U.S. patent application number 15/950326 was filed with the patent office on 2018-10-11 for extensible dressings.
The applicant listed for this patent is Johnson & Johnson Consumer Inc.. Invention is credited to Leonardo Caneppele, Andre Narcizo, Paulo Cesar de Godoy Oriani, Carmine Rizzo, Andre Luiz Santos.
Application Number | 20180289559 15/950326 |
Document ID | / |
Family ID | 62063659 |
Filed Date | 2018-10-11 |
United States Patent
Application |
20180289559 |
Kind Code |
A1 |
Caneppele; Leonardo ; et
al. |
October 11, 2018 |
EXTENSIBLE DRESSINGS
Abstract
The present invention relates to dressings such as bandages or
tapes having improved extensibility and conformability to human
skin and joints.
Inventors: |
Caneppele; Leonardo; (Sao
Jose dos Campos, BR) ; Narcizo; Andre; (Sao Jose dos
Campos, BR) ; Oriani; Paulo Cesar de Godoy; (Itatiba,
BR) ; Rizzo; Carmine; (Port St. Lucie, FL) ;
Santos; Andre Luiz; (Sao Jose dos Campos, BR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Johnson & Johnson Consumer Inc. |
Skillman |
NJ |
US |
|
|
Family ID: |
62063659 |
Appl. No.: |
15/950326 |
Filed: |
April 11, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62483989 |
Apr 11, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 13/0266 20130101;
A61F 13/00038 20130101; A61F 13/023 20130101; A61F 2013/00604
20130101; A61L 15/26 20130101; A61F 2013/00595 20130101; A61F
2013/00655 20130101; A61F 13/00025 20130101; A61F 13/0243 20130101;
A61F 13/0206 20130101; A61F 13/00 20130101 |
International
Class: |
A61F 13/02 20060101
A61F013/02; A61L 15/26 20060101 A61L015/26 |
Claims
1. A dressing comprising: a. a layer of non-swellable material, the
layer having at least two material free regions wherein the
material free regions are in the form of curvilinear sigmoidal
patterns, wherein the patterns are non-intersecting and arranged
adjacent to one another such that, upon application of a force to
the dressing, after the dressing is applied to a wound, the
material free regions freely open from a closed position to an open
position to facilitate stretching of the layer of material from a
first position to a second position in the direction of the force
and wherein once the force is no longer applied, the material free
regions freely close to the closed position to facilitate movement
of the layer of material back to the first position from the second
position; and b. a releasable layer releasably contacting the layer
of material while the material free regions are in the closed
position.
2. The dressing of claim 1 further comprising an adhesive disposed
between the releasable layer and the layer of material.
3. The dressing of claim 1, wherein the material free regions are
slits in the layer of material.
4. The dressing of claim 1, wherein each sigmoidal pattern has a
top and a bottom and further wherein the top and bottom of any
sigmoidal pattern in a row is aligned with the top and bottom of
the other similarly oriented sigmoidal patterns in that row.
5. The dressing of claim 1, wherein the non-swellable material
forming the layer of material is selected from polyurethanes,
polyethylene, polyisobutylene, polyamides, polyesters, polyether
polyesters, non-hydrophilic polyether-polyamides, plasticised
polyvinyl chloride, styrene-butadiene block copolymers,
styrene-isoprene block copolymer, polyacrylates, methacrylic
copolymers, polypropylene, rayon, rayon/polyester blends and
mixtures thereof.
6. The dressing of claim 5, wherein the material forming the layer
of material is a polyester.
7. The dressing of claim 1, wherein the sigmoidal patterns have a
length l and, optionally, wherein the length l of at least one
sigmoidal pattern is oriented perpendicular to the length l of an
adjacent sigmoidal pattern.
8. The dressing of claim 7, wherein the lengths l of each sigmoidal
pattern in a row is oriented perpendicular to the length l of its
adjacent sigmoidal pattern in that row.
9. The dressing of claim 7, wherein the sigmoidal patterns have a
width w and further wherein the length l of the sigmoidal pattern
is from about 1 to about 6 times the width w of sigmoidal
pattern.
10. The dressing of claim 1, wherein the surface density of pattern
units per square inch of the surface of the layer of material is
from about 10 pattern units/in.sup.2 to about 14 pattern
units/in.sup.2 of the surface of the layer of material.
11. The dressing of claim 1, wherein the layer of material extends
in at least one of the longitudinal or transverse directions at
least about 100% more than the same layer of material without
material free regions, as measured by the Stretchability
Test.sub.xy described in the Specification, when applying a force
of from about 0.1 kgf along such longitudinal or transverse
direction of the layer of material.
12. The dressing of claim 1, wherein the layer of material extends
in at least one of the longitudinal or transverse directions at
least about 150% more than the same layer of material without
material free regions, as measured by the Stretchability
Test.sub.xy described in the Specification, when applying a force
of from about 0.2 kgf along such longitudinal or transverse
direction of the layer of material.
13. The dressing of claim 1, wherein the layer of material extends
in at least one of the longitudinal or transverse directions at
least about 425% more than the same layer of material without
material free regions, as measured by the Stretchability
Test.sub.xy described in the Specification, when applying a force
of from about 0.3 kgf along such longitudinal or transverse
direction of the layer of material.
14. The dressing of claim 11, wherein the layer of material extends
in the other longitudinal or transverse direction at least about
75% more than the same layer of material without material free
regions, as measured by the Stretchability Test.sub.xy described in
the Specification, when applying a force of from about 0.1 kgf
along such other longitudinal or transverse direction of the layer
of material.
15. The dressing of claim 12, wherein the layer of material extends
in the other longitudinal or transverse directions at least about
150% more than the same layer of material without material free
regions, as measured by the Stretchability Test.sub.xy described in
the Specification, when applying a force of from about 0.2 kgf
along such other longitudinal or transverse direction of the layer
of material.
16. The dressing of claim 1, wherein the layer of material extends
in at least one of the 45.degree. diagonal directions at least
about 425% more than the same layer of material without material
free regions, as measured by the Stretchability Test.sub.xy
described in the Specification, when applying a force of from about
0.1 kgf along such 45.degree. diagonal direction of the layer of
material.
17. The dressing of claim 1, wherein the layer of material extends
in at least one of the 45.degree. diagonal directions at least
about 1125% more than the same layer of material without material
free regions, as measured by the Stretchability Test.sub.xy
described in the Specification, when applying a force of from about
0.2 kgf along such 45.degree. diagonal direction of the layer of
material.
18. The dressing of claim 1, wherein the layer of material extends
in the z direction at least about 1 mm to about 8 mm away from the
xy-plane of the layer of material, as measured by the
Stretchability Test.sub.z described in the Specification, when
applying a force of about 0.5 kgf along the z direction of the
layer of material.
