U.S. patent number 3,897,293 [Application Number 05/387,577] was granted by the patent office on 1975-07-29 for method for applying adhesive tape tabs to a disposable diaper.
This patent grant is currently assigned to Johnson & Johnson. Invention is credited to Donald Babcock.
United States Patent |
3,897,293 |
Babcock |
July 29, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
Method for applying adhesive tape tabs to a disposable diaper
Abstract
Tape tab fasteners are cut from a web stock, which includes a
substrate coated on one surface with a pressure-sensitive adhesive
and a release sheet positioned on the adhesive coating, and are
applied transversely at predetermined intervals along the edge of a
moving web of material, such as a web of plastic material suitable
as an impervious barrier layer in disposable diapers. The web stock
is drawn along a concave guide and a finger, positioned
transversely between the substrate and release sheets, separates a
predetermined width portion of the release sheet from the adhesive
along one side of the web. The separated portion of the release
sheet is folded over the remainder thereof. Tape tab fasteners of
predetermined width are cut transversely from the end of the web
stock and attached to the side edges of the moving web stock.
Inventors: |
Babcock; Donald (Oak Lawn,
IL) |
Assignee: |
Johnson & Johnson (New
Brunswick, NJ)
|
Family
ID: |
23530494 |
Appl.
No.: |
05/387,577 |
Filed: |
August 10, 1973 |
Current U.S.
Class: |
156/227; 156/762;
156/751; 156/265; 156/302; 156/519; 156/556; 156/568; 156/299;
156/552 |
Current CPC
Class: |
A61F
13/15756 (20130101); B65C 9/1819 (20130101); B65H
35/0013 (20130101); Y10T 156/1744 (20150115); Y10T
156/133 (20150115); Y10T 156/1967 (20150115); Y10T
156/1734 (20150115); Y10T 156/1097 (20150115); Y10T
156/1092 (20150115); Y10T 156/1051 (20150115); Y10T
156/1773 (20150115); Y10T 156/1906 (20150115); Y10T
156/1077 (20150115) |
Current International
Class: |
A61F
13/15 (20060101); B65C 9/08 (20060101); B65C
9/18 (20060101); B65H 35/00 (20060101); B32b
031/10 () |
Field of
Search: |
;156/152,199,200,201,204,227,230,254,256,264,265,289,290,292,297,299,302,344,459
;128/156,284,287 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Cosby; Clifton B.
Assistant Examiner: Kittle; John E.
Claims
What is claimed is:
1. A method for providing adhesive tape tabs on a disposable diaper
from a roll of a laminar assembly of a substrate material and a
release sheet material held together by a layer of a tacky,
pressure-sensitive adhesive which comprises: unwinding said roll
and paying out said laminar assembly therefrom; separating an edge
portion of said release sheet from said laminar assembly at an
unwound portion thereof; folding back said separated portion of
said release sheet into overlying relationship to an unseparated
portion thereof to thereby expose a portion of said adhesive layer
as an adhesive coating on said substrate by directing said laminar
assembly along a concave support surface, providing a folding plate
corresponding in curvature to said support surface and having a
width generally corresponding to the width of said unseparated
portion of the release sheet, positioning said plate in
juxtaposition with said support surface at one side thereof above
the path of said unseparated portion of the release sheet, and
directing said separated portion of the release sheet about the
inner edge of said plate; severing end segments of said laminar
assembly; spacing said severed end segments from each other by
distances corresponding to diaper lengths; and pressing said
severed end segments against a moving web of water-impervious
material at a marginal side portion thereof to adhere said end
segments to said web by said adhesive coating on said
substrate.
2. The method of claim 1 wherein an insertable finger is rotatably
mounted along the path of said payed out laminar assembly and in
juxtaposition to the inner edge of said plate and wherein said
separating step is performed by positioning said insertable finger
between said release sheet and said pressure-sensitive adhesive of
said laminar assembly and moving said laminar assembly past the
inserted rotatable finger at one side thereof.
3. The method of claim 1 wherein said severing step is performed at
intervals shorter than the width of said laminar assembly, said
intervals corresponding to the width of said tape tabs and the
width of said laminar assembly corresponding to the length of said
tape tabs.
