U.S. patent application number 09/800296 was filed with the patent office on 2001-08-02 for machine and process for placing and bonding elastic members in a relaxed state to a moving substrate web.
Invention is credited to McNichols, Patrick Sean.
Application Number | 20010010249 09/800296 |
Document ID | / |
Family ID | 22831085 |
Filed Date | 2001-08-02 |
United States Patent
Application |
20010010249 |
Kind Code |
A1 |
McNichols, Patrick Sean |
August 2, 2001 |
Machine and process for placing and bonding elastic members in a
relaxed state to a moving substrate web
Abstract
A machine and process are disclosed for bonding an elastic
member to a moving substrate web while the elastic member is in an
un-stretched condition. The machine provides for upwardly folding a
moving substrate web along a longitudinal centerline while
maintaining the side edge regions of the web in a flat un-folded or
un-gather condition. An elastic member is applied to the moving web
while the elastic member is un-stretched, applying the first and
second end regions of the elastic member to the respective first
and second side edge regions of the moving web. The end regions of
the elastic member are next bonded to the side edges of the web,
leaving the remainder of the elastic member un-bonded to the web.
The web is then un-folded or un-gathered to its first normal width,
stretching the bonded elastic member. At least a portion of the
remainder of the elastic member previously un-bonded to the web is
then bonded to the web, and the stretched elastic member is allowed
to relax.
Inventors: |
McNichols, Patrick Sean;
(Hortonville, WI) |
Correspondence
Address: |
WILHELM LAW SERVICE, S.C.
100 W LAWRENCE ST
THIRD FLOOR
APPLETON
WI
54911
|
Family ID: |
22831085 |
Appl. No.: |
09/800296 |
Filed: |
March 5, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09800296 |
Mar 5, 2001 |
|
|
|
09222153 |
Dec 29, 1998 |
|
|
|
6197138 |
|
|
|
|
Current U.S.
Class: |
156/229 |
Current CPC
Class: |
Y10T 156/1317 20150115;
A61F 13/15601 20130101; Y10T 156/1741 20150115 |
Class at
Publication: |
156/229 |
International
Class: |
B32B 031/00 |
Claims
What is claimed is:
1. A machine for placing and bonding elastic members in an
un-stretched state to a substrate web, said elastic members having
first and second ends defining a first un-stretched length, first
and second end regions respectively proximate said first and second
ends; said substrate web having a longitudinal axis, first second
edges defining a first width, and first and second edge regions
proximate said first and second edges; said machine comprising: a)
apparatus for folding the substrate web to a second width less than
said first width, and holding the gathered substrate web at said
second width to receive said elastic member in an un-stretched
state with the length of said elastic member being transverse to
said longitudinal axis of said substrate web, b) apparatus for
bonding said first and second end regions of said elastic member
respectively to said first and second edge regions of the folded
substrate web while said elastic member is in an un-stretched
state, leaving the remainder of said length of said elastic member
un-bonded to said substrate web: c) apparatus for stretching said
bonded elastic member and un-gathering said substrate web to its
first width: and d) apparatus for bonding a portion of said
remainder of the previously un-bonded length of the elastic member
to said substrate web while said elastic member is in the stretched
state.
2. The machine of claim 1 wherein said apparatus for folding the
substrate web comprises a header portion for folding the substrate
web, a tail portion for restoring said substrate web to an
un-folded condition and stretching the bonded elastic member, and a
central portion disposed between said header portion and said tail
portion for supporting and guiding the folded web.
3. The machine of claim 2 wherein said header portion comprises an
upwardly-ramping header plate having an upper surface, a leading
edge, a trailing edge, first and second side edges, and first and
second side regions respectively proximate said sides edges, said
first and second side regions being folded downwardly such that the
upper surface of said header plate is progressively reduced in
transverse dimension from said leading edge to said trailing edge
and said side regions correspondingly progressively increase in
transverse dimension from said leading edge to said trailing
edge.
4. The machine of claim 2 wherein said center portion of said
apparatus for folding the substrate web comprises a spine
comprising a vertical element having an upper surface and a lower
surface, a first end and a second end, said upper surface of said
spine proximate said first end being upwardly sloped to receive
said header portion of said apparatus and said upper surface of
said spine proximate said second end being downwardly sloped to
receive said tail portion of said apparatus, remainder of said
upper surface of said spine receiving a crown for supporting said
substrate web along said longitudinal centerline of said substrate
web, and web guide members attached to the lower surface of said
spine.
5. The machine of claim 4 wherein said web guide members are
laterally adjustable with respect to said longitudinal centerline
of said substrate web.
6. The machine of claim 2 wherein said tail portion comprises a
downwardly-ramping tail plate having an upper surface, a leading
edge, a trailing edge, first and second side edges, and first and
second side regions respectively proximate said sides edges, said
first and second side regions being folded downwardly such that the
upper surface of said tail plate increases in transverse dimension
from said leading edge to said trailing edge and said side regions
correspondingly decrease in transverse dimension from said leading
edge to said trailing edge.
7. The machine of claim 6 wherein said tail portion further
comprises first and second outwardly depending web guide members
for restoring said folded substrate web and for stretching an
elastic member bonded at its first and second ends to said
respective first and second edge regions of said substrate web.
8. The machine of claim 1 wherein said apparatus for bonding said
first and second end regions of said elastic member respectively to
said first and second edge regions of the folded substrate web
comprises first and second spaced-apart ultrasonic bonding horns, a
combination roller, and a rotary cutter, said first and second
rotary ultrasonic bonding horns having respective first and second
outer working surfaces acting cooperatively with the working
surface of said ultrasonic bonding anvils on said combination
roller.
9. The machine of claim 8 wherein said machine further comprises
ultrasonic bonding apparatus for bonding to said substrate web at
least a portion of the remainder of said elastic member not
previously bonded to said web.
