U.S. patent application number 12/310847 was filed with the patent office on 2010-03-11 for disposable hygiene article, surgical covering item, or surgical garment.
Invention is credited to Bernd Frank, Rudolf Groener, Ruediger Kesselmeier, Christian Koch.
Application Number | 20100059067 12/310847 |
Document ID | / |
Family ID | 39134368 |
Filed Date | 2010-03-11 |
United States Patent
Application |
20100059067 |
Kind Code |
A1 |
Frank; Bernd ; et
al. |
March 11, 2010 |
Disposable hygiene article, surgical covering item, or surgical
garment
Abstract
A disposable hygiene article (2), surgical covering item, or
surgical garment, such as an incontinence diaper, incontinence pad,
surgical drape, or surgical coat, has a composite non-woven fabric
(38) that is provided with at least one non-woven fabric component
(16) and another non-woven fabric or foil component (10, 12). The
first non-woven fabric component (14) is attached to the other
non-woven fabric or foil component (10, 12) in at least some areas
by means of a joining pattern (36) encompassing discrete ultrasonic
welding points (30) in order to form the composite non-woven fabric
(38). The joining pattern (36) extends in a first direction (32)
and a second direction (34) that runs perpendicular thereto, the
distance in the first direction (32) being longer than the distance
in the second direction (34). At least some sections of the joining
pattern (36) are not rectilinear. In order to make the formation of
the welded joint a secure process, the joining pattern is embodied
such that the maximum index (I) of variation of the area seized by
the ultrasonic welding points is 40 percent.
Inventors: |
Frank; Bernd; (Steinheim,
DE) ; Kesselmeier; Ruediger; (Herbrechtingen, DE)
; Koch; Christian; (Bachhagel, DE) ; Groener;
Rudolf; (Soehnstetten, DE) |
Correspondence
Address: |
DREISS, FUHLENDORF, STEIMLE & BECKER
POSTFACH 10 37 62
D-70032 STUTTGART
DE
|
Family ID: |
39134368 |
Appl. No.: |
12/310847 |
Filed: |
September 19, 2007 |
PCT Filed: |
September 19, 2007 |
PCT NO: |
PCT/EP2007/008134 |
371 Date: |
March 10, 2009 |
Current U.S.
Class: |
128/849 ;
156/73.1; 2/93; 604/365 |
Current CPC
Class: |
B29C 66/83411 20130101;
B29C 66/21 20130101; B29C 66/83511 20130101; B29C 66/433 20130101;
A61F 13/4753 20130101; B29C 66/81469 20130101; B29C 66/81433
20130101; B29C 66/72143 20130101; B29C 66/1122 20130101; B29C
66/7294 20130101; A61F 13/515 20130101; B29L 2031/4878 20130101;
A61F 13/539 20130101; B29C 66/244 20130101; B29C 65/086
20130101 |
Class at
Publication: |
128/849 ;
156/73.1; 604/365; 2/93 |
International
Class: |
A61F 13/84 20060101
A61F013/84; B29C 65/08 20060101 B29C065/08; A61B 19/08 20060101
A61B019/08; A41D 3/02 20060101 A41D003/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 22, 2006 |
DE |
10 2006 046 420.6 |
Claims
1-31. (canceled)
32. A hygiene article, surgical covering item, surgical garment for
single use, incontinence diaper, incontinence pad, surgical drape
or surgical coat, the article comprising: at least one first
nonwoven fabric component; a second nonwoven fabric or foil
component; and a joining pattern having discrete ultrasonic welding
points, said joining pattern disposed, structured and dimensioned
to attach said first nonwoven fabric component to said second
nonwoven fabric or foil component, thereby forming a composite
nonwoven fabric, wherein said joining pattern extends in a first
direction and a second direction that runs perpendicular to said
first direction, an extension of said joining pattern in said first
direction being longer than an extension of said joining pattern in
said second direction, wherein at least some sections of said
joining pattern are non-rectilinear and an index of variation of an
area seized by said ultrasonic welding points is no more than
40%.
33. The article of claim 32, wherein said index of variation of
said area seized by said ultrasonic welding points is no more than
35%, no more than 30% or no more than 25%.
34. The article of claim 32, wherein said composite nonwoven fabric
comprises at least one cuff element forming a leakage barrier on
both sides thereof and extending substantially in said first
direction, wherein said cuff element stands at least in some
sections.
35. The article of claim 34, wherein said cuff element comprises
said first nonwoven fabric component.
36. The article of claim 35, wherein the article comprises a
topsheet that is permeable at least in some areas, a backsheet that
is impermeable at least in some areas, and a storage core that
absorbs body fluids and is disposed between said top sheet and said
back sheet.
37. The article of claim 36, wherein said second nonwoven fabric or
foil component is said topsheet or said backsheet, wherein said
cuff element with said first nonwoven fabric component is attached
to said topsheet or said backsheet by said joining pattern.
38. The article of claim 32, wherein at least some areas of a first
partial joining pattern constitute a cuff base.
39. The article of claim 38, wherein some areas of said cuff base
are constituted by a second partial joining pattern that is largely
rectilinear or largely parallel to said first direction.
