Verification failures, like label adhesion issues during water submersion testing, highlight the need for a structured problem-solving approach. Conducting a root cause analysis using methods like the 5 Whys or Fishbone Diagram can help identify whether the problem lies in material compatibility, surface preparation, or application technique. For instance, if the labels were not designed for prolonged water exposure, exploring water-resistant adhesives with the vendor might be necessary. Additionally, assessing whether the ethanol wipe is effectively removing contaminants or altering the bottle surface is crucial. Before recommending design modifications, it would be prudent to perform additional testing, such as varying drying times or applying labels with different pressures, to pinpoint the exact cause of the failure. How do you think iterative testing can help refine the verification process and ensure robust product performance?

I agree that it is unwise to jump to design modifications without performing additional tests. It is necessary to pin point where the problem is before trying to solve it. I agree with the above idea that the ethanol wipe should be scrutinized to find out whether it is sufficiently cleaning the bottle surface. I'd like to add that testing the label in different water temperatures could be useful to figuring out the root of the adhesive failure. It could also be useful to allow the adhesive more time to sit before it is submerged in water. These are examples of two tests I would hope would be executed prior to suggesting any design changes. 

Label adhesion failure during water submersion testing presents a multifaceted challenge that requires a structured root cause analysis before considering design modifications. A key factor to investigate is the material compatibility—is the label adhesive specifically formulated for prolonged water exposure, or is it degrading under test conditions? If material incompatibility is suspected, collaborating with vendors to explore water-resistant adhesives or coatings may be necessary. Surface preparation is another critical variable; ethanol wiping could be altering the bottle’s surface energy, negatively impacting adhesion. An alternative cleaning method, such as isopropanol wiping or plasma treatment, might enhance bonding. Additionally, environmental conditions during application must be scrutinized—temperature, humidity, and pressure at the time of labeling can influence adhesion strength. Conducting iterative testing using Design of Experiments (DOE) would help systematically evaluate these factors by isolating variables such as drying time, pressure, and surface treatment. Moreover, an accelerated aging study could simulate real-world conditions, revealing whether adhesion deteriorates over time due to humidity, temperature fluctuations, or UV exposure. Testing in varied water temperatures and pH levels might also expose hidden vulnerabilities. Lastly, mechanical stress factors should be considered—if the labels experience strain due to container flexing, adjustments in label material flexibility or adhesive elasticity could be required. Given these considerations, what additional verification tests do you think could provide further insights into ensuring long-term label adhesion performance?

When dealing with verification failures in a project, I always find that a structured problem-solving approach is the best way forward. In the case of label adhesion failure during water submersion testing, the first step should be a thorough root cause analysis—tools like the 5 Whys or a Fishbone Diagram can help narrow down the issue.

One of the first things I'd check is the adhesive properties of the label material. Were these labels specifically designed for prolonged water exposure? If not, it might be worth reaching out to the vendor to explore water-resistant adhesives. Another possible issue is surface preparation—does the ethanol wipe actually remove contaminants effectively, or is it altering the bottle surface in a way that reduces adhesion?

Before jumping to design modifications, I’d want to run additional tests. Maybe varying drying times, adjusting the application pressure, or trying different cleaning methods could provide better insight into what’s going wrong. The key is to test systematically before making big changes.

References:

ASTM International. (2021). ASTM D903 - Standard Test Method for Peel or Stripping Strength of Adhesive Bonds.

Yes, before recommending design modifications, additional testing should be performed to validate the root cause of the verification failure. This helps ensure that any design changes are based on data rather than assumptions.
Recommended Steps:

1. Conduct Root Cause Analysis
   • Use the 5 Whys or Fishbone Diagram to systematically identify possible causes.
   • Categorize causes into material, method, measurement, machine, environment, or personnel-related factors.
2. Design Focused Experiments
   • Vary drying times: If adhesion or material integrity is a concern, testing different drying durations can confirm if inadequate drying is the root cause.
   • Apply labels with different pressures: If label adhesion is the issue, testing multiple application pressures can help determine the optimal force for consistency.
   • Environmental Testing: Consider humidity, temperature, or surface contamination as potential contributing factors.
3. Analyze Results Before Modifying Design
   • If parameter adjustments resolve the issue, design changes may not be necessary.
   • If failures persist, consider redesigning components based on collected data.

It is crucial to start medical technology product development with a clear definition of requirements. The team must explicitly delineate the intended product claims, identify the target practitioners for the use of the product, define the environmental constraints, and of course, assess the appropriate risk profile to drive the class designation. Even more critical than in commercial or consumer products, failure to define requirements early and clearly results in burning capital and lost time. Failure to identify or needing to modify requirements downstream on projects can also impact the architecture, risk profile, and validation/verification plans. It may require going far back into the design to assess and document the impact to claims and how they will be verified and validated. For this simulation example we can alter material, method, environment and process variability.

Ref:

1) https://www.biopharmadive.com/spons/how-to-eliminate-design-verification-failure-for-your-next-device/620356/

2) https://safetychain.com/blog/root-cause-analysis-informs-capa#:~:text=The%20root%20cause%20is%20why,to%20prevent%20the%20proble m's%20reoccurrence.

@amm7 To add on to your potential test, it may be better to test if the label does better on a flat surface or a curved surface. If the testing is done on a curved surface, it may cause problems such as the label experiencing tension at the edges, the label seems to fit at first because only the middle part is the only part bonded to the surface adequately. This all leads to curved surfaces tending to be penetrated by water easier than flat surfaces, which should be considered for a additional test before considering changing adhesives.