U.S. patent application number 13/328155 was filed with the patent office on 2013-06-20 for method and apparatus for winding webbed material with mandrel position control.
The applicant listed for this patent is James Leo Baggot, Gregory Michael Bixler, Frank Stephen Hada, Daniel Mark Heinz, Vivek Moreshwar Karandikar. Invention is credited to James Leo Baggot, Gregory Michael Bixler, Frank Stephen Hada, Daniel Mark Heinz, Vivek Moreshwar Karandikar.
Application Number | 20130153703 13/328155 |
Document ID | / |
Family ID | 48609143 |
Filed Date | 2013-06-20 |
United States Patent
Application |
20130153703 |
Kind Code |
A1 |
Bixler; Gregory Michael ; et
al. |
June 20, 2013 |
Method and Apparatus for Winding Webbed Material with Mandrel
Position Control
Abstract
A method and apparatus for winding a moving web upon a mandrel
is disclosed. A moving web with a leading edge is conveyed towards
a mandrel. The mandrel is adapted to allow the moving web to adhere
to the mandrel at a specific circumferential location on the
mandrel. To enable control of the location of the mandrel, the
mandrel further includes a reference input to identify the specific
circumferential location. A position sensor is used to determine
the position of the reference input. The position of the specific
circumferential location of the mandrel is controlled with a
position drive control that controls the rotational speed of the
mandrel. The position drive control sets the rotational speed of
the mandrel to allow transfer of the leading edge of the moving web
near the specific circumferential location.
Inventors: |
Bixler; Gregory Michael;
(Appleton, WI) ; Heinz; Daniel Mark; (Greenville,
WI) ; Karandikar; Vivek Moreshwar; (Neenah, WI)
; Hada; Frank Stephen; (Appleton, WI) ; Baggot;
James Leo; (Menasha, WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bixler; Gregory Michael
Heinz; Daniel Mark
Karandikar; Vivek Moreshwar
Hada; Frank Stephen
Baggot; James Leo |
Appleton
Greenville
Neenah
Appleton
Menasha |
WI
WI
WI
WI
WI |
US
US
US
US
US |
|
|
Family ID: |
48609143 |
Appl. No.: |
13/328155 |
Filed: |
December 16, 2011 |
Current U.S.
Class: |
242/532.3 |
Current CPC
Class: |
B65H 2301/41426
20130101; B65H 19/2276 20130101; B65H 19/28 20130101 |
Class at
Publication: |
242/532.3 |
International
Class: |
B65H 75/28 20060101
B65H075/28 |
Claims
1. A method of winding a moving web upon a mandrel comprising:
conveying a moving web having a leading edge; providing a mandrel,
the mandrel being adapted to adhere the moving web at a specific
circumferential location on the mandrel, the mandrel further
including a reference input to identify the specific
circumferential location; engaging the mandrel with a position
drive control to control the rotational speed of the mandrel;
determining the position of the reference input with a position
sensor; setting the rotational speed of the mandrel to allow
transfer of the leading edge of the moving web near the specific
circumferential location; transferring the moving web to the
mandrel near the specific circumferential location; and winding the
moving web.
2. The method of claim 1 wherein the mandrel is a coreless
mandrel.
3. The method of claim 2 wherein the specific circumferential
location on the mandrel is a line of vacuum openings.
4. The method of claim 2 wherein the specific circumferential
location on the mandrel is a line of engagement fingers.
5. The method of claim 1 further comprising loading a core onto the
mandrel, and wherein the specific circumferential location on the
mandrel is a strip of adhesive.
6. The method of claim 1 wherein transfer of the moving web to the
mandrel near the specific circumferential location occurs within
plus or minus 15 degrees of rotation of the specific
circumferential location.
7. The method of claim 1 wherein transfer of the moving web to the
mandrel near the specific circumferential location occurs within
plus or minus 10 degrees of rotation of the specific
circumferential location.
