What Is Melt Flow Index Tester & Why is it Important to Use MFI Testing?

Reviewed by Anurag Mishra (Sr. Technical Consultant)

Responsive image

Are you familiar with the melt flow index tester? This easy-to-use device is being widely used in industries such as Plastics, PET, and Preform manufacturing, and for good reason.

The melt Flow Index Tester measures the quality of plastic materials by examining their flow characteristics under specific conditions. In this article, we'll dive into what exactly the melt flow index tester is, how it works, and why you should consider using it for your own quality control needs.

Whether you're new to the industry or a seasoned expert, understanding the benefits of this testing method can help ensure success in your business endeavors.

So let's get started!

What is the Melt Flow Index Tester?

The melt flow index tester, also known as the MFI tester, is a device used to evaluate the quality of plastic materials. Specifically, it measures how easily molten plastic flows through a narrow tube under specific temperatures and pressures.

The test involves loading a sample of plastic into the machine's heated barrel and applying pressure to force it through a small orifice. The resulting measurement is given in grams per 10 minutes (g/10 min), which indicates how quickly the plastic material can be processed.

This testing method is widely used in industries that deal with plastics, such as packaging, automotive manufacturing, and construction. It helps manufacturers ensure that their products meet certain standards for strength and durability.

The melt flow index tester provides valuable insights into the properties of different types of plastics. By measuring their flow characteristics under controlled conditions, businesses can make informed decisions about production processes and product quality control.

How does the Melt Flow Index Tester work?

The Melt Flow Index Tester is a widely used device in the plastic industry that measures the melt flow rate of thermoplastics. But how does it work? Here is a step-by-step methodology:

  1. The basic principle behind the Melt Flow Index Tester is to measure the weight of molten material flowing through a capillary under controlled conditions of temperature, pressure, and time.

  2. The sample is placed in a heated barrel where it melts and then extrudes through a calibrated orifice.

  3. As soon as the molten polymer passes through the orifice, its weight is measured using an electronic balance. This data helps determine two parameters: Melt Flow Rate (MFR) and Melt Volume Rate (MVR).

  4. The test results are usually expressed in terms of grams per 10 minutes for MFR, while MVR uses cubic centimeters per 10 minutes. In simpler words, these values represent how much plastic can be extruded within 10 minutes.

By measuring these parameters with precision accuracy, manufacturers can ensure consistent quality control over their production processes and products.

What are the benefits of using the Melt Flow Index Tester?

The Melt Flow Index Tester is an essential tool for quality control in various industries, including plastics manufacturing. Using the MFI tester provides a range of benefits that help ensure consistent product quality and improved production efficiency.

  • One benefit of using the Melt Flow Index Tester is that it allows manufacturers to measure and monitor the flow properties of plastic materials accurately. This information can be used to adjust processing conditions, such as temperature and pressure, to achieve optimal processing results.

  • Another advantage of using this testing equipment is that it helps identify potential issues early on in the production process. By measuring melt flow rate regularly, manufacturers can detect any changes or variations in material properties that might impact product performance or consistency.

  • Additionally, using the Melt Flow Index Tester supports better decision-making by providing accurate data for the selection and blending of raw materials. Manufacturers can use this information to choose suitable polymer grades with specific melt characteristics needed for their products.

  • Using an MFI tester also enables companies to comply with industry standards and regulations more easily since these tests are required by many international organizations like ASTM (American Society for Testing Materials).

  • Incorporating a Melting Flow Index Tester into your manufacturing processes offers several advantages and optimized productivity through reducing downtime from defective batches or out-of-spec parts while ensuring high-quality output consistently.

How to use the Melt Flow Index Tester?

Using the Melt Flow Index Tester is a relatively simple process. Here are the steps you need to follow to use it:

  1. First, set up your testing apparatus by ensuring that all necessary components are in place and connected properly.

  2. Next, prepare your sample material according to industry standards. This involves cutting it into small pieces and drying it if necessary.

  3. Then, weigh out an appropriate amount of sample material and pour it into the hopper of the tester.

  4. After this, heat up the barrel of the tester to a specified temperature range as per industry standards.

  5. Once heated, load your prepared sample into the barrel using a plunger or other device provided with your specific testing apparatus model.

  6. Initiate the test sequence and wait for the results. The melt flow index value will be displayed on the machine's screen once complete.

It's important to note that each manufacturer may have slightly different instructions for their specific Melt Flow Index Tester model. Therefore, always refer to instruction manuals before operating any equipment.


The Melt Flow Index Tester is an essential tool for industries that require consistent quality control of their plastic materials. This testing machine measures the flow rate of thermoplastics and can provide valuable information on a material’s viscosity, molecular weight distribution, and processing behavior.

By using the Melt Flow Index Tester, manufacturers can ensure that their products meet industry standards and regulations. The MFI value obtained from this testing equipment helps in optimizing production processes to achieve desired properties such as stiffness or flexibility in end-use applications.

If you deal with plastics manufacturing or supply chain management related to plastics materials, then understanding the importance of melt flow index testing will be highly beneficial for your business's success. So, invest in a reliable MFI tester today and take advantage of its many benefits!

For further assistance, contact https://www.testronixinstruments.com/. Testronix Instruments offers a wide range of Lab Testing Instruments including the Melt Flow Index Tester. Testronix Instruments are relied upon for being durable, profitable, and highly accurate for quality testing. The instruments are made with the latest development and consequently are prepared for giving the best level of accuracy of testing data and giving repeatable results.

Contact Us
Related Blogs