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What is Melt Flow Index Tester? How does Melt Flow Index Tester work ?

What is Melt Flow Index Tester?  

Melt flow index tester DW5450A/DW5405B meets all dimensional temperature control and performance specifications of GB/T 3682-2000, ISO 1133:2005, ASTM D 1238. This Melt Flow Indexer can be used for testing MFR of polycarbonate, fluoroplastics, as well as polyethylene, polypropylene, ABS, POM, etc but is not applicable to thermoplastics for which the rheological behaviour is affected by phenomena such as hydrolysis, condensation or crosslinking. Please read the installation and operation manual before using this instrument.

1.2 Consist of Melt Flow Index Tester DW5450A/DW5450B

Melt Flow Testers has been designed to determine the melt flow index property of thermoplastics. It is not intended for any other use. Any other attempt to use this instrument in any fashion other than its intended use may expose the instrument or the operator to dangerous.

1.2.1 Basic Unit

Sturdy design includes housing for temperature and steel test cylinder, which is heated by a precision dual zone, insulated and jacked in a columniform housing. A tool rack is provided for convenient access to frequently used operating tools.

The Basic Unit consists of Temperature Measure Element, Temperature Control System, Automatic Cut-off System, Automatic Timing system, the Control Panel, the Pull Handle and the Tool Rack.

  • Temperature Measure Element

A platinum RTD probe senses the cylinder temperature, sending the temperature signals to the temperature controller, which regulates the temperature of the upper and lower portions of the cylinder to within 0.1℃. The test point of temperature is 1cm high over the Die and the temperature of the cylinder is displayed as the Actual Temperature.

1.2.3Temperature Control System

The scope of the temperature is controlled from 120℃to 450℃, the accuracy is ±0.5℃, the Temperature fluctuation is ±0.5℃.

  • Cut-off System

This unit is designed below the furnace and cut off specimens according to preset parameters. The unit of timer is one second.

  • How doesMelt Flow Index Tester work ?

13.1 Cylinder Operation

Loosen the adjusting bolt of the cylinder; make sure that the arc-beeline slot in the ektexine of the cylinder zeros in the outer circle of the screw cap. Next, insert the cylinder into the oven. After the cylinder extends to the bottom of the hearth, clamp the opening slot with the knob tool to rotate the cylinder about 20 degree clockwise, make the small flat of the cylinder below the adjusting bolt, then screw it with a screwdriver tight. At last impact the cylinder tight.

This instrument has been installed a cylinder, carry out the next operation directly.

  • Tungsten Carbide Die operation

Push the handle to the end rightward. Then place the Tungsten Carbide Die on the cylinder, and use the Charging Tool to help the Tungsten Carbide Die into the bottom of the oven. If pull the handle to the left, the Tungsten Carbide Die can fall off through the extrusion area from the underside of the oven.

  • Funnel Operation

Insert the funnel into the cylinder when testing; put the sample, which has been prepared into the cylinder through the funnel.

  • Weight Operation
  • Basic Weight Operation

The basic weight consists of Piston Rod, Guide Bushing, Weight Tray, Weight Lid. But the weight of the Guide Bushing is not contained in the weight of the Basic Weight. The total weight is 325g. Installation order as follow:

  1. Let the Guide Bushing through the Piston Rod.
  2. Let the Weight Lid through the Piston Rod.
  3. Tighten the Piston on the Weight Lid.
    • Weight Operation

According to the requirement of the sample standard, prepare for the needed weights. First, insert the Basic weight into the Cylinder, and then add the prepared weights to it one by one. And make sure that the round bulge of the previous one fasten the groove of the latter, otherwise the weight may glide down and may expose the operator to danger.

Appendix A


Test conditions for Melt Flow Rate determination

The conditions used shall be as indicated in the appropriate material designation or specification. Table A indicates test conditions that have been found useful.

List A

Condition (letter symbol) Testing temperature θ, ℃ Load (combination) mnom, kg
A 250 2.16
B 150 2.16
D 190 2.16
E 190 0.325
F 190 10.00
G 190 21.6
H 200 5.00
M 230 2.16
N 230 3.80
S 280 2.16
T 190 5.00
U 220 10.00
W 300 1.20
Z 125 0.325
NOTE: If, in the future, conditions other than those listed in this table are necessary,
e.g. for new thermoplastics, only the loads already in use shall be chosen.
Temperatures shall also be selected from those already in the table. If absolutely
necessary, new temperatures might have to be taken because of nature of the new thermoplastic.


If you need more information about Melt Flow Indexer testing procedure or theory , please send email to [email protected].

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