8. The method of claim 1 further comprising a registration system
including an imaging system, wherein the imaging system senses a
position of the leading edge of the moving web, compares the
position of the leading edge of the moving web to the specific
circumferential location, and then alters the position of the
leading edge of the moving web or the specific circumferential
location to correct for a position mismatch.
9. An apparatus for winding a moving web upon a mandrel comprising;
a conveying surface for conveying a moving web; a mandrel, the
mandrel being adapted to receive the moving web at a specific
circumferential location on the mandrel, the mandrel further
including a reference input to identify the specific
circumferential location; a position sensor to determine the
position of the reference input; and a position drive control to
control the rotational speed of the mandrel.
10. The apparatus of claim 9 wherein the mandrel is a coreless
mandrel.
11. The apparatus of claim 10 wherein the specific circumferential
location on the mandrel is a line of vacuum openings.
12. The apparatus of claim 10 wherein the specific circumferential
location on the mandrel is a line of engagement fingers.
13. The apparatus of claim 9 further comprising loading a core onto
the mandrel, and wherein the specific circumferential location on
the mandrel is a strip of adhesive.
14. The apparatus of claim 9 wherein transfer of the moving web to
the mandrel near the specific circumferential location occurs
within plus or minus 15 degrees of rotation of the specific
circumferential location.
15. The apparatus of claim 9 wherein transfer of the moving web to
the mandrel near the specific circumferential location occurs
within plus or minus 10 degrees of rotation of the specific
circumferential location.
16. The apparatus of claim 9 further comprising a registration
system including an imaging system, wherein the imaging system
senses a position of the leading edge of the moving web, compares
the position of the leading edge of the moving web to the specific
circumferential location, and then alters the position of the
leading edge of the moving web or the specific circumferential
location to correct for a position mismatch.
17. A process for producing a rolled product comprising: conveying
a moving web having a leading edge; providing a mandrel, the
mandrel being adapted to adhere the moving web at a specific
circumferential location on the mandrel; engaging the mandrel with
a position drive control to control the rotational speed of the
mandrel; setting the rotational speed of the mandrel to allow
transfer of the leading edge of the moving web near the specific
circumferential location; transferring the moving web to the
mandrel near the specific circumferential location; winding the
moving web on the mandrel into a rolled product; cutting the moving
web to complete the rolled product; and stripping the rolled
product from the mandrel.
18. The process of claim 17 wherein the mandrel is a coreless
mandrel.
19. The process of claim 18 wherein the specific circumferential
location on the mandrel is a line of vacuum openings.
20. The process of claim 18 wherein the specific circumferential
location on the mandrel is a line of engagement fingers.
21. The process of claim 17 further comprising loading a core onto
the mandrel, and wherein the specific circumferential location on
the mandrel is a strip of adhesive.
22. The process of claim 17 wherein transfer of the moving web to
the mandrel near the specific circumferential location occurs
within plus or minus 15 degrees of rotation of the specific
circumferential location.
23. The process of claim 17 wherein transfer of the moving web to
the mandrel near the specific circumferential location occurs
within plus or minus 10 degrees of rotation of the specific
circumferential location.
24. The process of claim 17 further comprising a registration
system including an imaging system, wherein the imaging system
senses a position of the leading edge of the moving web, compares
the position of the leading edge of the moving web to the specific
circumferential location, and then alters the position of the
leading edge of the moving web or the specific circumferential
location to correct for a position mismatch.
Description
BACKGROUND
[0001] Winders are machines that roll lengths of paper, commonly
known as paper webs, into logs. Winders are capable of rolling
lengths of web into logs at high speeds through an automated
process. Turret winders are well known to those skilled in the art.
Conventional turret winders contain a rotating turret assembly
which supports a plurality of mandrels for rotation about a turret
axis. The mandrels travel in a circular path at a fixed distance
from the turret axis. The mandrels engage hollow cores upon which a
paper web can be wound. Typically, the paper web is unwound from a
parent roll in a continuous fashion, and the turret winder rewinds
the paper web onto the cores supported on the mandrels to provide
individual, relatively small diameter logs. The rolled product log
is then cut to designated lengths into the final product. Final
products typically created by these machines and processes are
toilet tissue rolls, paper toweling rolls, paper rolls, and the
like.
