Melt Flow Rate is the best property that indicates the viscosity of the polymers in the molten state. It is expressed as the weight of the polymers in grams which flow out in a period of ten minutes through a capillary tube of specific length and diameter with the pressure which is applied with the standard weights at specific temperatures. Measuring the Melt Flow Index of Plastics is the simple test procedure that helps to measure the viscosity of the polymers that can be calculated very quickly with the help of testing instrument “Melt Flow Index Tester”. Moreover, the Melt Flow Index value is the symbolic of average molecular weight of the polymers, is using the two different values of MFR when calculated from two different weights and this is known as molecular weight distribution.
The test helps to determine the melting density of the polymers which is an important parameter in the overall estimation. Melt Flow Rate explains one of the most frequently used test in the plastic manufacturing industries to control the quality of the incoming materials as it requires little operator training to provide the appropriate results. Some manufacturers make use of the abbreviation melt volume rate (MVR) instead Melt Flow Rate. Melt Flow rate is an indirect measure of molecular weight which helps to calculate the high MFR corresponding to the low molecular mass. Same time, the MFR is a measure of the ability of the polymers to flow under a particular pressure.
The Melt Flow Rate of plastics is inversely proportional to the viscosity of the polymers at different test conditions although it is naturally in the mind that the viscosity of the polymers depends on the applied force. MFR is commonly used for the polyethylene, polyolefin that are measured at the temperature of 230 degree Celsius and 190-degree celsius respectively. The manufacturers in plastic industries should choose the best quality of polymers that must have a high melt flow index to convert the polymers easily in the material form but same time, if the mechanical strength of the material produces is less, it will be best to use as it can be shaped into any size and design easily.
Significance of Calculating Melt Flow Rate of Plastics
- It is the best and easy to use test method to measure the strength and quality of the polymers.
- It is best to test method to measure the average molecular weight of the polymers,
- Melt Flow Index Test helps to measure the viscosity of the melted plastics,
- It is the best indicative to determine the accurate distribution of molecular weight.
- The test is very easy to implement the test.