40. The article of claim 39, wherein at least some sections of said
cuff base are formed by said first partial joining pattern, said
second partial joining pattern, and a third non-rectilinear partial
joining pattern.
41. The article of claim 40, wherein, in said first direction, said
second partial joining pattern is disposed between said first and
said third partial joining pattern.
42. The article of claim 32, wherein, in said first direction, said
joining pattern has a first section, a second center section and a
third section adjoining said center section, wherein said first
section, said center section and said third section have
substantially equal lengths, an index of variation of an area of
said first section and/or of said third section of said joining
pattern seized by said ultrasonic welding points being no more than
40%, no more than 35%, no more than 30% or no more than 25%.
43. The article of claim 32, wherein a distance between discrete
said ultrasonic welding points in a first area is less than that in
a second area.
44. The article of claim 43, wherein a distance between individual
said ultrasonic welding points is 0.1 to 2.5 mm, 0.2 to 2.3 mm or
0.2 to 1.5 mm in said first area and 2 to 20 mm, 3 to 15 mm or 4 to
10 mm in said second area.
45. The article of claim 32, wherein a density per unit area of
said ultrasonic welding points in a first area is greater than that
in a second area.
46. The article of claim 43, wherein said first area forms at least
one partial area of a first and/or second and/or third partial
joining pattern of a cuff base.
47. The article of claim 43, wherein a first and/or third partial
joining pattern comprises a set of at least two, at least three, at
least four or at least five curves.
48. The article of claim 47, wherein at least two of curves of said
set are separated by a small maximum distance of 2 to 20 mm, 2 to
15 mm or 3 to 10 mm.
49. The article of claim 48, wherein at least two curves of said
set are separated by a greater maximum distance of 10 to 70 mm, 15
to 60 mm or 20 to 50 mm.
50. The article of claim 47, wherein one or more of said curves has
a radius of at least 60 mm, at least 70 mm, at least 80 mm, at
least 90 mm, at least 100 mm or of no more than 150 mm.
51. The article of claim 47, wherein said curves have a variable
distance between them.
52. The article of claim 32, wherein said joining pattern comprises
first discrete ultrasonic welding points with an area of 0.3 to 4
mm.sup.2, 0.3 to 3 mm.sup.2, 0.3 to 2 mm.sup.2, 0.5 to 1.1 mm.sup.2
or of 0.7 to 0.9 mm.sup.2.
53. The article of claim 32, wherein said joining pattern comprises
first and second discrete ultrasonic welding points, an area of
said first discrete ultrasonic welding points being smaller than
that of said second discrete ultrasonic welding points.
54. The article of claim 32, wherein an area of individual
ultrasonic welding points is circular, oval, triangular, polygonal,
sickle-shaped, dot-and-dashed, star-shaped or linear.
55. The article of claim 32, wherein a sum of areas of said
ultrasonic welding points of a 5-mm long section of said joining
pattern in said first direction is on average 2 to 25 mm.sup.2, 3
to 18 mm.sup.2, 4 to 12 mm.sup.2 or 6 to 10 mm.sup.2.
56. The article of claim 32, wherein an average sum of areas of
said ultrasonic welding points of a 5-mm long section of said
joining pattern in said first direction is no more than 30
mm.sup.2, no more than 23 mm.sup.2, no more than 18 mm.sup.2, no
more than 16 mm.sup.2 or no more than 15 mm.sup.2.
57. The article of claim 32, wherein a deviation of a sum of areas
of said ultrasonic welding points of each 5-mm long section of said
joining pattern in said first direction from a sum of areas of said
ultrasonic welding points of a directly adjacent 5-mm long section
of said joining pattern is less than 70%, less than 60%, less than
50% or less than 40%.
58. The article of claim 32, wherein a deviation of a sum of areas
of said ultrasonic welding points of at least 50%, of at least 60%,
of at least 70%, of at least 80% or of at least 90% of 5-mm long
sections of said joining pattern from a sum of areas of said
ultrasonic welding points of a directly adjacent 5-mm long section
of said joining pattern is less than 40%, less than 30% or less
than 25%.
59. The article of claim 32, wherein said joining pattern extends
300 to 2000 mm, 350 to 1500 mm, 400 to 1200 mm, 450 to 1100 mm or
500 to 1000 mm in said first direction and 10 to 1200 mm, 15 to
1000 mm, 20 to 500 mm, 30 to 200 mm, 40 to 150 mm or 50 to 130 mm
in said second direction.
60. A method for the production of the hygiene article, surgical
covering item, surgical garment for single use, incontinence
diaper, incontinence pad, surgical drape or surgical coat of claim
32, the article comprising a composite a nonwoven fabric having at
least one first nonwoven fabric component and a second nonwoven
fabric or foil component, the method comprising the step of:
welding said first nonwoven fabric component to said second
nonwoven fabric or foil component by means of an ultrasonic welding
device in at least some areas to form a joining pattern
encompassing discrete ultrasonic welding points, said joining
pattern extending in the first direction and in the second
direction, an extension in the first direction being greater than
an extension in the second direction, wherein at least some
sections of the joining pattern are not rectilinear and an index of
variation of an area seized by the ultrasonic welding points is no
more than 40%.
