M A G U I R E P R O D U C T S , I N C .
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G R A V I M E T R I C A U G E R F E E D E R
Interval Report Description
GRAVIMETRIC FEEDER ID# 000 WO 00000 RECIPE 00000 OP 000
ID#, WO, RECIPE, and OP are for tracking and identification only. These TAGS may be entered by the operator or downloaded by
MLAN communication.
LDR: 5.00%
The percentage that you have entered as the desired target percentage.
WEIGHT: 3402.1
The current weight reading at the end of the dispense cycle. This is the total weight of the color that remains in the hopper.
AVG. DISP 2.98
The average dispense since the last rate error correction has occurred, or since the hopper was last refilled. It is the accumulated
weight dispensed, divided by the accumulated cycles count.
TARGET: 3.45
The amount, in grams, that the feeder is targeting to dispense based on your entries of color percent, (LDR), and SHOT WEIGHT.
Shot weight times LDR (percent of color) will give you the target dispense.
ERROR: -2.8 (3)
The total error that has occurred to this point, since the last rate correction or since the hopper was last filled. In this example, we
have metered 1.9 grams more then we want, since the last correction. This is the "total" error. not one cycle, but all cycle errors
combined. The (3) is the trip point. If total error exceeds 3 grams, then a recalculation of rate will occur.
SIG ON: 8.07s
The length of the screw return time that was recorded on this cycle. This number is used to determine how fast we need to run the
auger to meter the required color uniformly over this time period.
SHOT WT: 69.0
The Gram weight number that you enter to tell the software how large a shot is being molded. It will include runners, and all parts if
this is a muti-cavity mold. In this example, 69 x 5% = 3.45 grams, shown above as the TARGET weight.
ON TIME: 171ms
On models using our 24 volt DC motor, we control motor speed by pulsing the motor every second for a portion of that second. In
this example, we will pulse the motor for 171 milliseconds, and then leave it off for the balance of the second, which is 829 ms off.
The software adjusts this number based on the metering rate is has learned, coupled with the machine screw ON TIME. As On-
Time varies, this number will also adjust. On models using a stepper motor, the off time between steps is adjusted to vary the
metering rate.
RATE ADJ: 0.8145
We begin all metering rate calculations using certain assumptions. We do not know the bulk density of the color being metered,
and we do not know the exact flow characteristics of the pellets which, together, will change the gram weight metered per
revolution of the auger. We start with a standard formula that assumes certain base numbers for these values. In the formula we
also have a factor, a multiplier, that starts with a value of 1.0000. At this value, it has no effect. As we learn of an error in our
dispense rate, we adjust this factor. In this example, we have adjusted it from 1.0000 downward to 0.8145, which tells us that
either the bulk density is higher than our standard assumption, or the pellets flow better then our standard assumption. In any
case, the software uses this number to keep the metering rate exactly correct, based on actual dispense rate learned from the loss-
in-weight load cell readings over time. This is the number that you will see adjust as the unit learns the exactly correct metering
rate.
ACC. WT: 17.89
The accumulated weight since the last correction, or the last hopper refill.
ACC. CT: 6
The cycle count since the last correction, or the last hopper refill. These two values, (accumulated) WEIGHT and CYCLE Count,
are used to check on how close we are to our target. The ERROR is based on these numbers as compared to what we would
expect if we run at a Perfect rate. TARGET per cycle times CYCLE CT is compared to (accumulated) WEIGHT, and the difference
is the ERROR.
TOT. WT:
The total weight dispensed since the last time this value was cleared to zero. This can be used to track total usage in
your plant.
TOT. CT:
The total cycle count since last cleared to zero. This number also are useful for keeping print-out pages in order, and to
reference cycles by number when highlighting problems or questions. These last two numbers are for convenience only. They do
not enter into control calculations.
Summary of Contents for GRAVIMETRIC AUGER FEEDER MGF-ST
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