U.S. patent number 3,853,129 [Application Number 05/402,089] was granted by the patent office on 1974-12-10 for pressure-sensitive tape fastener for disposable diapers.
This patent grant is currently assigned to Union Carbide Corporation. Invention is credited to Theodore F. Kozak.
United States Patent |
3,853,129 |
Kozak |
December 10, 1974 |
PRESSURE-SENSITIVE TAPE FASTENER FOR DISPOSABLE DIAPERS
Abstract
A disposable diaper having a topsheet, a backing sheet and an
absorbent core interposed therebetween and a pressure-sensitive
tape fastener having a fixed end segment, a middle segment having a
plastic material with a retiform surface defining hill portions and
valley portions, and a releasable end segment which is folded in a
manner such that the releasable end segment and the middle segment
are superimposed over the fixed end segment with the lower surface
of the releasable end segment being in contacting relation and
releasably secured to the hill portions of the plastic
material.
Inventors: |
Kozak; Theodore F. (Peekskill,
NY) |
Assignee: |
Union Carbide Corporation (New
York, NY)
|
Family
ID: |
23590469 |
Appl.
No.: |
05/402,089 |
Filed: |
October 1, 1973 |
Current U.S.
Class: |
604/390 |
Current CPC
Class: |
A61F
13/58 (20130101) |
Current International
Class: |
A61F
13/58 (20060101); A61F 13/56 (20060101); A61f
013/16 () |
Field of
Search: |
;128/287,284,286,156 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Yasko; J.
Attorney, Agent or Firm: Vicari; Clement J.
Claims
What is claimed is:
1. In a disposable diaper having a topsheet, a backing sheet and an
absorbent core interposed therebetween, the improvement comprising
a pressure-sensitive tape fastener having an upper surface and a
lower surface, said lower surface being divided widthwise into two
end segments at least one of which is adhesively treated, and an
adhesively treated middle segment, one of said end segments being a
fixed end segment which is secured to said backsheet, the other of
said end segments being a releasable end segment, said middle
segment being covered on the lower surface of said pressure
sensitive fastener with a plastic material having a retiform
surface defining a system of hill portions and valley portions,
said hill portions covering said adhesively treated lower surface
of said middle segment, and said valley portions exposing said
adhesively treated lower surface; said fastener when in
non-operating position being folded in a manner such that said
releasable end segment and said middle segment are superimposed
over said fixed end segment with the lower surface of said
releasable end segment being in contacting relation and releasably
secured to the hill portions of said middle segment.
2. A disposable diaper as claimed in claim 1 wherein said fixed end
segment is secured to said backing sheet by adhering said fixed end
segment to said backing sheet.
3. A disposable diaper as claimed in claim 1 wherein said backing
sheet and said pressure-sensitive tape fastener are fabricated from
a thermoplastic material and wherein said fixed end segment is
secured to said backing sheet by heat sealing.
4. A disposable diaper according to claim 3 wherein said backing
sheet and said pressure-sensitive tape fastener are fabricated from
polyethylene.
5. A disposable diaper according to claim 1 wherein said valley
portions expose 40 to 80 percent of adhesive are in the lower
surface of said middle segment.
6. A disposable diaper according to claim 1 characterized in that
when said diaper is in operating position, said backing sheet is
adhered to said pressure-sensitive tape fastener by the adhesive
disposed on said releasable end segment and by the adhesive exposed
through the valley portions of said plastic material.
Description
The present invention relates to disposable diapers and more
particularly to an improved pressure-sensitive tape fastener for
disposable diapers.
Disposable diapers are presently enjoying increasingly widespread
commercial acceptance due primarily to the ease of simplicity of
application to the diaper. At present, there are several devices
known to the art for securing the diaper on an infant. Widely used
devices are pressure-sensitive tape fasteners which are preferred
over conventional safety pins because of the elimination of the
well-known danger incident to the use of safety pins.