[0002] The winding technique used in turret winders is known as
center winding. A center winding apparatus, for instance, is
disclosed in U.S. Pat. Reissue No. 28,353 to Nystrand, which is
incorporated in its entirety herein by reference. In center
winding, a mandrel is rotated in order to wind a web into a
roll/log, either with or without a core. Typically, the core is
mounted on a mandrel that rotates at high speeds at the beginning
of a winding cycle and then slows down as the size of the rolled
product being wound increases, in order to maintain a constant
surface speed, approximately matching web speed. Center winders
work well when the web that is being wound has a printed, textured,
or slippery surface. Also, typically, center winders are preferable
for efficiently producing soft-wound, higher bulk rolled
products.
[0003] A problem found in center winders is that they are typically
not able to precisely position the mandrel for transfer. Thus, when
using a core on the mandrel, glue must be applied to the entire
circumference of the mandrel. This is typically done by applying
glue in rings to the surface of the core. It can be seen that the
spaces between the glue rings do not pick up the sheet which can
lead to a missed transfer. Also, it can be seen that the glue that
is not directly at the transfer point is not used and is wasted. A
similar issue is present when using vacuum to transfer a sheet to a
mandrel. If vacuum holes are spread out on the surface of the
mandrel the overall vacuum level is lower than if the holes are
placed in a line. It can be seen that a single line of glue is
better able to hold a sheet and maximizing the effectiveness of the
glue used. When a coreless mandrel is used with holes spread out on
the surface of the mandrel, failure to securely attach to the
mandrel may cause waste in the system or even potential machine
shut-down. Thus, there is a need to provide an apparatus and method
that controls the rotational mandrel position to allow for more
precise control and efficient operation of the winder.
SUMMARY
[0004] A method and apparatus for winding a moving web upon a
mandrel with mandrel position control is disclosed. An attachment
means is placed longitudinally along the length of the mandrel at a
specific circumferential location on the mandrel, wherein the
registration of the mandrel with the drive control facilitates the
subsequent placement of moving web at the specific circumferential
location upon the outer periphery of the mandrel. This process
enables adhesion of the moving web to the mandrel at a
predetermined and specific location. The system is designed to
reduce cost, increase production output, and avoid excess waste of
adhesive. Specifically, a moving web with a leading edge is
conveyed towards a mandrel. The mandrel is adapted to allow the
moving web to adhere to the mandrel at a specific circumferential
location on the mandrel. The specific circumferential location is
an axial or longitudinal area along the length of the mandrel. To
enable control of the location of the mandrel, the mandrel further
includes a reference input to identify the specific circumferential
location. A position sensor is used to determine the position of
the reference input. The position of the specific circumferential
location of the mandrel is controlled with a position drive control
that controls the rotational speed of the mandrel by torque applied
at one or each end of the mandrel. The position drive control sets
the rotational speed of the mandrel to allow transfer of the
leading edge of the moving web near the specific circumferential
location.
[0005] The transfer typically occurs so that the moving web
attaches to the mandrel within plus or minus 15 degrees of rotation
of the specific circumferential location. More desirably, transfer
typically occurs so that the moving web attaches to the mandrel
within plus or minus 10 degrees of rotation of the leading edge of
the sheet for a good coreless transfer on a coreless execution or
cored transfer when using cores.
[0006] A method and apparatus for winding a moving web upon a
mandrel with mandrel position control may be utilized to produce a
coreless product. A "coreless" product is one which does not have a
separate, relatively rigid, independent, non-tissue core component,
such as a cylindrical cardboard core typically used for
commercially available tissue products. In this type of product,
the process includes controlling the rotational speed of the
mandrel to allow transfer of the leading edge of the moving web
near a strip of vacuum openings or engagement fingers for the
specific circumferential location.
