M A G U I R E P R O D U C T S , I N C .
14
S e r i e s M P A
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 Wt) x (% let-down) x ('C' factor) x 120 / (G/L) = Setting
Example: Shot Weight = 400 grams
% color = 1.2%
Weight of liquid color = 12 lbs. per gallon
Green tube; 'C' factor = 1.3
400 x 1.2 x 1.3 / 12 = 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
(lbs/hr) x (% let-down) x ('E' factor) x 120 / (G/L) = Setting
Example: Extruder output = 900 pounds per hour
% color = 2%
Weight of liquid color = 16 lbs. per gallon
Red tube; 'E' factor = .47
900 x 2 x .47 / 16 = 52.875 -- Set Counter on 53
CHART OF 'C' and 'E' FACTORS:
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).
