U.S. patent number 3,848,594 [Application Number 05/374,188] was granted by the patent office on 1974-11-19 for tape fastening system for disposable diaper.
This patent grant is currently assigned to The Procter & Gamble Company. Invention is credited to Kenneth Barclay Buell.
United States Patent |
3,848,594 |
Buell |
November 19, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
TAPE FASTENING SYSTEM FOR DISPOSABLE DIAPER
Abstract
An improved tape fastener system for stronger securement of a
tape fastener to corners of a disposable diaper, especially for
diapers having relatively weak and/or extensible members. The tape
fastener system has several elements which are parallel and are
attached to the front and back surface of the diaper. The tape has
a generally Y-shaped cross-section with two legs fastened to a back
corner of the diaper and the third leg available to attach to a
front corner of the diaper.
Inventors: |
Buell; Kenneth Barclay
(Cincinnati, OH) |
Assignee: |
The Procter & Gamble
Company (Cincinnati, OH)
|
Family
ID: |
23475696 |
Appl.
No.: |
05/374,188 |
Filed: |
June 27, 1973 |
Current U.S.
Class: |
604/390;
428/40.1 |
Current CPC
Class: |
A61F
13/58 (20130101); Y10T 428/14 (20150115) |
Current International
Class: |
A61F
13/58 (20060101); A61F 13/56 (20060101); A61f
013/16 () |
Field of
Search: |
;128/284,287,290,286,296,156 ;117/122P ;161/39,149,406 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gauder; Richard A.
Assistant Examiner: McGowan; J. C.
Attorney, Agent or Firm: Linman; E. Kelly Braun; Frederick
H. Gorman; John V.
Claims
What is claimed is:
1. In a disposable diaper having a back surface and a front
surface, an improved tape fastener system, comprising:
a. a front surface portion;
b. first attachment means associated with the front surface portion
and the front surface of the diaper for attaching the front surface
portion to the front surface;
c. a back surface portion;
d. second attachment means associated with the back surface portion
and the back surface of the diaper for attaching the back surface
portion to the back surface;
e. a fastening portion; and
f. third attachment means associated with the fastening portion for
attaching the fastening portion to another part of the diaper;
g. the front surface portion, the back surface portion, and the
fastening portion joined and attached in an area of joinder
adjacent the edge of the diaper;
h. whereby forces imposed on the fastening portion are transmitted
to both the front and back surfaces of the diaper.
2. The improved tape fastener system of claim 1 wherein the front
surface portion is a release liner, the front surface portion
having its upper surface treated to give it moderate adhesive
attachment to the third attachment means, the fastening portion
being superposed on the front surface portion, and the third
attachment means being between the front surface portion and the
fastening portion, whereby the fastening portion is moderately held
superposed on the front surface of the diaper.
3. The improved tape fastener system of claim 2 wherein the first
common point of joinder of the front surface portion, the back
surface portion, and the fastening portion lies substantially in a
plane midway between the front and back surface of the diaper.
4. The improved tape fastener system of claim 3 wherein the back
portion and the fastening portion are an integral strip of tape
material.
5. The improved tape fastener system of claim 4 wherein the three
attachment means are pressure sensitive adhesives.
6. The improved tape fastener system of claim 3 wherein the three
attachment means are pressure sensitive adhesives.
7. The improved tape fastener system of claim 2 wherein the back
portion and the fastening portion are an integral strip of tape
material. l
8. The improved tape fastener system of claim 7 wherein the three
attachment means are pressure sensitive adhesives.
9. The improved tape fastener system of claim 2 wherein the three
attachment means are pressure sensitive adhesives.
10. The improved tape fastener system of claim 1 wherein the first
common point of joinder of the front surface portion, the back
surface portion, and the fastening portion lies substantially in a
plane midway between the front and back surface of the diaper.
11. The improved tape fastener system of claim 10 wherein the back
portion and the fastening portion are an integral strip of tape
material.
12. The improved tape fastener system of claim 11 wherein the three
attachment means are pressure sensitive adhesives.
13. The improved tape fastener system of claim 10 wherein the three
attachment means are pressure sensitive adhesives.
