U.S. patent number 3,766,922 [Application Number 05/168,159] was granted by the patent office on 1973-10-23 for throw-away boy and girl diapers.
Invention is credited to Evelyn H. Krusko.
United States Patent |
3,766,922 |
Krusko |
October 23, 1973 |
THROW-AWAY BOY AND GIRL DIAPERS
Abstract
Throw-away diapers having elongate, absorbent pads, or sections
of cellulosic fibers disposed within covering envelopes having a
fluid pervious and fluid containing facing cover layer, and a
backing cover layer. The absorbent pads have predetermined regions
of differing fiber weight through the thickness per unit surface
area thereof wherein the greatest weight of fibers through the
thickness per unit surface area is included in a predetermined
region where it is most needed to retain body fluids. An embossed
pattern in the facing layer and underlying absorbent pad defines
valleys and ridges in all of the predetermined regions, and the
density of the absorbent pad in the valleys is greater than the
density of the absorbent pad in the ridges. Absorbent pads in
throw-away diapers for use by girl babies comprise an elongate,
fluff batt of cellulosic fibers in which an elongate, middle
one-third thereof constitutes the predetermined region having the
greatest weight of fibers through the thickness per unit surface
area. Absorbent pads in throw-away diapers for use by boy babies
comprise a main fluff batt and a secondary fluff batt. The
elongate, forward one-third of the main fluff batt constitutes the
predetermined region having the greatest weight of fibers through
the thickness per unit surface area thereof. The secondary fluff
batt is disposed forwardly of the main fluff batt and is folded
over the main fluff batt during use of the diaper. The elongate,
absorbent pads utilized in the throw-away diapers of this invention
also constitute a part of the present invention.
Inventors: |
Krusko; Evelyn H.
(Philadelphia, PA) |
Family
ID: |
26748344 |
Appl.
No.: |
05/168,159 |
Filed: |
August 2, 1971 |
Current U.S.
Class: |
604/374; 604/366;
604/380; 19/148; 604/375 |
Current CPC
Class: |
A61F
13/532 (20130101); A61F 13/4915 (20130101); A61F
13/51104 (20130101); A61F 13/15626 (20130101); A61F
13/15634 (20130101); A61F 13/49466 (20130101); A61F
13/491 (20130101); A61F 13/51121 (20130101); A61F
2013/5326 (20130101) |
Current International
Class: |
A61F
13/15 (20060101); A61f 013/16 () |
Field of
Search: |
;128/284,286,287,288,290,296 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Rosenbaum; Charles F.
Claims
What is claimed is:
1. An absorbent pad comprising an elongate, absorbent section of
cellulosic fibers having opposed major surfaces, said absorbent
section having predetermined regions of different fiber weight
wherein the greatest weight of fibers is included in a
predetermined region where it is most needed to retain body fluids;
said absorbent section having an embossed pattern in at least one
major surface thereof, said embossed pattern defining a plurality
of ridges and valleys disposed in both said predetermined region of
greatest fiber weight and in said other predetermined regions, the
density of said batt in said valleys being greater than the density
of said batt in said ridges; the pattern of valleys in the
predetermined region of greatest fiber weight being different than
the pattern of valleys in the other predetermined regions such that
the percentage of the area of said predetermined region of greatest
fiber weight constituted by valleys is less than the percentage of
the area of the other predetermined regions which is constituted by
valleys.
2. The absorbent pad according to claim 1, wherein said absorbent
section comprises a fluff batt of cellulosic fibers having a
transverse dimension defined between spaced, elongate side margins,
at least a portion of said side margins being recessed to define a
narrow crotch region.
3. The absorbent pad according to claim 2, wherein said
predetermined regions are aligned with each other in the elongate
direction of said fluff batt.
4. The absorbent pad according to claim 3, wherein said fluff batt
has an elongate dimension defined between forward and rearward end
margins; said fluff batt having a forward elongate region
terminating at one end adjacent said forward end margin, a rearward
elongate region terminating at one end adjacent said rearward end
margin and a middle elongate region disposed between said forward
and rearward regions; the weight of fibers in one of said forward
and middle regions comprising the predetermined region of greatest
fiber weight.
5. The absorbent pad according to claim 4, wherein at least some of
said valleys bridge the predetermined region of greatest fiber
weight with the regions adjacent thereto.
6. The absorbent pad according to claim 4, wherein the weight of
fibers within each of said predetermined regions is substantially
uniform over substantially the entire extent of said respective
region.
7. The absorbent pad according to claim 6, wherein the elongate
dimension of said forward, middle and rearward elongate regions is
substantially the same, each comprising substantially one-third of
the elongate dimension of said fluff batt.
8. The absorbent pad according to claim 4 adapted for use as an
absorbent component in a throw-away diaper for use by a boy baby,
wherein said forward region is the predetermined region of greatest
fiber weight.
9. The absorbent pad according to claim 8, wherein the embossed
pattern includes valleys comprising a first set of spaced, elongate
channels extending substantially in the elongate direction of said
batt and for substantially the entire elongate dimension of said
rearward and middle regions of said batt and only partially into
said forward region of said batt.
10. The absorbent pad according to claim 9, wherein the embossed
pattern further includes valleys comprising substantially uniformly
spaced compressed islands in said forward region, and valleys
comprising a second set of spaced channels in said rearward and
middle regions of said batt, each of said channels of said second
set extending substantially transverse to the channels of said
first set for directing fluids transversely along said batt.
11. The absorbent pad according to claim 4 adapted for use as an
absorbent component in a throw-away diaper for use by a girl baby,
wherein said middle region is the predetermined region of greatest
fiber weight.
12. The absorbent pad according to claim 11, wherein the embossed
pattern includes valleys comprising a first set of spaced, elongate
channels extending substantially in the elongate direction of said
fluff batt for substantially the entire elongate dimension of said
rearward region and said forward region and only partially into
said middle region.
13. The absorbent pad according to claim 12, wherein the embossed
pattern further includes valleys comprising substantially uniformly
spaced compressed islands in said middle region, and valleys
comprising a second set of spaced channels in said rearward and
forward regions of said batt, each of said channels of said second
set extending substantially transverse to the channels of said
first set for directing fluids transversely along said batt.
14. A throw-away diaper having an elongate, absorbent fluff batt of
cellulosic fibers disposed within a covering envelope which has a
fluid pervious facing layer, said absorbent batt having
predetermined regions of differing fiber weight wherein the
greatest weight of fibers is included in a predetermined region
where it is most needed to retain body fluids; a first embossed
pattern in said facing layer and said underlying absorbent batt,
said embossed pattern defining a plurality of superimposed ridges
and superimposed valleys in said facing layer and said underlying
absorbent batt, said valleys being disposed in both said
predetermined region of greatest fiber weight and in said other
predetermined regions, the density of said batt in said valleys
being greater than the density of said batt in said ridges; the
pattern of valleys in the predetermined region of greatest fiber
weight being different than the pattern of valleys in the order
predetermined regions such that the percentage of the area of the
predetermined region of greatest fiber weight which is constituted
by valleys is less than the percentage of the area of the other
predetermined regions which is constituted by valleys.
15. The throw-away diaper according to claim 14, wherein said
absorbent batt has an elongate dimension defined between forward
and rearward end margins, said batt having a forward elongate
region terminating at one end adjacent said forward end margins, a
rearward elongate region terminating at one end adjacent said
rearward end margin and a middle elongate region disposed between
said forward and rearward regions, the weight of fibers in one of
said forward and middle regions comprising the predetermined region
of greatest fiber weight.
