Determining Metering Rate

To insure accuracy a METERING RATE must be determined for each color. It is only necessary to determine Metering Rate once for each color. Record Metering Rate for each color for future reference.
  1. Switch to CYCLE.
  2. Turn CALIBRATION knob (upper right corner) to "CALIBRATE".
    This will force one cycle of 100 counts to be dispensed.
    OR: Set counter to 100 and switch from OFF to CYCLE.
    Plug in SIGNAL cord to force cycle of 100 counts.
  3. Run several cycles and record GRAM WEIGHT metered each cycle.
    The average of these weights is the METERING RATE in grams/100ct.
    Example: Each CALIBRATION cycle produces 55 grams output.
    Your METERING RATE is 55 grams/100ct.

MPA Liquid Color Pump - Formulas for setting the counter

INJECTION MOLDING (Cycle Mode):

  1. Determine the WEIGHT of the entire shot IN GRAMS.
  2. Determine the LBS. of COLOR per 100 LBS. of natural required, (or KILOS of COLOR per 100 KILOS of natural).
  3. Determine the METERING RATE for each color in grams/100 counts.
  4. Set the digital counter using the following formula:
    (Shot wt) x (lbs/100) / (grams/100ct) = Setting
Use this Calculator to do the math for you. Fill in the fields in the green area then click Calculate.
Note: calculator rounds to the nearest 10th
Injection Molding (Cycle Mode):
Shot wt (grams): x lbs/100 / Grams 100ct Setting: 
  
Example: Shot weight = 400 grams
4 lbs color per 100 lbs of product
Metering rate = 52 grams/100ct
400 x 4 / 52 = 30.769 #-- Set Counter on 31

EXTRUSION (Continuous Mode):

  1. Determine the extruder output in pounds per hour.
  2. Determine the LBS. of COLOR per 100 LBS. of natural required, (or KILOS of COLOR per 100 KILOS of natural).
  3. Determine the METERING RATE in grams/100 counts.
  4. Set the digital counter using the following formula:
    (lbs/hr) x (lbs/100) / (grams/100ct) x .71 = Setting
Use this Calculator to do the math for you. Fill in the fields in the green area then click Calculate.
Note: calculator rounds to the nearest whole number.
Extrusion (Continuous Mode):
lbs/hr: x lbs/100 / Grams /100ct x .71 Setting: 
  
Example: Extruder Output = 900 pounds per hour
lbs/100 required = 5.5
Metering Rate = 42 grams/100ct
900 x 5.5 / 42 x .71 = 83.678  #--  Set Counter on 84.

ALTERNATE FORMULA METHOD

This method does not require calibration, but instead relies on an accurate knowledge of the weight of the liquid (lbs/gal) and accurate tube sizes.

INJECTION MOLDING (Cycle Mode):

  1. Determine the WEIGHT of the entire shot in GRAMS.
  2. Determine the PERCENT color let-down desired.
  3. Determine the weight of the liquid color in POUNDS per GALLON. or GRAMS per LITER (G/L).
  4. Set the digital counter using the following formula:
    (Shot Weight) x (% let-down) x ('C' factor) / (lbs/gal) = Setting
    or (Shot Weight) x (% let-down) x ('C' factor) x 120 / (G/L) = Setting
Use this Calculator to do the math for you. Fill in the fields in the green area then click Calculate.
Note: calculator rounds to the nearest 10th.
Injection Molding (Cycle Mode):
Shot wt (grams): X (% color) X("C" factor) / lbs/gal Setting: 
  
Injection Molding (Cycle Mode):
Shot wt (grams): X (% color) X("C" factor) x 120 / gr/liter Setting: 
  
Example: Shot Weight = 400 grams
% color = 1.2%
Green tube; 'C' factor = 1.3
Weight of liquid color = 12 lbs. per gallon (1440 grams per liter)
400 x 1.2 x 1.3 / 12 = 52 #-- Set Counter on 52 OR
400 x 1.2 x 1.3 x 120 / 1440 = 52 #-- Set Counter on 52

EXTRUSION (Continuous Mode):

  1. Determine the extruder output in pounds per hour.
  2. Determine the percent color let-down desired.
  3. Determine the weight of the liquid color in pounds per gallon or GRAMS per LITER (G/L).
  4. Set the digital counter using the following formula:
    (lbs/hr) x (% let-down) x ('E' factor) / (lbs/gal) = Setting (Use top Calculator)
    or (lbs/hr) x (% let-down) x ('E' factor) x 120 / (G/L) = Setting (Use bottom Calculator)
Use this Calculator to do the math for you. Fill in the fields in the green area then click Calculate.
Note: calculator rounds to the nearest whole number.
Extrusion (Continuous Mode):
lbs/hr: x (% color) x ("E" factor) / lbs/gal Setting: 
  
Example: Extruder Output = 900 pounds per hour
% color = 2%
Red tube; 'E' factor = .47
Weight of liquid color = 16 lbs. per gallon (1920 grams per liter)
900 x 2 x .47 / 16 = 52.875 #-- Set Counter on 53
or 900 x 2 x .47 / x 120 / 1920 = 52.875 #-- Set Counter on 53
Tube Size 'C' factor 'E' factor
1/8" I.D. (green) 1.3 .93
3/16" I.D. (red) .66 .47
1/4" I.D. (clear) .39 .28
NOTE: If you have Model MPA-6-18 (which uses an 18 RPM motor) then multiply these factors by six, i.e. (6 x C factor).