Polychem GP44, Operation And Maintenance Manual

Page: 28 / 105

GP44 Semi-Automatic Strapping Machine
OPERATION - 28-
Controlled Tension
On the Shoko machines, tension is controlled by the spring tension on the high tension arm as the high
tension arm drops into the groove in the end cam. The spring on this high tension arm should be set at 2 ¼”
and left alone. It is not something that should be constantly adjusted. On the MR machines, there are two
modes of controlled tension. On tall bundles, the tension is controlled as described previously. On small
bundles, a solenoid engages to intercept the high tension arm. There is also a slip clutch on the machines on
the high tension wheel. The slip clutch reduces the shock on the strap as the high tension wheels contact the
strap to pull tension. This slip clutch should be set to slip 1/4 - 1/3 turn as the machine pulls controlled tension.
On GP machines, the external tension knob limits the travel of the high arm can which limits its contact with the
strap and therefore reduces the tension.
Symptom Cause Solution GP
Strap is breaking Tension is set too high Reduce tension on the tension knob. The
spring on the tension control arm should be
set at 2 ¼”.
X
High tension wheel
is leaving a mark
on the strap. The slip clutch is not set
properly Make sure the slip clutch is on the high
tension wheel is slipping 1/4 – 1/3 turn during
high tension cycle.
The strap is too
loose/ too tight on
small bundles The small bundle tension
bolt on the solenoid is not
adjusted properly Adjust the small bundle tension bolt on the
solenoid to achieve proper tension.
The strap is too
loose/ too tight on
small bundles The top photo eye is
blocked and it is not
detecting the small
bundle Clean the photo eyes.
The strap is too
loose/ too tight on
small bundles The small bundle
solenoid is not operation
properly Check the solenoid, free up the plunger,
replace if necessary.