10. A process for placing and bonding elastic members in an
un-stretched state to a substrate web, said elastic members having
first and second ends defining a first un-stretched length, first
and second end regions respectively proximate said first and second
ends, and said substrate web having a longitudinal centerline,
first and second edges defining a first width, and first and second
edge regions respectively proximate said first and second edges,
said process comprising the steps of: a) gathering the substrate
web to a second width less than said first width, and holding the
gathered substrate web at said second width; b) placing an elastic
member in an un-stretched state on said substrate web with the
length of said elastic member being transverse to said longitudinal
axis of said substrate web, c) bonding said first and second ends
of said elastic member to said substrate web adjacent the
respective first and second edges of said substrate web while said
elastic member is in an un-stretched state, leaving the remainder
of said length of said elastic member un-bonded to said substrate
web; d) stretching said bonded elastic member and un-gathering said
substrate web to its first width; and e) bonding at least a portion
of said remainder of the previously un-bonded length of said
elastic member to said substrate web while said elastic member is
in the stretched state.
11. The process of claim 10 wherein said step of gathering the
substrate web comprises upwardly folding said web substantially
along said longitudinal centerline, thus drawing said first and
second edges toward one another to gather said substrate web to
said second width.
12. The process of claim 11 wherein said first and second edge
regions of said substrate web are maintained in a flat, un-folded
condition while the remainder of said substrate web is upwardly
folded.
13. The process of claim 12 wherein said first and second end
regions of said elastic member are placed respectively on said
first and second flat un-folded edge regions of said substrate
web.
14. The process of claim 13 wherein said first and second end
regions of said elastic member are bonded to said first and second
flat un-folded edge regions of said substrate web while said
elastic member is in a- substantially un-stretched state.
15. A process for placing and bonding elastic members in an
un-stretched state to a substrate web, said elastic members having
first and second ends defining a first un-stretched length, first
and second end regions respectively proximate said first and second
ends, and said substrate web having a longitudinal centerline,
first and second edges defining a first width, and first and second
edge regions respectively proximate said first and second edges,
said process comprising the steps of: a) upwardly folding said web
substantially along said longitudinal centerline, thus drawing said
first and second edges toward one another to gather said substrate
web to said second width less than said first width, and holding
the gathered substrate web at said second width; b) placing said
first and second end regions of said elastic member in an
un-stretched state respectively on said first and second flat
unfolded edge regions of said substrate web with the length of said
elastic member being transverse to said longitudinal axis of said
substrate web, c) bonding said first and second end portions of
said elastic member to said substrate web adjacent the respective
first and second edges of said substrate web while said elastic
member is in an un-stretched state, leaving the remainder of said
length of said elastic member un-bonded to said substrate web; d)
un-gathering said substrate web and stretching said elastic member
bonded at the first and second end regions thereof to said web; and
e) bonding at least a portion of said remainder of the previously
un-bonded length of said elastic member to said substrate web while
said elastic member is in the stretched state.
16. The process of claim 15 wherein said first and second edge
regions of said substrate web are maintained in a flat, un-folded
condition while the remainder of said substrate web is upwardly
folded.
Description
TECHNICAL FIELD
[0001] This invention relates to machines and to industrial
processes. More particularly, the invention concerns a machine and
a process for placing and bonding an elastic member to a moving
substrate web while the elastic member is in an un-stretched or
relaxed state.
BACKGROUND OF THE INVENTION
[0002] In the manufacture of infant diapers, adult incontinence
garments and the like, it is frequently desirable to attach an
elastic member to the remainder of the diaper or garment in order
to secure the diaper or garment about the legs or waist of the
user. Typically, these articles are manufactured by a high-speed
process in which individual parts of the diaper or garment are
affixed to a moving web of material by adhesive or ultrasonic
bonding. U.S. Pat. Nos. 3,987,794: 3,990,450: 3,995,638; 3,995,640;
and 4,014.338 to Schaar describe such infant diapers having an
elasticized waist band.
[0003] One problem associated with this process relates to the
attachment of the elastic member to the moving web. In prior art
machines and processes in which the elastic member is bonded to the
substrate web in the stretched condition, there is frequently a
tendency for the stretched elastic member to pull away from the
substrate web before the bonds become fully annealed. Attempts to
solve this problem center around various schemes for attaching the
elastic member to the substrate web in an un-stretched
condition.
[0004] U.S. Pat. No. 4,240,866 and its divisional, United States
Patent 4,285,747 to Rega describe a process of manufacture whereby
an elastic waist member is attached in an un-stretched state to a
substrate web in the manufacture of infant diapers.
[0005] U.S. Pat. No. 4,337,771 to Pieniak, et al. describes an
infant diaper with an elongated elastic strip secure to at least
one margin of the diaper at a central portion of the margin, with a
unitary, relatively inelastic reinforced region in a corner of the
diaper.
[0006] U.S. Pat. No. 4,400,227 to Riemersma discloses a method of
applying elasticized garment cuffs in a stretched condition to a
substrate web.
SUMMARY OF THE INVENTION
[0007] In accordance with the present invention the is provided, in
its principal embodiment, a machine for placing and bonding elastic
members in an un-stretched state to a substrate web. The elastic
members have first and second ends defining a first un-stretched
length, first and second end regions respectively proximate the
first and second ends, and the substrate web has a longitudinal
axis and first and second edges defining a first width, with first
and second side regions respectively proximate the first and second
edges.
[0008] The machine comprises an apparatus for gathering the
substrate web to a second width which is less than the first width,
and holding the gathered substrate web at this second width while
receiving the elastic member in an un-stretched state. The elastic
member is received on the substrate web in such an orientation that
its length is in a direction transverse to the longitudinal axis of
the substrate web.
[0009] An apparatus of the machine then bonds the first and second
end regions of the elastic member to the first and second edge
regions of the substrate web while the substrate web is gathered
and the elastic member is in an un-stretched state. The bonding of
the two ends of the relaxed elastic member to the substrate web
leaves the remainder of the length of the elastic member un-bonded
to the substrate web.
[0010] The machine further provides an apparatus for stretching the
bonded elastic member while simultaneously un-gathering the
substrate web to its first width. An apparatus of the machine then
bonds at least a portion of the remainder of the length of the
elastic member to the substrate web while the elastic member is in
the stretched state.
[0011] In an alternative embodiment, the present invention provides
a process for placing and bonding elastic members in an
un-stretched state to a substrate web. The elastic members have
first and second ends and a first un-stretched length, with first
and second end regions respectively proximate the first and second
ends. The substrate web has a longitudinal axis or centerline,
first and second side edges defining a first width, and first and
second side edge regions respectively proximate the first and
second side edges.