14. The improved tape fastener system of claim 1 wherein the back
portion and the fastening portion are an integral strip of tape
material.
15. The improved tape fastener system of claim 14 wherein the three
attachment means are pressure sensitive adhesives.
16. The improved tape fastener system of claim 1 wherein the three
attachment means are pressure sensitive adhesives.
17. The improved tape fastener system of claim 1 wherein the
transverse dimension of the front surface portion is longer than
the transverse dimension of the back surface portion.
18. The improved tape fastener system of claim 17 wherein the
transverse dimension of the front surface portion is at least about
twice as long as the transverse dimension of the back surface
portion.
19. The improved tape fastener of claim 1 wherein the attachment
between the front surface portion, the back surface portion, and
the fastening portion in the area of joinder is in shear when a
tensile force is applied to the fastening portion.
20. The improved tape fastener system of claim 19 wherein the
segments of the front surface portion, the back surface portion,
and the fastening portion, which are coextensive with the area of
joinder, are parallel and extend outwardly from the first common
point of joinder of the tape portions.
21. A disposable diaper comprising:
a. a thin, flexible, extensible backsheet;
b. an absorptive body having an absorptive core and a topsheet
superposed on the core, the absorptive body being superposed on the
backsheet so that the core is intermediate the topsheet and the
backsheet;
c. a tape fasener system having
i. a front surface portion;
ii. first attachment means associated with the front surface
portion and the front surface of the diaper for attaching the front
surface portion to the front surface;
iii. a back surface portion;
iv. second attachment means associated with the back surface
portion and the back surface of the diaper for attaching the back
surface portion to the back surface;
v. a fastening portion;
vi. third attachment means associated with the fastening portion
for attaching the fastening portion to another part of the
diaper;
vii. the front surface portion, the back surface portion, and the
fastening portion joined and attached in an area of joinder
adjacent the edge of the diaper;
d. whereby forces imposed on the fastening portion are transmitted
to both the front and back surfaces of the diaper.
22. The diaper of claim 21 wherein tape support means for attaching
the backsheet to the absorptive body is between the backsheet and
the absorptive body, the tape support means being between the back
surface portion and the absorptive body, whereby forces transmitted
to the back surface portion are in turn transmitted through the
backsheet to the absorptive body.
23. The diaper of claim 22 wherein the topsheet has a longitudinal
dimension longer than the longitudinal dimension of the absorptive
core and the excess topsheet is folded around and under the
longitudinal end of the core thereby forming a folded under
portion, the folded under portion being intermediate the back
surface portion of the tape fastener system and the absorptive
core.
24. The diaper of claim 22 wherein the front surface portion is
attached to the topsheet.
25. The diaper of claim 23 wherein the front surface portion is
attached to the topsheet.
Description
BACKGROUND OF THE INVENTION
The use of pressure sensitive tape fasteners for securing the
corners of a diaper is a well-known expedient in the art. In fact,
an example of this type of device is described in U.S. Pat. No. Re.
26,151 entitled DISPOSABLE DIAPER which issued to Robert C. Duncan
et al on Jan. 31, 1967. The Duncan et al patent is commonly owned
by the assignee of the present application.
Previous tape fasteners have, however, had a number of
shortcomings, one of which is that they are generally attached to
only one surface of the diaper, generally the back surface, and
thus all the force exerted on the tape fastener is directed to the
single joint between the tape fastener and the back surface of the
diaper. In addition, the most frequently used diaper construction
places a relatively weak or extensible thermoplastic material on
the back of the diaper. A back surface of this kind provides a
generally unsatisfactory base for mounting a tape fastener. A tape
fastener easily pulls out of such a back surface during the process
of fastening a diaper, thereby leaving a hole in the backsheet of
the diaper and leaving the user with an unusable fastener.
Such a failure wherein the tape fastener produces a hole in the
backsheet is undesirable because the diaper is essentially not
usable after this occurs. The backsheet is no longer moisture
impervious and there is no readily available means to fasten the
diaper on the baby since the tape fastener element has been
destroyed and diaper pins are not usually kept on hand when diapers
with tape fastening systems are used.