[0007] A method and apparatus for winding a moving web upon a
mandrel with mandrel position control may be utilized to produce a
traditional rolled product with a core. In this type of product,
the process includes loading a core onto the mandrel, and
controlling the rotational speed of the mandrel to allow transfer
of the leading edge of the moving web near a strip of adhesive for
the specific circumferential location. The adhesive for this method
is arranged on the surface of the core in a substantially linear
fashion parallel to the axis of the mandrel. The glue line can be
continuous or discontinuous if less adhesion is needed.
BRIEF DESCRIPTION
[0008] A full and enabling disclosure thereof, directed to one of
ordinary skill in the art, is set forth more particularly in the
remainder of the specification, which makes reference to the
appended figures in which:
[0009] FIG. 1 illustrates a schematic view of a rewinder using the
mandrel position control of this invention; and
[0010] FIG. 2 illustrates a schematic view of a mandrel for use in
the embodiment depicted in FIG. 1.
DETAILED DESCRIPTION
[0011] Reference now will be made in detail to various embodiments
of the invention, one or more examples of which are set forth
below. Each example is provided by way of explanation, not
limitation. In fact, it will be apparent to those skilled in the
art that various modifications and variations may be made in the
present disclosure without departing from the scope or spirit of
the claims. For instance, features illustrated or described as part
of one embodiment, may be used on another embodiment to yield a
still further embodiment. Thus, it is intended that the claims
cover such modifications and variations.
[0012] As described above, as moving webs of material are
manufactured into a rolled product on various types of winders, the
moving web needs to be placed onto the mandrel.
[0013] Generally, a method and apparatus for winding a moving web
upon a mandrel is disclosed. A moving web with a leading edge is
conveyed towards a mandrel. The mandrel is adapted to allow the
moving web to adhere to the mandrel at a specific circumferential
location on the mandrel. The specific circumferential location is
an axial or longitudinal area along the length of the mandrel. This
axial or longitudinal area along the length of the core could be a
plurality of engagement fingers, a plurality of openings which can
be used for vacuum, or a line of adhesive on a core to enable the
moving web to adhere to the mandrel for winding.
[0014] To enable control of the location of the mandrel, the
mandrel further includes a reference input to identify the specific
circumferential location. The reference input may be a flag or a
marking that corresponds to the specific circumferential location
on the mandrel. A position sensor is used to determine the position
of the reference input. It is also possible that the specific
circumferential position can be detected using an imaging system as
the position sensor that can analyze a video signal of the mandrel
rotation as well as the position of the leading edge of the moving
web.
[0015] The position of the specific circumferential location of the
mandrel is controlled with a position drive control to control the
rotational speed of the mandrel using torque applied at one or each
end of the mandrel. In one application, a belt and pulley system
may be used to apply torque to the mandrel. Desirably, the mandrel
is attached to a pulley and engaged by a flat metered winding belt.
The flat metered winding belt is driven by a metered winding drive
pulley. Other position drive controls may be used including, but
not limited to, timing belts, gearing or pulleys, rotational
surface friction, magnetic flux, and other means known by persons
of skill in the art. The position drive control sets the rotational
speed of the mandrel to allow transfer of the leading edge of the
moving web near the specific circumferential location.
[0016] A rolled product is then created by winding the moving web
on the mandrel into a finished rolled product. The mandrel is
rotated at changing rotational velocity so that the web speed and
the winding profile may be controlled as the rolled product builds.
In most cases, the axial position of the mandrel may change
gradually by mechanical means such as conveyor or timing belt drive
speed changes, cam track, or a rocker arm as the log diameter
increases to minimize web interference with machine components
during winding. Then, when the desired length of webbed material
has been wound upon the cored mandrel into a finished log, the web
is severed and transferred to another incoming cored mandrel by
standard bed roll means and the process begins once again on the
next successive mandrel.