[0012] The process of the invention comprises the steps of first
gathering the substrate web to a second width which is less than
the first width, and holding the gathered substrate web at this
second width. Next, an elastic member is placed in an un-stretched
state on the substrate web with the length of the elastic member
being transverse to the longitudinal axis of the substrate web.
[0013] In the next step, the first and second end regions of the
elastic member are bonded respectively to the first and second side
edge regions of the substrate web while the elastic member is in an
un-stretched state, leaving the remainder of the length of the
elastic member un-bonded to the substrate web.
[0014] Next, bonded elastic member is-stretched, simultaneously
un-gathering the substrate web to its first width. Finally, at
least a portion of the remaining previously un-bonded length of the
elastic member is bonded to the substrate web while the elastic
member is in the stretched state.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The operation of the machine and process of the invention
can be more readily understood by reference to the drawing figures
which form a part of the disclosure of the invention.
[0016] In The Drawing:
[0017] FIG. 1 is a schematic perspective representation of one
embodiment of the machine of the present invention.
[0018] FIG. 2 is a perspective view of a "shoe-horn" apparatus of
the machine of the invention for folding or gathering the substrate
web.
[0019] FIG. 3 is an exploded perspective view of the shoe-horn
apparatus of FIG. 2 showing its component parts.
[0020] FIG. 4 is a top view of the header plate of the shoe-horn
apparatus of FIG. 2.
[0021] FIG. 5 is a side view of the header plate of the shoe-horn
apparatus of FIG. 2.
[0022] FIG. 6 is an end view of the header plate of the shoe-horn
apparatus of FIG. 2.
[0023] FIG. 7 is a perspective view of one embodiment of the
combination roller of the machine of the present invention.
[0024] FIG. 8 is a perspective view of the main body member of the
combination roller of FIG. 7.
[0025] FIG. 9 is a perspective view of an ultrasonic bonding anvil
hold-down shoe for the combination roller of FIG. 7.
[0026] FIG. 10 is a perspective view of an ultrasonic bonding anvil
shoe for the combination roller of FIG. 7.
[0027] FIG. 11 is a cross-sectional view of the ultrasonic bonding
anvil hold-down shoe of FIG. 9 taken along cut line A-A.
[0028] FIG. 12 is a cross-sectional view of the ultrasonic bonding
anvil shoe of FIG. 10 taken along cut line B-B.
[0029] FIG. 12b is an enlarged view of the region designated "12b"
in FIG. 12.
[0030] FIG. 13 is a front view of the combination roller and rotary
cutter sub-assembly of the machine of FIG. 1.
[0031] FIG. 14 is an end view of the combination roller and rotary
cutter sub-assembly of FIG. 13.
[0032] FIG. 15 is an end view of the rotary cutter of FIG. 13.
[0033] FIG. 16 is a schematic side-view showing the movement of the
substrate web and cut elastic components through the machine of
FIG. 1.
[0034] FIG. 16b is an enlarged view of the region designated "16b"
in FIG. 16.
[0035] FIG. 17 is a cross section of the shoe-horn apparatus,
substrate web, elastic component, and a portion of the underlying
combination roller taken along cut line C-C of FIG. 16.
[0036] FIG. 18 is a perspective view of a vacuum take-off for the
roller sub-assembly of FIG. 13.
[0037] FIG. 19 is a cross-sectional view of the vacuum take-off of
FIG. 18 taken along cut line E-E.
[0038] FIG. 20 is a schematic plan view of the progress of the
substrate web and attached elastic members as they move through the
machine of FIG. 1, with underlying machine parts shown in dashed
lines.
[0039] FIG. 21 is a partial view of the second bonding apparatus of
the machine of FIG. 1 showing a cross-sectional view of the
stretched elastic member and un-gathered substrate web, taken along
cut line D-D of FIG. 18.
DETAILED DESCRIPTION
[0040] Referring to FIG. 1, a machine 100 of the present invention
comprises a "shoe-horn" apparatus 200 extending through the center
of the machine 100, a combination roller and rotary cutter
sub-assembly 300, first rotary ultrasonic bonding apparatus 400,
and second ultrasonic bonding apparatus 500.
[0041] The so-called "shoe-horn" apparatus 200 is designed to
receive a substrate web 602 and fold or gather the web to a width
less than the original width of the web and to hold the substrate
web in this narrower, gathered configuration while a strip 610 of
un-stretched elastic material is deposited onto the substrate web
and bonded to it by means of a first ultrasonic bonding apparatus
400. Gathering of the substrate web 602 to a width narrower than
its normal, or un-gathered width, permits depositing and bonding
the elastic member on and to the gathered substrate web while the
elastic member is in a relaxed or un-stretched state. This feature
of the machine and process of the invention insures proper
placement of the elastic member on the substrate web and prevents
detachment of the elastic member from the web before the bonds
holding the elastic member to the substrate web have annealed or
healed.
[0042] The manner in which the shoe-horn apparatus 200 receives,
gathers, and holds the substrate web 602 can be more readily seen
by reference to FIGS. 2 through 6 which show the apparatus and its
components in greater detail. FIG. 2 shows the assembled shoe-horn
apparatus, and FIG. 3 shows the apparatus or sub-assembly in an
exploded view showing its components parts. FIGS. 4-6 show the
header plate in top, side, and end views, respectively.
[0043] Referring to FIGS. 2 through 6, the shoe-horn apparatus 200
comprises a header plate 202 for folding or gathering the substrate
web, the header plate having an upper surface 204, a lower surface
206, a leading edge 208, a trailing edge 210, first and second side
regions 207 and 209, and first and second side edges 212 and 214.
(Throughout this specification and the appended claims, the terms
"leading" and "trailing," when applied to machine components, refer
to the direction of workpiece flow through the machine. "Leading"
features of a machine component are up-stream in the machine from
"trailing" features.)
[0044] The header plate 202 starts at its leading edge 208 as a
flat member and ramps upward at an angle .alpha. to the trailing
edge 210. The angle .alpha. is the arc sine h/L of FIGS. 4 and 5.
The values of h and L are pre-determined, based upon the initial
width of the substrate web and the narrower width to which it is to
be gathered or folded during processing for a particular product
line to be manufactured.