16. a throw-away diaper according to claim 15 for use by a girl
baby, wherein said middle region is the predetermined region of
greatest fiber weight.
17. The throw-away diaper according to claim 16, wherein said
facing layer is comprised of a sheet of randomly arranged,
intermingled, short cellulosic fibers and longer reinforcing
synthetic fibers, said sheet having a second embossed pattern in
the outer surface thereof for enhancing the flexibility and fluid
directing characteristics of said sheet, said second embossed
pattern being defined by a plurality of ridges and valleys
extending over substantially the entire surface of said sheet, the
density of the sheet in said valleys of said second embossed
pattern being greater than the density of said sheet in said ridges
of said second embossed pattern; and an adhesive network
interconnecting fibers of said sheet for enhancing the strength and
abrasion resistance of said sheet without destroying the
flexibility thereof.
18. The throw-away diaper according to claim 17, wherein the first
embossed pattern includes valleys comprising a first set of spaced,
elongate channels extending substantially in the elongate direction
of said fluff batt and for substantially the entire elongate
dimension of said rearward region and said forward region and only
partially into said middle region.
19. The throw-away diaper according to claim 18, wherein the first
embossed pattern includes valleys comprising substantially
uniformly spaced compressed islands in said middle region, and
valleys comprising a second set of spaced channels in said rearward
and forward regions of said fluff batt, each of said channels of
said second set extending substantially transverse to the channels
of said first set of directing body fluids transversely along said
fluff batt.
20. A throw-away diaper according to claim 15 for use by a boy
baby, wherein said forward region is the predetermined region of
greatest fiber weight.
21. The throw-away diaper according to claim 20, wherein said
facing layer is comprised of a sheet of randomly arranged,
intermingled short cellulosic fibers and longer reinforcing
synthetic fibers, said sheet having a second embossed pattern in
the outer surface thereof for enhancing the flexibility and fluid
directing characteristics of said sheet, said second embossed
pattern being defined by a plurality of ridges and valleys
extending over substantially the entire surface of said sheet, the
density of the sheet in said valleys of said second embossed
pattern being greater than the density of said sheet in said ridges
of said second embossed pattern; and an adhesive network
interconnecting fibers of said sheet for enhancing the strength and
abrasion resistance of said without destroying the flexibility
thereof.
22. The throw-away diaper according to claim 21, wherein the first
embossed pattern includes valleys comprising a first set of spaced,
elongate channels extending substantially in the elongate direction
of said fluff batt and for substantially the entire elongate
dimension of said rearward region and said middle region and only
partially into said forward region.
23. The throw-away diaper according to claim 22, wherein the first
embossed pattern includes valleys comprising substantially
uniformly spaced compressed islands in said forward region, and
valleys comprising a second set of spaced channels in said rearward
and middle regions of said fluff batt, each of said channels of
said second set extending substantially transverse to the channels
of said first set for directing body fluids transversely along said
fluff batt.
24. The throw-away diaper according to claim 20, wherein the first
embossed pattern includes valleys comprising a first set of spaced,
elongate channels extending substantially in the elongate direction
of said fluff batt and for substantially the entire elongate
dimension of said rearward region and said middle region and only
partially into said forward region.
25. A throw-away diaper according to claim 24, wherein the first
embossed pattern includes valleys comprising substantially
uniformly spaced compressed islands in said forward region, and
valleys comprising a second set of spaced channels in said rearward
and middle regions of said fluff batt, each of said channels of
said second set extending substantially transverse to the channels
of said first set for directing body fluids transversely along said
fluff batt.
26. the throw-away diaper according to claim 16, wherein the first
embossed pattern includes valleys comprising a first set of spaced,
elongate channels extending substantially in the elongate direction
of said fluff batt and for substantially the entire elongate
dimension of said rearward region and said forward region and only
partially into said middle region.
27. The throw-away diaper according to claim 26, wherein the first
embossed pattern includes valleys comprising substantially
uniformly spaced compressed islands in said middle region, and
valleys comprising a second set of spaced channels in said rearward
and forward regions of said fluff batt, each of said channels of
said second set extending substantially transverse to the channels
of said first for directing body fluids transversely along said
fluff batt.
28. A throw-away diaper for use by a boy baby comprising an
absorbent pad disposed within a covering envelope which has a fluid
pervious facing layer; said absorbent pad comprising a main
absorbent member and a secondary absorbent member, said main
absorbent member having an elongate dimension defined between
spaced forward and rearward margins, said covering envelope
extending beyond the forward margin of said main absorbent member
to define a forward marginal region, said secondary absorbent
member being disposed in said forward marginal region within said
covering envelope, said secondary absorbent member being separated
from said main absorbent member by a transversely extending region
having lower bulk than the transverse regions of said diaper which
include said main and secondary absorbent members wherein said
transverse region of lower bulk defines a transverse fold line
region along which the forward marginal region can be infolded to
superimpose said secondary absorbent member over said main
absorbent member to increase the absorptive capacity in the
superimposed region and to provide a physical impediment to the
escape of urine through the forward end of the diaper.
29. the throw-away diaper according to claim 28, wherein said main
absorbent member and said secondary absorbent member comprise fluff
batts of cellulosic fibers.
30. The throw-away diaper according to claim 29, said main and
secondary fluff batts being defined by separate fluff batts of
cellulosic fibers, said secondary fluff batt being spaced forwardly
of said main fluff batt to define the transverse fold line region
between said main and secondary fluff batts.
31. The throw-away diaper according to claim 29, said main fluff
batt and said secondary fluff batt being defined in a unitary fluff
batt of cellulosic fibers and being separated from each other by a
transversely extending compressed zone in said unitary fluff batt,
said transversely extending compressed zone defining said
transverse fold line region.
32. The throw-away diaper according to claim 29, wherein said main
fluff batt has a forward elongate region terminating at one end
adjacent said forward margin, a rearward elongate region
terminating at one end adjacent said rearward margin and a middle
elongate region disposed between said forward and rearward regions,
the weight of fibers in said forward region being greater than the
weight of fibers in the other two of said regions.
33. The throw-away diaper according to claim 32, wherein said
covering envelope includes a backing layer and a facing layer, said
facing and backing layer each comprising an elongate sheet having
side margins extending beyond side margins of the main and
secondary fluff batts and secured to each other in the regions
which extend beyond said side margins of said fluff batts.
34. The throw-away diaper according to claim 33 further comprising
a first embossed pattern defining a plurality of superimposed
ridges and superimposed valleys in said facing layer and in said
forward, rearward and middle elongate regions of said main fluff
batt, the density of said fluff batt in said valleys being greater
than the density of said fluff batt in said ridges.
35. The throw-away diaper according to claim 34, wherein said
facing sheet is comprised of randomly arranged, intermingled, short
cellulosic fibers and longer reinforcing synthetic fibers, said
facing sheet having a second embossed pattern in the outer surface
thereof for enhancing the flexibility and fluid-directing
characteristics of said sheet, said second embossed pattern being
defined by a plurality of ridges and valleys extending over
substantially the entire surface of said sheet, the density of the
sheet in said valleys of said second embossed pattern being greater
than the density of said sheet in said ridges of said second
embossed pattern; and an adhesive network interconnecting fibers of
said sheet for enhancing the strength and abrasion resistance of
said sheet without destroying the flexibility thereof.
36. The throw-away diaper according to claim 35, wherein the ratio
of the area of the valleys of said first embossed pattern in the
forward region of the main fluff batt to the total area of said
forward region is less than the ratio of the area of the valleys of
said first embossed pattern in the middle region of the main fluff
batt to the total area of said middle region, and is less than the
ratio of the area of the valleys of said first embossed pattern in
the rearward region of the main fluff batt to the total area of
said rearward region.