[0017] The roll is spirally wound from the hole in the center of
the roll to the outside, but effectively the roll can be thought to
consist of a large number of windings, which are the individual
layers or sheets between the axis and the outer surface as measured
along a radial direction. A single winding represents the sheet
being wound once around the roll. Typically, bath tissue rolls made
from through-air dried tissue have from about 150 to about 250
windings per roll. The actual number of windings will depend upon
the sheet count, the final desired diameter of the roll and the
thickness of the tissue sheets, but these are typical values for
commonly made products available for consumers. Similarly,
single-ply paper towels made from through-air dried tissue have
from about 50 to about 150 windings per roll.
[0018] The disclosed method of mandrel position control is based on
finding a specific circumferential location or position on the
mandrel. A means for identifying this specific circumferential
location or position on the mandrel is incorporated on the mandrel.
Specifically, a mandrel rotational position sensor that is mounted
on the machine frame detects the reference input on the mandrel to
indicate to the control of the machine where the specific
circumferential location is currently situated.
[0019] In typical applications, the exact position of the mandrel
is lost during removal of the wound roll and needs to be found by
the sensor to re-establish the circumferential position. The
mandrel is turned slowly until the mandrel rotational position
sensor detects the reference input on the mandrel and stops. At
this point the mandrel is in a known rotational position. The
machine controls are then programmed with a specific winding cam
that caused the flat drive belt to be moved in order to place the
specific circumferential position in the proper rotational position
to be in time with the leading edge of the sheet for proper
transfer.
[0020] Transfer typically occurs so that the moving web attaches to
the mandrel within plus or minus 15 degrees of rotation of the
specific circumferential location. More desirably, transfer
typically occurs so that the moving web attaches to the mandrel
within plus or minus 10 degrees of rotation of the leading edge of
the sheet for a good coreless transfer on a coreless execution or
cored transfer when using cores.
[0021] Typical center winder operations do not detect the mandrel
position and do not place the mandrel rotational position in the
proper time with the leading edge of the sheet. The conventional
operation requires rings of adhesive around a typical core for
transfer of the sheet to the mandrel.
[0022] The disclosed method and apparatus also differs from a
standard registration system that senses an eye mark or
registration mark. These systems typically sense a position of the
sheet and then advance or retard the sheet or the mandrel position
to correct for position mismatches by comparing the two relative to
each other. The mandrel position would have to be known or always
in contact with a drive means so that its position is always known.
This is not the case in the method and apparatus described herein
since the mandrel is not in contact with the drive belt for a
significant portion of the turret movement. This registration
feature could be added as an additional feature for the mandrel
position control above using an imaging system to compare mandrel
position and the sheet leading edge for fine tuning.
[0023] FIG. 1 illustrates a center rewinder 100 with a turret
assembly 110 that may be employed in the method of winding a web
disclosed herein. Turret assemblies are well known to those skilled
in the art to be useful for winding paper onto a mandrel. In
general, turret assemblies often include at least one mandrel that
is rotatably affixed to an indexing mechanism. The indexing
mechanism, or turret, can rotate a mandrel into a number of
positions or "stations" at which various steps of the winding
process can occur. For instance, at one position, the moving web
can be attached to the mandrel. At another position, the moving web
can be wound around the mandrel. And, at yet another position, the
wound rolled product can be removed from the mandrel. Any turret
assembly known to those skilled in the art is suitable for use in
the present invention. Examples of various turret assemblies that
can be used in the present invention include, but are not limited
to, the turret assemblies described in U.S. Pat. No. 4,133,495 to
Dowd; U.S. Pat. No. 5,337,968 to De Bin et al.; and U.S. Pat. No.
5,797,559 to Coffey, which are incorporated in their entirety
herein by reference. Other winding systems that may be used in
accordance with the present disclosure include the winders
disclosed in U.S. Patent Application Publication No. US2003/0160127
to Wojcik et al., U.S. Pat. No. 7,909,282 to Wojcik et al., and
U.S. Pat. No. 8,042,761 to Wojcik et al., which are all
incorporated herein by reference.