The manufacturer's joint, defined below, must be stronger than the
user's joint, defined below, because the user puts more tensile
force on the tape system in the process of fastening the diaper
than is put on the tape during wearing of the diaper. The user
pulls hard on the tape fastener while fastening a diaper, and it is
generally during fastening that a tape pulls out of the diaper.
Prior art diapers are subject to the "pull-out" type failure.
SUMMARY OF THE INVENTION
The nature and substance of the invention will be more readily
appreciated after giving consideration to its major aims and
purposes. The principal objects of the invention are recited in the
ensuing paragraphs in order to give a better appreciation of the
important aspects of the invention before describing the details of
the preferred embodiment in later portions of the description.
The major object of the invention is to provide an improved tape
fastener system for a disposable diaper which has a stronger
manufacturer's joint, i.e., the attachment between the fastener
tape and the diaper which is made by the manufacturer.
Another object of the invention is the provision of an improved
fastener system of the above character which distributes the load
exerted on the tape fastener at the manufacturer's joint over a
larger area.
A further object of the invention is a provision of an improved
fastener system of the above character wherein the tape fastener is
attached to several different materials in providing the
manufacturer's joint.
An additional object of the invention is the provision of an
improved tape fastener system of the above character wherein the
adhesive on the fastening portion is covered for a distance
outwardly from the edge of the diaper to reduce the potential
adhesive exposure to an infant's leg during wearing.
These and other objects are achieved by providing an improved tape
fastener system for a disposable diaper having a back surface and a
front surface wherein the tape fastener system has a front surface
portion, a first attachment means associated with the front surface
portion and the front surface of the diaper to attach the front
surface portion to the front surface, a back surface portion of the
tape fastener, a second attachment means associated with the back
surface portion and the back surface of the diaper to attach the
back surface portion to the back surface, a fastening portion of
the tape fastener, and a third attachment means associated with the
fastening portion to attach the fastening portion to another part
of the diaper and thereby form the user's joint, i.e., the joint
made by the user when fitting and fastening a diaper to an infant.
The front surface portion, the back surface portion and the
fastening portion are joined and attached in an area of joinder
adjacent the edge of the diaper so that the forces imposed on the
fastening portion are transmitted to both front and back surfaces
of the diaper.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing
out and distinctly claiming the subject matter regarded as forming
the present invention, it is believed the invention will be better
understood from the following description taken in connection with
the accompanying drawing in which the thickness of some of the
materials are exaggerated for clarity and in which:
FIG. 1 is a fragmentary perspective view of a corner of a
disposable diaper to which the invention has been applied in one
form;
FIG. 2 is a fragmentary perspective view, partially broken away, of
a corner of a disposable diaper to which an alternate embodiment of
the invention has been applied;
FIG. 3 is a cross-section in elevation of the corner of the diaper
taken on the line 3--3 of FIG. 1;
FIG. 4 is a cross-section in elevation of the corner of the diaper
taken on the line 4--4 of FIG. 2;
FIG. 5 is a cross-section in elevation, similar to FIGS. 3 and 4,
showing an alternate diaper construction with a tape fastener
system of this invention;
FIG. 6 is a cross-section in elevation, similar to FIG. 5, of an
alternate embodiment of a tape fastener system of this invention;
and
FIG. 7 is a perspective view showing a form of a disposable diaper
illustrating the improved tape fastener system when in use for
holding adjoining diaper corners.
DETAILED DESCRIPTION OF THE INVENTION
Pressure sensitive tape fasteners of the invention are useful and
beneficial when applied to conventional disposable diapers,
particularly of the kind that have a plastic backing sheet. As an
illustration of the kind of diaper to which the invention is very
readily adapted, reference is again made to the above cited Duncan
et al U.S. Pat. No. Re. 26,151 which is incorporated herein by
reference. It will be apparent from the following description that
the tape fastener illustrated and described herein may be applied
to the corner of a diaper of that particular design and
configuration. On the other hand, it will be understood that the
invention is not limited to any specific diaper structure or
configuration and the diaper of the Duncan et al patent is merely a
typical example of the kind of diaper to which the present
invention can be usefully applied.
