PAPER INDUSTRY WEB (PIW)
LUIGI'S WINDER SCRAPBOOK
- TWO DRUM WINDERS
to the 1960s a paper mill did not have much choice in winder designs.
The two drum winder with equal size drums and a horizontal slitter
section was the dominant, and in a practical sense, the only winder
concept available. A couple innovative winders were produced but
did not have wide acceptance which resulted in a very short life.
- This vintage winder
used cast iron frames and wound the rolls on a full width winder
coreshaft on either iron pipe or paper cores. Maximum winder speed
was determined by a rough formula of 2.5 times the maximum paper
machine design speed. The winder operation was manual with a cycle
time more than adequate for the times. Paper machines in this
period were operating in the 2000 FPM maximum speed range. The
winder drive used a single motor drive with a belt tie between
the two winder drums. Tissue machines used a similar winder the
notable exceptions being a surface driven unwind stand and a coreshaft
weight relieving system to maintain bulk. A modern version of
the horizontal sheet run two drum winder is still produced today
in very limited numbers for special applications.
vertical slitter section 2 drum winder appeared in the late 60's
and was popularized in the 70's. There was a lot happening in
winding in the 60's. The early 60's saw the first two motor- torque
differential drives, load cell tension systems, sectional paper
carrying rolls, dual component spreader elements and other significant
WINDER developments.. The first automatic slitter sections appeared
in the late 60's. Shaftless winding, a unique and different concept
was just coming to being. The change that had the greatest impact
on winder designs was the advent of fabricated winder frames as
opposed to cast iron. This permitted a flexibility in design not
possible in the past.
- To accommodate the
changes in paper grades, basis weights, sheet densities and other
paper properties, there was a great flurry of roll structure control
systems and larger diameter winder drums to improve shipping roll
quality to meet the demands of larger shipping roll sizes. As
the two drum winder matured and was mechanically opimized to the
fullest the "traditional" two drum winder was found
lacking when winding large, heavy shipping rolls of dense grades
of paper, particularly in the coated and super calendered papers.
- The duplex winder
concept emerged in the early 60's but due to it's poor productivity
performance, winder builders continued to develop new two drum
winder designs to wind heavier shipping rolls and maintain the
productivity advantages of the two drum winder.
Working in concert with paper mills, winder builders designed
new and innovative concepts to extend the usefulness of the two
drum winder . One of the earlier developments was the "unequal
drum diameter" concept. When winding on the two drum winder
with unequal drum sizes the major portion of the winding roll
weight was transferred to the broader nip of the larger winder
drum reducing the PSI load of the paper winding on the drums resulting
in less "wound in tension" caused by drum nip load.
Another development was "soft nip winding". Again the
goal was for a broader drum nip to reduce the tension being wound
into the roll. This winder concept uses a resilient material on
one of the winder drums that can deform under load, producing
a wider nip. In some installations, the "soft nip" concept
is further enhanced by the application of a narrow based articulating
rider roll that minimizes the effect of caliper variations in
The "air support winding concept" uses a completely
different approach. This concept reduces drum nip load by pumping
air into the pocket formed by the two winder drums and the winding
roll of paper. The air produces a lifting effect on the winding
paper rolls thereby "releiving the weight of the paper on
the winder drum nip.
Another very unique approach is the "three drum winder"
concept. This concept embodies both the two drum and duplex approach.
The concept in effect is a pair of two drum winders, the common
center drum acting as the second drum on each of the two drum
winders. The winding rolls in a set are wound on alternate pairs
of drums. This concept has several advantages not the least of
allowing individual rolls to be weight relieved.
another unique configuration is the "belted winding"
concept. The Belted winder replaces one of the winder drums of
the traditional two drum with a belt arrangement. It is only similar
to other concepts in that the goal is to broaden the nip that
supports the winding roll of paper. As the roll builds in size
during the winding process, more of the wound roll surface bears
on the belt arrangement-in essence widening the drum nip proportionate
to wound roll diameter.
|All the "enhanced"
two drum winder concepts described are operating successfully
today in the marketplace. For the most part these designs are
grade specific and in many instances the concepts are adaptable
to retrofit on existing traditional two drums.
contains conceptual sketches of winder configurations in present
use in the Pulp & Paper Industry. The sketches are not drawn
to scale and use generic sheet runs and are not intended to represent
equipment as designed and sold by winder manufacturers. For specific details, arrangements, specifications
or other issues concerning the concepts illustrated, contact a
manufacturer that produces such concepts.
Scrapbook #2 - Duplex Winding