How to Check Melt Flow Rate?

How to Check Melt Flow Rate?

Usage of the polymer has exceeded a lot due to increased applications of plastic products. Due to cost-effective nature and strong other properties like recyclability, food-grade varieties, environment barrier and so on. Choosing the right plastic is an intricate task. A plastic is tested on different properties for different applications. Melt flow rate is one major property that is tested for choosing the raw material for any application. The melt flow rate is defined as the rate of flow of polymer in a molten state. It is very important to decide the extrusion process to be incorporated in the manufacturing process. Not only for selecting the right material, but it is important to know the MFR to understand and plan the disposal of the product and its behaviour under different circumstances. For instance, in case of fire mishap. It will be dangerous for people trapped in the fire to avoid the molten plastic which is flowing at the high rate.

Melt flow index tester is used to check the MFR of the polymers.

Standard Operating Procedure

To test the flow rate, first of all, the sample has to be in granulated form. The machine comprises of a barrel which is charged with the granulated plastic. It is to be assured that there is no empty space in the barrel. A specified load is applied on the granules using the piston. It is very important that the machine is kept in a levelled floor, otherwise, the readings would be inappropriate. A plumb line is provided with the machine for checking the level of the surface.

As the barrel starts heating. The granules start to melt. There is a die or orifice provided beneath the barrel for the outflow if the molten plastic. The orifice has defined dimension according to ASTM.

ASTM D1238 and ISO 1133 are the most common standards for melt flow tests and define the equipment specifications, as well as test methods.

The molten plastic comes out from the barrel in the form of a thin string. The molten plastic comes out from the barrel in 10 minutes is weighed and the value got after the measurement is the MFR of polymer in g/10mins.

Presto offers multiple models of Melt flow index tester with varied features. Depending upon the industrial requirements features can be chosen. Call our experts to share your requirements, they will help you in choosing the best model as per your specifications.