Although the standard does not specifically address this, I believe that it is a good idea to perform all of your testing using the same seal parameters.  That being said, I would recommend performing this testing using the same parameters as the performance testing.

If the procedure is FDA approved than I would see no reason why you could not use this methodology. There is a list of approved standards on the FDA Web site.  If this is not on the site, then you may need to perform an internal validation showing it is better to support your cause for using this test method.

We purchased our materials form Consolidated Electronic Wire / Cable but a simple Web search will give you multiple suppliers.  Some of them do not manufacture wire this small.  I don’t know that the material of the wire is critical however stainless would be ideal because it will not rust over time.  It might be difficult finding stainless wire of this size.

There is no minimum seal thickness for a rigid tray in the industry.  The minimum thickness required is whatever is needed to achieve and maintain your desired strength and integrity criteria for your packaging.

This is a difficult one in that there are some test methods you could use for these containers, but none of them will have been validated by ASTM because they are only guidance documents. The test is a pressure differential test, which is performed by internally pressurizing the container using water. You can reference section 12 of ASTM D4919 or Title 49 CFR 178.605 to determine how the test is performed. This should allow you to qualify the bottles for shipments.

In regard to the test method validation, perhaps you could use a torque setting that is less than your specified torque range to show that the samples will fail if not torqued properly.

You could also perform the test using vacuum but it would require the use of a vacuum chamber large enough to accommodate a 20 L carboy.  Again, the only way to validate this methodology would be to use the torque spec and check bottles that have been improperly torqued.

Performing a side-by-side test method validation will give you the answers you are looking for.  Use a predetermined sample population, having both positive and negative controls within it (0.002 in per the standard for the positive controls), and testing all of the samples using both solutions per the standard.  If the results are the same, then you can use the food coloring solution.

Positive migration would be the forcing out of atmosphere inside of a package by internally pressurizing the package (blowing it up like a balloon). The negative migration would also be the forcing out of atmosphere from the package, but it is done by changing the atmosphere outside of the package (vacuum test simulating an airplane environment when pressurization is lost). This could potentially draw in the outside atmosphere at equilibrium.

A more simple explanation might be that positive migration pushes out atmosphere while negative migration draws in atmosphere.

There is no industry standard, as it pertains to the number of samples required for a test.  This is based on the statistical confidence that you would like for your sealing process. My belief is that many of our customers use the sample size of ten samples for a lot-to-lot comparison.

I would suggest sticking with the 0.002-in. wire since that is the sensitivity of the standard. Perhaps there is a gage block of this size out there, which might make it easier to extract the standard from the package. We typically use a wire, however that has been used on mostly pouch samples and not a tray, and we have not seemed to have this same problem. An alternative contact on this might be to speak with the technical contact of the ASTM F1929 standard. This information is readily available on the ASTM Web site and is accessible to the general public. This individual could probably give you some insight as to how they did this during the Precision and Bias for the standard.

Yes, you should be performing an internal study to show that your internal process that you have set up for seal-strength testing remains consistent.

This would hold true especially if multiple technicians are performing seal-strength testing. It would be very important to verify that the process is being performed identically, data generated by the multiple technicians remain consistent, and variability is kept to a minimum.