Referring now to FIGS. 1 and 2 of the drawing, it will be noted
that these views represent the back corner portion 21 and 22 of a
diaper in FIGS. 1 and 2, respectively, each corner portion having
an absorptive body 23. The absorptive body 23 has an absorptive
core 24 formed from any of the well-known materials having good
moisture absorbing characteristics such as absorbent wadding,
cellulosic fluff or the like. The absorptive body 23 may also
include a topsheet 25 superposed over the absorptive core 24. The
topsheet 25 may be any of the well-known topsheets, for example,
that topsheet described in the above cited Duncan et al patent
which is a hydrophobic nonwoven material. These diapers generally
have a moisture impervious backsheet 26, some of which are thin,
flexible, extensible materials, such as 11/2 mil polyethylene
film.
Such a diaper has a back surface 27 and a front surface 28. When a
backsheet 26 is used, it forms the back surface 27 of the diaper.
The front surface 28 is that surface of the diaper opposite the
back surface 27 and in the embodiment of FIG. 1 is formed by the
topsheet 25. In general, the back surface of the diaper extends
from one lateral edge to the other lateral edge of the diaper and
from one longitudinal end to the other longitudinal end of the
diaper and is the surface furthest from a baby during wearing of a
diaper. In general, the front surface 28 of the diaper is that area
coextensive with the back surface 27 and which is for the greater
part in contact with an infant when the diaper is worn.
Referring again to FIGS. 1 and 2, several embodiments of the tape
fastener system 29 of this invention are shown. This tape fastener
system is one which is anchored to both the front surface 28 and
the back surface 27 of a diaper to create the "manufacturer's"
joint, i.e., that attachment of the tape fastener system to the
diaper made during manufacture of the diaper. The tape fastener
system has another element which forms the "user's" joint, i.e.,
that joint made by the person fitting and securing a diaper to an
infant. The tape fastener system 29 of this invention has at least
three elements, which are the front surface portion 30, the back
surface portion 31, and the fastening portion 32. The front surface
portion 30 is that portion of the tape fastener system which is
attached to the front surface 28 of the diaper. The back surface
portion 31 is that portion of the tape fastener system which is
attached to the back surface 27 of the diaper. The fastening
portion 32 is that portion of the tape fastening system which is
attached to another portion of the diaper, generally the front
corner or adjacent corner 33 of a diaper such as is shown in FIG.
7, by the user when securing a diaper on an infant after it is
fitted to the infant. The fastening portion 32 is used in forming
the user's joint. The front corner 33 is in contrast to the back
corner 34 such as is shown in FIG. 7. The back corner 34 and front
corner 33 are designated as such in that they are a corner on the
back portion and the front portion, respectively, of the diaper
before the diaper is fitted to an infant.
The front surface portion 30, the back surface portion 31, and the
fastening portion 32 meet and are joined in an area of joinder 57.
The attachment between these three portions is strong in the area
of joinder 57. Preferably, the attachment between the various
components of the tape of this invention is subjected to shear
stresses, rather than peel stresses, when a tensile force away from
lateral edge 40 of the diaper is put on fastening portion 32.
The stresses put on the area of joinder 57 are shear stresses. When
the tape is in its "in use" configuration, as is shown in FIG. 7,
the segments of the front surface portion 30, the back surface
portion 31, and the fastening portion 32 coextensive with the area
of joinder 57 are parallel with each other and each of the segments
coextensive with the area of joinder 57 extend laterally outwardly
from the first common point of joinder 41 when the tape is in its
"in use" configuration.
Looking at FIG. 4 wherein the tape is shown in substantially its
"in use" configuration, the segments of the top surface portion 30
and the bottom surface portion 31 (bottom surface portion 31 being
integral with the fastening portion 32) which are coextensive with
the area of joinder 57 extend laterally outwardly, i.e., to the
right in FIG. 4, from the first common point of joinder 41. In
addition, the lower surface 58 of the front surface portion 30 is
facing the upper surface 59 of the back surface portion 31 and the
fastening portion 32, which are integral, in the region of the area
of joinder 57. This structure puts the area of joinder 57 in shear
when a tensile force is put on the fastening portion 32 in contrast
to a peel stress which is put on the area of joinder in a tape
system wherein the upper surface of the top surface portion is
facing the upper surface of the back surface portion such as is
taught in U.S. Pat. No. 3,646,937, issued to Gellert on Mar. 7,
1972, and is commonly owned by the assignee of the present
application.