[0045] As shown in FIG. 6, the side regions 207 and 209 of the
header plate 202 are folded downwardly, or away from the top
surface 204 of the header plate at an angle .alpha., and re-folded
upwardly through the same angle .beta. to bring the outermost
surfaces of the side regions back into a parallel relationship with
the crown 205 of the top surface of the header plate. This upward
ramping of the header surface, and downward and outward folding of
the side regions 207 and 209 of the header plate 202 causes the
transverse dimension of the top surface 204 of the header plate to
be progressively reduced from its leading edge 208 to its trailing
edge 210 while the side regions 207 and 209 are correspondingly
progressively increased from the leading edge 208 to the trailing
edge 210. This brings the side edges 212 and 214 toward one
another, narrowing the header plate from its initial width W.sub.1
at the leading edge 208 to a narrower width W.sub.5 at the trailing
edge 210. At the same time, the
[0046] As shown in FIG. 3, the header plate 202 is bolted by means
of bolts 216, or is otherwise fastened, to the upwardly ramping top
surface 224 of a central spine member 220. A downwardly ramping
tail plate 240 is likewise bolted by means of bolts 248, or
otherwise fastened, to the downwardly ramping top surface 226 of
the central spine 220. While the length of tail plate 240 is not
critical, its width, when side regions 244 and 245 are folded
downwardly away from top surface 242 through an angle .beta., is
also equal to W.sub.5.
[0047] When the header plate 202 and tail plate 240 are fastened to
the central spine 220. the open space which remains along the top
surface 222 of spine 220 between the header plate 202 and tail
plate 240 is filled by a crown piece 230. The crown piece 230 is
attached by bolts 237, or other wise fastened, to a slideably
adjustable crown piece mounting member 232. The crown piece
mounting member is, in turn, bolted by bolts 238 to spine 220. The
side regions 234 and 236 of crown piece 230 are folded downwardly
through an angle .beta. to conform to the trailing edge 210 of
header piece 202 and the leading edge 246 of tail plate 240. When
the shoe-horn apparatus is assembled, the ends of crown piece 230
abut respectively the trailing edge 210 of header plate 202 and the
leading edge 246 of tail plate 240. The upwardly ramping header
plate 202, crown piece 230 and downwardly ramping tail plate 240
thus provide a smooth surface over which substrate web 602 passes
during operation of the machine.
[0048] Laterally or slideably adjustable side web guides 250 and
252 are bolted, respectively, by bolts 254 and 255 to the bottom
surface 228 of spine 220 directly beneath crown piece 230. First
260 and second 262 laterally or slideably adjustable tail portion
web guides are likewise fastened, respectively by bolts 268 and 269
to spine 220 directly beneath tail plate 240. The side edge 261 of
tail portion web guide 260 is fitted with a web guide rod 264 which
extends beyond tail portion web guide 260 and is bent inwardly,
i.e. towards the other tail portion web guide 262, at its end
furthest from attachment of rod 264 to tail portion web guide 262.
Likewise, the side edge 263 of tail portion web guide 262 is fitted
with a web guide rod 266 which is also bent at its end furthest
from attachment to tail portion web guide 262, inwardly toward web
guide rod 260.
[0049] The spine 220, crown piece 230, crown piece support member
232, and adjustable web guide members 250 and 252 may each be of
unitary construction, as shown in FIG. 2. In an alternative
embodiment, any or all of these members may be split into two or
more parts to aid in assembly or maintenance of the machine
100.
[0050] The cooperative interaction of the shoe-horn apparatus 200
with other elements of the machine can be seen by reference again
to FIG. 1. The machine comprises, in addition to the shoe-horn
apparatus 200, a combination roller and rotary cutter apparatus 300
which comprises a combination roller 302 and a rotary cutter 352.
The edge of a cutting blade 354 on the rotary cutter and a cutter
anvil bar (306 in FIG. 7) on the combination roller 302 cooperate
to cut discrete elastic members 610 from the web of elastic
material 608 as the web passes between the rotary cutter 352 and
the combination roller 302. Details of the combination roller and
rotary cutter are described more fully below. The combination
roller 302 and rotary cutter 352 are driven to contra-rotate by a
meshed 1:1 gear set driven, in turn, by servo-motor 380 through
right angle transmission 382. The servo-motor 380 is controlled by
electronic controller 384.
[0051] Servomotors having the requisite torque are commercially
available. A suitable servomotor for use in the machine of the
present invention is available, for example, from the INDRAMAT
Division of Mannesmann Rexroth, 5150 Prairie Stone Parkway, Hoffman
Estates, Ill. 60192. The servomotor is controlled by a Model DDS or
HDS controller which has been programmed in the manner taught by
the manufacturer using the desired speed profile for a given
product.
[0052] The speed profiles for one cycle of a process using the
machine of the present invention comprises a lower dwell speed
during which the elastic web 608 is received on combination roller
302 and cut into discrete components 610 by the cooperative action
of the cutting bar 354 on rotary cutter 352 and cutter anvil bar
306 on combination roller 302. This lower constant dwell speed is
maintained for a portion, preferably one-fourth, of each revolution
of the combination roller and rotary cutter, and is equal to the
linear speed of advancing web 608 of elastic material. The cut
elastic member 610 is held to the working surface of the
combination roller 302 by vacuum means while the roller and
attached elastic member 610 are accelerated to a second constant
dwell speed equal to that of the linear speed of advancing
substrate web 602. The acceleration takes place during a portion of
each revolution, preferably one-fourth revolution, of the
combination roller. The second constant dwell speed is maintained
for a portion, again preferably one-fourth cycle, of each rotation
of the combination roller 302 while the elastic member passes
through the nips between combination roller 302 and the two rotary
ultrasonic bonding horns 402 and 404 during which the elastic
member 610 is bonded to the substrate web 602 The combination
roller is then decelerated, during the final portion, preferably
one-fourth cycle, of rotation of the combination roller to the
first lower constant dwell speed, completing one rotation
cycle.
[0053] A graphical speed profile is constructed for the process
using the linear speed of the combination roller as the ordinate of
the graph, and a scale from zero to one complete cycle being the
abscissa of the graph. For convenience, the four periods of each
cycle of rotation (i.e. first lower constant dwell speed,
acceleration, second higher constant dwell speed, and deceleration)
are divided equally to each form one-fourth rotation cycle. A data
table of velocity for n points along the time axis of the speed
profile is generated. The resulting data table is used as the data
control set for controlling the variable speed of the servomotor
during each revolution of the machine rollers. For example, a data
table of roller speed at each {fraction (1/2000)} revolution is
constructed. These data are fed into the servomotor controller to
drive the servomotor, combination roller, and rotary cutter at the
desired speeds during each cycle of rotation. To convert the
machine to the production of a new product with different
configuration, it is merely necessary to generate a new data table
for that product to drive the servomotor.