37. The throw-away diaper according to claim 35, wherein the first
embossed pattern includes valleys comprising a first set of spaced,
elongate channels extending substantially in the elongate direction
of said fluff batt and for substantially the entire elongate
dimension of said rearward and middle regions and only partially
into said forward region.
38. The throw-away diaper according to claim 37, wherein the first
embossed pattern includes valleys comprising substantially
uniformly spaced compressed islands in said forward region, and
valleys comprising a second set of spaced channels in said rearward
and middle regions of said main fluff batt, each of said channels
of said second set extending substantially transverse to the
channels of said first set for directing body fluids transversely
along said main fluff batt.
39. The throw-away diaper according to claim 38, wherein the first
and second set of spaced, elongate channels are impressed into the
facing layer and underlying secondary fluff batt.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to throw-away diapers, and more
particularly to separate throw-away diapers constructed for use by
boy babies and girl babies, respectively.
2. Description of the Prior Art
A demand exists for throw-away diapers which are inexpensive,
non-bulky, and capable of absorbing and retaining urine and fecal
matter at least as effectively as cloth diapers when such
throw-away diapers are utilized by either boy or girl babies. It is
known in the prior art, as exemplified in Canadian Pat. No.
820,551, to provide throw-away diapers with profiled, absorbent
fluff batts of cellulosic fibers as one component thereof; i.e.
fluff batts having regions of differing fiber weight per unit
surface area through the thickness thereof to position the greatest
weight of fibers were it is most needed to store urine. These
throw-away diapers are not believed to represent the preferred
forms for obtaining the above demand. Even in such throw-away
diapers the urine tends to strike completely through the thickness
of said fluff batt in the region in which it is initially impinged
before a sufficient volume of said urine can be directed into other
areas of said fluff batt for containment in said other areas to
prevent excessive leakage.
Furthermore, the fluff batts disclosed in the above-referred-to
Canadian Patent extend for the entire transverse extent of the
throw-away diapers. The use of fluff batts which extends for the
entire transverse extent of the throw-away diapers results in the
application of excessive stresses to said diapers when they are in
use. These excessive stresses occur because the fluff batt is
extremely bulky in the crotch and thigh-encircling regions, and the
confining nature of the crotch and thigh-encircling regions imposes
excessive stresses on said fluff batt. The excessive stresses
imposed upon the throw-away diapers cause the fluff batts to lose
their structural integrity and break up into separated clumps to
thereby adversely affect the fluid absorbing capability of said
fluff batts.
It has been suggested in the prior art to emboss fluff batts having
a substantially uniform fiber weight distribution over its entire
extent, i.e. unprofiled. It has never been suggested in the prior
art to emboss profiled fluff batts since it has been thought that
the inclusion of an embossed pattern in the region of greatest
fiber weight in profiled fluff batts would seriously detract from
the fluid storing capabilities of said fluff batts in said region.
Therefore, it was thought that embossing would directly defeat the
purpose for non-uniformly distributing the weight of fibers in a
fluff batt; namely, to provide a fiber region having a greater
fluid storing capability than other regions of said fluff batt.
SUMMARY OF THE INVENTION
Although it is known in the prior art that urine emitted by a boy
baby is directed to a different area of a diaper than urine emitted
by a girl baby, it remained for applicant to invent unique,
separate, throw-away diapers for use by boy and girl babies,
respectively, wherein an acceptable volume of urine is retained, or
stored within said diapers without excessive leakage therefrom.
Applicant's invention is in unique structures of absorbent pads, or
sections of cellulosic fibers to accommodate the specific urinating
characteristics of boy and girl babies, and to the throw-away
diapers utilized in said absorbent pads.
Each throw-away diaper of this invention includes an absorbent pad
defined by a profiled, embossed fluff batt of cellulosic fibers.
The term "profiled," as used throughout the specification and
claims of this application in describing the structure of a fluff
batt, refers to a varying weight distribution of fibers throughout
said fluff batt such that the fluff batt has regions of differing
fiber weight per unit surface area throughout the thickness thereof
to position the greatest weight of fibers in a predetermined region
of the fluff batt wherein it is most needed to store urine.
Reference to "weight of fibers.infin. or to "fiber weight"
throughout this application, including the claims, refers to the
weight of fibers per unit surface area through the thickness of the
region referred to, unless clearly indicated to the contrary.
Each throw-away diaper of this invention includes a covering
envelope which has a fluid pervious and containing facing cover
layer, and a backing cover layer. A profiled fluff batt is disposed
within said covering layer, and an embossed pattern is impressed
into the facing layer and the underlying profiled fluff batt to
define the profiled, embossed fluff batts of this invention. The
embossed pattern impressed into the profiled fluff batt defines
ridges and valleys in both the predetermined region of greatest
fiber weight and in the other regions of said fluff batt; the
desity of the fluff batt in the valleys being greater than the
density of the fluff batt in the ridges.
In the most preferred embodiments of this invention the
predetermined region of greatest fiber weight has a less percentage
of its surface area defined by compressed valleys than the other
predetermined regions of said fluff batt. The compressed valleys in
the predetermined region of greatest fiber weight are preferably in
the form of uniformly spaced, substantially circular, compressed
islands. These compressed islands prevent an excessive volume of
urine from striking through the thickness of the fluff batt by
acting as a fluid wick for the urine which is initially directed
onto the predetermined region of greatest fiber weight to aid in
directing urine along the fluff batt.
It is known that the fluid storing capacity of a fluff batt is
decreased as the percentage of the surface area defined by
compressed valleys is increased. Applicant has found, quite
surprisingly, that the area of urine transmission along the
profiled, embossed fluff batts in the throw-away diapers of this
invention is approximately the same, regardless of whether the
percentage of compressed area in the predetermined region of
greatest fiber weight is less than, or substantially equal to the
percentage of compressed area in the other predetermined regions of
said fluff batt. Therefore, by reducing the embossed area in the
predetermined region of greatest fiber weight, the fluid storing
capacity of the diaper is enhanced without adversely affecting the
fluid wicking characteristics of said diaper.
In the most preferred embodiments of this invention the compressed
valleys extend partially into the predetermined region of greatest
fiber weight from at least one of the other regions of the
absorbent fluff batt to function as a fluid wick for the urine
initially imbibed within the predetermined region of greatest fiber
weight to direct urine from the region of greatest fiber weight
into other regions of the fluff batt.
In a throw-away diaper of this invention for use by a girl baby the
fluff batt is profiled to provide the greatest weight of fibers in
the center, elongate one-third region of the absorbent fluff batt.
In a throw-away diaper of this invention for use by a boy baby, a
main fluff batt is profiled to provide the greatest weight of
fibers in the forward, elongate one-third region thereof.
Preferably, the throw-away diaper for use by a boy baby is provided
with a secondary fluff batt which is disposed forwardly of the main
fluff batt and is enclosed within the covering envelope. In use,
the forward portion of the diaper containing the secondary fluff
batt is infolded such that the secondary fluff batt is superimposed
over the forward region of the main fluff batt to provide a thick,
absorptive region in the upper front portion of the diaper. In
addition, the infolded region provides a ledge, or dam, to prevent
leakage of urine which is initially directed, or which flows toward
the highest front edge of the diaper.