19. The dressing of claim 1, wherein the releasable layer comprises
polyethylene, polypropylene, kraft papers, polyester or composites
thereof.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of the earlier
filing date of U.S. provisional patent application 62/483,989,
filed Apr. 11, 2017, the entirety of which application is hereby
incorporated by reference herein as if fully set forth herein.
FIELD OF THE INVENTION
[0002] The present invention relates to dressings such as bandages
or tapes having improved extensibility and conformability to human
skin and joints.
BACKGROUND OF THE INVENTION
[0003] Dressings such as bandages and tapes for applying to and/or
covering the skin have been known for some time. Such dressings
have gained wide acceptance for closing minor wounds, protecting
minor wounds and/or covering abrasions. In some instances,
microporous or breathable, bandages or tapes have been developed
and are used either to cover minor wounds (including wounds that
have been partially healed).
[0004] While such dressings have been greatly improved over the
years in that, for example, they have incorporated microporous
materials allowing the wound to breath and permitting water vapor
to escape from the wound, hence, reducing chances of wound
maceration, there remains a need for dressing which provide
improved extensibility and elasticity of the dressing such that the
dressing will cover and accommodate the dimensional contours of
skin or tissues and move with (i.e., accommodating movement of)
that portion of the skin or tissues covered by or in contact with
the dressing, particularly in the situation where the dressing
covers or is in contact with areas of the human tissue associated
with jointed regions such as the joints of the fingers, ankles,
elbows or knees. Accordingly, in order for a dressing to provide
the aforementioned attributes, the dressing should also be able to
dynamically conform to and with changing three dimensional contour
of the skin or tissue surfaces to which it is applied.
[0005] The dressing should also be conformable to, or provide
sufficient drapability, over the area human skin tissue contacted
by the dressing or to which it is adhered.
[0006] It is, therefore, an aspect of the present invention to
provide dressings that may be used to cover, protect wounds and
facilitate wound healing. It is a further aspect of the present
invention to provide bandages and tapes that conform to a wounded
area of the skin and have improved extensibility, elasticity and
conformability for better coverage of movable areas such as joints.
Other aspects of the present invention will be readily apparent
from the ensuing description and claims.
SUMMARY OF THE INVENTION
[0007] In one embodiment, the present invention relates to a
dressing comprising: [0008] a. a layer of non-swellable material,
the layer having at least two (or, a plurality of) material free
regions wherein the material free regions are in the form of
curvilinear sigmoidal patterns, wherein the patterns are
non-intersecting and arranged adjacent to one another such that,
upon application of a force to the dressing, after the dressing is
applied to a wound, the material free regions freely open from a
closed position to an open position to facilitate stretching of the
layer of material from a first position to a second position in the
direction of the force and wherein once the force is no longer
applied, the material free regions freely close to the closed
position to facilitate movement of the layer of material back to
the first position from the second position; and [0009] b. a
releasable layer releasably attached to or contacting the layer of
material while (or when) the material free regions are in the
closed position, or the releasable layer releasably contacting the
layer of material such that the material free regions are in the
closed position.
[0010] The present invention also relates to methods of
using/applying the dressings of the present invention, including
the disclosed embodiments, on skin surfaces covering jointed areas
(or areas prone to movement) of human or mammalian bodies.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] An embodiment of this invention will now be described in
greater detail, by way of illustration only, with reference to the
accompanying drawings, in which:
[0012] FIG. 1 is a perspective view of the dressing of the present
invention with directional xyz-axis;
[0013] FIG. 2 is a plan view of the figure of FIG. 1;
[0014] FIG. 2A is an enlarged top view of certain of the rows of
pattern units of FIG. 2;
[0015] FIG. 3 is cross-sectional view of FIG. 2 taken along line
3-3;
[0016] FIG. 4A shows the distinct material free regions in the
closed position prior to application of force F;
[0017] FIG. 4B shows the distinct material free regions in the open
position during application of force F;
[0018] FIG. 4C shows the distinct material free regions returned to
closed position after terminating application of force F;
[0019] FIG. 5A shows a differently formed (or non-curvilinear)
sigmoidal pattern units suitable for use in dressing of the present
invention arranged where the pattern units in a row are aligned
with respect to the pattern units in its adjacent rows;
[0020] FIG. 5B shows the pattern of FIG. 5A where the pattern units
in a row are off set with respect to the pattern units in adjacent
rows;
[0021] FIG. 5C shows sigmoidal pattern units of FIGS. 2 and 2A
arranged where the pattern units in a row are aligned with respect
to the pattern units in its adjacent rows;
[0022] FIG. 6 is an exploded view of dressing of present invention
showing an additional layer in between the layer of material of the
present invention and the releasable layer;
[0023] FIG. 7 is an exploded view of dressing of present invention
showing the layer of material of the present invention in between a
backing layer and the releasable layer;
[0024] FIG. 8 shows the longitudinal, transverse and 45.degree.
diagonal directions (L, T and D.sub.45) of the stretch force for
the layer of material; and
[0025] FIG. 9 shows a previously disclosed pattern of slit units
used for comparison purposes.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The dressing of the present invention can comprise, consist
of, or consist essentially of the essential elements and
limitations of the invention described herein, as well any of the
additional or optional features, components, or limitations
described herein.
[0027] The term "comprising" (and its grammatical variations) as
used herein is used in the inclusive sense of (and, interchangeably
with the terms) "having" or "including" and not in the exclusive
sense of "consisting only of" The terms "a" and "the" as used
herein are understood to encompass the plural as well as the
singular.
[0028] As used herein, terms "skin" and "tissue" are
interchangeable and refer to mammalian skin.
[0029] As used herein, the terms "visual inspection" or "visually
inspected" means inspection with the unaided eye (excepting
standard corrective lenses adapted to compensate for
near-sightedness, farsightedness, or stigmatism, or other corrected
vision) in lighting at least equal to the illumination of a
standard 75 watt incandescent white light bulb at a distance of
about 0.25 meter.
[0030] All documents incorporated herein by reference, by portion
or in their entirety, are only incorporated herein to the extent
that they are not inconsistent with this specification.
[0031] In certain embodiments, the present invention as disclosed
herein may be practiced in the absence of any component, element
(or group of components or elements) or method step which is not
specifically disclosed herein.