Referring now to FIG. 3, which is a section of the diaper corner
shown in FIG. 1, additional detail of the tape fastener system 29
is shown. The backsheet 26 in this diaper embodiment is folded
around and onto the top of the lateral edge 40 of the absorptive
core 24 to form a side flap 39. The side flap 39 is attached to the
topsheet 25 by flap securement means 38. The flap securement means
38 can be any of the adhesives well-known to those of ordinary
skill in the art, such as hot melt glues and double sided adhesive
tapes. The flap securement means 38 is generally parallel to and
adjacent to the lateral edge 40 of the diaper as is well shown in
FIG. 1.
FIG. 3 also shows attachment means for securing the tape fastener
system to a diaper. These attachment means are any of those which
provide an adequate bond, and preferably are any of the pressure
sensitive adhesives well-known to those of ordinary skill in the
adhesive art. The front surface portion 30 is fixed to the front
surface 28 of the diaper by a first attachment means 35. The back
surface portion 31 is attached to the back surface 27 of the diaper
by a second attachment means 36. The fastening portion 32 of the
tape fastener system has a third attachment means 37 connected to
and associated therewith. This third attachment means 37 forms a
joint between the fastening portion 32 and a front corner 33 of a
diaper when the diaper is in its "in use" configuration as shown in
FIG. 7.
Additional features may be incorporated with this improved tape
fastener system. Referring now to FIG. 4, the first common point of
joinder 41 for the front surface portion 30, back surface portion
31, and fastening portion 32 of the tape fastener system 29
preferably lies in a plane midway between the front and back
surfaces of the diaper. The first common point of joinder 41 is, in
general, the common meeting of the three basic tape elements, the
top surface portion, the back surface portion, and the fastening
portion, nearest the lateral edge 40 of the diaper. These portions
of the tape system thus preferably come together at a point which
is about equidistant from the front surface 28 and back surface 27
of the diaper. This provides equal distribution of strain to both
the front and back surfaces of a diaper resulting from a force
applied to the fastening portion 32. Of course, if it is desirable
to allocate the distribution of strain to the front and back
surfaces of the diaper in some other manner, the first common point
of joinder 41 can be positioned elsewhere, e.g., in the same plane
as the front or back surface of the diaper.
Referring now to FIGS. 1 and 3, it is seen that the fastening
portion 32 with its associated third attachment means 37 is folded
on top of the front surface portion 30 such that the fastening
portion 32 is superposed on the front surface portion 30. Since in
the preferred embodiment the third attachment means 37 is one of
the well-known pressure sensitive adhesives, the upper surface 42
of the front surface portion 30 is preferably silicone treated so
that it has moderate adhesive attachment to the third attachment
means 37 and thereby provides a release liner for the fastening
portion 32 with its third attachment means 37.
When the fastening portion 32 is superposed on the front surface
portion 30 and the upper surface 42 of the front surface portion 30
is treated to provide a release liner, it is important that the
third attachment means 37 be isolated from contacting any of the
front surface 28 of the diaper. This isolation is required in order
to provide easy releasability of the fastening portion 32 when the
diaper is to be fitted and secured to an infant. This isolation can
be insured by making the area of the upper surface 42 at least as
great as and coextensive with the area of the third attachment
means 37. In fact, it is desirable that the upper surface 42 of the
front surface portion 30 be somewhat larger than the effective area
of the third attachment means 37. In FIgS. 1 and 3 it is shown that
the front surface portion 30 is longer than fastening portion 32.
This structure forms a discontinuity to provide a fastening portion
32 which is easier to grip and lift.