Unfortunately, however, the known pressure-sensitive tape fasteners
for diaper use are not entirely satisfactory from a practical
standpoint. For example, in general, some types of
pressure-sensitive tape fasteners utilize a throw-away release
paper which is normally adhered to a portion of the tape tab. When
it is desired to secure the diaper on an infant, the operator
removes the release paper from the tab exposing an adhesively
treated surface which is, thereafter, fixed in adhesive relation on
the desired surface of the diaper. Since this operation is
conducted while the diaper is on the infant, it is difficult for
the operator to both apply the diaper to the infant while at the
same time releasing the release paper from the tape fastener.
It is therefore an object of the present invention to provide an
improved pressure-sensitive tape fastener for a disposable diaper
which does not utilize a disposable throw-away release material,
such as a release paper, with the pressure-sensitive tape
fastener.
Another object of the present invention is the provision of an
improved pressure-sensitive tape fastener for a disposable diaper
which is easily manufactured, and is simple to apply to an
infant.
A further object of the present invention is to provide an improved
pressure-sensitive tape fastener for a disposable diaper which does
not utilize a throw-away release material, and which provides a
great degree of holding power when in closed position on the
diaper.
These and other objects will become apparent from the following
description of the invention taken in conjunction with the
accompanying drawings in which:
FIG. 1 is a perspective view looking upwardly at the bottom of the
improved pressure-sensitive tape fastener of the present invention
showing the location of the adhesive surfaces and the release
surface of the fastener.
FIG. 2 is an enlarged partial view of the release surface of the
fastener depicted in FIG. 1.
FIG. 3 is a side view showing the pressure-sensitive tape fastener
indicating the location of the folds of the fastener.
FIG. 4 is a fragmentary perspective view of a disposable diaper
showing the position of the tape fastener in non-operating
position, i.e., only one end affixed to a corner of the diaper.
FIG. 5 is a view showing the tape fastener in operating position,
i.e., both ends and the middle segment affixed to adjoining corners
of a diaper in securing position.
Broadly contemplated, the present invention provides an improvement
in a disposable diaper having a topsheet, a backing sheet and an
absorbent core interposed therebetween, the improvement comprising
a pressure sensitive tape fastener having an upper surface and a
lower surface, said lower surface being divided widthwise into two
end segments at least one of which is adhesively treated, and an
adhesively treated middle segment, one of said end segments being a
fixed end segment which is secured to said backsheet, the other of
said end segments being a releasable end segment, said middle
segment being covered on the lower surface of said pressure
sensitive fastener with a plastic material having a retiform
surface defining a system of hill portions and valley portions,
said hill portions covering said adhesively treated lower surface
of said middle segment, and said valley portions exposing said
adhesively treated lower surface; said fastener when in
non-operating position being folded in a manner such that said
releasable end segment and said middle segment are superimposed
over said fixed end segment with the lower surface of said
releasable end segment being in contacting relation and releasably
secured to the hill portions of said middle segment.
Referring to FIG. 1 of the drawings, it will be seen that the
pressure-sensitive tape fastener of the present invention,
generally indicated by reference numeral 10 has an upper surface 11
and a lower surface 12. The lower surface is divided widthwise into
three segments, including two end segments or ends 13 and 15 and a
middle segment 14. Depending upon the positioning of the tape
fastener on the diaper, either end 13 or 15 can be termed a fixed
or attached end in which case the other end would be termed a free
or releasable end. The pressure-sensitive tape is preferably a
paperbacked tape but it can also be any of several well-known
commercial types including the type having a polyethylene backing.
In either case, it can be used with or without reinforcing. At
least one of the end segments 13 and 15 on the lower surface 12 are
coated with a pressure-sensitive adhesive which can be any of the
conventional types well known in the art. The middle segment 14 has
a plastic material 16 covering the lower surface of the middle
segment. The plastic material has a retiform surface defining a
system of hill portions 17 and valley portions 18, so that when the
releasable end is adhered to the hill portions of the plastic
material, as will hereafter be described, there is a minimal
adhesive attachment therewith. Thus, according to the invention,
the adhesive portions and the release portion are all disposed on
the same side of the pressure-sensitive tape, i.e., the lower
surface 12 of the tape. When the pressure-sensitive tape fastener
is in non-operating position, i.e., prior to securing the diaper on
an infant, the pressure-sensitive tape has a system of folds as
indicated in FIG. 3.