Layer of Material
[0032] In certain embodiments, dressing 10 can be in the form of a
wound dressing. In certain embodiments, dressing 10 can be in the
form of a bandage or tape. Referring to the drawings, in FIG. 1,
there is shown an exemplary embodiment of the improved dressing 10
of the present invention. In certain embodiments, the dressing 10
comprises a layer of material 11 formed from a woven or a nonwoven,
non-swellable material. In one embodiment, the layer of material 11
is formed from a non-swellable, nonwoven material. The term
"non-swellable" as used herein means materials that are incapable
or substantially incapable of imbibing fluid such that there is
little or no increase in the volume of the layer of material when
it is in contact with fluid present in the environment of use,
i.e., wound exudate or excretions or bodily sweat. In one
embodiment, the layer of material increases in volume by no greater
than about 5%, optionally, no greater than about 2.5%, optionally,
or optionally, no greater than about 1% by weight aqueous saline
solution based on the dry weight of the layer of material. These
values may be obtained using a saline absorbency test in which a
dry, weighed sample of layer of material is immersed for 1 minute
at 37.degree. C. in saline containing 0.9 wt. % NaCl for subsequent
weighing.
[0033] Suitable non-swellable material includes, but is limited to,
(or selected from or selected from the group consisting of)
polyurethanes, polyethylene, polyisobutadiene, polyisobutylene,
neoprene, polyamides, polyesters, polyether polyesters,
non-hydrophilic polyether-polyamides, plasticised polyvinyl
chloride, styrene-butadiene block copolymers, styrene-isoprene
block copolymer, polyacrylates, methacrylic copolymers,
polypropylene, rayon, rayon/polyester blends and mixtures
thereof.
[0034] In certain embodiments, the non-swellable material is
polyurethane. Suitable polyurethanes include, polyester and
polyether polyurethanes examples of which are the Estanes
(Registered trade mark of B.F. Goodrich Ltd). Suitable Estanes are
those grades which are designated 5702, 5701, 5714F and 580201.
[0035] In certain embodiments, the non-swellable material is
polyester. Suitable polyesters include polyethylene terephthalate
(PET), polybutylene terephthalate (PBT) and mixtures thereof. PET
substrates are commercially available from Fibertex Nonwovens
(Ingleside, Ill.).
[0036] In certain embodiments, the layer of material is free of or
substantially free of swellable materials such as cross-linked
polyvinyl alcohol, cross-linked polyvinyl pyrrolidone, hydrophilic
polyurethanes, hydrophilic hydroxyalkyl esters of poly(meth)
acrylic aid and copolymers thereof, hydrophilic polyether-polyamide
polymers, hydrophilic, water insoluble cellulosic derivatives such
as cellulose acetate, cellulose acetate-proprionate. The term
"substantially free of" as used herein means an amount of swellable
materials of up to 5% (or about 5%), optionally, up to 2.5% (or
about 2.5%), optionally, up to 1.0% (or about 1.0%), optionally up
to 0.1% (or about 0.1%) by weight of the layer of material.
[0037] In certain embodiments, the layer of material 11 is porous
and readily allows both water vapor and air to pass through the
layer of material 11. In certain embodiments, as may be seen in
FIGS. 1 and 3, the top and bottom surfaces 12, 13 of the layer of
material 11 are smooth and flat (or substantially smooth and flat)
such that the top and bottom surfaces 12, 13 of the layer of
material 11 are free of or substantially free of channels or raised
portions in the surfaces.
[0038] In certain embodiments, the layer of material 11 may include
channels or raised portions such as created by conventional
embossing technology. In certain such embodiments, the channels or
raised portions do not coincide with the pattern outlined by the
sigmoidal pattern units discussed in further detail below. Examples
of channels or raised portions can be found in US patent
publications US20120220973 to Chan et al. and US20120220974 to Chan
et al., each of which patent publications are herein incorporated
by reference in its entirety.
[0039] In certain embodiments, the layer of material 11 has a
thickness of from about 0.2 mm to about 3 mm, optionally from about
0.77 mm to about 1.5 mm.
Material Free Regions
[0040] The layer of material 11 of dressing 10 further incorporates
one or more (or, plurality of) distinct material free regions 15
extending through the thickness (i.e., distance from top to bottom
surfaces 12, 13) of the layer of material 11. The term "material
free" or "free of material" as used herein means regions or areas
of the layer of material that are free of material or substantially
free of material such that the continuity of the material is
disrupted or such regions or areas are devoid of material and
include but not limited to, cuts, holes, slits or openings in the
material. Accordingly, the terms "cuts", "holes", "slits" or
"openings" in the material are interchangeable with each other and
with the term "material free region". In certain embodiments, the
distinct material free regions 15 include such distinct regions
which may not be discernable by the naked eye (i.e., viewing
without the aid of optical lenses which magnify the field of view);
examples of such include ultra-thin slits formed in the layer of
material 11 by cutting the layer of material 11 with a knife
thickness of about 1 .mu.m to about 25 .mu.m, or a laser having
laser thickness of about 10 .mu.m to 1000 .mu.m.
[0041] In certain embodiments, the distinct material free regions
15 are individual slits forming discrete, non-straight line,
continuous, pattern units, each pattern unit being spaced from and
unconnected to the other pattern units (for example, as in the
discrete sigmoidal shaped pattern units shown in the Figures). In
one embodiment, the slitted pattern units may be arranged in rows
staggered from those on the next row or aligned with the slitted
pattern units on the next row. In an alternative embodiment, the
slitted pattern units of one row may be at right angles to the
slitted pattern units of any adjacent row. In certain embodiments,
the distinct material free regions 15 are sigmoidal shaped
slits.
[0042] In certain embodiments, the pattern units (or slitted
pattern units) 15 are formed into the layer of material 11 and have
dimensions so as to provide a pattern surface density (i.e.,
pattern units 15 spatially arranged per square inch of the surface
of the layer of material 11) of from 4 pattern units/in.sup.2 to 14
pattern units/in.sup.2, optionally from 10 pattern units/in.sup.2
to 14 pattern units/in.sup.2, or, optionally 12 pattern
units/in.sup.2 of the surface of the layer of material 11 when
counting full and complete pattern units (i.e., partial or
incomplete patterns are not counted when determining the pattern
surface density). Varying (or scaling) the pattern surface density
outside (i.e., either below or above) the described 4 pattern
units/in.sup.2 to 14 pattern units/in.sup.2 range reduces any
increase in extensibility of layer of material 11 provided by the
incorporated pattern units (or material free regions) 15.
[0043] One embodiment of the distinct material free regions 15 is
illustrated in FIG. 2 showing the distinct material free regions 15
formed as individual sigmoidal slit pattern units 15. The term
"sigmoidal" as used herein means patterns generally shaped in the
form of an "S" and includes curvilinear patterns such as having
curves defined by the mathematical formula S(t)=1/1+e.sup.-t and
non-curvilinear patterns such as "block" or angled-cornered "S"
shapes as illustrated by the pattern units in the rows of FIG. 5A.