The fluff batt utilized in the girl diaper, and the main fluff batt
utilized in the boy diaper are contoured to provide a reduced width
in the region adapted to be positioned within the crotch and
thigh-encircling areas during use of the diaper. This contoured
configuration reduces the stresses which are applied to the fluff
batts during use of the diapers to a level which will not cause the
fluff batts to break up into separated clumps, which would reduce
the fluid absorbing capability of said fluff batts. In addition,
the contoured configuration of the fluff batt provides an extremely
comfortable construction by minimizing bulk in the confining region
of the crotch.
The preferred embodiments of the throw-away diapers of this
invention have covering envelopes defined by a facing cover layer
and a backing cover layer which are substantially identical. Each
layer comprises an air-laid, embossed, adhesively bonded web of
randomly arranged, intermingled, cellulosic fibers as specifically
described in co-pending application Ser. No. 23,752, assigned to
the assignee of this application, and hereby incorporated by
reference. The facing and backing cover layers have the capability
of retaining urine, and therefore, of cooperating with the
absorbent pads to provide an extremely high fluid storing capacity
in the diapers of this invention. In addition, the facing cover
layer is fluid pervious and will permit urine which it is incapable
of retaining to be transmitted into the fluff batts.
It is an object of this invention to provide throw-away diapers
wherein efficient utilization of all absorbent components thereof
is achieved.
It is a further object of this invention to provide throw-away
diapers having a different construction for use by boy and girl
babies, respectively, and in which urine is retained at least as
effectively as it is retained in conventional cloth diapers.
It is a further object of this invention to provide absorbent pads
for use in throw-away diapers, wherein said absorbent pads
efficiently retain urine during use of said throw-away diapers.
Other objects and advantages of this invention will be readily
understood by referring to the detailed description which follows
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a first embodiment of a throw-away
diaper of this invention for use by a girl;
FIG. 2 is a sectional view along line 2--2 of FIG. 1;
FIG. 3 is an isometric view of the fluff batt defining the
absorbent pad of the diaper shown in FIG. 1;
FIG. 4 is an isometric view of a second embodiment of a throw-away
diaper of this invention for use by a boy;
FIG. 5 is an isometric view of the main and secondary fluff batts
defining the absorbent pad of the diaper shown in FIG. 4;
FIG. 6 is an isometric view of the diaper shown in FIG. 4 in folded
condition for use on a boy;
FIG. 7 is a sectional view along line 7--7 of FIG. 6;
FIG. 8 is a schematic view of an apparatus for forming the fluff
batts shown in FIGS. 3 and 5;
FIG. 8A is an enlarged view of the blocked portion identified as
"8A" in FIG. 8;
FIG. 9 is an exploded isometric view of portions of the apparatus
shown in FIG. 9 utilized for forming the absorbent pad shown in
FIG. 3;
FIG. 10 is an exploded isometric view of portions of the apparatus
shown in FIG. 9 utilized for forming the absorbent pad shown in
FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The throw-away diapers of this invention each have a profiled,
absorbent pad disposed within a covering envelope defined by a
fluid-pervious and containing facing cover layer, and a backing
cover layer. The throw-away diaper for use by a girl baby has an
absorbent pad, or section comprising a fluff batt of cellulosic
fibers having a predetermined region of greatest fiber weight
therein which is different from the predetermined region of
greatest fiber weight in an absorbent pad of a throw-away diaper
for use by a boy baby.
Referring to FIGS. 1-3, a throw-away diaper 10 of this invention
for use by a girl baby has an elongate, absorbent pad 12 disposed
between a fluid-pervious and containing facing cover layer 14, and
a backing cover layer 16. The facing and backing cover layers
define a covering envelope for the absorbent pad. The backing cover
layer 16 has end margins extending beyond end margins of the facing
cover layer 14, and the end margins of the backing cover layer are
folded over the facing cover layer to form end panels 20, 22. These
end panels 20, 22 define thickened, strong regions of the diaper
for receiving pins, without tearing, to permit reliable attachment
of the diaper about the torso of a girl baby.
The facing cover layer 14 and backing cover layer 16 are preferably
identical and each comprises an embossed, adhesively bonded,
randomly arranged, intermingled fibrous web having approximately 75
percent wood pulp fibers of short paper-making length less than
one-fourth inch, and approximately 25 percent longer synthetic
fibers, such as 11/2 denier, 2 inch rayon fibers. Other short
fibers, such as cotton linters, can be utilized in the cover
layers; however, wood pulp fibers are preferred because they are
less expensive than other short fibers and are readily available.
Other long fibers can be utilized which enhance the strength of the
covering layers without adversely affecting the absorbency,
flexibility, drape, softness and "hand" of said layers. Also, other
ratios of short to long fibers can be utilized; however, it is
preferred to use as large a percentage of inexpensive short fibers
as possible without adversely affecting the above-referred-to
characteritics. These covering layers have a basis weight of up to
about 2 ounces per square yard. The facing cover layer 14 and
backing cover layer 16 are made with the aid of suitable air-laying
equipment such as the Rando-Webber, or Rando-Mizer which are both
manufactured by Curlator Corporation of Rochester, New York.
A loosely compacted, continuous fibrous web is formed by utilizing
the above-described air-laying equipment, and the continuous
fibrous web is then sprayed with water and passed through a nip
defined between a pair of rolls. At least one of the rolls has a
raised pattern on the periphery thereof for embossing the
continuous air-laid web to form compressed valleys separated by
uncompressed ridges extending over the entire elongate extent of
said continuous air-laid web. The mositure content in the web aids
in ensuring that the embossed pattern which is impressed into the
continuous air-laid web is retained therein. Adhesive is then
applied to opposed surfaces of the embossed web to provide strenth
and abrasion resistance to said web. Preferably the adhesives
utilized are the self-cross-linkable acrylic latices; however,
other adhesives which provide the required degree of strength and
abrasion resistance can be utilized. The continuous web is then
passed through a heating oven in which it is dried and the adhesive
is cured to form the facing and backing cover layer material 14 and
16. The above-described facing and backing cover layers 14 and 16,
and their method of manufacture are described in detail in United
States patent application, Ser. No. 23,752, which was hereinbefore
incorporated by reference.
If desired, a fluid impervious, thin plastic backing layer can
either be secured to the exposed surface of the backing cover layer
16, or can be utilized in place of the backing cover layer 16 to
provide an outer exposed member through which body fluids cannot
pass. A throw-away diaper 10 of this invention which is provided
with a fluid impervious backing layer can be utilized without any
protective garments, such as rubber, or plastic pants, which are
presently required when utilizing conventional cloth diapers. The
facing cover layer 14 must be fluid-pervious in order to permit the
passage of body fluids into the underlying absorbent pad 12. In the
preferred embodiment of this invention the facing cover layer 14,
in addition to being fluid-pervious, will retain urine therein to
cooperate with the absorbent pad 12 in providing an extremely
effective moisture absorbing and retaining throw-away diaper.
The elongate absorbent pad 12 is preferably comprised of a fluff
batt of cellulosic fibers, such as wood pulp fibers of a short
paper-making length less than one-fourth inch. This fluff batt can
be formed on any suitable batt forming equipment, such as a Joa
Fiberizer which is manufactured by Joa, Inc., of North Wales,
Florida. The absorbent pad 12 has a forward end margin 24 and a
rearward end margin 26 interconnected by opposed, curved side
margins 28, 30 to define a contoured absorbent pad of substantially
hour-glass configuration having a reduced width region adapted to
be positioned within the crotch and thigh-encircling region. This
contoured configuration reduces the stresses which are applied to
the fluff batt during use of the diaper 10 to thereby prevent the
fluff batt from breaking up into separated clumps of fibers which
would impair the fluid absorbing capability of said fluff batt.