[0024] In this embodiment, a bedroll 102 defines a conveying
surface 104 of the center winder 100. In an exemplary embodiment,
the bedroll 102 rotating in the direction of the arrow represented
by arrow 103 may also be a vacuum transfer roll utilized to hold
the moving web 136 on the conveying surface of the rotating roll
102. The moving web is moving in the direction of the arrow
represented by number 101. A web cut-off assembly 190 is mounted in
proximity to the bedroll 102 to cause a break in the moving web 136
when a web break is desired.
[0025] The turret assembly 110 is rotatably mounted below the
bedroll 102 and rotating in the direction of the arrow represented
by number 107. The turret assembly 110 further includes a plurality
of rotating mandrels such as winding position mandrel 112 where
paper is wound upon a core. Typically, the centerline of the turret
is directly in line with the centerline of the bedroll.
[0026] The winding position defined as the "core load position,"
which is the position occupied by mandrel 113. In this position, on
at least one end of the mandrel, a mandrel pulley 146 is attached
to at least one end of the mandrel 113. The mandrel pulley 146
interacts with the position drive control 140 to control the
rotational speed of the mandrel by torque applied at one or each
end of the mandrel.
[0027] In embodiments where a core is desired to be included with
the final rolled product, the winding process can be initiated by
the "core load position," by first placing a core onto the mandrel
according to any method known in the art. Once the core is placed
onto mandrel 113, the turret assembly 110 can then be indexed into
an "adhesive application position," which is the position occupied
by mandrel 114. In particular, an adhesive can be applied to the
specific circumferential position by any method known in the art to
the core. Generally, the adhesive used can comprise any of a
variety of materials, such as glue, known to adhere paper to a
surface. Although not necessarily required, such an adhesive
facilitates attachment of the paper web onto a core. While rings of
adhesive are usually places on the core in this position, it is
also possible to apply a line of adhesive at the reference
position. It is typical to have a small drive (not shown) to slowly
rotate the cored mandrel to apply glue. The same drive can be used
to index the core to the correct position to apply a line of
adhesive.
[0028] In coreless executions of the rolled product, no core or
adhesive is placed onto the mandrel. Alternative attachment means
such as vacuum suction or temporary mechanical attachments
described in more detail below are used to adhere the moving web to
the specific circumferential location.
[0029] Once adhesive or other attachment means is applied to the
mandrel, the mandrel can be indexed by turret 110 into the
"pre-spin position," which is the position occupied by mandrel 116.
At this position, the specific circumferential location of the
mandrel is controlled to allow transfer of the leading edge of the
moving web near the specific circumferential location. To enable
control of the location of the mandrel, the mandrel further
includes a reference input 138 as illustrated in FIG. 2 to identify
the specific circumferential location. The reference input 138 may
be a flag or a marking that corresponds to the specific
circumferential location on the mandrel. A position sensor 156 is
used to determine the position of the reference input 138.
[0030] The position of the specific circumferential location of the
mandrel is controlled with a position drive control 140 to control
the rotational speed of the mandrel using torque applied at one or
each end of the mandrel. In one application, a belt and pulley
system may be used to apply torque to the mandrel. Desirably, the
mandrel is attached to a pulley 146 that engages by a flat metered
winding belt 142. The flat metered winding belt 142 is driven by a
metered winding drive pulley 144. The position drive control 140
sets the rotational speed of the mandrel to allow transfer of the
leading edge of the moving web near the specific circumferential
location. The position drive control 140 is only in contact with
the mandrel at the "pre-spin position," the "winding position" and
until just before the "tail-seal position," and not in contact with
the mandrel throughout the turret assembly. This requires the
mandrel position control system 100 to interact with the mandrel
and find the position of the reference input to match the leading
edge of the sheet each time.
[0031] It is important to note that only one flat metered winding
belt 146 is shown in FIG. 1 to illustrate the principle of this
invention. There are actually two metered winding belts on a
machine to allow winding on the previous mandrel in position 112
while the next mandrel is in the "pre-spin position" getting up to
the operating speed in preparation for transfer.