[0054] The first ultrasonic bonding apparatus 400 comprises first
402 and second 404 rotary ultrasonic bonding horns of the type
known in the art and disclosed in U.S. Pat. Nos. 5,707,470 and
5,711,847. The horns are shown with their respective transducers
406 and 408. The first and second ultrasonic bonding horns 402 and
404 rotate at the same linear speec, which is the speed of the
advancing substrate web 602, and are driven by jack shaft 408,
pulleys 410 and 412 and gear belts 414 and 416. Jack shaft 408 is,
in turn, driven by pulley 418 and gear belt 420 by a motor, not
shown.
[0055] A second ultrasonic bonding apparatus 500 is disposed
downstream in the machine from the first ultrasonic bonding
apparatus 400. The second ultrasonic bonding apparatus 500
comprised a stationary ultrasonic bonding horn 502, transducer 504
and a rotary anvil 506. The nip between the stationary ultrasonic
bonding horn 502 working surface and the cooperating working
surface of the rotary anvil 506 is placed laterally between the
first cylindrical web guide rod 264 attached to tail portion web
guide 260 and cylindrical web guide rod 266 attached to tail
portion web guide 262, and vertically in line with the substrate
web 602 as it advances through the machine 100.
[0056] Details of the combination roller of one embodiment of the
invention are depicted in FIG. 7 where the roller is shown as 302.
The roller comprises a shaft portion 308, a body portion 304, and
two vacuum cap or end plates, one of which, 710 is shown. The other
of the two vacuum cap or end plates is identical to plate 710 and
fits over shaft 308 at the opposite end of the roller 302. In the
embodiment depicted in FIG. 8, spaced-apart first 310 and second
312 ultrasonic bonding anvil shoes are shown flanked, respectively,
by ultrasonic bonding anvil hold-down shoes 316, 318, and 320, and
322. In a manner described in further detail below, the ultrasonic
bonding anvil hold-down shoes 316, 318, 320, and 322 are bolted or
otherwise fastened to the body portion 304 of the combination
roller and hold the ultrasonic bonding anvil shoes 310 and 312 to
the roller body portion 304. Also shown in FIG. 7, comprising an
element of the combination roller 302, is the cutter anvil bar 306
which cooperates with the cutting edge of the cutting bar 354
attached to the rotary cutter 352 to cut discrete components 610
from the elastic web.
[0057] FIG. 8 shows the body portion 304 of the roller with the
ultrasonic bonding anvil shoes and ultrasonic bonding anvil
hold-down shoes removed. Additional features of the combination
roller body may be seen including vanes or stand-offs 330, and 332,
the former having threaded holes 338 for receiving bolts or other
fasteners. The body portion of the combination roller has an outer
surface which defines an intermittent or interrupted surface
defined by the extremities of the vanes or stand-offs 330, and 332.
While this outer surface may conform to an interrupted cylindrical,
hexagonal, octagonal or other similar shape, it is preferred that
the interrupted outer surface of the body portion of the roller
conform to a cylinder for ease of fabrication of the ultrasonic
bonding anvil and ultrasonic bonding anvil hold-down shoes. In any
case, the shoes are fabricated to have an inner surface which
conforms to and fits closely against the interrupted outer surface
of the body portion 304 of the combination roller.
[0058] In a particularly preferred embodiment, the body portion of
the combination roller is fabricated by machining grooves, slots,
or channels in a hollow cylinder of the appropriate material,
preferably steel. These grooves, slots, or channels, typified by
grooves or channels 334 in FIG. 9, extend inwardly from the surface
of the body portion 304 and run in a longitudinal direction along
the length of the body portion 304. Certain of the vanes or
stand-offs (for example 330) are also machined to form slots or
channels 336 running in a transverse direction with respect to the
grooves or channels 334. These transverse channels, which may be of
a depth equal to, or preferably less than, the longitudinal
channels 334, permit air flow laterally between the longitudinal
grooves, slots or channels 334.
[0059] The body 304 and shaft 308 portions of the combination
roller may alternatively be a unitary assembly fabricated by
machining a single piece of material to form both the shaft and
body portion, but advantages gained by forming the body and shaft
portions of the roller as separate pieces make unitary fabrication
less desirable. In a preferred embodiment of the combination roller
body 304, the body is fabricated from a hollow cylinder which is
cut or split into two pieces along longitudinal cuts 324 and 326.
The body portion may, of course, be split into more than two
sections, but a two-section body portion is preferred. This
embodiment has the advantage of permitting affixing the body
portion pieces to the combination roller shaft portion after the
latter has already been assembled to the machine, thus simplifying
machine set-up and maintenance. In the split, two-piece, embodiment
of the body portion 304 of the combination roller shown in FIG. 8,
the body portion pieces are affixed to the shaft portion 308 by
bolts or other fasteners passing through holes 339 and the pieces
are kept from slipping on the shaft by means of key-way 328
cooperating with a key (not shown) on shaft 308. The body portion
304 may be slideably moved along the shaft portion 308 of the
roller prior to affixing the body portion to the shaft portion.
This permits variations in machine set-up to accommodate different
product configurations.
[0060] The ultrasonic bonding anvil shoes 310 and 312 and
ultrasonic bonding anvil hold-down shoes 316, 318, 320, and 322 are
depicted in greater detail in FIGS. 9-12b. Both types of shoes
comprise pieces having outer or working surfaces which are sections
of a cylindrical surface. While the inside surfaces of both types
of shoes are shown in the embodiments depicted in FIGS. 9 and 10 as
also comprising sections of a cylindrical surface, the inner
surface of the shoes can be of any shape which conforms to and fits
closely with the outer surface of the combination roller body
portion 304 as described above. Thus, when the shoes are affixed to
the body portion 304 of the combination roller, regardless of their
inner surface shape, they form a cylindrical outer working surface
of the combination roller 302.