Referring to FIG. 3, the absorbent pad 12 is comprised of a fluff
batt of cellulosic fibers having a forward elongate region 32, a
rearward elongate region 34 and a middle elongate region 36, and
each of these regions constitutes approximately one-third of the
elongate dimension of the absorbent pad 12. It is known that urine
emitted by girl babies is initially directed toward the middle
region of a diaper; therefore, the absorbent pad 12 is profiled to
provide the greatest weight of fibers in the middle elongate region
36. Merely placing the greatest weight of fibers in the region of
the diaper which initially receives the impingement of urine does
not prevent excessive urine leakage from the diaper. Applicant has
discovered that the urine which is impinged on the middle region
(which is the region of greatest fiber weight) tends to strike
completely through the thickness of the fluff batt in said middle
region without diffusing along a substantial area of said fluff
batt, i.e. large areas of the fluff batt remain dry, and are
therefore not utilized to retain urine.
Applicant has discovered that the absorbent pad 12 performs best
when an embossed pattern is impressed into the middle elongate
region 36 and also into the forward and rearward elongate regions
32 and 34, respectively. The embossed pattern is impressed into the
facing cover layer 14 and the underlying absorbent pad 12 to form
substantially identical embossed patterns in both the absorbent pad
12 and said facing cover layer 14.
Referring to FIGS. 1 and 3, the embossed pattern includes
substantially identical patterns in the forward elongate region 32
and the rearward elongate region 34 of the absorbent pad 12. These
identical embossed patterns are comprised of compressed valleys
defined by a first set of spaced, elongate channels 38 extending
for substantially the entire elongate extent of said forward and
rearward elongate regions, and extending partially into the middle
elongate region 36. These identical embossed patterns further
include a second set of spaced, elongate channels 40 extending
transverse to, and intersecting the first set of channels. The
elongate channels 38 and 40 preferably are disposed in a straight
line; however, other patterns, such as zig-zag, or wavy patterns
can be utilized. The intersecting areas of the sets of channels can
be compressed in a circular, square, or other geometric
configuration.
The embossed pattern in the middle elongate region 36 includes
valleys in the form of uniformly spaced, substantially circular,
compressed islands 42 defining uncompressed ridges 44 therearound.
The ratio of the area of compressed islands 42 in the middle region
36 to the total area of said middle region is less than the ratios
of the areas of the compressed sets of channels 38 and 40 in each
of the forward and rearward regions, to the total area of the
respective forward and rearward regions. In one preferred
embodiment of this invention the percentage surface area of the
compressed regions 42 in the middle elongate region is
approximately 6 percent, and the percentage surface area of the
compressed sets of channels 38 and 40 in the forward and rearward
elongate regions is between approximately 13 to 20 percent. The
circular, compressed islands 42 in the middle elongate region 36
prevents excessive strike-through by aiding in dispersing urine
along substantially the entire extent of the fluff batt. Since the
compressed islands 42 account for only a small percentage of the
surface area of the middle region 36, these compressed regions do
not unduly detract from the high absorptive capacity of the middle
elongate region which results from having the greatest weight of
fibers therein. It has been found, quite surprisingly, that the
compressed islands 42 cooperate with the sets of channels 38 and
40, to direct urine as effectively as a fluff batt in which the
compressed islands 42 are replaced by a greater percentage of
compressed valleys in the form of sets of channels 38 and 40. The
elongate channels 38 extend into the middle elongate region 36 to
direct excessive urine in an elongate direction from the middle
region into the forward and rearward elongate regions, and the
transverse channels 40 direct the urine in a transverse direction
between side margins 28 and 30 of the forward and rearward elongate
regions.
The above-described profiled, embossed fluff batt provides for an
extremely efficient utilization of fibrous material in absorbing
urine in the throw-away diaper 10. Applicant is not aware of any
suggestion in the prior art of providing an embossed, profiled
fluff batt in throw-away diapers; and accordingly, applicant is not
aware of any suggestion in the prior art of providing the specific
embossed, profiled pattern in a profiled fluff batt as described
above.
The fluid absorbing capacity of the throw-away diaper 10 is
enhanced by the fact that the facing cover layer 14 is a fibrous
web which both retains urine, to act as an absorbent component in
cooperation with the elongate absorbent pad 12, and passes
quantities of urine into the absorbent pad 12 which it is unable to
retain. The facing cover layer 14 preferably is provided with an
overall embossed pattern as described above in connection with its
method of manufacture. This overall embossed pattern provides a
fluid wicking function to direct urine along a substantial area of
the facing cover layer to utilize most effectively the fluid
absorbing capabilities of said facing cover layer. In addition,
this overall embossed pattern cooperates with the embossed pattern
impressed into the facing cover layer and underlying absorbent pad
12 to aid in directing fluid along substantially the entire extent
of the absorbent pad.
The profiled, contoured absorbent pad 12 is disposed between the
facing cover layer 14 and the backing cover layer 16. The facing
and backing cover layers 14 and 16 are secured to each other by any
suitable securing means such as adhesive stripes or tacks disposed
between facing surfaces of said facing and backing cover layers
lying outside the region of the absorbent pad 12. The embossed
pattern which is impressed into the facing cover layer and fluff
batt, in addition to directing urine flow in the fluff batt, serves
to stabilize the fluff batt within the facing and backing cover
layers.
The following example is illustrative of a preferred form of a girl
throw-away diaper 10, and of some of the benefits obtained by said
girl diaper. It is understood that different size diapers can be
made according to this invention, and that fluff batts of different
weight distribution can be utilized depending upon the specific use
of the diaper, i.e. daytime use, nighttime use, toddler use, infant
use, etc.
Example
A throw-away diaper 10 according to this invention has a profiled,
contoured, absorbent pad disposed between a facing and backing
layer of the embossed structure described above. The facing layer
is approximately 16 inches in length and 14 inches wide. The
backing layer has a length which exceeds that of the facing layer
by approximately 3 inches, i.e. 19 inches total length, to provide
a 1-1/2 inch overlap at the opposed ends of the diaper to form end
panels 20 and 22. The fluff batt has an elongate dimension of 12
inches, and is contoured in a substantially hour-glass shaped
configuration to provide a minimum width in the center thereof of
approximately 3 inches. The maximum width of the absorbent pad at
the opposed elongate ends thereof is 7 inches. The forward and
rearward one-third regions of the absorbent pad have 5 grams of
fibrous material therein, and the middle one-third region has 10
grams therein.
Four diapers each of the following constructions were prepared:
I. No additional embossed pattern impressed into the fluff batt
through the facing cover layer.
II. Compressed sets of channels 38 and 40 impressed into the
forward and rearward regions of the fluff batt through the facing
cover layer. The middle region was left unembossed, and the sets of
channels did not extend into the middle region of the fluff
batt.
III. The same as II, with the addition of circular, compressed
islands 42 impressed into the facing cover layer and the underlying
fluff batt in the middle region of said fluff batt.
IV. The same as III with the exception that the compressed set of
channels 38 extend approximately one-half inch into the middle
region of the fluff batt.
V. Compressed sets of channels 38 and 40 impressed into the facing
cover layer and the underlying fluff batt in the forward, rearward
and middle regions thereof.
The compressed channels 38 and 40 in the above samples comprise
straight lines having approximately a one-sixteenth inch width. The
compressed lines are spaced on approximately thirteen-sixteenths
inch centers, and the intersections of the sets of channels are
defined by one-fourth inch diameter circular compressed regions.
The compressed islands 42 are substantially circular and are
approximately one-fourth inch in diameter. These islands are
disposed in transversely extending rows, with the islands in each
row being transversely offset midway between the islands of an
adjacent row. The islands within each row are spaced on 1-1/2 inch
centers, and the spacing between adjacent rows in approximately
three-eighths inch.
