Challenge

A medical device manufacturer faced a growing number of field complaints involving cracked connectors during device use and storage. The component, originally molded from Acrylonitrile Butadiene Styrene (ABS) polymer was exhibiting environmental stress cracking (ESC), leading to potential sterility breaches and clinical usability issues. The failures were sporadic and not evident during standard in-process quality control, making the issue difficult to isolate

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Chemva’s Solution

Chemva launched a structured root cause investigation, beginning with a systematic review of all possible chemical, mechanical, and environmental exposures the connectors could experience from manufacturing through clinical use.
Our review considered:

• Residual stress from molding
• Reviewing list of all potential chemicals/formulations interacting with the ABS part
• Mechanical loads from connections and torquing

We then designed custom benchtop experiments, exposing ABS parts to combinations of stress and chemical agents that mimicked real-world scenarios. Under this simulated environment, cracking consistently occurred under a certain stress level, confirming ESC from isopropyl alcohol exposure as the root cause.Through iterative mechanical testing and compatibility assessments, rigid polyurethane emerged as the optimal replacement, balancing strength, moldability, biocompatibility, and resistance to cracking under alcohol exposure.

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Impact Delivered

Chemva’s systematic approach not only resolved the cracking issue but also enhanced the product’s long-term reliability and manufacturability. By selecting a validated alternative material, the partner prevented further field failures, avoided a costly recall, and achieved regulatory acceptance for the material change with minimal disruption. The improved connector has now been in the field for over two years with zero reported failures.