Melt Flow Index Testing – Why it is Important for Plastics?

Melt Flow Index Testing – Why it is Important for Plastics?

What makes plastic so popular among people? Its flexibility to fit into any application makes is the first choice. It can be easily molded into any shape and recycled. You can find polymers in the wide range of colors, which eliminates the need to die according to the application. For instance, a toy manufacturer doesn’t have to do the dying process because he can get colored polymers. He just needs to mold it into different shapes. Melt flow index is the property of the plastic that which for of plastic is suitable for which application. A Melt flow index tester determines the flowing property of the plastic.

Why is it important to test properties of molten plastic?

Viscosity is another property of plastic that is important to measure to check its suitability of the product for the particular application. But why it is important to measure the fluidity properties of plastics? Plastic is often used after melting it down. A manufacturer should know how his raw material would behave when he actually starts processing it? This would help him choose the best raw material for his production line. There are huge resources available to know what specification are required for which applications. But you cannot know the exact values unless you perform the test. For instance, you cannot judge the melt flow index of polymer just by looking at it unless you melt it to test it using a standardized machine.

How to check the melt flow index?

Presto offers instrument named Melt flow index tester to determine the properties of molten plastic. In this lab testing instrument, you put granulated plastic in a hot barrel. This hot barrel can take temperature up to 400°C. As soon, plastic starts melting, it tends to come out from the orifice placed at the bottom of the barrel. This orifice is designed as per the standards released by the regulatory organizations. Simultaneously a timer is running. This test will run for 10 minutes. After 10 minutes an auto cutter will cut the string of molten plastic coming out of the orifice. You need to measure the weight of the molten plastic that came out, the MFI is equivalent to the weight of plastic. You can see a mirror is placed on the platform to inspect the output of the barrel.

Now, this test sounds very simple, but you need to take many precautions while performing this test. First, make sure that barrel is fully packed with the granules. Any space in the barrel may lead to inaccurate results. Before testing a sample, you have cleaned the barrel properly so that no two plastics get mixed together.