[0032] At the "pre-spin position," the mandrel may then be rotated
to ensure that the mandrel achieves a certain rotational speed
before the paper web is wound thereon. The mandrel 26, for
instance, can be accelerated to a speed wherein the surface speed
of the mandrel substantially matches the surface speed of the web
136. For instance, the mandrel may be rotated at a speed that is
equal to, slightly greater than or slightly less than the speed of
the moving web. As used herein, for instance, indicating that the
mandrel is accelerated to a rotational speed that is
"substantially" equal to a speed at which the tissue sheet is
moving refers to the fact that the mandrel speed is within about 10
percent of the speed of the tissue sheet. In other embodiments,
however, the mandrel speed may be within about 5 percent, such as
within about 2 percent of the speed of the tissue sheet. In still
another embodiment, the mandrel may be accelerated so as to be at
the same speed or slightly greater than the speed of the tissue
web. Additionally, the mandrel is indexed at the moment of transfer
so that the specific circumferential position may meet the leading
edge of the moving web.
[0033] Once the mandrel is set into the proper location at the
"pre-spin position" so that the specific circumferential position
may meet the leading edge of the moving web, the mandrel can then
be indexed by the turret assembly 110 into the "winding position,"
which is the position occupied by mandrel 112. A transfer device
127 may be used to move the moving web 136 from the bedroll 102 to
the turret assembly 110 near the specific circumferential position
of the mandrel 112. The transfer device 127 can be mounted onto a
bearing and driven by any suitable driving device 129, such as an
actuating cylinder as is illustrated in FIG. 1 or a cam
mechanism.
[0034] The rotational speed of the mandrel imparted at the
"pre-spin position," is generally greater than the feed speed of
the paper web such that, as the rotating mandrel is indexed into
the "winding position," the paper web can wind around the mandrel.
Moreover, mandrel 112, for example, can be further rotated in a
clockwise direction, while in the "winding position", such that
moving web 136 can be wound thereon. In some embodiments, the
rotational speed of mandrel 112 can be controlled such that the
surface speed of the winding log maintains a substantially constant
rate from the time that it first contacts the leading edge of paper
web 136 until the end of the winding period. After winding of the
web is complete, the web cut-off assembly 190 acts to break the
moving web to create a new rolled product.
[0035] After the moving web 136 is wound onto the mandrel, it can
then be further indexed by turret 110 into a "tail seal position",
which is the position occupied by mandrel 118. At the "tail seal
position", the unattached portions of web 136 can be sealed to the
roll of paper via a sealing device (not shown). In some
embodiments, for example, the sealing device can be configured to
apply glue or some other adhesive to the paper web such that the
tail can be sealed thereto. An external roll (not shown) can also
be used for rotating mandrel 118 at the "tail seal position," of
this embodiment. As such, mandrel 118 can rotate at a slower speed,
which can aid in the sealing process. In many applications, the
tail seal is done on a separate tail sealing machine that is
outside the rewinder.
[0036] Once sealed, the finished rolled product can then be
removed. In some embodiments, mandrel containing a finished roll of
paper can be indexed by turret 110 into a "removal position," which
is the position occupied by mandrel 120. A finished roll product
can be axially removed from mandrel 120 by any method known in the
art.
[0037] As described throughout the application, the mandrel is
adapted to provide an attachment means to allow the moving web to
adhere to the specific circumferential location 150 on the mandrel.
As illustrated in FIG. 2, this specific circumferential location
150 is an axial or longitudinal area along the length of the
mandrel. This axial or longitudinal area along the length of the
mandrel 134 could be a plurality of engagement fingers, a plurality
of openings, or a line of adhesive to enable the moving web to
adhere to the mandrel for winding. Corresponding with the specific
circumferential location 150 is reference input 138 that interacts
with the position sensor to enable the mandrel control system 100
to correctly position the mandrel.