4. The method of claim 1 wherein said severing step is performed by
directing the leading edge of said laminar assembly to cutter
means; advancing an end portion of said laminar assembly past said
cutter means corresponding to said end segments; and synchronizing
the advancement of said end portion with the operating of said
cutter means whereby said end segments are severed.
5. The method of claim 1 wherein said spacing step is performed by
positioning said end segments on a continuously rotating vacuum
roller in timed relationship with the movement of said web of
water-impervious material.
6. The method of claim 1 wherein said pressing step is performed by
positioning said end segments on a vacuum pickup roller, rotating
said vacuum pickup roller to place said exposed position of said
adhesive layer in contact with said water-impervious web and
holding said end segments on said vacuum pickup roller until the
adherence of said tape tab to said web overcomes the suction of
said vacuum pickup roller.
7. A method of providing adhesive tape tabs on a disposable diaper
from a roll of a laminar assembly of a substrate material and a
release sheet material held together by a layer of a tacky,
pressure-sensitive adhesive, said roll having a width corresponding
to the length of said tape tabs, which comprises: unwinding said
roll and paying out said laminar assembly therefrom, moving said
laminar assembly past an inserted finger at one side thereof to
separate an edge portion of said release sheet from said laminar
assembly at an unwound portion thereof; directing said laminar
assembly along an upwardly inclined concave support surface;
providing a folding plate corresponding in curvature to said
support surface and having a width generally corresponding to the
width of the unseparated edge portion of said release sheet;
positioning said plate in juxtaposition with said support surface
at the side thereof above the path of said unseparated portion of
said release sheet; directing said separated portion of the release
sheet about the inner edge of said plate to cause said separate
portion to be folded back into overlying relationship with said
unseparated portion and to thereby expose a portion of said
adhesive layer as an adhesive coating on said substrate;
positioning the leading end of said laminar assembly on a
continuously rotating vacuum pickup roller disposed adjacent the
path of a moving water-impervious web; providing a cutter means
adjacent said vacuum pickup roller; advancing the leading end
portion of said laminar assembly on said vacuum pickup roller past
said cutter in timed relationship to the movement of said
water-impervious web to provide end portions corresponding to the
width of said tape tabs; said vacuum pickup roller rotating
relative to the advancement of said end portions of said laminar
assembly thereby to produce slippage therebetween; synchronizing
said cutter means with the movement of said water-impervious web
and severing said end portion from said laminar assembly to provide
segments; carrying said segments on said vacuum pickup roller to
engagement with a marginal side portion of said water-impervious
web; and holding said segments on said vacuum pickup roller until
the adherence of said tape tab to said web overcomes the suction of
said vacuum pickup roller.
Description
BACKGROUND OF THE INVENTION
This invention relates to an applicator for pressure-sensitive
adhesive fasteners and, more particularly, concerns a waist band
fastener applicator for disposable diapers.
With the ever increasing acceptance of disposable diapers by
consumers, and the corresponding increase in demand for such
diapers, new materials and sophisticated manufacturing techniques
and apparatus have been introduced to mass produce disposable
diapers. Conventional disposable diapers are now provided with a
fluid impervious backing sheet which eliminates the need for
plastic or rubber pants and thus, increases the convenience in
using such diapers. In recent years in order to further increase
the convenience of disposable diapers as well as provide a safer
means for fastening the diaper on an infant, pressure-sensitive
adhesive fasteners have been substituted for the conventional
safety pin.
Adhesive fasteners are usually supplied in pairs, one attached at
each side portion of the water-impervious backing sheet near one
end of the diaper so that as the diaper is conformed to an infant,
a free end of each fastener may be attached to the corresponding
opposite end of the diaper to secure about the infant. Various
types of adhesive fasteners have been proposed in the past. In
general, such adhesive fasteners are covered on their free adhesive
ends by a release paper which is removed during the application of
the diaper to the baby. The adhesive tape and the release paper are
obtained during manufacture from separate rolls thereof. One method
and apparatus for providing adhesive fasteners from separate rolls
of adhesive tape and release paper is disclosed in Wierzba et al.,
U.S. Pat. No. 3,728,191, issued Apr. 17, 1973.