Fifty cubic centimeters of water was emptied from a buret in
approximately 60 seconds directly onto the middle region of each of
the diapers, i.e. the region containing the greatest weight of
fibers therein. Three minutes after the water was emptied onto the
diaper the facing cover layer was peeled off of the fluff batt, and
the area of fluid spread on the fluff batt was measured. In
addition, the area of fluid spread along the backing cover layer
was also measured. Averages of the four diapers of each sample were
calculated and these averages are reported in the following
table:
SAMPLES AREA OF FLUID SPREAD (in.sup.2) I II III IV V Along the
upper surface of fluff batt 1.98 1.6 15.5 26.6 24.4 Along backing
cover layer 27.0 25.8 12.1 14.4 10.2
As can be seen from the above results, the samples which did not
contain any embossed pattern in the middle region of the fluff batt
(I and II) did not effectively spread urine along the fluff batt.
In addition, substantial urine strike-through occured through the
backing cover layer as indicated by the high values of surface area
spread on the backing cover layer. Samples III, IV and V had
approximately the same area of fluid spread on the backing cover
layer, and this area of fluid spread was substantially less than
that encountered in samples I and II. This suggests that the
embossing of the middle region affects the fluid wicking
characterisitics along the fluff batt to prevent excessive
strikethrough of fluid. In addition, Sample IV, which contained the
compressed channels 38 extending partially into the middle region
of the fluff batt, wicked fluid substantially better than a diaper
in which the compressed channels 38 did not extend into the middle
region (Sample III). In fact, the area of fluid spread along the
fluff batt was greater in Sample IV, wherein a dot pattern was
included in the middle region than in Sample V, wherein the
compressed sets of channels 38 and 40 extended completely along the
forward, rearward and middle regions of the fluff batt.
The above test was conducted on a substantially flat diaper, and
therefore, the specific values obtained may not validly represent
the values which would be obtained when the diaper is in use.
However, the above testing procedure is believed to reliably
indicate the relative values of area of fluid spread which one
would expect in utilizing the diapers of the above five
constructions. Therefore, the test procedure utilized above is
believed to clearly indicate the desirability of providing an
embossed pattern in all regions of a profiled fluff batt, and
furthermore, is believed to indicate the desirability of extending
the compressed channels 38 into the middle region of greatest fiber
weight to aid in spreading urine along the fluff batt to
effectively utilize the absorbent material of said fluff batt.
Furthermore, it is more desirable to utilize uniformly spaced,
substantially circular compressed islands 42 in the middle region
of the diaper, than it is to utilize the sets of embossed channels
38 and 40 in said region, since the compressed islands constitute a
smaller percentage of the surface area of the middle region than
the compressed sets of channels, and therefore, will not adversely
affect the fluid storing capabilities of the middle region as
greatly as would the sets of compressed channels.
Referring now to FIGS. 4-7, a throw-away diaper 10a specifically
constructed for use by a boy baby has an elongate absorbent pad 12a
which is different from the elongate absorbent pad 12 of the first
embodiment. The facing cover layer 14a and backing cover layer 16a
form a covering envelope which is identical to the covering
envelope formed by the facing and backing cover layers 14 and 16 of
the throw-away diaper 10. The backing and facing cover layers 14a
and 16a cooperate with the absorbent pad 12a, in the same manner as
the covering envelope cooperates with the absorbent pad 12 in the
throw-away diaper 10, and a fluid impervious, thin plastic backing
layer can be provided in the throw-away diaper 10a in the same
manner as in the throw-away diaper 10.
Referring to FIG. 5, the absorbent pad 12a comprises a main fluff
batt 50 and a secondary fluff batt 52. The main fluff batt 50 has
an elongate dimension defined between spaced forward and rearward
end margins 54 and 56, respectively. The facing and backing cover
layers 14a and 16a extend beyond the forward end margin 54 of the
main fluff batt to define a forward marginal region 55 of the
throw-away diaper 10a in which the secondary fluff batt 52 is
disposed. This secondary fluff batt 52 is spaced from the forward
end margin 54 of the main fluff batt 50 to define a transversely
extending region 58 having a lower bulk than the transversely
regions of said diaper including the main and secondary fluff batts
to define a transverse fold line along which the forward marginal
region 55 can be infolded to superimpose the secondary fluff batt
52 over the forward section of the main fluff batt 50 (FIGS. 6 and
7). If desired, a single fluff batt can be provided with a
transverse compressed line to define the main and secondary fluff
batts on opposed sides thereof; the compressed line constituting
the low bulk region along which the diaper can be infolded.
Referring to FIG. 5, the main fluff batt 50 is profiled to define a
forward elongate region 32a, a rearward elongate region 34a and a
middle elongate region 36a, each of which constitutes approximately
one-third of the elongate extent of said main fluff batt 50. It is
known that a boy baby initially directs urine to the forward region
of a diaper; therefore, themain fluff batt 50 is profiled to
provide a greater weight of fibers in the forward elongate region
32a than in the rearward and middle regions 34a and 36a, to provide
a greater weight of fibers in the region wherein the greatest
absorptive capacity is required. The rearward elongate region 34a
has the least weight of fibers because it is intended to absorb
primarily the moisture content contained in the fecal matter, and
is not relied upon to retain a large volume of urine. The secondary
fluff batt 52 has substantially the same weight of fibers as the
middle elongate region 36a, and is approximately one-half of the
elongate extent of the forward elongate region 32a of the main
fluff batt 50.
Referring to FIGS. 4 and 5, an embossed pattern is impressed into
the facing layer 14a and the underlying absorbent pad 12a in the
regions of the forward elongate region 32a, the middle elongate
region 36a and the rearward elongate region 34a. The embossed
pattern in the middle and rearward elongate regions is comprised of
compressed valleys defined by a first set of spaced, elongate
channels 38a extending for substantially the entire elongate extent
of said rearward and middle elongate regions, and only partially
into the forward elongate region 32a. This embossed pattern further
includes a second set of spaced, elongate channels 40a extending
transverse to, and intersecting the first set of channels in both
the rearward and middle elongate regions for directing urine
transversely along said fluff batt. The sets of channels 38a and
40a are identical to the sets of channels 38 and 40 in the girl
throw-away diaper 10. The embossed pattern in the forward elongate
region 32a includes valleys in the form of spaced, substantially
circular, compressed islands 42a defining uncompressed regions 44a
therearound. These islands 42a are identical to the islands 42 of
the girl throw-away diaper 10.
The ratio of the area of compressed islands 42a in the forward
elongate region 32a to the total area of said forward elongate
region is less than the ratios of the area of the compressed sets
of channels 38a and 40a in each of the forward and rearward
elongate regions to total area of the respective forward and
rearward regions. In one preferred embodiment of this invention the
percentage surface area of the compressed islands 42a in the
forward elongate region is approximately 6 percent, and the
percentage surface area of the compressed sets of channels 38a and
40 a in the rearward and middle elongate regions is between 13-20
percent. The circular compressed islands 42a, and the sets of
compressed channels 38a and 40a perform the same function in their
respective sections as the circular, compressed islands 42 and the
sets of compressed channels 38 and 40 perform in their respective
sections of the absorbent pad 12. In the preferred embodiment of
this invention, the secondary fluff batt 52 also is provided with
the elongate and transverse channels 38a and 40a, respectively, to
aid in directing fluid along said secondary fluff batt.
