Melt mass flow rate, also referred to as melt index, is the melt flow of resin melt through a standard capillary within a certain period of time (usually 10 minutes) in a standard melt index instrument at a certain temperature and pressure. Feed gram, unit is g/10min. Melt flow rate is an important reference for the selection of plastic processing materials and grades. It can make the selected raw materials better adapt to the requirements of processing technology and improve the reliability and quality of products.
The flow index meter is based on the test method of GB/T 3682, which is used to determine the fluidity of thermoplastic polymers at high temperatures, such as polyethylene, polypropylene, polyoxymethylene, ABS resin, polycarbonate, nylon fluoroplastics and other high molecular polymers . GBB-R type adopts industrial PLC programmable controller, LCD operation platform display operation, temperature control plus temperature control unit; the machine is divided into manual, time control and automatic cutting methods from the operation mode, and can realize mass method (MFR) and volume Method (MVR) two test methods, which can measure the melting density temperature of raw materials during testing. The system also features temperature calibration.
Test principle:
The melt flow rate Tester uses a high-temperature heating furnace to make the measured object become molten under the specified temperature conditions. The test object in this molten state is subjected to an extrusion test through a small hole of a certain diameter under a specified load. In the production of plastics, the melt index is often used to indicate the physical properties of polymer materials such as fluidity and viscosity in the molten state. The so-called melt flow rate refers to the mass or volume converted from the average mass or volume of each extruded sample into 10 minutes.
experimental method:
1. Turn on the power of the instrument, enter the main operation interface, click "melt" to enter the password, click "OK", and then click "melt" to enter the temperature control setting interface. If you feel that the temperature is deviated, you can choose to modify the temperature, (for example: the temperature is low) 2°C, click to enter, enter -2, if the temperature is 2°C higher, enter 2)
2. Click "Settings" to enter the parameter setting interface, and set the "test time", "set temperature", "nominal load", "measurement displacement" and "lower limit of displacement" of the experiment in sequence (the lower limit parameter is "measurement displacement" " Minus the length to be extruded" and other parameters. The test time and the lower limit of the displacement belong to the judgment conditions. When one of the conditions is reached during the test, it will be cut automatically.
3. After the parameter setting is completed, click "Parameter Setting" to return to the main interface.
4. Click "Temperature Control" to control the temperature and control the temperature to the set temperature. Click Clear to return to zero.
5. After the temperature reaches the set temperature, add the material manually until the scale line on the piston rod is exposed.
6. Click "Run" to run the experiment. Apply load weight to piston until "measured displacement" is reached and automatically cut off front end waste. The experiment starts timing. (If the set time is used as the judgment condition, it is better to set the "lower limit of displacement" to 0, and it will be automatically cut when the set time is reached. This section is the quality of extrusion within a certain period of time. After the experiment is over, the instrument will automatically Extrude the remaining material. If the extrusion length is used as the judgment condition, the "test time" setting should be greater than the time required to extrude the length. When the piston rod drops to the "lower limit of displacement", it will be automatically cut off. After the experiment is over,
7. After the experiment, the melt volume flow MVR can be read directly. If the melt mass flow rate MFR is also required, it is necessary to weigh the waste slag obtained in the experiment, and input the weight of the waste slag to obtain the result. Clean and turn off the instrument.
8. If this experiment needs to be repeated many times, you can predict whether the material in the barrel is enough to feed according to the judgment conditions; if there is enough material for the next experiment, remove the weight after automatic cutting in step 6, and press step 7 Calculate step by step and record the result.
9. According to the current piston height, return to the parameter setting interface and set "measurement displacement". If time is used as the judgment condition, return to the test interface directly and repeat steps 6~7. If the extrusion length is used as the judgment condition, set the "lower limit displacement", then set the interface, and repeat steps 6~7. If the material is insufficient, add it after the remaining material is squeezed out.
