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Carton/Blister
Pack Verifier
Prime
spends time scouting for metal thickness problems
to solve. Here is an example of a solution
in the packaging industry. This solution is
a good example of how our detectors are not
just "Double Detectors". In this
application the detector senses not a 2 to
1 (double) change, but a 12 to 1 change.
This
project originally started using our Model
DS3400. We found additional features were
needed to solve the problem. The final result
is found in the current Model DS3410.
A
customer that packages pharmaceutical products
needed to monitor the number of aluminum foil
laminated packages in two different cartons
sizes. One carton had eight packages
and the other had twelve. We assumed
that if we could detect the number of packages
in the largest carton, the smaller was also
possible. The largest carton was 215 mm high,
90 mm wide, and 55 mm deep. The picture at
the bottom of this page is the largest carton
with twelve packages in it. A sketch is also
available through the following link. Illustration
of sensor arrangement
We
mounted a set of probes at the discharge of
a carton machine. The probes transmitted an
inductive signal across the path of the passing
cartons. The probes were separated by 60 mm
and centered 110 mm above the bottom of the
carton as the picture below illustrates. With
the carton in the same position a second photoelectric
sensor (not in photo) was mounted so the lead
edge of the carton is immediately detected.
This trigger sensor is either a reflective
or thru-beam type. The system consists of
a Model DS3410 and
2 Model P1CS probes. We used a reflective
photoelectric for the trigger sensor.
The
goal is to calibrate the detector for a normal
number of packages in each carton. Then to
recognize if there is one additional or one
less than normal. Then to reject the carton
when it moves to a reject station.
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SIMPLE
TO CALIBRATE: With the normal number
of packs in the carton and the carton
centered between the probes, the CALIBRATE
button on the detector is pushed only
once.
The
control measures the signal level received
through the packages; flashes it’s LED
indicators and the alphanumeric display
shows “CA” followed by a number. This
number is the Normal value. Over and
Under Reject values are numeric values
that exceed the Normal by a definable
percentage.
After
the Norm value is accepted the detector
is ready to measure each carton. A
package is removed from the carton
to make sure the detector rejects too
many or to few. The detector indicates
the missing foil by illuminating the
UNDER lamp on the control front panel.
If not, the lower threshold which determines
the reject threshold, must be lowered.
This is done by holding the calibrate
button in for three seconds. After three
seconds the two digit display flashes
UT for upper threshold,
LT for lower threshold
and several other adjustable parameters.
Letting up on the calibration button,
when LT flashes, opens
up the threshold value adjustment window.
It is a number from 1 to 99. Making
the value less than the initial value
increases sensitive to one missing package.
For example an initial 50% value is
decreased to 10% or less. This tells
the control to reject any value that
is less than 10% of the normal value.
This procedure is also done for too
many packages. In this case the UT
values is changed. UT
stands for upper threshold.
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Note:
The
photos on this page are used for
the purpose of illustrating examples.
Any package or likeness of a particular
package is not an indication the
manufacture uses Prime products
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Rejects
Over, Under or Nothing in a closed
carton
Memorize
up to 8 carton applications
Detects up to 10 foil packages
in a carton
Detects carton width to 90
mm Fast & simple push-button teach
calibration.
Outputs,
two DPDT, max. 10 Amps
@ 240 VAC
Reject threshold adjustment
to 1%
Display
signal strength and fault codes with
two digit alphanumeric display
Power
with 100-240 VAC @ 50-60 Hz
Quick
connect terminals Easy to install
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When
one Package is removed, the Under output
relay de-energizes (reject outputs de-energize
for fail-safe purposes) if a **trigger feature
is disabled. When the removed package is
replaced, the green Nominal LED indicator
turns on and the Under relay energizes.
With the conveyor running the system detects
all missing and extra packages in the carton
of twelve or eight. In the actual application
the cartons came out of the machine on their
sides. The carton was held up on each end.
The reject station pulls the guides after
from the carton. It falls off the conveyor.
The guides extend out before the next carton
arrives.
Each
carton size and count requires a separate
calibration. The Model DS3410 stores up
to eight separate carton/package calibration
combinations.
**A
sensor is used to detect the lead edge of
the carton as it moves through or out of
the machine. This sensor triggers a sequence
which looks at the foil sensor measurement.
When the carton clears the sensor it causes
the controls to energize the reject relays
if the number of foils are less than or
greater than the nominal value.
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