Label stock, a laminar assembly of a substrate and a release paper
adhered to each other by an adhesive layer and wound together on a
single roll, is more economical than conventional adhesive tape and
release paper and this invention provides a suitable method and
apparatus for utilizing label stock in the preparation of adhesive
tabs for diapers.
SUMMARY OF THE INVENTION
The tape applicator of the present invention provides a novel
method and apparatus for cutting and applying fasteners formed from
label stock which is readily adaptable for mass-production of
disposable diapers.
Label stock is produced in rolls and consists of a substrate which
may be formed from various suitable materials. Label stock is made
by coating a release paper with a tacky, pressure-sensitive
adhesive layer and then covering the release paper with a substrate
material. The latter material adheres to the pressure-sensitive
material much more strongly than the release paper; and in any
subsequent separation of the layers, the adhesive layer remains on
the substrate.
The present invention is particularly adaptable for use with label
stock having a substrate which possesses isotropic tensile strength
so that re-orientation of the fasteners cut therefrom is
eliminated. Substrates having maximum tensile strength in the
transverse direction may also be utilized. One substrate which is
substantially isotropic in tensile strength is formed by melt
extruding polyethylene fibers in random orientation to form a
continuous film having isotropic tensile strength.
The use of label stock by the method and apparatus of the present
invention, as opposed to prior art pressure-sensitive adhesive
fasteners, results in machinery and products savings due to the
fact that the release sheet need only be as wide as the substrate
since it is not necessary to accommodate for fluctuations in
positioning. Since both the substrate and release sheet are
positioned together, the release paper functions in effect as the
sizing, as well as providing the release paper for use on the
diaper.
The present invention is particularly adaptable for use on mass
production lines for producing disposable diapers and may be
positioned at any position along the production line wherein the
impervious backing sheet is moving. Label stock of the type
described above is unwound and payed out from a roll thereof and is
conveyed along a concave arcuate guide member as a web with the
release sheet facing upwardly. The label stock web moves past a
stationary separation finger, introduced between the release sheet,
and the adhesive layer along one side of the web to cause the
release paper to separate at that side from the adhesive layer. As
the web is conveyed along the arcuate guide, the separated release
paper is directed into an overlying position onto the unattached
portion of the release paper by means of a folding roller which is
disposed at an angle to the movement of and in contact with the
web. A guide plate complementary in shape with and positioned over
the unattached portion of the release paper co-operates with the
arcuate path defined by the guide and the roller to cause the
separated release sheet to fold over the unattached release
paper.
After the portion of the release paper has been folded over and
creased so as to maintain the fold, the web is fed over a
continuously moving vacuum wheel disposed adjacent the path of the
water-impervious sheet. The label stock web is controlled by drive
means upstream of the vacuum roller so that the vacuum roller may
slip relative to the label stock web. A rotating cutter blade
disposed adjacent the vacuum roller and driven in timed
relationship with the movement of the water-impervious sheet cuts
fasteners from the web which are carried by the vacuum roller into
engagement with the water-impervious sheet in timed relationship
with its movement in the production line. The uncovered adhesive
coating of the fastener is adhered to the backing sheet to fasten
the fastener thereon and separate from the vacuum roller. The
fasteners are then carried along the production line with the
impervious sheet for further processing and packaging.
Since fasteners are attached at both sides of the water-impervious
sheet, two label stock applicator units, one for each side of the
diaper web, are used in accordance with the present invention.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of the apparatus in accordance with
the present invention;
FIG. 2 is a section view taken along plane 2--2 on FIG. 1;
FIG. 3 is a plan view with certain portions in section of the
separator and folding mechanism; and
FIG. 4 is a perspective view of the apparatus of this
invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
While this invention is susceptible of embodiment in many different
forms, there is shown in the drawings and will herein be described
in detail only a preferred embodiment of the invention, with the
understanding that the present invention is to be considered as an
exemplification of the principles of the invention and is not
intended to limit the invention to the embodiments illustrated.