An alternate embodiment to that just described for protecting a
third attachment means 37 until the diaper is to be attached to an
infant is shown in FIGS. 2 and 4. In this embodiment, a separate
release liner 43 is provided to cover the third attachment means
37. The release liner may be polyethylene or paper or any suitable
equivalent thereof that will provide protection. The release liner
43 is again treated on its surface which contacts the third
attachment means 37 so that it has moderate adhesive attachment to
the third attachment means 37. A silicone treatment has been found
to provide this moderate adhesive attachment with pressure
sensitive adhesives.
On some diapers the backsheet 26 has a narrow lateral margin folded
around and over the lateral edge 40 of the absorptive body 23 to
form the side flap 39 shown in FIGS. 2 and 4. In this instance, it
is preferable that the side flap 39 be attached to the absorptive
body 23 by flap securement means 38. In the attached figures, the
side flap 39 is shown attached to the topsheet 25. The flap
securement means 38 can be any of those well-known to those of
ordinary skill in the art, for example, double-sided tapes and hot
melt glues.
In addition, when the diaper incorporates a side flap 39 superposed
on the topsheet 25 such as is shown in FIGS. 2 and 4, it is
desirable (but not essential if flap securement means 38 is used to
provide a "support" glue line) that the front surface portion 30
and its associated attachment means 35 extend beyond the inward
margin 44 of the side flap 39 and be in contact with the topsheet
25. Thus in a diaper having a side flap 39 such as shown in FIGS. 2
and 4, the front surface portion 30 can be attached to only the
side flap 39, only the topsheet 25, or both the side flap 39 and
the topsheet 25.
Another refinement in diaper construction which provides a stronger
diaper in connection with the improved tape fastener system of this
invention is shown in FIGS. 2 and 4. The topsheet 25 has a
longitudinal dimension longer than the longitudinal dimension of
the absorptive core 24. This greater length of the topsheet 25 is
folded around and under the longitudinal end 45 of the absorptive
core 24 to provide a folded under portion 46 of the topsheet 25.
The folded under portion 46 forms a waistband element, at the
longitudinal end of a diaper, which provides a strong member to
which a fastening system can be attached. The folded under portion
46 traverses the width of the diaper and has a longitudinal length
sufficient so that it is included between the front surface portion
30 and the back surface portion 31 of the tape fastener system 29
of this invention.
A waistband element can be formed by various other members as part
of the absorptive body. For example, wet strength tissue or other
layers, not shown in the drawing, having high tensile strength
which underlie the absorptive core, i.e., on the side of the
absorptive core opposite the topsheet, and extend across the width
of the diaper could form a waistband element.
The additional strength available by providing a folded under
portion 46 can be acquired by fastening the backsheet 26 to the
folded under portion 46 with tape support means 47. Tape support
means 47 can be any attachment means compatible with both the
backsheet 26 and the folded under portion 46, such as hot melt
glues. Tape support means 47 is positioned so that is falls within
the area projected by the back surface portion 31 onto the folded
under portion 46. A tape support means 47 is especially beneficial
at the back corners of the diaper such as back corner 34.
The tape fastener system 29 of this invention can be constructed in
several ways. Its three main elements, i.e., the front surface
portion 30, the back surface portion 31, and the fastening portion
32, can each be separate tapes which meet and are joined adjacent
the lateral edge 40 of the diaper. A more practical structure for
this tape fastener system 29 is one in which the fastening portion
32 and either the back surface portion 31 or the front surface
portion 30 is an integral strip of tape material. If the fastening
portion 32 is integral with the back surface portion 31 as shown in
the attached drawing, then the front surface portion 30 is a
separate element which is attached to the combined fastening
portion 32 and back surface portion 31 at the lateral edge 40 of
the diaper. This is easily accomplished by mating the first
attachment means 35 of the front surface portion 30 with the second
attachment means 36 and the third attachment means 37, the second
and third attachment means being generally the same when the
fastening portion 32 and the back surface portion 31 are
integral.
When the front surface portion 30 and the fastening portion 32 are
integral, the first attachment means 35 must be placed on one side
of the tape while the third attachment means 37 must be placed on
the opposite side of the tape and the back surface portion 31 is
joined with that tape adjacent the lateral edge 40 of the
diaper.
