Heat seal strength test

ISO11607-2 (Validation requirements for forming, sealing and assembly processes), requires Performance Qualification (PQ) of packaging devices to be carried out and documented. During PQ proof must be provided after sterilization that the process is under control and produces optimally sealed or closed sterile barrier systems.

Verification is being done by means of a heat seal strength test as per EN 868-5. The heat seal strength test is a test which validates the sealing process. By testing the sealed pouches one tests the combination of the packaging material and the heat sealing process. If the results are good, then it can be concluded that he sealing process went well too.

The test is being carried out as follows:

  1. From each seal that needs to be tested, a length of 15mm is being cut. At least one sample of a produced seal seam must be taken from each packaging. In case the length of a seal is more than 500mm, additional samples may be needed.
  2. The laminate foil is being separated from the paper at a speed of 200mm/min by means of a calibrated strength testing machine
  3. The resistance of the seal is being indicated in N/15mm

The results of the heat seal strength test are being indicated in a report and the resistance is being shown in a graph. In compliance with EN 868-5 the maximum strength must be at least 1.5N/15mm width. We advise you to get this test performed every six months in order to guarantee that your sealing machine will continue to comply with the standards as mentioned above. We recommend to perform this test in the following cases:

  • When new packaging material is going to be used
  • When maintenance of the heat sealer has taken place
  • When a repair of the heat sealer has taken place

In case you want us to perform a heat seal strength test, we kindly ask you to send us the packaging material, so we can perform these tests. In this case, it is important to indicate the following on the packaging which you want us to test:

  • Brand of the heat sealer that has been used
  • Type of the heat sealer that has been used
  • The serial number of the heat sealer that has been used
  • The temperature that had been set when the packaging material was sealed
  • The brand and specifications (like the dimensions) of the packaging material that needs to be tested