61. The method of claim 60, wherein the ultrasonic welding device
comprises a sonotrode or a stationary sonotrode and a contour
roller.
62. The method of claim 60, wherein welding of components is
performed at a path velocity of 100 to 1000 m/min.
Description
[0001] The invention relates to a disposable hygiene article or
surgical covering item, or surgical garment for single use, such as
an incontinence diaper, incontinence pad, surgical drape, or
surgical coat, comprising a composite nonwoven fabric, that is
provided with at least one nonwoven fabric component and another
nonwoven fabric or foil component. The first nonwoven fabric
component is attached to the other nonwoven fabric or foil
component in at least some areas by means of a joining pattern
encompassing discrete ultrasonic welding points in order to form
the composite nonwoven fabric. The joining pattern extends in a
first direction and a second direction that runs perpendicular
thereto, the distance in the first direction being longer than the
distance in the second direction. At least some sections of the
joining pattern are not rectilinear.
[0002] For example, on hygiene articles, in particular,
incontinence products, such as incontinence diapers, lateral
barriers standing toward the user during use, called cuff elements,
are provided that comprise a nonwoven fabric component and are
attached in the longitudinal direction of the product to another
nonwoven fabric or foil component of the hygiene article by means
of ultrasonic welding or bonding. In the field of the hygiene
articles addressed here, the joining of nonwoven fabric and/or foil
components by means of ultrasonic welding devices is generally
known. For example, a joining pattern comprising discrete
ultrasonic welding points can be implemented in a continuous, that
is, never-ending production machine for nonwoven articles of the
type stated above by using a contour roller rolling in the machine
direction and an anvil made to vibrate in the ultrasonic range,
which is termed a sonotrode. The contour roller and sonotrode form
a gap between them through which the weldable components to be
joined are fed during the continuous production process. The
nonwoven fabric or foil components are then welded by transfer of
the vibration energy on the raised areas of the contour roller. The
strength of the weld can be adjusted by varying the distance
between the sonotrode and the contour roller and by controlling the
vibration of the sonotrode.
[0003] The applicant has ascertained that, in particular, on
fast-operating production machines, it is extremely difficult to
achieve a uniformly secure weld without damaging the components if
the area of the weld varies greatly in the machine direction,
because this necessitates very frequent variation in control of the
welding device or its sonotrode. It is extremely difficult to
almost impossible to achieve a stable operating condition. If, on
the other hand, the area of a joining pattern varies little or not
at all in the machine direction, for example, if it does not vary
in the circumferential direction of the contour roller and, for
example, comprises concentric embossing lines or embossing points
on the contour roller, the problem described above does not occur
because the welded area does not change so rapidly in the machine
direction. If, on the other hand, the joining pattern is oblique
with respect to the machine direction or comprises oblique
sections, the proportion of the welded area in the machine
direction will vary greatly and the problems described above will
occur. If, for example, on one product, the joining pattern
comprises arc-shaped areas with tight curvature with respect to the
machine direction, achieving process reliability in the welding of
nonwoven fabric components poses a problem. If this problem is not
solved, unwelded points or damage to the nonwoven fabric or foil
components due to overwelding will occur. In either case, correct
functioning of the article being produced is jeopardized. Extremely
short control cycles in operating the ultrasonic welding device can
also result in the device overshooting and frequently causing
direct contact between the contour roller and the sonotrode. This
results in damage to the device, considerably reducing its service
life. The sonotrode and contour roller then require frequent
replacement due to the high wear caused by direct contact between
the two machine components.
[0004] The object of this invention is to provide a hygiene article
or a surgical covering item or surgical garment of the type
described above with which the problems described above do not
occur, while nevertheless permitting production of a joining
pattern of discrete ultrasonic welding points that varies in the
machine direction. For example, it must be possible to fix a
standing cuff element according to a joining pattern that
oscillates in the form of arcs with respect to the machine
direction or generally to join weldable nonwoven fabric or foil
components of the article stated above fed in as flat material
without being limited to a joint that is precisely rectilinear in
the machine direction. In particular, damage to components being
welded together during the welding process and partially deficient
welding of the components must be precluded. Similarly, damage to
the ultrasonic welding device must be avoided and a long service
life ensured in conjunction with fast-operating production
machines.
[0005] This object is inventively achieved in an article of the
type stated above by ensuring that the index of variation of the
area seized by the ultrasonic welding points is no more than 40%.
The solution is to design the joining pattern of the ultrasonic
welding points in such a way that the area seized by the welding in
the machine direction does not vary so much that the problems
described above occur. For example, this can be achieved by
variation and appropriate disposition of the number of ultrasonic
welding points per unit area, that is, e.g. by selecting the
distance between the ultrasonic welding points and/or by varying
the respective area of the ultrasonic welding points.
