Keys to Bioabsorbable Process Development
Consistency & Control
A medical device company developed a bioabsorbable fixation design and concept that was celebrated by surgeons. They worked with a reputable molder to produce the design, but after several years, the molder had limited success and was unable to produce the part represented in the drawing. By guiding the customer through material characterization and developing the unique tooling construction concept to reduce secondary operations, MTD’s micromolded parts achieved minimal and consistent IV loss and were much more consistent shot to shot. This confidence in the repeatability of device function allowed reliable testing and successful proof of concept to take place.
An OEM developed a bioabsorbable fixation suture design and concept celebrated by surgeons. They worked with a reputable molder, but after about five years, the molder had limited success and could not produce the part represented in the drawing.
They were seeing about 30% IV loss with consistency issues. To assess part functionality, a secondary operation was required to heat and bend the part into the final shape/orientation. This secondary process sacrificed further IV loss and introduced stresses into the product, causing more inconsistency. The molder was unable to produce reliable test results to allow for successful proof of concept.
With quality being the customer’s top priority, they needed to transition to a different path. They reached out to MTD.
One of MTD’s first steps was to create a custom tool. With an extremely challenging design so complex that it took approximately two months to design the mold—much longer than the usual one-week design process. Typical side action clearance for steel movement is approximately .125″ to eject the part out of the micro-mold, but this complex design allowed for only .001″ per side of clearance. Creative side action techniques were also utilized to accomplish proper part ejection from the tool.
By guiding the customer through material characterization and developing the unique tooling construction concept to reduce secondary operations, parts achieved minimal and consistent IV loss and are much more consistent shot to shot. This confidence in the repeatability of device function allowed for reliable testing and successful proof of concept to take place.
Tips for Working with Molders for Bioabsorbable Success
- Involve your micro molder as early in the project as possible. Involve your molder at material selection.
- Lean on your expert molder and their knowledge with materials, processing, strategy, techniques, and development requirements to get the best outcome possible, in the least amount of time.
- Understand the requirements of your part in terms of consistency. The two things we have found to be most important to our customers with bioresorbable products:
- Consistency. The percentage of IV loss is often less important than achieving consistent IV loss.
- Control. Select a molder with in-house processes and equipment to support the development and measurement of the bioabsorbable molding process. It is imperative for a molder to have a means for establishing a baseline and performing internal testing.