[0061] A typical ultrasonic bonding anvil hold-down shoe 316 is
shown in FIG. 9 where vacuum apertures 375 are shown forming a
pattern in the shoe. Bolt or fastener apertures 374 in the
hold-down shoe receive bolts or fasteners for attaching the
hold-down shoes to the threaded holes 338 of vanes or stand-offs
such as 330 in combination roller body portion 304 as shown in FIG.
8.
[0062] As can be seen in FIG. 9 and the cross-sectional view in
FIG. 11, taken along cut line A-A of FIG. 9, the edges of the anvil
hold-down shoes 316 are provided with inwardly-facing flanges 376
and 377. The term "inwardly facing" flanges means that the outer or
working surface 370 of the anvil hold-down shoes are under-cut to
form the flanges such that the outer surface 370 is wider than the
inner surface 371 of the shoes.
[0063] The ultrasonic bonding anvil shoes are represented by
ultrasonic bonding anvil shoe 310 depicted in FIG. 10 and the
cross-sectional view of FIG. 12 taken along cut line B-B of FIG.
10. As with the hold-down shoes 316, the ultrasonic bonding anvil
shoes 310 are provided with a pattern of vacuum 5 apertures 384. In
addition, the outer or working surfaces of the ultrasonic bonding
anvil shoes are provided with a raised pattern of stippling, shown
as a pattern of dots 388 in the embodiment depicted in FIGS. 10,
12a and 12b. The pattern may take any form which effectively
interacts with the working surface of the ultrasonic bonding horn
to form bonds between webs of materials passing between the two.
The pattern of stippling is typically formed in the outer working
surface of the ultrasonic bonding shoes by machining or chemically
etching away a portion of the outer surface of the shoes to leave
the raised stippling pattern. The resulting raised stipples 388 and
the etched or machined valleys between 389 can be more clearly seen
in the magnified view of the top surface 380 of the ultrasonic
bonding anvil shoe shown in FIG. 12b. Initially the outside
cylinder diameter of the pre-fabricated ultrasonic bonding anvil is
a few mils (1 mil 0.0254 mm) greater than the outside diameter of
the hold-down shoes. The pattern of stippling which remains on the
ultrasonic bonding anvil shoes after machining or etching is thus
raised slightly above the surface of the anvil hold-down shoes.
[0064] Unlike the anvil hold-down shoes, however, the ultrasonic
bonding anvil shoes are not provided with bolt or fastener holes or
apertures. It has been found that when the ultrasonic bonding anvil
shoes are, themselves, bolted or otherwise attached with fasteners
to the combination roller body, the vibratory energy of the
ultrasonic bonding horns tends to loosen or, in some instances,
ultimately burn out the fasteners.
[0065] Instead, the first 382 and second 383 edges of the
ultrasonic bonding anvil shoes are provided with respective
outwardly-facing flanges 386 and 387. The term "outwardly facing"
flanges means that the outer or working surface 380 of the anvil
shoes are over-cut so that the outer or working surface 380 of the
anvil shoes is narrower than the inner surface 381. In the
assembled combination roller 302, the ultrasonic bonding anvil
shoes are thus held firmly to the outer surface of the body portion
304 of the combination roller by flanking pairs of hold-down shoes.
The cooperative action of the ultrasonic bonding anvil shoes and
the hold-down shoes can be seen by reference to FIG. 17 which shows
the shoes in cross-section.
[0066] In assembling the anvil and anvil hold-down shoes to roller
302 of FIG. 7, the first edge 372 of hold-down shoe 316 is placed
against the first edge 382 of anvil shoe 310 on the roller body 304
and moved laterally so that the inwardly-facing flange 376 of the
hold-down shoe 316 overlies the outwardly-facing flange 386 of the
anvil shoe 310. The anvil hold-down shoe is then bolted or
otherwise fastened to the roller body 304. The first edge of a
second anvil hold-down shoe is likewise placed against the second
edge 383 of the anvil shoe 310 and moved laterally so that the
inwardly-facing flange of the second hold-down shoe overlies the
outwardly facing flange 387 along the second edge 383 of the anvil
shoe. This second anvil hold-down shoe is likewise bolted or
otherwise fastened to the body portion 304 of the combination
roller 302. In a similar manner, a second ultrasonic bonding shoe
is affixed to the roller body 304 by flanking pairs of hold-down
shoes. The cooperative interaction of the inwardly facing flanges
on the bolted hold-down shoes and the outwardly facing flanges of
the ultrasonic bonding anvil shoes urges the inside surface 381 of
anvil shoes against the outside surface of the combination roller
body portion 304. In this manner, the ultrasonic bonding anvil
shoes are held firmly in place on the roller body. Since the bolts
or fasteners holding the anvil hold-down shoes are thus distanced
from the rotary ultrasonic bonding horns, the problem alluded to
above of vibratory loosening or burning off of the bolts or
fasteners is considerably diminished, lengthening the period of
usable life of the anvils between required machine maintenance.
[0067] The spacer shoe(s) 314 have the same construction as the
anvil shoes with outwardly-facing flanges along each edge of the
spacer shoes and a pattern of vacuum apertures. However, unlike the
anvil shoes, the spacer shoes have a smooth outer surface and lack
the raised stippling of the anvil shoes. In a preferred embodiment,
the spacer shoes are made of a material lighter than that making up
the anvil and anvil hold-down shoes, such as nylon, ABS plastic, or
the like. This reduces the overall mass of the combination roller.
The spacer shoes are fabricated in any width to appropriately space
the two anvil shoes for the particular work product.
[0068] When the anvil, spacer, and anvil hold-down shoes are thus
affixed to the combination roller body, vacuum tubular channels or
cavities 390 (FIG. 7) are formed between the inner surfaces 371 and
381 of the shoes and the walls and floor of grooves, channels, or
slots 334 in the combination roller body portion 304 as can be seen
in FIG. 7. These channels or cavities 390 provide means for drawing
air in through the vacuum apertures 375 and 384, respectively, in
the anvil hold-down shoes 316 and the bonding anvil shoes 310. The
tubes or channels permit the movement of air along the inside of
the assembled combination roller assembly shown in FIG. 7, and
slots or grooves 335 (cf. FIG. 8) permit lateral movement between
adjacent channels or tubes in the assembled combination roller.
[0069] Referring to FIG. 7, the vacuum cap or end plate 710 fits
over shaft 308, and an identical vacuum cap or end plate (not
shown) fits over shaft 308 at the opposite end of the roller 302.