[0006] The index of variation of the area seized by the ultrasonic
welding points is calculated as follows: The article in accordance
with the invention is considered divided into 5-mm wide
longitudinal sections in the first direction. These longitudinal
sections therefore extend over 5 mm in the first direction, which
is also the machine direction, and perpendicular thereto in the
second direction, which is the transverse direction on the product.
Each of these sections extending 5 mm in the longitudinal direction
encompasses a number of ultrasonic welding points, each of which
constitutes a welded proportion of the area. It is possible to
calculate the welded area A.sub.i of each 5-mm section (sum of the
areas of the individual ultrasonic welding points in a 5-mm
section). It is also possible to calculate a mean value of the area
A.sub.i seized by the ultrasonic welding points of each section.
For example, it is possible to divide an 820-mm long article into
164 such 5-mm sections in the first direction. For each section, it
is possible to calculate the welded area A.sub.i and from these 164
A.sub.i values, it is then possible to calculate the arithmetic
mean of the welded area of the 5-mm sections. A value s can be
calculated from these according to the following formula:
s = 1 N - 1 i = 1 N ( A i - A _ ) 2 ##EQU00001##
[0007] Thus the error sum of squares of A.sub.i of the individual
5-mm sections is calculated from the mean value of the welded
surfaces of the 5-mm sections and divided by (N-I) and the square
root is taken of the result. Based on this, the said index I (in %)
of variation of the area seized by the ultrasonic welding points is
defined as follows:
I = s A _ .times. 100 [ % ] ##EQU00002##
[0008] It has been shown that the range of the index of variation
of the area seized by the ultrasonic welding points of no more than
40% that is stated in the claims is suitable, in particular, for
the machine velocities relevant here of 100 m/min to 1000 m/min, in
particular, of 150 m/min to 700 m/min, to ensure process
reliability of the ultrasonic weld joint between nonwoven fabric
components and/or foil components of the articles in question here.
It has proven especially advantageous if the index of variation of
the area seized by the ultrasonic welding points is no more than
35%, in particular, no more than 30% and further, in particular, no
more than 25% (claim 2).
[0009] This invention proves especially advantageous on an article
in which the composite nonwoven fabric comprises on both sides at
least one cuff element standing at least in sections, forming a
leakage barrier, and essentially extending in the first direction
(claim 3). As mentioned above, a cuff element is a lateral barrier
formed from a flat material that is raised from the substrate
mostly due to elastification, in particular, toward the body of the
user and thus provides a leakage barrier, chiefly at the sides of
the article. In the case of an inventive article, this cuff element
is joined to further (chassis) nonwoven fabric or foil components
of the article by an inventively constituted joining pattern of
ultrasonic welding points. The cuff element therefore
advantageously also comprises the first nonwoven fabric component
(claim 4).
[0010] In particular, if the article according to the claims is a
hygiene article for single use, it proves advantageous if the
article comprises a topsheet that is permeable at least in some
areas, a backsheet that is impermeable at least in some areas, and
a storage core that absorbs body fluids and is disposed between the
two (claim 5). In such a case, it can be advantageous for the other
nonwoven fabric or foil component to be the topsheet or the
backsheet, so that a preferably additionally provided cuff element
with its first nonwoven fabric component is attached to the
topsheet or backsheet by the inventive joining pattern of
ultrasonic welding points (claim 6).
[0011] To join a cuff element to further components of the article
by means of ultrasonic welding, it proves advantageous if the
joining pattern comprises a first partial joining pattern that, at
least in areas, constitutes a cuff base, that is, an area along
which the cuff element is attached to the further nonwoven fabric
component or foil component (claim 7). When the article is put to
its intended use, this then constitutes a fold line along which the
cuff element is raised away from a base plane.
[0012] In a further embodiment of this inventive concept, the cuff
base constituted in some areas by the said first partial joining
pattern can additionally be constituted or limited in some areas by
a second partial joining pattern that is largely rectilinear and,
in particular, largely extends parallel to the first direction
(claim 8). Here and hereafter a partial joining pattern is referred
to as largely rectilinear when, over a length of 200 mm in the
first direction, an extension in the second direction of no more
than 6 mm can be ascertained.
[0013] In yet a further embodiment, the cuff base is constituted at
least in sections by the first partial joining pattern, the second
partial joining pattern and a third non-rectilinear partial joining
pattern (claim 9). In the first direction, the second partial
joining pattern is disposed preferably between the first and the
third partial joining pattern (claim 10). The result is therefore a
cuff base that, in a front area and in a rear area of the article,
extends transverse to the longitudinal direction, in particular,
curved in the shape of an arc with respect to the longitudinal
direction and, in the intermediate area, is largely rectilinear
and, in particular, parallel to the first direction. Such a
configuration proves especially advantageous, particularly for
hygiene articles for single use, such as incontinence diapers,
incontinence pads. The invention makes it possible to dispose the
cuff elements relatively far toward the outside in the transverse
direction in a front and rear region of the article and then to
have them curve inward toward the crotch area. In the crotch area,
the cuff elements or the cuff base or cuff base lines then
advantageously extend largely parallel and have a smaller distance
between them in the transverse direction (second direction) than in
the front and rear areas. With this invention, it becomes possible
to establish a stable connection between the cuff element and
chassis materials of a hygiene article that meets the desired
requirements for configuration of the article and is nevertheless
producible with process reliability by complying with the inventive
design of the joining pattern.
