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PAPER INDUSTRY WEB (PIW)
DESIGN A CORE LOADING CART
FOR
YOUR TWO DRUM WINDER!
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A
core loading cart can be a means to make a 2 drum winder more
efficient from the time cycle standpoint if the winder is not
presently equipped with an automatic core loading system. It is
not uncommon, with good planning and crew training to reduce set
change time by 45 to 60 seconds. On an average production winder,
a good core loading cart operation can save an hour or more a
day.
If the core loading cart is used properly, it can reduce the possibility
of injury at the front aisle of the winder between the winder
drums and roll discharge system particularly in nip related injuries.
The sketch shown shows the end view of the core loading cart.
The width of the cart must accommodate the maximum number of cores
used in a set. An open design will permit storing spare sets in
the space below if it is left open.
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A major concern when considering a core loading cart is the space
at the tending side of the winder between the winder side frame
and the benchboard. The cart must be deep enough to handle the
longest single core to be installed in the winder. Keep in mind
that the core cart can be "rotated" into the winder
if there is enough clearance to move the core loading extension
into the winder at an angle and then align the cart to the winder
drums when it clears the benchboard. In this instance it is necessary
to use casters that can rotate 360 degrees.
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If the cart cannot
fit in this space, obviously the cart cannot be used unless the
benchboard is relocated. If the benchboard does not interfere,
and there is ample space, some mills use single direction casters
and use a track in the floor to guide the cart into and out of
the drum pocket. Design the track so it does not become a tripping
area or injury can occur by turning an ankle.
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Another area that must be checked carefully is the space in the
drum pocket and it's relationship to the MAXIMUM core OD that
will be used in the winder. The sketch at left shows a 40"
diameter wound roll on a pair of 24" diameter winder drums.
The brown core shown is 3 5/8" OD. The red core is a 6"
OD and shows the core size limitation of this pocket. A cart of this type is
used with fibre cores only, plain or tipped ends.. |
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When
loading the cores, the core loading cart extension is aligned
with the valley formed by the two winder drums. The extension
can be a simple "V" or if preferred, a curved member
with a compatible radius to the core O. D. in use.
Note that the wound roll of paper is still in position on the
winder drums. The cores are loaded BEFORE the wound roll is ejected
from the winder but NOT BEFORE THE WINDER HAS COME TO A COMPLETE
STOP. A complete stop means the winder drums are NO LONGER ROTATING.
If the cores are pre-tapped, they can be positioned in a manner
to stick to the tail of the set after the set is ejected. The
crews must be trained to insure the wound roll will not be ejected
until the cores are fully loaded and the operator responsible
for loading the cores is completely clear of the area.
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CORE LOADING SEQUENCE
SEQUENCE 1
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The
cores are loaded in the core loader in the sequence they will
be inserted in the winder, #1 core being the back side core and
#6 the front side core. The core cart is positioned at the winder
so the first core to be inserted is properly aligned. Design the
core loading cart so it "bumps" up against a point on
the winder to "register:" the same position on the drums
each time the cores are loaded. The core loading extension is
designed to just sit over the top of the winder drums. When the
cores are pushed off the extension they will drop the very small
vertical dimension to rest on the drums. This drop should be minimized
in the design. Design the extension with the maximum trim width
of the winder in mind.
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SEQUENCE 2
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THE INSERTION SEQUENCE: The cores are loaded into the winder in
a sequence consistent with the slitter arrangement of the winder.
Each core is pushed into the winder using the next subsequent
core as the pusher tool to load the previous core. As an example,
#2 is used to push #1, #3 is used to push #2, etc. In this manner,
the operator inserting the cores can keep his hands and arms well
away from the winder and out of harm's way. In the case of this
sketch, core #1 is the back side core, cores #3 through #5 are
intermediate cores and core #6 is the front side core. Core #6
has a special consideration for safety and is described in the
next sketch.
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SEQUENCE 3
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When all but the #6 core are loaded in the winder, the operator
uses a "dummy" core or a special tool designed specifically
to insert the last core in the winder. The outside end of the
last core inserted will be positioned inside the trim line of
the winder.
SAFETY NOTE:
Handling the last core to be loaded by hand places the operator's hand
and arm at risk of injury if a malfunction or premature roll ejection
were to take place. It is mandatory that a "dummy" core or other suitable pusher be used to insert the last core into
the winder. The dummy core or pusher must be long enough to keep the operator
well away from any possible pinch or nip point
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After all the cores are loaded and properly positioned, the core
loading cart removed, the mechanical elements properly positioned
and interlocks satisfied, the wound roll can be ejected from the
winder. The new tails are fastened to the cores, and the winder
restarted to wind the next set of rolls.
While the new roll is winding, the new set of cores are placed
on the core loading table to be ready for core loading for the
next set to be wound.
Try to design the cart lightweight so it is easy to handle. With
proper design, crew training and planning, a core loading cart
can be a SAFE and USEFUL tool to advance the efficiency of
the winding operation.
Paper Industry Web
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