The plate 718 is attached to the roller body 304 by bolts 318
passing through bolt holes 714 and received into threaded holes 716
in the roller body 304. A vacuum aperture 712 in plate 710 and a
similar aperture in the plate not shown communicate with the vacuum
tubes or channels 390 formed in the assembled roller 302.
[0070] The combination roller and rotary cutter sub-assembly is
shown in front view in FIG. 13. Machine frame 340 supports the
upper combination roller shaft 308 on bearings 342 and 344 and the
lower rotary cutter shaft 341 on bearings 343 and 345. The
ultrasonic bonding anvil shoes 310 and 312 are shown on combination
roller 302 flanked by and held in place by hold-down shoes 316,
318, 320, and 322 in the manner described above, and the
combination roller is flanked at each end by vacuum commutators 702
and 704. First 402 and second 404 rotary ultrasonic horns are shown
in partial cut-away above the combination roller 302.
[0071] The combination roller and rotary cutter sub-assembly 300 is
shown in end view in FIG. 14. In addition to features described
above, and assigned the same reference numerals, the end view shows
a cutter blade oiler assembly 902 and cutter blade oiler roller
904. Gear housing 808 has been removed in this view to show
intermeshed 1:1 gears 810 and 812 driving, respectively, the upper
combination roller shaft 308 and lower rotary cutter shaft 341.
[0072] FIG. 15 shows an end view of one embodiment of the rotary
cutter 352. The body of the rotary cutter has been machined to have
one or more flats; the embodiment shown in FIG. 19 showing four
such flats, indicated as 356, 358, 360, and 362. The number of
flats may vary from one to four, with one or three flats being
preferred. More than four flats is theoretically possible on the
rotary cutter, but such an arrangement becomes increasingly
crowded.
[0073] In FIG. 15, one of these flats, 356 is shown occupied by a
cutting bar apparatus which comprises a base plate 364 a cutting
bar 354, a cutting bar retainer 366, and retainer bolt or fastener
368. The other three flats are shown unoccupied, with "ghost"
cutter bar elements shown in dotted outline. As can best be seen in
FIG. 16b, this arrangement permits the cutting bar 354 to strike
the cutting anvil bar 306 on the combination roller 302 at an
angle. This arrangement has two distinct advantages. First, the
edge of the cutting bar 354 which strikes the cutting anvil bar
306, and serves as the cutting edge, is only one of four such edges
on the cutting bar 354. When this edge becomes dulled or nicked
during operation of the machine, it is a simple matter to turn the
cutting bar to begin using a new edge. Second, the cutting bar 354
strikes the anvil bar 306 at an angle and can thus flex, somewhat
in the manner of a spring-board or diving board at a swimming pool.
This eliminates the need for careful or precise placement of the
cutting bar on the rotary cutter during machine set-up and
operation.
[0074] Details of the vacuum commutators 702 and 704 shown in the
combination roller sub-assembly of FIG. 13 are shown in FIGS. 18
and 19 which show vacuum commutator 702 in perspective and
cross-sectional views, respectively. The commutator 702 has a
central opening 716 which accommodates the shaft portion 308 of the
combination roller 302, and a vacuum take-off tube 706. An arcuate
groove 712 is machined into one face 710 of the commutator 702,
which subtends an arc .delta.. The groove 712 is machined into the
face 710 of the commutator, but does not extend completely though
the commutator to the other face. The groove 712 continues inside
the commutator to communicate with the opening 714 in the vacuum
take-off tube 706 as can be seen in the cross-sectional view of
commutator in FIG. 19 taken along cut line E-E of FIG. 18. As shown
in FIG. 13, commutator 702 abuts the end- or cap-plate fastened to
the left-hand end of combination roller 302. In a similar manner,
vacuum commutator 704, which is the mirror image of commutator 702
abuts end- or cap-plate 718, fastened to the right-hand end of
combination roller 302. (The designations "right-" and "left-hand"
with regard to combination roller 302 refer to the front view of
the roller sub-assembly shown in FIG. 13.) As the machine is
operated, the cap or endplates rotate slideably, with the roller to
which they are attached, against vacuum commutators 702 and 704.
The aperture in the cap or end-plates (for example, aperture 726 in
FIG. 7) communicates with the slots (for example 712 in FIGS. 18
and 19) in the commutators 702 and 704 during that portion of each
rotation of the combination roller while the apertures are adjacent
that portion of the vacuum commutator slot 712 subtended by the arc
.delta.. During this portion of each rotation, suction, externally
applied to the vacuum commutators through openings 706 and 708 draw
air in through the vacuum openings in the ultrasonic bonding anvil
shoes, the anvil hold-down shoes, and the spacer shoe(s) making up
the outer working surface of the combination roller. This air
passes, internal to the combination roller, through the channels
390 in the combination roller, and out of the roller through the
vacuum aperture 726 in the roller vacuum cap or end-plate. During
the remainder of the portion of each rotation, when the aperture
726 in each cap or end-plate is adjacent to the non-slotted face of
vacuum commutators, the aperture is closed off and no air can be
drawn from the combination roller or commutator. In this manner, by
selecting the appropriate arc .delta., the web 608 of elastic
material and discrete pieces 610 cut therefrom can be held to or
released from the working surface of the combination roller 302
during each any desired portion of each cycle of its rotation.
[0075] Having thus described the principle features of the machine
100 up-stream in the process of the invention, the functioning of
these parts of the machine in the process will now be described.
The process and machine of the invention are optimized for making
articles of manufacture having an elastic member attached to a
substrate web. Such articles include, for example, infant diapers
and adult incontinence garments having an elastic waist band.
Typically these articles comprise a moisture impervious or barrier
layer which is worn nearest the garment of the user, a moisture
pervious layer worn nearest the body of the user, and an absorbent
layer for receiving and retaining body fluids sandwiched between.
The moisture impervious or barrier layer, and the moisture pervious
lay are generally wider than that of the absorbent layer. The
barrier layer and moisture pervious layer are typically bonded
together at each side edge to sandwich the absorbent layer between.
This combination of elements, in a continuous web used in the
manufacture of infant diapers and adult incontinence garments, is
often termed a web "sausage" from which the individual diapers or
garments are eventually cut. Such diaper or incontinence garments
are also typically provided with one or more elastic waist band
elements and waist tabs which serve to hold the diaper or garment
to the user's body.