[0014] In a further embodiment of the invention, it proves
advantageous if, in an inventive article, the joining pattern in
the first direction is considered virtually in three sections of
equal length, that is, is divisible into a start section, an
adjoining center section, and an end section adjoining the center
section and the index of variation of the area of the start section
and/or of the end sections seized by the ultrasonic welding points
of the joining pattern is no more than 40%, in particular, no more
than 35%, further, in particular, no more than 30%, further, in
particular, no more than 25% (claim 11). According to this further
embodiment of the invention, the inventively imposed condition is
not only fulfilled over the entire claimed article, considering all
5-mm sections containing ultrasonic welding points, but also for
the corresponding 5-mm sections of the start section overlapping by
one third and the end section overlapping by one third.
[0015] As already stated, the inventive design of the joining
pattern of the ultrasonic welding points can be achieved by various
measures. In particular, it can prove advantageous if the distance
between the discrete ultrasonic welding points is smaller in a
first area than in a second area (claim 12).
[0016] In particular, it proves useful if the distance between
individual (discrete) ultrasonic welding points in a first area is
0.1 to 2.5 mm, in particular, 0.2 to 1.5 mm, and further, in
particular, 0.2 to 1.0 mm and, in a second area, is 2 to 20 mm, in
particular, 3 to 15 mm, further, in particular, 4 to 10 mm (claim
13).
[0017] It is also possible for the density per unit area of the
ultrasonic welding points (number of points per unit area) to be
greater in a first area than in a second area (claim 14).
[0018] The said first area is a partial area of the joining
pattern; it can constitute, in particular, one partial area of the
first and/or second and/or third partial joining pattern of the
cuff base (claim 15).
[0019] According to a further embodiment of the invention, the
first and/or third partial joining pattern comprises a set of at
least two, in particular, at least three curves, further, in
particular, at least four, further, in particular, at least five
curves (claim 16). Preferably at least two of the curves of a set
should be separated by a small maximum distance of 2 to 20 mm, in
particular, 2 to 15 mm and further, in particular, 3 to 10 mm
(claim 17). Furthermore, it proves advantageous if at least two of
the curves of a set are separated by a greater maximum distance of
10 to 70 mm, in particular, 15 to 60 mm and further, in particular,
20 to 50 mm (claim 18). For example, this is possible and
advantageous if the set consists of three curves and the maximum
distance of the first outer curve from the center curve has the
previously stated low value and the maximum distance of the second
outer curve from the center curve is a greater distance. Of course,
in the case of a set of more than three curves, at least two curves
of a set can have a different maximum distance between them.
[0020] Moreover, it proves advantageous if one or more of the
curves has a radius of at least 60 mm, in particular, at least 70
mm, further, in particular, 80 mm, further, in particular, at least
90 mm, further, in particular, at least 100 mm and further, in
particular, no more than 150 mm (claim 19). The curves can also
have a variable distance between them (claim 20).
[0021] The curves are advantageously not a weld line that is
continuous over its extension but a series of consecutive
ultrasonic welding points that is then largely linear and thus
forms the curve. By varying the distance between the ultrasonic
welding points and/or by changing the distance between the curves
it is possible to vary the proportion of the area of the weld
points in each 5-mm section, so that, overall, the claimed index
range is complied with.
[0022] It proves advantageous if the joining pattern has first
discrete ultrasonic welding points with an area of 0.3 to 4
mm.sup.2, in particular, 0.3 to 3 mm.sup.2, further, in particular,
0.3 to 2 mm.sup.2, further, in particular, 0.5 to 1.1 mm.sup.2 and
further, in particular, 0.7 to 0.9 mm.sup.2 (claim 21).
[0023] As already stated, it can be advantageous if the joining
pattern encompasses first and second discrete ultrasonic welding
points and the area of the first discrete ultrasonic welding points
is smaller than that of the second discrete ultrasonic welding
points (claim 22).
[0024] The shape of the area of the ultrasonic welding points is
relatively uncritical; they can be circular or oval or triangular
or polygonal or sickle-shaped or dot-and-dashed or star-shaped or
linear (claim 23).
[0025] For example, in the production of hygiene articles, it can
prove advantageous if the sum (A.sub.i) of the areas of the
ultrasonic welding points of a 5-mm long section of the joining
pattern in the first direction is on average 2 to 25 mm.sup.2, in
particular, 3 to 18 mm.sup.2, in particular, 4 to 12 mm.sup.2 and
further, in particular, 6 to 10 mm.sup.2 (claim 24). In the case of
a hygiene article with cuff elements on both sides, these are
preferably the values that apply to the joining pattern of one of
the cuff elements.