With reference to FIG. 1, the present invention is particularly
adaptable for use in a mass production line for producing
disposable diapers. The apparatus may be located at any position in
the production line through which a continuous web 10 passes which
will form the water-impervious backing sheet of the disposable
diaper. As illustrated, web 10 has a web of absorbent material 12
positioned on one surface thereof and is being directed in the
direction indicated on FIG. 1 along an elevated horizontal path
defined by rollers 13 and 14 above the fastener applicator 16 of
this invention. In a diaper having a separate facing layer and
absorbent pad, both of these elements are glued to the upper face
of web 10, as shown in the upper left of FIG. 1. The diaper stock
web is then directed vertically downward around roller 15 to
position the backing sheet in a vertical plane adjacent vacuum
roller 20 which transfers fasteners 21 onto the backing sheet, as
described in greater detail below. The diaper stock web is then
directed horizontally by roller 22 and the web passes beneath two
vertically disposed compression rollers 23 and 24 positioned
adjacent each side of the diaper stock. The diaper stock then moves
forwardly for further processing.
Label stock 30 is provided from a supply roll 32 and drawn through
an inclined separator and folding mechanism 33 with the release
sheet 30a facing upwardly which separates a predetermined width of
release paper 30a above one edge from the adhesive coating on the
substrate 30b to expose a portion of the coating for adherence to
the backing sheet and folds over the separated portion of the
release paper to provide a manually grippable portion for removing
the release paper from the finished diaper during use.
Web 30 is drawn through mechanism 33 by a pair of drive rollers 34
positioned down-stream from mechanism 33 and which controls the
advancement of the web during application to the backing sheet, as
described in greater detail below.
After a portion of the release paper has been folded over, the web
passes beneath a U-wrap tensioning roller 35 and through a spring
loaded impact absorber mechanism 36 and about the top surface of
the cylindrical vacuum roller 20. The movement of web 30 is
controlled by the pair of drive rollers which advances a
predetermined length of web beyond the point of tangency between
vacuum roller 20 and cutter 37, disposed adjacent roller 20. The
predetermined length corresponds in size to the width of the
fastener to be formed. The advanced portion of the web overlying
vacuum roller 20 is free to slip relative to the rotation of the
vacuum roller so that a slip clutch effect is produced.
Cutter 37 operates in timed relationship with the movement of the
diaper stock web so that fasteners 21 are cut from web 30,
transferred by vacuum roller 20 into contact with the water
impervious backing sheet, and adhered thereto at preselected
intervals. Roller 20 is provided with a plurality of radially
extending vacuum ports which receive vacuum from a suitable source
to transfer fasteners 21 cut from web 30 by rotating cutter 37 as
well as tension the web downstream from the drive roller.
The fasteners utilized with the present apparatus have sufficient
tack to adhere to the backing sheet and overcome the vacuum of
roller 20 so that the fastener is carried along the process line by
the backing sheet web. A compression roller 40 disposed in an
overlying relationship to the point of attachment of the fasteners
on the side of the diaper web stock is rotatably mounted at the
free end of an inverted L-shaped bracket 41 which is pivotally
attached to the machine frame at the other free end and biased into
engagement with the diaper web stock by spring 42.
Since fasteners are applied on both side portions of a disposable
diaper, it will be appreciated that a corresponding mechanism of
the type to be described may be positioned in mirror image
relationship thereto to provide fasteners to the other side of the
diaper web stock. By virtue of the mirror image mounting the
apparatus, different diaper widths may be readily accommodated by
moving the fastener applicators horizontally relative to one
another and corresponding to the change in width of the diaper to
be produced.
Referring to FIGS. 3 and 4, label stock web 30 is fed upwardly from
roll 32 about a U-wrap roller 50 which directs the web into
separator and folding mechanism 33. Roller 50 is rotatably mounted
by internal bearings 51 at each end thereof on a transversely
disposed shaft 52. Shaft 52 extends between side plates 53 and 54
of the folding mechanism. Side plate 54 which is mounted to frame
plates 56 by bracket 56a mounts, as by bolt 58, an arcuate shaped
guide block 57, which is complementary in shape to roller 50. Block
57 provides a side guide portion 57a for directing web 30 into the
folding mechanism 33.
As the web is drawn through the folding mechanism by the pair of
drive rollers 34, the web is directed along an inclined concave
arcuate path defined by a concave base plate 60 located between
plates 54 and 55, and which may be integrally formed therewith. The
upper arcuate surface of base plate 60, FIG. 2, is provided with a
Teflon plate 61 to permit easy sliding of the web thereon during
the folding process.
