How is melt flow index measured?
1 Melt Flow Index. The melt flow index (MFI) is a measure of the ease of flow of the melt of a thermoplastic polymer. It is defined as the weight of polymer in grams flowing in 10 min through a die of specific diameter and length by a pressure applied by a given weight at a given temperature.
What is MFI test write down its process?
The test measures the melt flow properties of resins (in g/10 min) at a particular shear stress (related to applied load) and temperature. The test is done with an extrusion plastometer, which is often referred to as a melt indexer. It is used to test virgin, compounded, and post-process thermoplastics.
What is melt flow testing?
A melt flow test measures the melt flow rate (MFR) and melt volume rate (MVR) of a molten polymer. Values are taken at a certain temperature and with a certain mass applied, dependant on material. The test system consists of: Temperature control of the barrel. A piston to fit in the barrel.
What is MFR testing?
Melt flow testing is simply a measure of the flow of a polymer when melted. The result of a melt flow test, called the melt mass-flow rate (MFR) or melt volume-flow rate (MVR), is defined as the amount of mass or volume of a polymer that flows through a small die at a specified temperature and pressure.
What is a high melt flow index?
Melt Flow Indexer In general, a higher MFI indicates a lower material viscosity, and when comparing polymers of the same class, a lower melt flow rate corresponds to a higher molecular weight and/or less branching.
How do you find melt density?
Dividing the mass from the MFR test by the volume from the MVR test gives you the melt density. Alternately, you can use an MFR tester to measure the melt density of a material.
What is a good melt flow index?
The melt flow index only tests the material at one shear stress, and temperature. In general, a higher melt flow index indicates a lower material viscosity. This means that a material with a melt flow index of 20 flows easier than a material with a melt flow index of 5.
What is melt index test?
This test method is used to determine the melt mass flow rate and melt volume flow rate of polymers. A polymer melt is extruded through a standard die under the influence of a defined force and temperature.
What is melt flow index used for?
The melt flow index (MFI) or melt flow rate (MFR) is a measure for the ease of flow of melted plastics. It is often used in the plastic industry for quality control of thermoplastics.
What is the difference between MFI and MFR?
Melt flow index (MFI) or Melt Flow Rate (MFR) is a measure of a given polymers’ flow characteristics also known as the Rheological properties in the molten state under a known applied pressure….Hygroscopic Polymers.
| Hygroscopic | Non-Hygroscopic |
|---|---|
| PC | Polystyrene |
| PMMA | |
| Polyurethane |
How can I increase my MFI?
You can increase MFI by mixing with some lubricant. However it may reduce mechanical properties. So it would be better to conduct a small scale experiment in advance to know the optimum amount of lubricant you should add.