Dynamic Testing To Test Packaging Containers

Numerous testing strategies are followed to test the effect of transportation conditions on packaging containers. One of the major tests perform on the packaging products is the impact of continuous vibration. This can be tested efficiently with the help of vibration table. The vibration tester machine is designed to scientifically simulate the vibrations and jolts subjected to various filled containers during the transportation, within the laboratory. The machine is based on the guidelines provided in ASTM D-999, TAPPI T-817-pm, and IS7028 (part II).

Why the need of Dynamic Testing Arises?

The packaging containers are designed to fulfill the purposes of packaging and transportation and to fulfill the chief purpose of physical protection to the content which is packed inside. Normally the transportation is by road, rail, sea, and air, either by single or by various amalgamations of these modes. At the time of transportation, the packaging containers are subjected to the different vibrations and jolts of varying intensities. It is quite tough to create these vibrations in totality. That is why vibration tables are used to create the actual vibration conditions inside the laboratory for the purpose of testing. The vibration tester offers best means to determine the effect of vibrations on the packaging products and helps to conclude that how the material will behave during the product distribution. The test is performed to measure the performance of the containers in terms of strength, protection when subjected to vibrations that occur during transportation.

Calculation

Acceleration = amplitude x w2

                        Where w = angular velocity in rad/sec (2 x PI x frequency)

How Presto’s Vibration Table is different?

Presto® Vibration tester is rigidly fabricated from MS structure. The upper tabletop is suspended for vibration by bearing blocks. The fixed amplitude of 25.4mm is generated using cam assembly. The frequency of vibration can be varied using the panel box from 2 Hz to 6 Hz. The machine can generate the vibrations in three modes viz.

• Synchronous vibrations that are, both the cam assembly is in phase, and the tabletop ends moves simultaneously in circular motion.
• Non-Synchronous or out of phase, that is the cam assembly is not in phase with each other. One end of the table moves out of phase with respect to the other, in circular motion
• Vertical, that is, Table Top move purely in up-down motion eliminating the lateral elliptical movement

The position of the locating Pins and chain sprocket selects the mode and motion of vibration. The locating pins should be replaced (removed and inserted in another position) one at a time to change the motion of vibration. Changing the position of locating pin will change the vibration motion from vertical to circular. There are four holes (0, 30, 60 & 90 degrees) in the cam plate.

When a hole in the cam plate is bolted with the sprocket, it changes the relative position of the rear cam assembly with respect to the front cam assembly. At 0 degrees, the mode of vibration is synchronous and at other positions, the mode is asynchronous respectively.

The machine is supplied with the panel. The input to the panel is 220V, 1 Ph, 50 Hz. The output from the panel is supplied to the electric motor, which then drives the vibrating table through a set of pulleys. The frequency of the table can be varied, by the arrow keys provided on the panel, from 0 to 6 Hz. and are displayed on the panel. A timer is also provided on the panel to set the test duration.