How to Calculate Extruder Flowrate

By William Hirsch, eHow Contributor
updated: January 31, 2011

Determine the productivity of your workshop extruder by calculating its flow rate. Extruders channel materials, such as dough or clay, though a rigid tube. When the material exits the extruder it takes on the shape it was forced through and is ready for your craft or project use. These tubes generally come in different shapes and sizes depending on the application. A flow rate describes the number of pounds of material passing out of or into the tube every minute. (See Reference 1)

Difficulty: Moderate
What you'll need: Stopwatch, scale

1) Start a stopwatch at the same time the extruding process begins. Stop the stopwatch when the extruding process ends. For example, the time that passes may be 350.0 seconds.

2) Convert the time to minutes by dividing by 60, since each minute contains 60 seconds. Performing this step yields 350.0 seconds divided by 60 seconds per minute which equals 5.8 minutes.

3) Place all the material that passed out of the extruder onto a scale. Record the weight in pounds. Assume a weight of 45.0 lbs. for the exercise.

4) Divide the weight by the time to obtain the flow rate in pounds per minute of the extruder. Completing the example leads to 45.0 lb. divided by 5.8 minutes, or 7.8 lb. per minute. Read original article