How to Check Quality of PET Bottles?

PET bottle act as a strong barrier against water, moisture, light, other environmental factors and has non-reactive properties. This has made PET bottles favourite form of packing for the beverage industry. Carbonated and non-carbonated drinks are safe inside PET packings. But what make them so reliable? Different industries conduct different tests in accordance with expected working conditions.

For instance, packing for carbonated drinks are tested with GV shaker to investigate if the bottle would be able to sustain the carbonated pressure that is forming inside due to shaking. But this test is not performed when non-aerated drinks are packed with energy drinks, juices, etc. Some tests are performed in every beverage industry, irrespective of nature of inside contents.

Bottle burst testing – In this test, a bottle is clamped inside the cavity of bottle burst tester. This test can be performed in two ways, proof test and resistance test. During the proof test, a predefined pressure is created inside the bottle and made to hold it for a predefined time. This helps in investigating that for how much time it could bear the pressure without getting damaged. For resistance test, the pressure is kept on increasing and the point at which bottle bursts is assessed as the standard for that sample.

Torque testing – How much rotational force is required to open the bottle cap is measured by a torque tester? Neither too loose nor too tight, should the cap be conveniently opened by intended user only. A bottle to be tested is mounted on the torque tester. To avoid any slippage, anti-slip pegs are provided. The cap is opened by the operator. The force applied by the operator is sensed by a torque sensor and displayed on the screen which is torque measurement.

Top load testing – How the bottle will behave when subjected to weight on it, is determined by the top load tester? This test is again performed in 2 ways; proof test and resistance test. The proof test determines the behaviour of bottle when a predefined load is applied if it shows any deformity or not. In resistance test, what is the load bearing capacity of the bottle when subjected weight is increasing constantly? A top load tester machine is used for this purpose. The load will keep on increasing until buckling appears.

Vacuum leak test – This test is performed to check any leakage after the bottle is blown moulded. The bottle is placed inside the vacuum kit and vacuum is created and hold for a defined time. If the bottle collapse when the vacuum is released, it is faulty.

For more information about bottle burst tester, top load tester and vacuum leak tester, contact us.