest
DFM pain point is secondary operation
oversights and the best strategy to change
that is early engagement and collaboration.

13. paragonmedical.com
What is considered a secondary
operation?
• For Paragon Medical…
– An operation driven by print specifications that
occurs after primary machining.
– Operations that are mostly manual and difficult
or impossible to validate.
– Requirements can be subjective…
cosmetics for example

14. paragonmedical.com
Secondary Operations
• Coatings
– Hard Coat Chrome
– PVD Coatings
– Anodization, etc.
• Assembly
– Press Fits
– Staking and Swaging
• Welding
• Cosmetic Requirements

15. paragonmedical.com
Welding Pain Points
• Stringent weld specifications
– Requires expensive testing
• Radiographic X-ray
• Destructive metallurgical testing
• Mechanical testing
– What happens if a failure is detected?
• Scrap entire lot?
• Deviation?

16. paragonmedical.com
Welding Pain Points
• Controlling weld quality
– Mostly manual process
• Difficult to validate
• Variation between operators
• Variation due to environmental factors
• Verification necessary to ensure
specification conformance

17. paragonmedical.com
Welding Pain Points
• Manufacturing Example
– Instrument assembly with 10 weld junctions
• GTAW Welding and Laser Welding
• Metallurgical Testing required on weld joints
• 3 assemblies per lot of 50 sectioned for testing
• $14,000 per lot testing cost
• 4 week additional lead time
• Resulted in 38% cost increase per assembly

18. paragonmedical.com
Welding Pain Points
• Example of common issues

19. paragonmedical.com
Welding Pain Points
• Example- Alternatives to welding

20. paragonmedical.com
Welding Pain Points
• Alternatives
– Staking or Swaging
– Threaded Junctions
• Epoxied threads
• Peened Threads
– Single Piece solutions
– Welding as secondary fixation

21. paragonmedical.com
Welding Pain Points
• If Welding can not be avoided
– Early engagement with manufacturing
• Proper design of weld junctions to ensure success
• Weld callouts scrutinized
• Test pieces developed
• Verification protocol developed

22. paragonmedical.com
DFM in General
• Ultimately the best way to mitigate
manufacturing issues is collaboration
between the design team and the
manufacturing team early in the project

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