The main fluff batt 50 has a contour defined by shaped side margins
28a and 30a to define a reduced width in the region of said main
fluff batt which is adapted to be disposed within the crotch and
thigh-encircling areas during use. This contoured configuration
reduces the stresses which are applied to the main fluff batt
during use to thereby prevent said main fluff batt from breaking up
into separated clumps of fibers which would impair the fluid
absorbing capability of said fluff batt.
The throw-away diaper 10a is intended for use with its forward
marginal region 55 infolded, as indicated in FIGS. 6 and 7, to a
position wherein the secondary fluff batt 52 is disposed in
overlying relationship with the forward elongate region 32a of the
main fluff batt 50. This infolded arrangement provides the two-fold
function of placing a greater quantity of absorbent material in the
forward area of the diaper where it is needed for absorbing urine
emitted by a boy baby; and of providing a damlike structure which
acts as a physical impediment to the escape of urine directed at
the forward end of the diaper. The urine will tend to be blocked by
the stepped configuration resulting from the infolding of the
forward marginal region 55 of the diaper about its transverse fold
line 58, as indicated in FIG. 7.
The following example describes a preferred form of a boy
throw-away diaper 10a according to this invention, and is intended
as illustrative only. It is understood that different size diapers
can be made according to this invention, and that fluff batts of
different weight distribution can be utilized depending upon the
specific use of the diaper, i.e. daytime use, nighttime use,
toddler use, infant use, etc.
Example
A main fluff batt and secondary fluff batt are disposed between a
facing cover layer and a backing cover layer made in the manner
indicated above. The facing cover layer has an elongate dimension
of 17 inches and a width-wise dimension of 14 inches. The backing
cover layer has an elongate dimension of 19-1/4 inches to provide a
1-1/8 inch overlap of the facing cover layer at each end thereof to
form the end panels 20 and 22. The main fluff batt has an elongate
dimension of 12 inches and has forward, rearward, and middle
elongate regions, each of which has an elongate dimension of 4
inches. The middle elongate region has a reduced transverse
dimension defining a 3 inch minimum width of the main absorbent
batt. The forward region of the main fluff batt is substantially
rectangular and has a width of approximately 5 inches. The rearward
region of the main fluff batt is substantially square having a
width-wise dimension of 4 inches. The secondary fluff batt is
spaced approximately one-fourth inch from the forward region of the
main fluff batt and has 4.3 grams of fibrous material therein. The
forward region of the main fluff batt has 8.6 grams of fibers
therein, the middle region of the main fluff batt has 4.3 grams of
fibers therein and the rearward region of the main fluff batt has
2.8 grams of fibers therein. The embossed pattern impressed into
the facing cover layer is identical to that described with respect
to the girl throw-away diaper 10.
The profiled fluff batts of this invention include fluff batts
having a region of greatest fiber weight which is thicker and/or
denser than other regions thereof. When the density of the entire
profiled fluff batt is substantially uniform, the region of
greatest fiber weight will be the thickest region of the fluff
batt. When the thickness of the entire profiled fluff batt is
substantially uniform, the region of greatest fiber weight will be
the densest region of the fluff batt.
Referring to FIGS. 8, 8A and 9, an apparatus 100 is shown for
forming the profiled, contoured, absorbent pads 12 utilized in the
throw-away diaper 10 for use by girl babies. This apparatus 100 is
the invention of Charles G. Kolbach, and will be covered in a later
filed patent application.
Referring to FIG. 8, a fiberizing section 101 includes a rotary
lickerin roll 102 disposed within a formation chamber 103. The
lickerin roll 102 is of conventional design, and comprises a
plurality of teeth disposed about the outer periphery thereof for
doffing individual fibers from sheets of pulp lap 104 and 104' and
entraining said fibers in an airstream. The fibers which are
entrained in the airstream are directed into discrete compartments
120 of a formation belt assembly 106 within the formation chamber
103 by a pressure differential created through the compartments 120
by pad-forming vacuum boxes 108, 110 and 112 disposed under, and in
close proximity to an upper run 114 of the formation belt assembly
106. The formation belt assembly 106 is trained about spaced
support rolls 109 and 111, at least one of which is driven to drive
the formation belt assembly through the formation chamber 103 in
the direction indicated by arrow 107.
If desired, only one of the sheets 104, 104' can be fed into the
fiberizing section. Also, the fiberizing section 101 can be
relocated to the position shown in dotted representation at 101'.
Alternatively, a second fiberizing section can be located at 101',
and two fiberizing sections can be utilized in forming the
profiled, contoured, absorbent pads 12.
Referring to FIG. 9, the formation belt assembly 106 includes a
relatively thin, open mesh conveyor belt 116 to which is laminated
a relatively thick (e.g. approximately one-half inch) fluid
impervious belt 118 having sections removed therefrom to define the
elongate compartments 120 having the specific contour of the
absorbent pads 12. The conveyor belt 116 is provided with spaced
openings 113 adjacent end margins thereof to cooperate with pins
(not shown) on the belt assembly support rolls 109 and 111. The
fluid impervious belt 118 is preferably made of a semi-conductive
material which dissipates static charges developed during the
pad-forming operation. Each compartment 120 has a lower surface
which is defined by the open mesh conveyor belt 116 (FIGS. 8A and
9), and the absorbent pads 12 are formed with their elongate
dimension extending transverse to the direction of feed of the
formation belt assembly 106.
Profiling masks 122, 124 and 126 are disposed over the pad-forming
vacuum boxes 108, 110 and 112, respectively, between said
pad-forming vacuum boxes and the open mesh conveyor belt 116. The
profiling mask 122 has an open mesh, air-pervious center elongate
region 122a, and air-impervious and elongate regions 122b and 122c.
The profiling mask 124 also has an open mesh, air-pervious center
elongate region 124a, and air-impervious end elongate regions 124b
and 124c. The profiling mask 126 has an air-impervious center
elongate region 126a, and open mesh, air-pervious end elongate
regions 126b and 126c.
The individual pad-forming vacuum boxes 108, 110 and 112 are
connected to an exhaust fan, or similar exhaust device (not shown),
through connecting conduits 127 (only one of which is shown in FIG.
9). Each connecting conduit 127 can be provided with a suitable
valve therein to control the volume of air which is pulled through
its respective vacuum box. Alternatively, the valves can be omitted
and separate exhaust fans can be connected to each of the vacuum
boxes.
In operation, the formation belt assembly 106 moves sequentially
over the profiling masks 122, 124 and 126 in the direction
indicated by arrow 107. The air-suspension of fibers is pulled into
the compartments 120 by each of the vacuum boxes causing the fibers
to be deposited on the conveyor belt 116, as the air which carries
said fibers is pulled through the conveyor belt. The elongate,
middle region 36 of each absorbent pad 12 is formed in the center
region of each compartment 120, and this region is aligned with the
center regions 122a, 124a and 126a of the profiling masks 122, 124
and 126, respectively. The forward and rearward regions 132 and 134
of each absorbent pad 12 is formed in the end regions of each
compartment 120, and these end regions are aligned with the end
regions of each of the profiling masks 122, 124 and 126,
respectively. Therefore, the air-suspension of fibers is directed
into the center region of each compartment to form the middle,
elongate region 36 of each absorbent pad 12 ad each compartment 120
passes over the profiling masks 122 and 124 and the underlying
vacuum boxes 108 and 110, respectively, since this is the only
region of each compartment 120 through which air is pulled by the
operation of vacuum boxes 108 and 110. The air-suspension of fibers
is directed into the end regions of each compartment 120 to form
the forward and rearward elongate regions 132 and 136 of each
absorbent pad 12 as each compartment 120 passes over the profiling
mask 126 since the end regions are the only ones through which air
is directed by operation of the vacuum box 112. Since the center
region of each compartment 120 is exposed to the pressure
differential created by the operation of the vacuum boxes for a
greater length of time than the end regions of each compartment, a
greater weight of fibers will be deposited in the center region
than in the end regions to form the profiled elongate, absorbent
pads 12.
