Keys To Success In Medical Micro Molding

It’s no secret that medical devices are getting smaller. Implants, tubing and drug delivery systems now often require injection molders capable of fabricating parts at a micro level. The smaller the part; the more complex the injection molding process since material behaves differently in smaller shot sizes. Forefront Medical Technology, a specialty contract manufacturer with a focus in disposable diagnostic, drug delivery systems and medical device systems, has experience with both standard and micro molded products. This white paper describes the product development and process complexities found in micro molding in greater detail, plus looks at how these capabilities were successfully applied in a recent micro molding project.

Standard Injection Molding or Micro Molding—What’s the Difference?
From a non-technical perspective, the logical assumption is that micro molded parts simply require a mold with smaller cavities. The reality is that there are significant differences between the processes including:

• Equipment and molds must be carefully matched
• Smaller shot sizes and specialized material require higher melting points and faster cooling
• cycles, which impacts material selection for molds, along with the mold design
• Process development often requires multiple design of experiments (DoE) to determine
• optimum settings for all variables within the process
• Specialized material cost can run several thousands of dollars per kilo so there must be minimal
• waste
• Small size limits the ability to rework after molding, so quality must be consistently high
• The mold fabrication and qualification process is significantly more complex and requires longer lead-time compared to a standard mold.