As will be seen from FIGS. 1 and 2, the plastic material 16 covers
the lower surface of the middle segment 14 and is characterized by
a retiform surface. Thus, the plastic material has a system of hill
portions 17 and valley portions 18, the latter exposing the
adhesively treated lower surface of the middle segment. The plastic
material contemplated for use in the present invention is one
having a lesser degree of flexibility than the material
constituting the backing sheet of the diaper. The degree of
rigidity of the plastic material should be sufficient to enable the
operator, when applying the diaper to the infant, to urge the
surface of the backing sheet into the valley portions 18 of the
plastic material 16 in contact with the adhesive on the lower
surface of the middle segment. Thus, since the backing sheet of the
diaper is more flexible than the plastic material on the middle
segment, the film of backing sheet can conform to the contours of
the valley portions 18 and portions of the backing sheet adhered to
the adhesive surface of the middle segment providing additional
holding power for the pressure-sensitive tape fastener when it is
in operating position on the diaper.
The materials used in the fabrication of the plastic material of
the present invention are not limited to any particular chemical
composition since it is their physical properties rather than their
chemical properties which are important according to the invention.
These materials should, of course, be less flexible than the
materials of the backing sheet and self-supporting.
The plastic material can be an olefinic or vinyl material.
Polyethylene is an example of a suitable material. The plastic
material of choice is one which is available commercially from
Hercules Corporation under the trademark "Delnet." The height of
the plastic material is determined by the height of the hill
portions 17. The appropriate height would, of course, depend upon
the rigidity of the plastic material as compared to the rigidity of
the backing sheet, the selection being determined by the
requirement that the backing sheet must not contact the exposed
adhesive portion of the middle segment when the tape fastener is in
non-operating position. On the other hand, the backing sheet must
contact the adhesive portion of the middle segment, when the
operator compresses the backing sheet against the middle segment of
the tape fastener. As a general rule, the height of the plastic
material, as determined by the height of the hill portions, should
be from about 1 to 5 mils depending upon, as stated previously, the
choice of materials and degree of rigidity of the plastic material.
The size of the valley portions 18 exposing the adhesive surface of
the middle segment are determined among other things by the
frequency of the valley portions. As a general rule, there can be
from 40 to 80 percent exposed adhesive areas in the lower surface
of the middle segment. The configuration of the exposed areas are
not critical, and they can be diamond shaped, square shaped,
circular and the like.
Referring specifically to FIG. 3, it will be seen that the folds
occur at the inward ends of the segments 13 and 15 with the
releasable end 15 being superimposed and in contact with the hill
portions 17 of the plastic material situated on the middle segment
14. The resultant configuration depends upon which end is the fixed
end. When segment 13 is the fixed end, i.e., the end permanently
secured to the diaper, the resultant configuration has an "S"
shape, whereas if the fixed end is segment 15, then the resultant
configuration is "Z" shaped.
The pressure-sensitive tape fastener can be employed with any
conventional disposable diaper particularly of the kind that has a
plastic backing sheet. Merely as illustrative, of the kind of
diaper to which the invention is readily adapted, reference is made
to the diaper described in my copending application Ser. No.
312,131 filed on Dec. 4, 1972.
It will be obvious 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 disclosure of the above co-pending
application is incorporated herein by reference merely for the sake
of illustrating a typical example of the kind of diaper to which
the present invention can be usefully applied.