Referring to FIG. 10, absorbent pads 12a are manufactured by
substituting in apparatus 100 the formation belt assembly 106' for
the formation belt assembly 106, and substituting profiling masks
122', 12' and 126' for the profiling masks 122, 124 and 126,
respectively. The formation belt assembly 106' includes a
relatively thin, open mesh conveyor belt 116' to which is laminated
a relatively thick (e.g. approximately one-half inch)
fluid-impervious belt 118'. The conveyor belt 116' is identical to
conveyor belt 116, and the fluid-impervious belt 118' differs from
the fluid-impervious belt 118 by having sections removed therefrom
to define a plurality of sets of compartments; each set comprising
transversely aligned main and secondary compartments 120' and 120".
The main compartments 120' have a contour corresponding to the
contour of the main fluff batt 50 of the absorbent pad 12a, and the
secondary compartments 120" have a contour corresponding to the
contour of the secondary fluff batt 52 of the absorbent pad 12a.
Each set of compartments is spaced from an adjacent set of
compartments in the direction of feed of the formation belt which
is indicated by the arrow 107'.
The profiling mask 122' is disposed over the pad-forming vacuum box
108, and is comprised of four discrete regions 122a', 122b', 122c'
and 122d'. The regions 122a' and 122d' are of an open mesh
construction, and are therefore permeable to the passage of air
which is pulled therethrough by an exhaust fan, or similar exhaust
device (not shown), which is connected through a conduit (not
shown) to the vacuum box 108. The air-pervious region 122a' is in
alignment with the center region of each main compartment 120' in
which the middle elongate region 36a of the main fluff batt 50 is
formed, and the air-pervious region 122d' is in alignment with each
secondary compartment 120", as the formation belt assembly 106' is
passed over the vacuum box 108 in the direction indicated by arrow
107'. Therefore, as each set of compartments 120' and 120" passes
over the vacuum box 108, the air-usspension of fibers in the
formation chamber 103 is directed into the center region of the
main compartment 120', and into the secondary compartment 120" to
deposit the fibers on the mesh conveyor belt 116'.
The profiling mask 124' has only one region 124a' which is of an
open mesh construction and is pervious to air; the remaining
regions being impervious to air. This region 124a' is in alignment
with the end region of each compartment 120' in which the forward
elongate region 32a of the main fluff batt 50 is formed. As each
set of compartments 120' and 120" pass over the vacuum box 110 the
air-suspension of fibers in the formation chamber 103 is directed
into the end region of the main compartment 120' to form the
forward elongate region 32a of the main fluff batt 50. Since the
forward elongate region 32a of the diaper is required to have a
greater weight of fibers therein than the other regions of the
absorbent pad 12a, a greater volume of air is pulled through vacuum
box 110 than through vacuum boxes 108 and 112 by appropriately
adjusting valves (not shown) which are disposed in the conduits 127
which interconnect the exhaust fan, or similar exhaust device, to
the vacuum boxes.
The profiling mask 126' has only one region 126a' which is of an
open mesh construction and therefore pervious to air; the remaining
regions of this profiling mask being impervious to air. The
air-pervious region 126a' is aligned with the end region of the
main compartment 120' in which the rearward region 34a of the main
fluff batt 50 is formed. Since the weight of fibers disposed in the
rearward region 34a is less than the weight of fibers contained in
the other regions of the absorbent pads 12a, the least volume of
air is pulled through vacuum box 112.
In operation, as each set of compartments passes over the vacuum
box 108, and its superimposed profiling mask 122', the center
region 36a of the main fluff batt 50 and the secondary fluff batt
52 are formed with the same weight of fibers therein. As each set
of compartments passes over the vacuum box 110, and its
superimposed profiling mask 124', the forward elongate region 32a
of the main fluff batt 50 is formed, and as each set of
compartments passes over the vacuum box 112, and its superimposed
profiling mask 126', the rearward region 34a of the main fluff batt
is formed.
Referring to FIGS. 9 and 10, each profiling mask is provided with a
handle 130, or other similar grasping means, adjacent one end
thereof to permit easy removal of each profiling mask when it is
desired to substitute a different profiling mask therefor or run
the apparatus 200 without a profiling mask. By substituting or
omitting profiling masks, the apparatus 100 can be utilized to form
many different varieties of absorbent pads.
In manufacturing both the throw-away diapers 10 for use by girl
babies and the throw-away diapers 10a for use by boy babies, the
method and apparatus for positioning formed absorbent pads between
a facing cover layer and a backing cover layer is identical.
Therefore, the following description will be limited to the method
of positioning the formed absorbent pads 12 between the facing
cover layer 14 and backing cover layer 16 in manufacturing the
throw-away diapers 10 for use by girl babies.
Referring to FIGS. 8 and 8A, the formed absorbent pads 12, in the
form of fluff batts of cellulosic fibers, have an exposed upper
surface 140 which is leveled by the teeth, or bristles, of a
rotating spinnerette 142 disposed at the exit end of the formation
chamber 103. The absorbent pads 12 are then fed about the formation
belt assembly support roll 109 where they are contacted by the
locking cover layer 16. This backing cover layer 16 cooperates with
the mesh conveyor belt 116 to confine the absorbent pads within the
compartments 120. The backing cover layer 16 is moved in
synchronism with the formation belt 106 by drive means (not shown)
to a position where it is in contact with the upper run 144 of a
transfer conveyor 146. The backing cover layer 16, and the
overlying absorbent pads 12 are fed over a transfer vacuum box 148
disposed directly under the upper run 144 of the transfer conveyor
146. The vacuum applied through the vacuum box 148 creates a
pressure differential across the fluff batt 12 to transfer
allegiance of the fluff batt from the lower run of the formation
belt assembly 106 to the upper run 144 of the transfer conveyor
146. This vacuum can be pulled through the backing cover layer 16
since said backing cover layer is air-pervious; however, the fluff
batt is relatively thick, and prevents the air drawn through the
vacuum box from being drawn easily through the fluff batt to
thereby create the above-described pressure differential. This
pressure differential is maintained on the fluff batt as the
formation belt assembly 106 passes around the formation belt
assembly support roll 111 to separate the lower run of the
formation belt assembly 106 from the upper run of the transfer
conveyor 146. The absorbent pads 12 are positioned on the backing
cover layer 16 as the backing cover layer is fed off the transfer
conveyor 146. Adhesive is applied to the upper exposed sureface 147
of the backing cover layer 16 which is disposed between adjacent
absorbent pads 12 at a suitable adhesive station indicated
schematically at 150. A facing cover layer 14 is superimposed over
the spaced absorbent pads 12 downstream of the adhesive station 150
to form a composite structure consisting of the absorbent pads 12
and the facing and backing cover layers 14 and 16. The composite
structure is then fed to subsequent finishing stations (not shown)
whereat the individual throw-away diapers are formed.
The apparatus 100 has been disclosed to clearly indicate a method
in which contoured, profiled absorbent fluff batts are formed in
manufacturing the throw-away diapers 20 and 10a of this invention.
It is understood that converting equipment for positioning the
fluff batts between facing and backing cover layers to form a
composite structure, and forming complete individual diapers from
the composite structure is well within the purview of one skilled
in the art, and therefore, a complete disclosure of this converting
equipment has been omitted from this application.
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