[0038] For one embodiment of coreless tissue products, in order to
assist in placing the tissue web on the mandrel 134 the specific
circumferential location 150 may include a plurality of openings
and may be in communication with a vacuum source. In this manner,
the mandrel forms a suction against the tissue web in order to at
least initiate winding. In the case of a vacuum mandrel, the
leading edge or slighted after the leading edge of the tissue web
is lightly wetted prior to contact with the mandrel. Lightly
wetting the tissue web allows for hydrogen bonds to form between
the layers of the tissue web that are directly adjacent to the
mandrel. The light hydrogen bonding allows for a passageway to be
formed into the roll or log of material without compromising the
tissue web. The layers of the tissue web are lightly bonded such
that the layers can be separated during later use.
[0039] For another embodiment of coreless tissue products, in order
to assist in placing the tissue web on the mandrel 134 the specific
circumferential location 150 may include a plurality of retractable
pins or engagement fingers. The retractable engagement fingers
extend from the surface of the mandrel and perforate the tissue web
for winding, such that the pins perforate two or more windings of
the resulting roll of tissue, thereby forming a soft core. The
engagement fingers need to be removed from the rolled product once
finished to allow removal of the log. The engagement fingers are
sharp, pointed, generally elongated tapered structures that are
capable of piercing at least two windings of a tissue web. In
general, the base of the engagement finger needs to be sufficiently
large to provide the necessary strength needed to withstand the
demands of high speed commercial manufacturing, where the mandrels
rotate at speeds of from about 3000 to about 6000 revolutions per
minute depending on sheet speed and mandrel diameter. The tips of
the engagement fingers, which must also have sufficient strength
and durability, are as sharp as reasonably possible in order to
easily punch through sheets of tissue during the winding operation.
In cross-section, the engagement fingers can be any shape, such as
round, elliptical, square, triangular, etc. The length of the
engagement fingers, as measured from the surface of the mandrel to
the tip of the engagement finger, can be from about 0.1 to about
0.4 inch. The base of the engagement fingers can be from about 0.1
to about 0.3 inch in width. Testing has shown that the tip of the
engagement finger needs to be sharp to penetrate the sheet.
Suitable shapes for the engagement finger would be a pyramid or a
cone ending at a tip. In all cases the engagement finger tapers in
all directions to a point. A frustum of a pyramid or cone, where
the tip has a significant width, would not be suitable for use as
an engagement finger because such structures would not penetrate
more than one sheet, if at all. By way of example, a typical
engagement finger suitable for purposes herein will have a point
comparable to that of the transfer engagement fingers currently
used in the bedroll of rewinder lines, such as those manufactured
by the Paper Converting Machine Company, Green Bay, Wis. Another
more common example is that the sharpness of the engagement finger
would be similar to a common safety thumb tack. A suitable material
for making the engagement fingers includes spring steel hardened to
about 40 on the Rockwell "C" scale. This level of hardening
provides good durability and wear resistance.
[0040] In the embodiment with a product including a core, in order
to assist in placing the tissue web on the mandrel 134 the specific
circumferential location 150 may include a line of adhesive. The
speed of the overall process may be increased by applying glue
axially along the length of the core. For example, prior art
methods which applied glue to the entire exterior surface of the
core, all the way around the circumference, tended to be wasteful
and caused maintenance clean up problems due to excessive amounts
of glue being thrown by centrifugal force upon the machinery during
core rotation. The adhesive may be applied in a solid line or a
series of solid lines, or may be applied in an interrupted line.
Only the amount of adhesive actually needed to adhere paper to the
core is provided.
[0041] In another embodiment, a mandrel is permanently attached to
a drive mechanism and the position of the circumferential location
150 is known at all times. It is then possible to synchronize the
leading edge of the sheet with the circumferential location at all
times without the need to find the reference mark on the
mandrel.
[0042] Other modifications and variations to the appended claims
may be practiced by those of ordinary skill in the art, without
departing from the spirit and scope as set forth in the appended
claims. It is understood that features of the various examples may
be interchanged in whole or part. The preceding description, given
by way of example in order to enable one of ordinary skill in the
art to practice the claimed invention, is not to be construed as
limiting the scope of the invention, which is defined by the claims
and all equivalents thereto.
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