Published: 2016-02-29   Views: 1927
Author: prestogroup
Published in: Advertising
How Can MFI Be Calculated Accurately?

Melt Flow Index Test is used among different segments of the plastic industry. The problem arises when two types of plastics easily come up with different results that make it difficult to determine whether a material meets required Melt Flow Index Specifications or not. Here are some factors  that cause the occurrence of discrepancies need a specific time to think about them?

Melt Flow Index also known as the Melt Flow Rate that determines the melt flow properties measured in grams per 10 minutes of material at some specific shear stress according to the applied force and temperatures. The extrusion plastomers also known as melt flow index testers is used to determine the Melt Flow Index of virgin, post processed thermoplastics.

The Melt Flow Test is used widely in the different segments of the plastic industry. Testing suppliers usually look for MFI variations as a Quality control check to detect and troubleshooting variations in the compounding processes and polymerization. As a part of their material inspection procedures, some processors are used to determine the amount of recycled material that can be used in their product to maintain the specifications of the end products. The problem arises when the laboratories can come up with different results and makes it difficult to determine whether the material meets the desired specification of melt flow index. Here are certain reasons why such problems occur and what can be done about them.

Know Your Standards for Better Determination of MFI

  • ASTM D1238: Standard Test Method for Melt Flow Rates of Thermoplastics by Extrusion Plastometer
  • ISO1133: Determination of the Melt Mass-Flow Rate (MFR) and Melt Volume-Flow Rate (MVR) of Thermoplastics.

Both the standards are introduced to measure the property of the plastic resins, but slight procedural and equipment differences can return different results. Both offers a manual means and automatic means for flow measurement. But if the test is performed according to both the standards identically, the results will be different.

There is no consensus to which the method is best, and there are some guidelines that can be used to make a choice. No matter which procedure is selected, it is common for the organizations to test the required material and come up with two different test results, setting off a search to determine the reason for the difference.

There are numerous factors  that affect the accuracy and precision of a test. Is MFI testing machine in good working condition? Has the machine completely calibrated by the certified metrologists for measuring the temperature, physical dimensions, time and distance accuracy? Is the machine clean? Are the operators properly trained and following the standard operating procedure to perform the test?

The changes of obtaining accurate and precise test results can be increased to a great extent by following proper testing procedure and testing requirements for machine verification and by periodic testing of controlled materials. ASTM D 1238 offers best troubleshooting guide to sort out all machine related problems and helps the extruders to perform the test in easy and efficient manner. 

Author Bio

I am professional content writer working with Digital Marketing Agency in the UK.

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