Teflon plate 61 is mounted to base plate 60 by inverted, generally
L-shaped, arcuate clamps 70 and bolts 72. The lower surface of the
arcuate portions of clamps 70 bear against the upper surface of
plate 61 and thus maintain the Teflon plate in contact with base
plate 60.
An arcuate folder plate 62 complementary to the arcuate Teflon
plate 61 is mounted thereabove along the side of the folder
mechanism by inverted generally L-shaped clamps 65 and pins 66 to
define a generally U-shaped path. Release paper 30a is folded about
the free edge of plate 62, FIG. 2, as the web is carried along the
folding mechanism. L-shaped clamps 65 are mounted on base plate 60
as by bolts 67. In order to assure that no sticking occurs between
the web and the folder plate, it is preferred that the folder plate
be coated with Teflon at all its working surfaces.
In order to separate the release sheet 30a from the adhesive coated
substrate 30b, a separation finger 75, is positioned to extend
inwardly from plate 54 between the release paper and substrate.
Referring to FIG. 3, finger 75 is in the form of a slender knurled
member having a conical point 75a, which extends transversely to
the path of the web and is mounted on frame plate 54 at the
elevation of the web by means of bearings 76 and housing 77.
Housing 77 is secured to frame 54 by bolts 78. It will be
appreciated that separation finger 75 is in contact with the
adhesive surface of substrate 30b and therefore must be of a type
which will not stick to the substrate or cause the release sheet to
be ripped. It has been found desirable to utilize a knurled surface
which provides a minimum contact area with the adhesive coated
substrate. It is also preferred to use a separation finger which
rotates in the direction of the web movement of the adhesive
substrate, although other finger configurations may be used.
As the release sheet is separated from the substrate, it is
directed beneath a folding roller 80 which is mounted for rotation
at an angle to the path of the web and cooperates with folder plate
62 to initially fold the separated release sheet into overlying
relationship with the folder plate. Roller 80 is mounted to side
plate 55 adjacent the output portion of the folding mechanism by
frame mounting bracket 81, and a spring biased mounting assembly
82. Mounting assembly 82 includes a roller axle 83 which mounts
roller 80 to an angled support bracket 84. Bracket 84 is provided
with a mounting flange 85, FIG. 4, at one end, by which roller axle
83 is mounted as by end bolt 86, and a mounting collar 87 at its
opposite end. A stud shaft 88 extends transversely from bracket 81
to mount collar 87 thereon by means of bearings 89 so that angled
brackets 84 may rotate thereabout. A torsion spring 90 is disposed
between bracket 81 and angle support bracket 84 to bias roller 80
into engagement with the separated release sheets 30a, and the
output end of folder plate 62. Roller 80 is preferably formed with
a rubber working surface so that resilient engagement may be
maintained with the release paper and thus assure proper folding
thereof.
To prevent the uncovered portion of the substrate from being folded
with the release sheet, a Teflon roller 97 is positioned to overlie
and contact the exposed substrate. Roller 97 is rotatably mounted
to frame member 54 by a generally L-shaped mounting bracket 98
positioned slightly upstream from roller 80.
After the release paper has been initially folded, the web passes
over a second transversely disposed roller 95 which is mounted by
shaft 96 in similar fashion to roller 50 to frame plates 54 and
55.
As indicated above, the web movement is controlled by a pair of
drive rollers 34 which include a lower Teflon-coated drive roller
100 mounted on shaft 100a which receives power input (not shown) in
timed relationship with the movement of the diaper web stock and
which is geared to advance the label stock web at predetermined
length corresponding to the width of the fasteners 21. In order to
assure proper braking of the movement of the web, upper
Teflon-coated roller 101 is rotatably mounted on shaft 101a of a
lever mechanism 102 which is biased downwardly by spring 103 to
maintain roller 101 into gripping engagement with roller 100. A
handle 104 is provided outboard of roller 101 for lifting roller
101 during start-up and maintenance of the apparatus.