In certain embodiments, one or more (or all) of the sigmoidal
pattern units in FIG. 2 are replaced with the non-curvilinear
pattern units of FIG. 5A, yet retaining the same arrangement of the
pattern units as shown in FIG. 2).
[0044] In addition to lasers and knifes, the material free regions
may also be incorporated into the layer of material 11 during the
formation of the layer of material 11 such as by water jet cutting,
high pressure steam cutting, ultrasound cutting or punch cutting
and the like.
[0045] In certain embodiments, the sigmoidal slit pattern units 15
are arranged adjacent to one another. In certain embodiments, the
sigmoidal slit pattern units 15 are non-intersecting and spaced
apart relative to one another. Optionally, the sigmoidal slit
pattern units 15 are further arranged to form one or more linear
rows 14 of sigmoidal slit pattern units 15. In certain embodiments,
the sigmoidal slit pattern units 15 are further arranged to form
one or more linear rows 14 of sigmoidal slit pattern units 15 such
that the top t and bottom b of any sigmoidal slit pattern unit 15
in a row 14 are spatially aligned with the respective top t and
bottom b of the other similarly oriented sigmoidal slit pattern
units 15 in that row (e.g., the top t and bottom b of any sigmoidal
slit pattern unit 15 in a row 14 whose length l extends in one
direction is spatially aligned with the top t and bottom b of any
other sigmoidal slit pattern units 15 in that row whose length l
extends in the same direction) as illustrated in FIG. 2A. The term
"linear" as used herein means following straight, or substantially
straight, line direction.
[0046] In any of the above-described embodiments, when applied to
the skin so as to cover or contact a wound and/or skin surface, the
dressing 10 extends or stretches upon movement of the skin surface
at or around such covered or contacted area so as to minimize
detachment (i.e., loss of adherence to skin or wound) of dressing
10 as result of such movement. In such embodiments, any movement of
the covered or contacted skin surface causes a force F (i.e.,
F>0) to the dressing 10. The sigmoidal slit pattern units 15 are
arranged such that, after application of a force F (i.e., F>0)
(in any direction) to the dressing 10, one or more of the material
free regions freely open from a an initial closed position (or
configuration) to an open position to facilitate stretching of the
layer of material 11 from a first position p1 to second, stretched
or extended, position p2 which is stretched or extended in the
direction of the force F and wherein once the force F is no longer
applied (i.e., F=0), the material free regions freely close (or
return) to the initial closed position (or configuration) to
facilitate movement of the layer of material 11 back to the first
position p1 from the second position p2 as shown in FIGS. 4a, 4b
and 4c. Accordingly, when an applied force is lessened or increased
the degree to which the one or more material free regions are
opened is respectively decreased or increased. It is further
understood that the material free regions 15 open in accordance
with the direction of the force F. The term "freely" as used herein
means that the material used to form the layer of material 11 will
not swell so as to restrict or inhibit the opening or closing of
the material free regions 15 and/or, once the releasable layer is
removed, the layer of material 11 is not attached to any additional
layer or substrate so as restrict or inhibit the opening or closing
of the material free regions 15. The term "closed", "closed
position" or "closed configuration", as used herein with respect to
the material free regions 15, means that the material free regions
15 are closed or substantially closed such that there is no, or
substantially no, visibility through the material free regions 15
upon visual inspection. The term "open", "open position" or "open
configuration", as used herein with respect to the material free
regions 15, means that the material free regions 15 are open such
that there is visibility through the material free regions 15 upon
visual inspection. The term "visibility" as used herein means the
ability to see and identify distinct features of animate or
inanimate objects.
[0047] As is shown in FIG. 2a, in certain embodiments, the length l
of each sigmoidal slit pattern unit 15 can be large relative to its
width w. In certain embodiments, the length l of the sigmoidal slit
pattern unit 15 is from about 1 to about 6 times the width w of
sigmoidal slit pattern unit 15, optionally the from 2.5 to about
4.7 times the width w. In certain embodiments, the length l of the
sigmoidal slit pattern unit 15 is three times the width w of
sigmoidal slit pattern unit 15.
[0048] In certain embodiments, the length l of the sigmoidal slit
pattern units 15 can be oriented to run in the transverse direction
A of dressing 10 or to run in the longitudinal direction B of
dressing 10. Transverse direction A is perpendicular to
longitudinal direction B. Alternatively, one of more of the
sigmoidal slit pattern units 15 can be arranged and oriented such
that their lengths l run in the longitudinal direction B of
dressing 10 and one or more of the sigmoidal slit pattern units 15
arranged or oriented such that one of more of the sigmoidal slit
pattern units 15 run in the transverse direction A of dressing 10.
Moreover, one of more of the sigmoidal slit pattern units 15 can be
arranged and oriented such that their lengths l run in a direction
diagonal to the transverse and longitudinal directions A and B. The
term "diagonal" as used herein refers to a direction (or
directional line) which forms an angle other than a right angle
upon intersecting either the transverse or longitudinal directions
A and B. Diagonal direction D.sub.45 of FIG. 8 is an example of a
direction diagonal to the transverse and longitudinal directions A
and B.
[0049] In other embodiments, the length l sigmoidal slit pattern
units 15 are oriented such that the length l of a sigmoidal slit
pattern unit 15 is directionally perpendicular to the length l of
an adjacent sigmoidal slit pattern unit 15. In one embodiment, as
shown in Figures s. 1, 2 and 2A, the length l of the sigmoidal slit
pattern units 15 are oriented such that the length l of each
sigmoidal slit pattern unit 15 in a row 14 is oriented
directionally perpendicular to its adjacent sigmoidal slit pattern
unit 15 in such row 14.
[0050] In certain embodiments, the linear rows 14 of sigmoidal slit
pattern units 15 are disposed adjacent to and parallel with other
linear rows sigmoidal slit pattern unit 15. Where the linear rows
of sigmoidal slit pattern units 15 are disposed parallel with other
linear rows 14 of sigmoidal slit pattern unit 15, the stability of
the layer of material upon application of a pulling force is
reduced. As seen in FIGS. 5A and 5C, in certain embodiments, the
linear rows 14 of sigmoidal slit pattern units 15 be arranged so
that the sigmoidal slit pattern units 15 of one such row 14 are: i)
aligned with respect to the sigmoidal slit pattern units 15 of an
adjacent parallel row 14 (such that the aligned sigmoidal slit
pattern units 15 of the rows 14 form an aligned column 16 of
sigmoidal slit pattern units 15); or, alternately as shown in FIG.