In many diaper constructions, for example, that taught in the above
mentioned Duncan et al patent, the topsheet is one of the
strongest, if not the strongest, component of the diaper. When this
is the case, the strongest tape attachment can be achieved by
insuring that the tape fastening system is attached either directly
or indirectly to the topsheet. A tape fastening system can
indirectly be attached to a topsheet through, for example, flap
securement means 38 and tape support means 47.
Another beneficial structure for a tape fastener system such as
that of this invention, is shown in FIGS. 1 and 3. This structure
is a grip tab 48 at the distal end of the fastening portion 32. The
grip tab 48 in this instance was formed by folding over a small
margin of the distal end of the fastening portion and attaching it
to itself. This forms an end on the fastening portion 32 which is
easier to grasp by the diaper user when the diaper is to be fitted
and attached to an infant. It is most beneficial when used with a
fastening portion 32 which is superposed on the front surface
portion 30.
FIGS. 5 and 6 show the tape fastener system 29 applied to an
alternate diaper construction wherein the absorptive core 49 does
not extend to the lateral edges of the diaper and the lateral
extension 50 of the topsheet 51 is attached to the lateral
extension 52 of the backsheet 53 by securement means 54, e.g., hot
melt adhesives, double sided adhesive tapes, fusion of the lateral
extensions, etc., associated with the lateral extensions 50 and 52
for holding them together. In this construction the front surface
portion 55 and the back surface portion 56 of the tape fastener
system can be attached to the respective diaper surfaces primarily
in the lateral extension portion of the diaper as shown in FIG. 5.
In some instances, it is found to be advantageous to make the front
surface portion 55 longer in its transverse dimension, i.e., the
dimension parallel to the width of the diaper, than the transverse
dimension of the back surface portion 56 as is shown in FIG. 6. For
example, it may be desirable that the front surface portion 55
overlies some of the absorptive core 49 of the diaper such as is
shown in FIG. 6 or that the front surface portion extends beyond an
element -- such as a side flap 39 in FIG. 3 -- which forms part of
the front surface of the diaper. Thus, the transverse dimension of
the front surface portion may be longer than the transverse
dimension of the back surface portion; in fact, it may be at least
about twice as long as the transverse dimension of the back surface
portion.
The preferred embodiment of this tape fastener system with regard
to the location of the first common point of joinder 41 is also
shown in both FIGS. 5 and 6. This preferred embodiment is that the
first common point of joinder 41 is adjacent to the lateral edge of
the diaper and is substantially in a plane equidistant between the
front surface of the diaper and the back surface of the diaper.
Any of the back surface portion, the front surface portion, or the
fastening portion of this tape fastener system and their attachment
means can be pressure sensitive tapes as are well-known to those of
ordinary skill in the art. Any of these pressure sensitive tapes
are preferably a paperbacked tape but can also be any one of
several well-known commercial types including types having a
polyethylene backing. In either case, these tapes can be with or
without reinforcing elements. The pressure sensitive adhesive on
these tapes is preferably selected so that it will be least
irritating to a baby's tender skin.
In practice, the back surface portion and the fastening portion --
as separate pieces or as an integral piece -- and their associated
attachment means may be a saturated creped paper tape having a
pressure sensitive adhesive tailored to bond to polyethylene, such
as tape No. Y-9030 available from the Minnesota Mining and
Manufacturing Co. The front surface portion in the embodiment of
FIG. 1, i.e., having its upper surface treated to provide a release
liner, and its associated attachment means can be a polypropylene
film having a pressure sensitive adhesive tailored to bond to
polyethylene and having a silicone release coating on its upper
surface to provide easy release, such as tape No. Y-9376 or tape
No. Y-840 available from the Minnesota Mining and Manufacturing
Co.
Thus it is apparent that there has been provided, in accordance
with the invention, an improved tape fastener system that fully
satisfies the objects, aims, and advantages set forth above. While
the invention has been described in conjunction with specific
embodiments thereof, it is evident that many alternatives,
modifications, and variations will be apparent to those skilled in
the art in light of the foregoing description. Accordingly, it is
intended to embrace all such alternatives, modifications, and
variations as fall within the spirit and broad scope of the
appended claims.
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