Importance of COF Testing in Flex Packs

Importance of COF Testing in Flex Packs

In flexible packings, estimating the stacking friction is very important. Failing to do so would result in slippage of packets in warehouses or in the supermarket shelves. Such a packing can be declared as failed packing as it does not support the intended working conditions. This is why Coefficient of friction is measured so that flexible packing can be altered to fulfil the conditions. The COF testing helps to determine two values, i.e. Static friction and Kinetic Friction. 

Static energy is the determination of the energy required to start the motion.
Kinetic energy is the determination of the resistance against motions. 
There are many factors that contribute to generating inaccurate test results. Thus, a lot of precision and care is required when performing this test. The biggest factor is foreign particles stick to the specimen surface. Thus, it is important to clean the specimen surface and the coefficient of friction tester apparatus before starting the test. The standard test method ASTM D 1894 is the best. With this, film manufacturers can assure best test results.
Test procedure
The apparatus has a movable block attached to the pulley. Two specimens from the same sample are required. One specimen is wrapped around the movable block and other will be placed on the platform. It has to be made sure that both the samples are facing towards each other. As the test begins, the pulley starts to move the block on the sample. The resistance against the movement is measured by the sensor. This signal is processed and displayed on the screen in human-readable form. This obtained value is the coefficient of friction. 
Apart from plastic film flexible packing, this test determines the COF of other materials like paper, pipes, plastic sheets etc. This test highlights a very important factor of packaging industry that can reduce the rate of accidents considerably. During transit, due to excessive slippage, there is a possibility of the spoilage of the whole lot, as packet bursts due to slippage and free falling. Also, it highlights the uneven friction observed on the surface which is caused by the uneven plastic deposits. Presto is the leading manufacturer and supplier of COF tester. Apart from this, we offer a wide range of other paper testing equipment that helps in identifying different properties of the paper and packing. Contac our experts today and ask for testing instruments suitable for your industry. 

To know more information about its features, price, and technical specifications, give us a call at +91 9210903903 or email us at

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