5C, ii) staggered with respect to the sigmoidal slit pattern units
15 of an adjacent parallel row 14 (such that the sigmoidal slit
pattern units 15 of one row 14 are offset from the sigmoidal slit
pattern units 15 of any adjacent parallel row 14).
[0051] In certain embodiments, the length l ranges from 1 (or about
1) mm to 10 (or about 10) mm. In certain embodiments, the length l
is from 4 (or about 4) mm to 8 (or about 8) mm. In certain
embodiments, the width w ranges from 1 (or about 1) mm to 10 (or
about 10) mm. In certain embodiments, the width w is from 3 (or
about 3) mm to 4 (or about 4) mm.
[0052] The sigmoidal slit pattern unit 15 can be curvilinear or
non-curvilinear. The term "curvilinear" as used herein means
formed, bounded, or characterized by curved lines and free of
angled edges or segments.
[0053] As further shown in FIG. 2a, in certain embodiments, each
sigmoidal slit pattern unit 15 in a row 14 of sigmoidal slit
pattern units 15 has a vertical centerline Vcl such that the
vertical centerline Vcl of each sigmoidal slit pattern unit 15 is
spaced from the vertical centerline Vcl of each other
longitudinally, linearly adjacent sigmoidal slit pattern unit 15 by
a width w'. And, in certain embodiments, each row 14 of sigmoidal
slit pattern units 15 has a horizontal centerline Hcl. In certain
embodiments, the horizontal centerline Hcl of each row 14 of
sigmoidal slit pattern units 15 is spaced from the horizontal
centerline Hcl of each other row 14 of sigmoidal slit pattern units
15 by a distance d. The vertical centerline Vcl is perpendicular to
horizontal centerline Hcl.
[0054] The term "centerline" means a straight line intersecting and
passing vertically or horizontally through the longitudinal center
or transverse center, respectively, of either the distinct units of
material free regions 15 or row 14 of distinct units of material
free regions 15.
[0055] In certain embodiments, distance d is equal to width w'. In
certain embodiments, the width w' ranges from 2.5 (or about 2.5) mm
to 10 (or about 10) mm. In certain embodiments, the width w' is 6.5
(or about 6.5) mm. In certain embodiments, the distance d ranges
from 2.5 (or about 2.5) mm to 10 (or about 10) mm. In certain
embodiments, the distance d is 6.5 (or about 6.5) mm.
[0056] In certain embodiments, the plurality sigmoidal slit pattern
units 15 and/or rows 14 are formed into the layer of material 11 at
a surface density (i.e., slit pattern units/per in.sup.2) to cover
from about 50% to about 100%, optionally at least about 75% to
about 100%, optionally from about 90% to about 100%, or optionally
100% (or about 100%), of the surface area of a surface (of both top
and bottom planar surfaces) of the layer of material 11. As used
herein, "cover 100% of the surface area of a surface of the layer
of material" or "100% surface area coverage of the surface of the
layer of material" or means that a plurality of slit pattern units
are arranged at a surface density (i.e., slit pattern units/per
in.sup.2) and the plurality of slit pattern units cover the entire
surface area of the surface of the layer of material and extend to
the perimeter edges of the layer of material.
[0057] Without being limited by theory, it is believed the
above-described sigmoidal slit pattern units 15 provide improved
extensibility and conformability properties to dressing 10 by
permitting stretch (or movement) in the longitudinal, transverse
and diagonal (i.e., directionally neither longitudinal [or
horizontal] nor transverse [or vertical] directions of the xy
plane. In certain embodiments, the above-described sigmoidal slit
pattern units 15 permit stretch (or movement) in the z axis
direction. By utilizing this sigmoidal slit pattern, the dressing
10 unexpectedly requires less force in extending the dressing 10 as
compared with the same dressing not incorporating the
above-described sigmoidal slit pattern units 15.
Drapability
[0058] In certain embodiments, layer of material 11 comprising the
material free slit pattern units of the present invention provides
improved drapability. In certain embodiments, the material free
slit pattern units of the present invention improves drapability of
the layer of material without any slits by at least 30% based on
the Bending Length of the layer of material tested for the
longitudinal direction and by at least 50% in at least one of the
two 45.degree. diagonal directions based on the Bending Length of
the layer of material tested in both two 45.degree. diagonal
directions as illustrated by longitudinal and 45.degree. diagonal
directions (B, D.sub.45 and D'.sub.45) in FIG. 8. The Bending
Lengths and percent drapability are determined using the following
Drapability Test.
[0059] Drapability Test (Stiffness Test)
[0060] The stiffness tester to be used in performing the
Drapability Test consists of a platform, having a smooth low
friction, flat plastic surface and calibrated scale. A rectangular
strip of fabric is supported on a horizontal platform of the
stiffness tester and extended in the direction of its length, so
that an increasing part overhangs and bends under its own mass. The
platform is supported by two side pieces made of plastic. Index
lines are engraved on these side pieces, inclined at an angle of
41.5.degree. below the plane of the platform surface. At this
angle, the bending length is the overhanging length divided by two.
A mirror is attached to the Stiffness Tester to enable the operator
to view both index lines from a convenient position. A calibrated
scale is supplied with the Stiffness Tester to measure the bending
length and is graduated in cm. The test is conducted at
24.5.degree. C. and 40% relative humidity.
[0061] Sample Preparation:
[0062] Test (i.e., with material free slit pattern units) and
Control (i.e., without slits) samples are cut from a layer of
material (described below) along the longitudinal and transverse
directions and along the two 45.degree. diagonal directions as
illustrated by longitudinal, transverse and 45.degree. diagonal
directions (B, A, D.sub.45 and D'.sub.45) in FIG. 8 4. Three
8''.times.1'' samples are cut for each of the longitudinal
direction, transverse direction and along the two 45.degree.
diagonal directions for the Test samples. Three 8''.times.1''
samples are cut for each of the longitudinal direction, transverse
direction and along the two 45.degree. diagonal directions for the
Control samples. The samples are conditioned for 24 hours at a
relative humidity of 50% and a temperature 23.degree. C. [0063] i.
The layer of material used in preparing the samples is a bilayer
substrate comprised of: [0064] A nonwoven layer manufactured from
100% PET fibers having a fiber length about 38 mm by passing the
fibers through a dry-laid carding process to form a blanket roll
and then passed through a needle punching process. The nonwoven has
a weight of 3.7 oz/square yard. [0065] A layer of nonstick, HDPE
net is heat laminated onto the nonwoven substrate. The net has the
following properties: [0066] Thickness=102-127 microns [0067] Boss
Count: longitudinal direction: 22-28 bosses/inch/transverse 27-33
bosses/inch [0068] Aperture (hole) size about 300 .mu.m [0069]
Basis weight=0.48-0.59 oz/sq yd [0070] Geometry=hexagonal [0071]
Such HDPE nets are available from Delnet Technologies (Del.) under
Delnet.RTM. AC530WHT net. [0072] The above described bilayer
material can be obtained from Delstar Technologies, DEL under the
name Stratex.TM. 3.7NPET-E (which incorporates the Delnet.RTM.