[0026] Furthermore, it proves advantageous if the sum (A.sub.i) of
the areas of the ultrasonic welding points of one, in particular,
each 5-mm long section of the joining pattern in the first
direction is no more than 30 mm.sup.2, in particular, no more than
23 mm.sup.2, further, in particular, no more than 18 mm.sup.2,
further, in particular, no more than 16 mm.sup.2, further, in
particular, no more than 15 mm.sup.2 (claim 25).
[0027] In the production of an inventive article, it proves
advantageous if, in the design of the joining pattern of the
ultrasonic welding points, the deviation of the sum (A.sub.i) of
the areas of the ultrasonic welding points of each 5-mm long
section of the joining pattern in the first direction from the sum
(A.sub.i) of the areas of the ultrasonic welding points of a
directly adjacent 5-mm long section of the joining pattern is less
than 70%, in particular, less than 60%, in particular, less than
50%, further, in particular, less than 40% (claim 26). This means
that the entire welded area (A.sub.i) of two adjacently disposed
5-mm sections must differ by no more than the above-mentioned
ranges. In this case, this deviation of two adjacent 5-mm long
sections refers to the sum A.sub.i of the areas of the ultrasonic
welding points of the section whose sum A.sub.i of the areas of the
ultrasonic welding points has the higher value.
[0028] Furthermore, it proves advantageous with respect to
consistent product quality if the deviation of the sum of the areas
of the ultrasonic welding points of at least 50%, in particular, of
at least 60%, further, in particular, of at least 70% and further,
in particular, of at least 80%, and, very especially, of at least
90% of the 5-mm long sections of the joining pattern from the sum
(A.sub.i) of the areas of the ultrasonic welding points of a
directly adjacent 5-mm long section of the joining pattern is less
than 40%, in particular, less than 30%, in particular, less than
25% (claim 27).
[0029] The invention also relates to a method for the production of
a hygiene article or surgical covering item, or surgical garment of
the inventive type with the characteristics stated in the claims
29, 30, and 31.
[0030] Furthermore, it proves advantageous if the claimed article
is constituted such that the joining pattern extends 300 to 2000
mm, in particular, 350 to 1500 mm, in particular, 400 to 1200 mm,
further, in particular, 450 to 1100 mm and further, in particular,
500 to 1000 mm in a first direction and running perpendicular
thereto preferably 10 to 1200 mm, in particular, 15 to 1000 mm, in
particular, 20 to 500 mm, further, in particular, 30 to 200 mm and
further, in particular, 40 to 150 mm and further, in particular, 50
to 130 mm in a second direction.
[0031] Further characteristics, details, and advantages of the
invention can be seen from the appended patent claims and from the
drawings and the following description of the invention using
explanatory examples. The drawings show:
[0032] FIG. 1 a top view of a hygiene article in the form of an
incontinence diaper in the unfolded condition;
[0033] FIG. 2 a sectional view with intersection plane II-II in
FIG. 3;
[0034] FIGS. 3, 4 a partially perspective view of an ultrasonic
welding device for production of inventive articles in a continuous
production process using continuously fed flat material;
[0035] FIG. 5 an enlarged detailed view of a joining pattern from
FIGS. 5, 6 (viewed as a top view according to the Arrow V onto the
device according to FIG. 4;
[0036] FIG. 6 a top view of an inventively constituted joining
pattern to illustrate the conceptual division into 5-mm
sections;
[0037] FIG. 7 a diagram in which the area proportion of the
ultrasonic welding points of each 5-mm section is entered and the
underlying joining pattern is indicated (not comprised in the scope
of protection of the invention); and
[0038] FIG. 8 a corresponding diagram with an inventively
constituted joining pattern structure.
[0039] FIG. 1 shows a hygiene article numbered in its entirety with
the reference symbol 2 in the form of an incontinence diaper for
single use. FIG. 2 depicts a schematic sectional view with
intersection plane II-II in FIG. 1. Hygiene article 2 comprises a
topsheet 4 and an impermeable backsheet 6 and an interposed
absorption body 8. The topsheet 4 is a permeable nonwoven fabric
component, in particular, a card or spunbonded nonwoven, preferably
with a mass per unit area of 8-30 g/m.sup.2, in particular, 12 to
25 g/m.sup.2, in particular, 14 to 22 g/m.sup.2 and the backsheet 6
is an impermeable foil component or a composite nonwoven/foil
material 12. Moreover, as is best seen in FIG. 2, the hygiene
article comprises lateral cuff elements 14 with thread-like
elastification means (15) disposed on their distal edge, fixed on
them in the pretensioned condition preferably by hot melt adhesive,
which form a lateral leakage barrier. These cuff elements (14) also
preferably comprise a nonwoven fabric component 16, in particular,
a hydrophobic spunbonded nonwoven or a spunbond-meltblown (SM) or a
spunbond-meltblown-spunbond (SMS) nonwoven laminate with a mass per
unit area of 8 to 30 g/m.sup.2, in particular, 12 to 20 g/m.sup.2,
in particular, 13 to 18 g/m.sup.2.
[0040] Laterally extending side flaps 22 and 24 are provided in a
respective front area 18 and in a respective back area 20. The side
flaps 22, 24 extend between topsheet 4 and backsheet 6 and are
fixed there by welding or gluing. A weld or glue line is indicated
with reference symbol 26.
