Checking the tightness of packaging by immersion and observation of bubbles.

ASTM D3078 is a standard test method for determining gross leakage in flexible packages containing a headspace gas by bubble emission. The test is performed by submerging the packages in water inside a vacuum chamber, and the positive pressure inside the package after evacuation can force the package to plug small leaks.

Control Sensei is a testing laboratory that can guide companies through the process of complying with the requirements of ASTM D3078.

Test procedure in accordance with ASTM D3078

In order to be tested under the best conditions, the samples must contain a maximum amount of air or modified atmosphere (MAP).

It is this air which, under the effect of the negative pressure, will increase in volume and apply stress to the sealing elements of the packaging.

The samples are placed in the chamber, which is filled with water. The holding grid keeps the samples submerged when the bonnet is closed.

Once the samples are in place, we start to generate the vacuum in the chamber.

The standard does not specify the vacuum level required to perform the test. The preliminary tests will determine the test parameters. We need to determine the maximum vacuum level before the product explodes. Once this vacuum level has been precisely determined, we will work at 75% of this maximum level to obtain meaningful results.

Under the effect of the vacuum, if a leak is present, a column of bubbles forms.

The test time will also be determined by the characteristics of the packaging: volume, materials, packaged products, etc.

The standard tells us that this level of vacuum must be maintained for a minimum of 30 seconds.

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