AC530WHT net).
[0073] Procedure: [0074] a) The Stiffness Tester is placed on a
level surface and the levels are checked with the help of the sprit
level. [0075] b) One of the conditioned Test samples cut out of one
of the directions of the layer of material is placed flat on the
flat plastic surface of the Tester in the length direction with
leading edge of sample coincident with edge of flat plastic surface
at point of incline. [0076] c) The calibrated scale is gently put
on the Test sample at the zero calibrated position. [0077] d) The
index lines the side pieces of the Stiffness Tester is viewed in
the mirror of the Stiffness Tester. [0078] e) The calibrated scale
is then gently slid till the leading edge of the Test sample bends
downward away from the calibrated scale and touches the two
inclined index lines as viewed in the mirror. [0079] f) In case the
leading edge of the Test Sample is twisted, make the center point
of the leading edge coincide with the plane. If the twist is more
than 45.degree., disregard the reading. [0080] g) The reading on
the calibrated scale is recorded. [0081] h) Steps b) through g) are
repeated again with the opposite surface of Test sample positioned
upwards and, then, two more times in the width direction--one for
each surface of Test sample in the width direction. [0082] i) The
average of the 4 measured bending lengths are determined and
recorded for the Test sample. [0083] j) Steps b) through i) are
repeated for each of the remaining Test samples cut out of same the
direction of the layer of material. [0084] k) The average of the
bending lengths for each of the 3 Test samples in the same
direction are averaged and recorded as the sample mean (referred to
herein as the "Bending Length") for the samples in the same
direction. [0085] l) Steps b) through k) are repeated for the Test
samples cut from the remaining directions. [0086] m) Steps b)
through l) are repeated in the same way by using the conditioned
Control samples instead of Test samples. [0087] n) The percent
drapability of the slit containing layer of material along a given
direction is calculated by dividing the Bending Length of the Test
Sample cut out in that given direction by the Bending Length of the
Control Sample cut out in that given direction.
Extensibility Along at Least One of the Longitudinal and Transverse
Directions
[0088] In certain embodiments, the layer or material 11 with the
sigmoidal slit pattern units 15 stretches or extends in at least
one of the longitudinal B or transverse A directions at least 100%
(or about 100%), optionally at least 150% (or about 150%),
optionally at least 200% (or about 200%), optionally at least 300%
(or about 300%), optionally at least 400% (or about 400%), or
optionally at least 450% (or about 450%), or optionally at least
475% (or about 475%), more than the same layer of material 11
without material free regions, as measured by the Stretchability
Test.sub.xy described in the Specification when a force of 0.1 (or
about 0.1) kgf along is applied along such at least one of the
longitudinal B or transverse A directions of the layer of material
11.
[0089] In certain embodiments, the layer or material 11 with the
sigmoidal slit pattern units 15 stretches or extends in at least
one of the longitudinal B or transverse A directions at least 150%
(or about 150%), at least 200% (or about 200%), at least 250% (or
about 250%), optionally at least 300 (or about 300%), optionally at
least 350% (or about 350%), optionally at least 400% (or about
400%), optionally at least 500 (or about 500%), optionally at least
600% (or about 600%), optionally at least 700% (or about 700%),
optionally at least 800% (or about 800%), optionally at least 825%
(or about 825%), optionally at least 850% (or about 850%), or
optionally at least 870% (or about 870%), more than the same layer
of material 11 without material free regions, as measured by the
Stretchability Test described in the Specification when a force of
0.2 (or about 0.2) kgf is applied along such at least one of the
longitudinal B or transverse A directions of the layer of material
11.
[0090] In certain embodiments, the layer or material 11 with the
sigmoidal slit pattern units 15 stretches or extends in at least
one of the longitudinal B or transverse A directions at least 425%
(or about 425%), optionally at least 450 (or about 450%),
optionally at least 500% (or about 500%), optionally at least 550%
(or about 550%), optionally at least 600% (or about 600%),
optionally at least 650% (or about 650%), optionally at least 700%
(or about 700%), optionally at least 750% (or about 750%),
optionally at least 800% (or about 800%), optionally at least 900%
(or about 900%), optionally at least 1000% (or about 1000%),
optionally at least 1025% (or about 1025%), or optionally at least
1050% (or about 1050%), more than the same layer of material 11
without material free regions, as measured by the Stretchability
Test.sub.xy described in the Specification when a force of 0.3 (or
about 0.3) kgf is applied along such at least one of the
longitudinal B or transverse A directions of the layer of material
11.
[0091] In certain embodiments, the layer or material 11 with the
sigmoidal slit pattern units 15 stretches or extends in at least
one of the longitudinal B or transverse A directions at least 650%
(or about 650%), optionally at least 700% (or about 700%),
optionally at least 750% (or about 750%), optionally at least 800%
(or about 800%), optionally at least 900% (or about 900%),
optionally at least 1000% (or about 1000%), optionally at least
1050% (or about 1050%), optionally at least 1100% (or about 1100%),
optionally at least 1125% (or about 1125%), or optionally at least
1150% (or about 1150%), more than the same layer of material 11
without material free regions, as measured by the Stretchability
Test described in the Specification when a force of 0.4 (or about
0.4) kgf is applied along such at least one of the longitudinal B
or transverse A directions of the layer of material 11.