[0041] Moreover, the cuff elements 14 of both sides are joined in a
first area 27 along a so-called cuff base 28 and in a second area
29 with the nonwoven fabric component 10 of the topsheet 4 by
discrete ultrasonic welding points 30 forming a joining pattern.
The discrete ultrasonic welding points 30 have a maximum distance
between them of 0.1 mm to 2.5 mm in a first area 27 and a maximum
distance between them of 4.0 mm to 10.0 mm in a second area 29 and
have an area of 0.7 to 0.9 mm.sup.2 in each case. The extent of the
cuff base 28 is best visible in FIG. 1. For better clarity only,
FIG. 1 does not show the second joining pattern that fixes the
right cuff element to the topsheet 4. The second joining pattern
that is not shown is the mirror image of the first.
[0042] It would be possible and advantageous, in an embodiment not
shown here, to fix the cuff base 14 directly to the backsheet 6 by
means of the joining pattern. This would be advantageous, in
particular, if the cuff base 14 were outside the absorption body
contour and outside the transverse extent of the topsheet 4.
[0043] Hygiene article 2 furthermore has a first direction 32 that
constitutes the longitudinal direction of the hygiene article and
matches the machine direction during production of the hygiene
article. In continuous production, the topsheet 4, backsheet 6,
side flaps 24, and cuff elements 14 constituting the corresponding
webs of flat material therefore extend in this first direction 32.
The cuff base 28 or the series of ultrasonic welding points 30 also
largely extends along this first direction 32. However, as can be
seen in FIG. 1, the cuff base 28 is, at least in areas, not
straight and parallel to the first direction 32, but extends in the
shape of a curve or arc and therefore also has a component in a
second direction 34 that is perpendicular to the first direction
(transverse direction of the hygiene article). The joining pattern
36 that is at least partially formed by the ultrasonic welding
points 30 will be described in detail below. The nonwoven fabric
components and/or foil components that are permanently joined to
each other while the article is being put to its intended use also
constitute a composite nonwoven fabric 38.
[0044] The schematic representation of an ultrasonic welding device
designated in its entirety with reference sign 40 in FIGS. 3, 4
illustrates a contour roller 42 that rolls in the machine direction
or first direction 32 and a sonotrode 44 that can be excited in the
ultrasonic range. The ultrasonic welding device 40 can be
integrated into a fast-operating machine for producing modern
hygiene articles. FIG. 3 depicts an ultrasonic welding device with
two sonotrodes 44 for producing the welded joint between two cuff
elements on both sides, while the device according to FIG. 4 only
shows one sonotrode 44 and is only intended for production of the
ultrasonic welded joint with one cuff element. The corresponding
further contour roller and sonotrode for the other half could be
disposed before, after, or parallel with the first. It is also
possible, in the case of the embodiment according to FIG. 3, to
have a single continuous sonotrode in the second direction 34
instead of two parallel sonotrodes.
[0045] During production of the hygiene articles shown in FIGS. 1
and 2, for example, a cuff element 14 and the topsheet 4 in a
configuration with one on top of the other would be introduced into
the gap of the ultrasonic welding device constituted by the
sonotrode and contour roller according to FIG. 3 to join these
components to form the composite nonwoven fabric and to place it on
the absorption body 8.
[0046] On the circumference of the contour roller 42, numerous
protrusions 46 can be seen that are disposed and constituted
according to the joining pattern 36 to be produced. FIG. 5 shows a
top view onto the surface of the contour roller 42 viewed in the
direction of arrow V in FIG. 4. The figure shows the protrusions 46
on the contour roller 42 and the corresponding identical joining
pattern 36 produced by them as the roller turns on the flat
material web being fed through. A linear or serial configuration of
protrusions 46 that constitute ultrasonic welding points 30 of the
subsequent cuff base 28 can be seen. Moreover, it can be seen that
the distance between the protrusions 46 and the number of
protrusions 46 per unit area on the roller surface 42 vary, so that
the conditions described in detail below for the relevant joining
pattern 36 are met.
[0047] FIG. 6 shows a schematic top view of a joining pattern to
illustrate the conceptual division of the joining pattern into 5-mm
wide sections 48 in the longitudinal direction 32. The sections 48
are therefore contiguous in the first direction 32. Within each
5-mm section 48, a number of ultrasonic welding points 30 are
provided that form for each 5-mm section 48 a proportion A.sub.i of
embossed or welded area. If N such 5-mm sections 48 are provided
that are conceptually disposed in the first direction 32 from the
beginning to the end of the ultrasonic joining pattern 36, a mean
value can be calculated as follows:
A _ = A i N ##EQU00003##
[0048] It is also possible to calculate a value s from the error
sum of squares of the individual A.sub.i values from this mean
value according to the following formula:
s = 1 N - 1 i = 1 N ( A i - A _ ) 2 ##EQU00004##
[0049] From this, it is possible to derive an index I of variation
of the area seized by the ultrasonic welding points in the first
direction 32 for the entire joining pattern 36 or the conceptual
division into N 5-mm sections 48 as follows:
I = s A _ .times. 100 [ % ] ##EQU00005##
[0050] It was inventively determined that this index of variation
of the area seized by the ultrasonic welding points 30 should be no
more than 40% in the first direction 32.