[0076] In manufacturing infant diapers or adult incontinence
garments using the machine and process of the present invention, a
substrate sausage web 602 enters the machine from the left (process
up-stream side) of the machine shown in FIG. 1, passing over the
lip 211 of the leading edge 208 of the shoe-horn header plate 202
with the barrier layer of the web sausage 602 lying atop the upper
surface of header plate 202. As the web sausage moves up the
surface 204 of the header piece 202, the side regions of the
sausage web conform to the downwardly folded side regions 207 and
209 of the header plate 202 and are, themselves, similarly
downwardly folded. This folding of the web sausage 602 brings the
side edges 604 and 606 of the web sausage 602 toward one another,
resulting in the width of the substrate web 602 being lessened
compared with its original width as it comes off the supply roller
603. The dimensions of the shoe-horn header plate 202 are
pre-determined so that the narrowest folded or gathered width of
the substrate web sausage is the same as or less than the width of
the web of elastic material 608. During machine set-up, the rotary
ultrasonic bonding horns 402 and 404 are adjusted on their bearing
shaft so that the outer surfaces of the respective horns are spaced
apart by a distance equal to the narrowest or folded width of the
substrate web. The laterally adjustable web guide members 250 and
252 on the shoe-horn folding apparatus 200 are likewise adjusted so
that they leave a small gap between their respective outer edges
and the inside surfaces of the rotary ultrasonic bonding horns.
(This arrangement can best be seen in the detail of FIG. 17.
[0077] FIG. 17 is cross-sectional view from the down-stream process
end of the machine, taken along cut line C-C of FIG. 16. The figure
shows a vertical cross-section of the substrate sausage web 602,
cut elastic piece 610, portions of the rotary ultrasonic bonding
horns 402 and 404 the web-supporting central spine 220 and crown
piece 230 of the shoe-horn apparatus, and the anvil shoes 310 and
312, with their hold-down shoes 316, 318, 320, and 322 and spacer
shoe 314 attached to the underlying combination roller. This
cross-sectional view is taken at the point where the substrate web
602 is passing directly beneath the rotary ultrasonic bonding horns
402 and 404, and where a cut elastic piece 610, held to the working
surface of combination roller 302, has been presented to the
substrate web 602 for bonding.
[0078] In FIG. 17, the folded width of substrate web 602 from edge
604 to edge 606 is shown to be about the same as the length of the
un-stretched elastic member 610 measured from edge 612 to edge 614.
That is to say, edge 604 of substrate web 602 and edge 612 of
un-stretched elastic member 610 are matched up; similarly, edge 606
of substrate web 602 and edge 614 of un-stretched elastic member
610 are likewise matched up.
[0079] The edge portion 605 of web sausage 602 and the end region
613 of elastic member 610 are shown pressed in the nip between
ultrasonic bonding horn 402 and ultrasonic bonding anvil shoe 310
of the combination roller. Vibratory energy applied to the horn
402, acting against the anvil 310 forms a weld or bond between the
edge portion 604 of the substrate web 602 and the end region 613 of
the elastic member. In a similar fashion, edge region 607 of
substrate web 602 is pressed, together with the end portion 615 of
elastic member 610 in the nip between rotary ultrasonic bonding
horn 404 and anvil shoe 312 and are ultrasonically bonded one to
the other. This edge/end bonding of the substrate web 602 to
elastic member 610 is thus carried out wile elastic member 610 is
in a relaxed or un-stretched state, and permits the ultrasonic
bonds to anneal or heal while no stress is placed to either the
substrate web 602 or the bonded, un-stretched elastic member
616.
[0080] In FIG. 20, the substrate web and two attached elastic
members can be seen moving through the machine and process of the
invention. In the region designated "A" of FIG. 20, the substrate
web 602 is shown after it emerges from the nips between the rotary
ultrasonic bonding horns and the combination roller. with
un-stretched elastic member 616 bonded to substrate web 602 by
means of first and second ultrasonic welds or bonds 624 and 625. At
this stage of the process, substrate web 602 is folded over the top
of crown piece 230, while the attached un-stretched elastic member
616 lies under web guide members 250 and 252 of the shoe-horn
apparatus 200. This can be seen more readily by reference to FIG.
17.
[0081] As the substrate web 620 and attached elastic member 616
move into stage "B" of the machine and process depicted in FIG. 20,
the substrate web moves down the upper surface of tail plate 240,
and tail portion web guide rod members 260 and 262 begin to spread
the substrate web flat, stretching the attached elastic member 618
between them. At this point, the flattened, un-folded or
un-gathered substrate web 602 and attached, stretched elastic
member 618 pass into the nip between the second ultrasonic bonding
horn 502 and rotary anvil 506. This arrangement is seen in partial
cross-section in FIG. 21. As the working surface of rotating anvil
506 meets and forms a nip with stationary second ultrasonic bonding
horn 502, an ultrasonic weld or bond 627 is formed between
substrate web 602 and stretched elastic member 618. This weld or
bond 627 is formed along the length of stretched transverse elastic
member 618 in the region of the elastic member lying between tail
portion web guide rod 264 and tail portion web guide rod 266.
[0082] In the final stage of the process, designated region "C" in
FIG. 20, the elastic member 618, now fully bonded to the substrate
web 602 by both edge bonds or welds 624 and 625 and central bond or
weld 627. is allowed to relax back to its un-stretched state by the
inwardly curving ends of tail portion web guide rods 264 and 266.
The substrate web 602 with attached elastic member 618 is then
subjected to further processes not forming a part of this
invention, to produce the finished infant diaper or adult
incontinence garment. However, it should be noted that in the
embodiment shown in FIG. 20, the length of un-stretched elastic
member 616 is shown to be wider than the folded width of substrate
web 602 in order to provide side tabs 620 and 622. In this
alternative embodiment, tabs 620 and 622 can be fitted in
subsequent operations with mechanical or adhesive elements to
function as means for fastening the diaper or garment around the
waist of the user.
[0083] While there have been shown and described what are believed
to be the preferred embodiments of the invention, one skilled in
the art will appreciate that various modifications may be made in
the machine and process described without departing from the scope
of the invention as it is defined by the appended claims.
* * * * *