Extensibility Along the Other (or Remaining) Longitudinal and
Transverse Directions
[0092] In certain embodiments, where stretching or extensibility of
at least one of the longitudinal or transverse directions is
determined as above using the Stretchability Test described in the
Specification, the other (or remaining) longitudinal or transverse
direction can likewise be determined using the Stretchability
Test.sub.xy described in the Specification. In the case of such
"other" longitudinal or transverse direction: [0093] in certain
embodiments, the layer or material 11 with the sigmoidal slit
pattern units 15 stretches or extends in the other longitudinal B
or transverse A direction at least 75% (or about 75%), optionally
at least 100% (or about 100%), optionally at least 125% (or about
125%), optionally at least 150% (or about 150%), optionally at
least 175% (or about 175%), or optionally at least 190% (or about
190%), more than the same layer of material 11 without material
free regions, as measured by the Stretchability Test.sub.xy
described in the Specification, when a force of from 0.1 (or about
0.1) kgf is applied along such other longitudinal B or transverse A
direction of the layer of material 11. [0094] in certain
embodiments, the layer or material 11 with the sigmoidal slit
pattern units 15 stretches or extends in the other longitudinal B
or transverse A direction at least 150% (or about 150%), optionally
at least 200% (or about 200%), optionally at least 250% (or about
250%), optionally at least 300% (or about 300%), optionally at
least 350% (or about 350%), optionally at least 375% (or about
375%), or optionally at least 390% (or about 390%), more than the
same layer of material 11 without material free regions, as
measured by the Stretchability Test described in the Specification
when a force of from 0.2 (or about 0.2) kgf is applied along such
other longitudinal B or transverse A direction of the layer of
material 11. [0095] in certain embodiments, the layer or material
11 with the sigmoidal slit pattern units 15 stretches or extends in
the other longitudinal B or transverse A direction at least 350%
(or about 350%), optionally at least 400% (or about 400%),
optionally at least 425% (or about 425%), optionally at least 450%
(or about 450%) or optionally at least 475% (or about 475%), more
than the same layer of material 11 without material free regions,
as measured by the Stretchability Test.sub.xy described in the
Specification when a force of from 0.3 (or about 0.3) kgf is
applied along such other longitudinal B or transverse A direction
of the layer of material 11.
Diagonal Extension
[0096] In certain embodiments, the layer or material 11 with the
sigmoidal slit pattern units 15 stretches or extends in at least
one of the 45.degree. diagonal direction D.sub.45 or D'.sub.45 at
least 425% (or about 425%), optionally at least 450% (or about
450%), optionally at least 500% (or about 500%), optionally at
least 550% (or about 550%), optionally at least 600% (or about
600%), optionally at least 700% (or about 700%), optionally at
least 800% (or about 800%), optionally at least 900% (or about
900%), optionally at least 1000% (or about 1000%), optionally at
least 1100% (or about 1100%), optionally at least 1200% (or about
1200%), or optionally at least 1300% (or about 1300%), optionally
at least 1400% (or about 1400%), optionally at least 1500% (or
about 1500%), optionally at least 1600% (or about 1600%),
optionally at least 1700% (or about 1700%), or optionally at least
1800% (or about 1800%), optionally at least 1900% (or about 1900%),
optionally at least 2000% (or about 2000%), optionally at least
2100% (or about 2100%), optionally at least 2200% (or about 2200%),
or optionally at least 2300% (or about 2300%), optionally at least
2350% (or about 2350%) or optionally at least 2375% (or about
2375%), more than the same layer of material without the sigmoidal
slit pattern units 15, as measured by the Stretchability
Test.sub.xy described in the Specification when a force of 0.1 (or
about 0.1) kgf is applied along such 45.degree. diagonal direction
D.sub.45 or D'.sub.45 of the layer of material 11. The "45.degree.
diagonal direction D.sub.45" or "45.degree. diagonal direction
D'.sub.45" refers to diagonally directional lines of force
extending through center point P and forming a 45.degree. angle
with the longitudinal and traverse centerlines of the layer of
material 11 intersecting at center point P.
[0097] In certain embodiments, the layer or material 11 with the
sigmoidal slit pattern units 15 stretches or extends in at least
one of the 45.degree. diagonal direction D.sub.45 or D'.sub.45 at
least 1125% (or about 1125%), optionally at least 1150% (or about
1150%), optionally at least 1175% (or about 1175%), optionally at
least 1200% (or about 1200%), or optionally at least 1300% (or
about 1300%), optionally at least 1400% (or about 1400%),
optionally at least 1500% (or about 1500%), optionally at least
1600% (or about 1600%), optionally at least 1700% (or about 1700%),
optionally at least 1800% (or about 1800%), optionally at least
1900% (or about 1900%), optionally at least 2000% (or about 2000%),
optionally at least 2100% (or about 2100%), optionally at least
2200% (or about 2200%), optionally at least 2300% (or about 2300%),
optionally at least 2400% (or about 2400%), optionally at least
2500% (or about 2500%), or optionally at least 2550% (or about
2550%), more than the same layer of material without the sigmoidal
slit pattern units 15, as measured by the Stretchability
Test.sub.xy described in the Specification when a force of 0.2 (or
about 0.2) kgf is applied along such 45.degree. diagonal direction
D.sub.45 or D'.sub.45 of the layer of material 11.
[0098] In certain embodiments, the layer or material 11 with the
sigmoidal slit pattern units 15 stretches or extends in at least
one of the 45.degree. diagonal direction D.sub.45 or D'.sub.45 at
least 1725% (or about 1725%), optionally at least 1800% (or about
1800%), optionally at least 1800% (or about 1800%), optionally at
least 1900% (or about 1900%), optionally at least 2000% (or about
2000%), optionally at least 2100% (or about 2100%), optionally at
least 2200% (or about 2200%), optionally at least 2300% (or about
2300%), optionally at least 2325% (or about 2325%), or optionally
at least 2350% (or about 2350%), more than the same layer of
material without the sigmoidal slit pattern units 15, as measured
by the Stretchability Test.sub.xy described in the Specification
when a force of 0.3 (or about 0.3) kgf is applied along such
45.degree. diagonal direction D.sub.45 or D'.sub.45 of the layer of
material 11.
[0099] In certain embodiments, the layer or material 11 with the
sigmoidal slit pattern units 15 stretches or extends in at least
one of the 45.degree. diagonal direction D.sub.45 or D'.sub.45 at
least 1650% (or about 1650%), optionally at least 1700% (or about
1700%), optionally at least 1750% (or about 1750%), optionally at
least 1800% (or about 1800%), optionally at least 1800% (or about
1800%), optionally at least 1900% (or about 1900%), optionally at
least 2000% (or about 2000%), optionally at least 2100% (or about
2100%), optionally at least 2125% (or about 2125%), or optionally
at least 2150% (or about 2150%), more than the same layer of
material without the sigmoidal slit pattern units 15, as measured
by the Stretchability Test.sub.xy described in the Specification
when a force of 0.4 (or about 0.4) kgf is applied along such
45.degree. diagonal direction D.sub.45 or D'.sub.45 of the layer of
material 11.
[0100] The above referenced longitudinal, transverse and 45.degree.
diagonal directions (B, A, D.sub.45 and D'.sub.45) of stretch or
extension force used in conducting the Stretchability Test.sub.xy
are in the xy-plane and are illustrated in FIG. 8. The term
"longitudinal" direction refers to the machine direction of the
layer of material when formed using a continuous manufacturing
process. As used herein, the term "machine direction" means the
direction along the length of the roll layer of material or the
direction in which the material flows into the substrate forming
machine in the continuous manufacturing process. The "transverse"
direction is the direction transverse to the longitudinal
direction.