[0051] Based on FIGS. 7 and 8, two different joining patterns of
discrete ultrasonic welding points are examined below. As can be
seen, it is a joining pattern for fixing cuff elements 14 shown in
FIGS. 1 and 2, that is, fixing the nonwoven fabric component 16 of
these cuff elements 14 to a further nonwoven fabric or foil
component 10 of a hygiene article. The joining pattern of one of
the two cuff elements 14 of the hygiene article was considered.
[0052] The lower part of FIG. 7 shows along the abscissa the form
of the joining pattern under consideration of ultrasonic welding
points that have a small distance between them in a first area 27
and a larger distance between them in a second area 29. The extent
of the joining pattern in the first direction (machine direction)
is 820 mm, resulting in 164 5-mm sections. Above the said joining
pattern, FIG. 7 shows those welded proportions of the area within
each relevant 5-mm section, which are connected to form a curve.
There are therefore 164 area proportions A.sub.i, one for each 5-mm
section. Due to the relatively small radius of curvature of the
cuff bases 28 having a high raster density of the ultrasonic
welding points, a very high variation of the area proportions can
be seen in the first direction 32. However, this results in the
problems described above. The curve shown for the area proportions
A.sub.i results in a mean value of 9.01 mm.sup.2 over all N=164
5-mm sections. This results in a value s of 3.85 and in an index I
of 42.7%.
[0053] If the joining pattern 36 is divided into a start section
50, a center section 52, and an end section 54 that each extend
over a third of the extent of the joining pattern 36 in the
longitudinal direction, the following values are obtained for these
sections 50, 52, 54 when the N/3 5-mm sections contained in them
are each evaluated in isolation:
Start section: =9.55, s=4.66, I=48.8% Center section 52: =7.62,
s=0.71, I=9.3% End section 54: =9.90, s=4.49, I=45.3%.
[0054] Due to this value of the index I of variation of the area
seized by the ultrasonic welding points, a hygiene article with the
joining pattern 36 shown in FIG. 7 would not be in accordance with
the invention.
[0055] An inventive joining pattern 36 is shown in FIG. 8. The
following values are obtained when the N/3 5-mm sections contained
in sections 50, 52, 54 are each evaluated in isolation:
Start section: =9.56, s=1.67, I=17.5% Center section 52: =7.34,
s=0.91, I=12.4% End section 54: =9.25, s=2.33, I=25.1%.
[0056] It can be seen from FIG. 8, the welded proportions of the
area A.sub.i in the first direction 32 varies very much less than
in the joining pattern according to FIG. 7. This is achieved with
respect to the lowest possible index of variation of the area
seized by the ultrasonic welding points. In particular, it can be
seen that a first partial joining pattern 60 that forms a part of a
cuff base 28 and extends curved in the shape of an arc is formed
from a set of several curves 62. The term curve is used here for a
series of successive discrete ultrasonic welding points 30 (as can
be seen in FIG. 5). This set of curves 62 is, for example, disposed
in a range of approx. 200 to 270 mm, a small distance apart, and
running parallel and largely in the first direction 32. In the
adjoining area (of approx. 200 to approx. 50 mm), the curves 62 are
curved in the shape of an arc, and the distance between increases
in the first direction 32. In this way, it is inventively achieved
that the area proportions A.sub.i of the 5 mm-sections in the first
direction 32 do not vary as much, for example, as in the case of
the joining pattern according to FIG. 7. In total, a very much
lower index of variation of the area seized by the ultrasonic
welding points results.
[0057] It is immediately apparent that there are several ways of
ensuring that the variation of the area proportions A.sub.i of the
5-mm sections in the first direction 32 is not too large. A first
possibility is to keep the radius of curvature of curved partial
joining patterns as large as possible, that is, not to permit tight
curvature. A further possibility, which is shown in FIG. 8, is the
formation of curved partial joining patterns in the form of
multiple curves or series of ultrasonic welding points, whose
distance from each other is especially variable. Also, the distance
between the individual ultrasonic welding points, in particular,
those of a series could be varied. Also the area of the individual
ultrasonic welding points or protrusions on the contour roller
could be varied, in particular, additionally. Moreover, the
disposition and the distance between the ultrasonic welding points
in a second area, that is, where the ultrasonic welding points are
further apart, can be varied.
[0058] Finally, FIG. 8 shows a second partial joining pattern 64
that is largely rectilinear and extends in the first direction 32.
It is said to extend largely in the first direction 32 if, over a
length of about 200 mm in the first direction 32, an extent in the
second direction 34 of no more than 5 mm can be determined. A third
partial joining pattern 66 is adjoined to this, which, like the
first partial joining pattern 60, extends curved in the shape of an
arc and comprises a set of several curves 62. It therefore also has
a component in the second direction 34.
* * * * *