The web of label stock advanced by drive rollers 34 passes beneath
tensioning roller 35 which includes a Teflon-coated cylindrical
folding portion 105 which is rotatably mounted on shaft 106. Shaft
106 is fixedly positioned on a generally triangular shaped mounting
plate 107 which may be moved horizontally relative to frame member
56 by guide slot 107a through which pass mounting bolt 108.
Referring to FIG. 1, it will be observed that shaft 100a is also
mounted on triangular shaped plate 107. Bracket 102 is rotatably
mounted about a portion of shaft 106 extending beyond plate 107 so
that the pair of drive rollers and the tensioning roller may be
moved in unison in a horizontal plane for adjustment, as will be
described below.
After the release paper has been finally folded by roller 105, the
web passes through impact absorber 36 positioned above the
elevation of roller 105. Impact absorber 36 includes a generally
flat base guide member 110 which is rotatably mounted to the
machine frame by shaft 111 at its downstream portion so as to
produce a lever. Guide member 110 is maintained in an inclined
position by spring 112 which is attached at the upstream end of
impact absorber 36 and to the machine frame at the other end. Guide
member 110 is preferably Teflon-coated to provide easy slippage of
the web thereon and includes a downwardly flared entrance lip 110a
to assure easy entrance of the web. Two elongated guide members 115
and 116 are attached at the sides of guide member 110 in overlying
relationship to the path of the web 30 as by bolts 120. Guide
member 115 is Teflon-coated and positioned in overlying
relationship to the exposed adhesive coated substrate 30b to
cooperate with guide member 110 in guiding the web to vacuum roller
20. Guide member 116 is disposed in overlying relationship with the
folded release sheet. Guides 115 and 116 are also preferably
Teflon-coated to assure slippage of the web.
As the web passes from impact absorber 136 onto the vacuum roller
20, the advancement of the web is controlled by the pair of drive
rollers so that the vacuum roller slips relative to the web as the
roller 20 maintains tension in the web. Due to the tension in web
30, when a fastener is severed therefrom, a pulling effect will be
generated in the web as the fastener is cut therefrom. Accordingly,
to prevent the release sheet 30a from ripping during the folding
operation or being pulled through the drive rollers when a fastener
is cut the tensioning roller 105 is adjusted horizontally relative
to impact absorber 36 to produce an S-Shape curve in the web. In
this manner, as the web tension is increased during the cutting
operation, the upstream end of the impact absorber will be pivoted
downwardly, as indicated on FIG. 1, to take up the impact. Thus, by
adjusting the position of plate 107, the loading impact on the
absorber may be controlled and adjusted by the degree of
S-wrapping.
As previously indicated, the apparatus as described includes a
mirror image apparatus for applying fasteners to the other side of
the diaper web stock and accordingly cutter 37 and vacuum wheel 20
may extend between the two label stock webs fed from the apparatus
since the fasteners are positioned at the same relative location on
the backing sheet.
As fasteners are cut from the web, they are carried by vacuum
roller 20 by means of radially extending passage ways 20a which
receive vacuum from a suitable source (not shown). As fasteners 21
are carried by vacuum roller 20, they are brought into contact with
the impervious backing sheet 10 and are forced to adhere thereto by
the adhesive coated substrate 30b under the influence of
compression roller 40. Compression roller 40 may be of the type of
individual rollers for each side of the diaper web or may be a
continuous roll extending coterminously vacuum roll 20.
The diaper web with the fasteners attached thereto then passes
beneath a second set of compression rollers 23 and 24 which may be
individual rollers for each side of the diaper web or may be a
continuous roller extending across the width of the diaper. When
the apparatus is used with a diaper web on which the absorbent
material has already been positioned, it is preferable that rollers
40 and 23 and 24 are individual rollers to prevent compression of
the absorbent material which may be undesirable in the production
of the diaper.
It should be pointed out, that by adjusting the drive to roller
100, or substituting a new roller with a larger diameter, the
amount of web fed forwardly and correspondingly the width of the
tab fastener cut from the web may be readily adjusted. Likewise,
the width of the label stock 30 may be changed with a resulting
requirement that the folder plate be adjusted in width to
correspond to the unattached portion of the release sheet on the
fasteners to be produced by the apparatus. These and other
modifications of the present invention may be utilized by those
skilled in the art without departing from the scope and spirit of
the invention as pointed out in the appended claims.
* * * * *