Referring to FIG. 4 which illustrates the location of the tape
fastener 10 in non-operating position, on a corner of a disposable
diaper, the diaper generally designated by reference numeral 19
contains an absorbent core 21. The core can be formed from any
well-known material having good fluid-absorbing characteristics
such as absorbent wadding, cellulosic fluff and the like.
Preferably, however, the absorbent core is in the form of an
absorbent pad which is substantially centrally located and
sandwiched between the thin flexible backing sheet 22 of liquid
impermeable material such as polyethylene film, and the thin
flexible topsheet 23 also of a normally liquid impermeable material
which has been treated such as by providing openings or slits
therein so as to permit the passage of liquid therethrough. It will
be understood however, that both the topsheet 23 and backing sheet
22 may be any suitable material and need not be plastic,
particularly when the diaper is to be covered with plastic panties
or the like. In its preferred form, backing sheet 22 and topsheet
23 are of approximately equal size and are of a length and width
slightly greater than the corresponding dimensions of the absorbent
core 21. The edges of backing sheet 22 and topsheet 23 are sealed
to each other (if plastic) around the entire periphery of the
diaper and just outside the outermost edges of absorbent core (pad)
21.
The sealing can be accomplished by any convenient means, such as by
the use of an adhesive, however, heat sealing around the periphery
of the diaper is preferred.
The pressure-sensitive tape fastener 10 has one end, e.g., the
fixed end 13 which is strongly adhered and permanently secured to
the backing sheet 22 as shown in FIG. 4 (for simplicity of
illustration, only one tape 10 is shown but it will be understood
that normally two tapes are provided on two diaper corners in a
complete diaper structure). When the pressure-sensitive tape
fastener is fabricated from a thermoplastic material for
application to a backsheet also of thermoplastic material, then the
securing of the fixed end can be effected by heat sealing. However,
when heat sealing is not possible, then the fixed end segment can
be coated on the lower surface with an adhesive material so that
both end segments would be adhesively treated. The other end of the
tape, i.e., the releasable end 15 when in non-operating position,
is superimposed over the middle segment 14, and in contact with the
hill portions 17 of the plastic material 16, and is adhesively,
albeit minimally, secured thereto.
FIG. 5 illustrates the tape fastener 10 after the operator has
released the releasable end 15 and positioned the middle segment
and releasable end on the adjacent corner of a diaper in securing
engagement therewith. Advantageously, the operator can utilize the
lower surface of the middle segment by positioning the middle
segment as well as the releasable end over the backing sheet. Thus
additional holding power can be obtained by compressing the upper
surface of the fastener 10 against the backing sheet with enough
pressure so that the backing sheet contacts the exposed adhesive
areas of the middle section.
In a typical mode of operation, the operator unfolds the diaper and
wraps it around the infant in the usual manner. The
pressure-sensitive tape fastener 10 is in the non-operating
position as shown in FIG. 4. The operator thereafter grasps the
releasable end and releases it from the hill portions 17 of the
plastic material 16 situated on the middle segment 14. The adjacent
corners of the diaper are urged towards each other and the operator
positions and with sufficient pressure secures the releasable end
as well as the middle segment on the backing sheet of the adjacent
corner of the diaper as shown in FIG. 5. The operation is repeated
on the other adjacent corners with sufficient force being exerted
so as to provide a tight, comfortable fitting diaper.
As mentioned previously, the end segments 13 and 15 of the tape
fastener 10 can be treated on the lower surface 12 with a
conventional adhesive material. The adhesive material should be of
sufficient bond strength to adhere to the backing sheet 22 under
normal stress and strain during movement of the infant. The middle
segment 14 of the tape fastener 10 is likewise treated on the lower
surface with an adhesive agent so as to provide minimal adhesive
attachment with the releasable end through the valley portions 18
exposing the adhesively treated lower surface.
While particular embodiments of the invention have been illustrated
and described, it will be obvious to those skilled in the art that
various changes and modifications can be made without departing
from the spirit and scope of the invention and it is intended to
cover in the appended claims all such changes and modifications
that are within the scope of this invention.
* * * * *