PET Bottle Cap Torque Testing

In this case study, Mecmesin supplies highly accurate and easy-to-use digital torque testers for Áqua de Luso, one of Portugal’s most famous names in mineral water, to guarantee the quality of their packaging.


Água de Luso‘s mineral water is packaged in a variety of sizes of plastic (PET) bottles. The caps on their bottles must be easy to open, while at the same time applied tightly enough to ensure the bottles do not leak. To guarantee the quality of their packaging, Água de Luso wanted to test the slip torque and bridge torque on their tamper-evident bottle caps.

They acquired five Mecmesin Tornado digital torque testers to precisely quantify the torque applied to the bottle caps. The easy-to-use 10 N.m capacity Tornados have proven to be a good choice for Agua de Luso.



  • Simple and quick test with operator control
  • Clear and immediate peak torque indication
  • Indication of initial TE bridge torque
Application torque is checked by removal torque measurement with short dwell times


To ensure quality and consistency, Água de Luso tests its bottles for compliance with company standards. At routine intervals, operators at the bottling plant in Luso place filled bottles onto the Tornado digital torque tester, and the cap is tested for ease of opening and tightness of the seal. Before Água de Luso purchased the Tornados, torque testing of bottle caps was performed using a less accurate analogue gauge-based manual testing device.

The Tornado’s digital torque capture technology, combined with clear, intuitive controls, onboard memory to keep statistical results, and easy-to-read pass/fail parameters, offers far greater accuracy and ease of use.

Água do Luso commends the Mecmesin Tornado digital torque tester for its accuracy, portability, and simplicity of use, and praises the technical support and efficient calibration service provided by Mecmesin’s distributor in Portugal, Egitron.

For Água de Luso, the rewards of the Tornado closure torque testers are obvious; ensuring customer satisfaction with cap openability, while retaining the integrity of their packaging and avoiding quality-related problems.

Miguel Carvalho, Quality Assurance Manager at Água de Luso, commented: “Mecmesin, through their Portuguese supplier Egitron, presented us with a good solution: reliable equipment and user-friendliness that was adequate for our needs. All our operators are capable of using this equipment because it is very simple to operate. I enjoy dealing with Egitron because they offer excellent technical support.

Test equipment


Globally many manufacturers of plastics and rubber materials, components and finished products use Mecmesin test equipment to ensure their quality, strength, performance and usability. For more examples Mecmesin test equipment in use in the plastics and rubber industries, visit the Mecmesin website.

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Mecmesin Limited
+44 (0) 1403 799 979

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