[0101] In certain embodiments, the layer or material 11 with the
sigmoidal slit pattern units 15, when applying a force of about 0.1
kgf along the z-axis of (or in the direction perpendicular to
xy-plane of) the layer of material 11, stretches or extends along
the z-axis or in the z direction about 1 mm to about 5 mm,
optionally between about 4 mm to about 5 mm, away from the xy-plane
of the layer of material 11, as measured by the Stretchability
Testy described in the Specification.
[0102] In certain embodiments, the layer or material 11 with the
sigmoidal slit pattern units 15, when applying a force of about 0.5
kgf along the z-axis of (or in the direction perpendicular to
xy-plane of) the layer of material 11, stretches or extends along
the z-axis or in the z direction about 1 mm to about 10 mm,
optionally from about 1 mm to about 8 mm, or optionally between
about 8 mm and 10 mm, away from the xy-plane of the layer of
material 11, as measured by the Stretchability Testy described in
the Specification.
[0103] In certain embodiment, to improve the stretchability or
extensibility in the (or along the) z-axis (or the direction
perpendicular to xy-plane) of the layer of material 11, the pattern
units (or slitted pattern units) 15 are formed into the layer of
material 11 having dimensions so as to provide a pattern surface
density of from 4 pattern units/in.sup.2 to 14, optionally from 10
to 14 pattern units/in.sup.2, or optionally 12 pattern
units/in.sup.2.
[0104] In certain embodiments, the layer of material 11 with the
sigmoidal slit pattern units 15 meets any one, any combination or
all of the above described stretch parameters using the
Stretchability Tests described below.
[0105] Stretchability Tests:
[0106] The directional extensibility of the dressings of the
present invention are measured using procedures of the following
the Stretchabilty Tests which include test procedures for testing
stretching or extensibility of the layer of material along the
longitudinal, transverse and 45.degree. diagonal directions
D.sub.45 directions of the layer of material:
[0107] Stretchability Test.sub.xy--Test to measure displacement of
layer of material under force F along directions of in xy-plane of
the layer of material.
[0108] The Stretchability Test.sub.xy is modeled after the ASTM
D882, Standard Test Method for Tensile Properties of Thin Plastic
Sheeting (ASTM International, West Conshohocken, Pa., 2016). The
ASTM D882 procedure was slightly modified and performed as follows:
a sample layer of material is clamped between two gripped flat
surfaces, attached to a load cell in order to apply force tension
at a constant-rate. The force is exerted against the sample
extending both clamps in opposing directions (including opposing
directions which are oriented longitudinally and transversely with
respect to the sample and opposing directions which are oriented
along the negatively and positively sloping 45.degree. diagonal
directions D.sub.45 of the sample) until rupture occurs in the
sample. Samples are measured in triplicate. The test is conducted
at 23.degree. C. and 50% relative humidity.
[0109] A. Apparatus:
The testing apparatus used is Instru-Met & Instron 1122
(Instru-Met Corporation, Union, N.J. 07083) with an Instru-Met
Pneumatic Wedge Action Grips
[0110] B. Procedure: [0111] a) Test samples (samples with material
free slit pattern units) are prepared by cutting a layer material
having the slits (or material free regions) of the present
invention into 5 inches by 1 inch strips. [0112] i. The layer of
material used in preparing the samples is a bilayer substrate
comprised of: [0113] A nonwoven layer manufactured from 100% PET
fibers having a fiber length about 38 mm by passing the fibers
through a dry-laid carding process to form a blanket roll which is
then passed through a needle punching process. The nonwoven has a
weight of 3.7 oz/square yard. [0114] A layer of nonstick, HDPE net
is heat laminated onto the nonwoven substrate. The net has the
following properties: [0115] Thickness=102-127 microns [0116] Boss
Count: longitudinal direction: 22-28 bosses/inch/transverse 27-33
bosses/inch [0117] Aperture (hole) size 300 .mu.m [0118] Basis
weight=0.48-0.59 oz/sq yd [0119] Geometry=hexagonal [0120] Such
HDPE nets are available from Delnet Technologies (Del.) under
Delnet.RTM. AC530WHT net. [0121] The above described bilayer
material can be obtained from Delstar Technologies, DEL under the
name Stratex.TM. 3.7NPET-E (which incorporates Delnet.RTM. AC530WHT
net). [0122] ii. The slit pattern units formed into the layer of
material are incorporated using a 90 watt CO.sub.2 laser (Full
Spectrum Laser [NV], Model P2012) having a laser thickness of 406
.mu.m such that the slit pattern units are arranged as parallel
rows of slit pattern units having the following the measurements:
[0123] Slit pattern units provide a surface density of slit pattern
units of 12 slit pattern units/in.sup.2 (counting only complete
pattern units) [0124] Slit pattern units cover 100% of surface area
of surface of layer of material. [0125] b) Control samples (i.e.
samples not having slits [or material free regions]) are prepared
by cutting a layer material without the slits into 5 inch by 1 inch
strips [0126] i. The layer of material used for this step is the
same as the layer of material of step a). [0127] c) The test and
control cut samples are conditioned by leaving them in a room which
is 23.+-.1.degree. C. and 50.+-.2% relative humidity for a period
of twenty-four hours. [0128] d) The grips of testing apparatus are
distanced 2'' a part. [0129] e) A control sample to be tested is
placed into the grips of testing apparatus, and fastened securely;
[0130] f) There should be no tension in the sample. [0131] g) A
force is applied to the sample in the machine direction (or
longitudinal direction B) with the one grip remaining stationary
and the other grip traveling in an opposing direction at a constant
rate of speed as specified in the internal test standard (12
inches/min). [0132] h) Application of the force is continued until
the sample yielded (i.e., there is a rupture anywhere in the
sample). [0133] i) The applied force at percent displacements (or
extensions) of length of the sample (along the respective
directions of force) of 2%, 5%, 10%, 25% and 50% is recorded (as
kgf) into an MTS Test Works 4.12 F software application (Instru-Met
Corporation, N.J.) [0134] j) A test sample is tested in accordance
with steps e) through i). [0135] k) The above steps e) through j)
are repeated two additional times using different test and control
samples, respectively. [0136] l) The data recorded into the MTS
Test Works 4.12 F software for the respective control and test
samples at the 2%, 5%, 10%, 25% and 50% increments are then
averaged and recorded. [0137] m) The percent difference in the
directional extensions in the longitudinal (or machine direction)
between the test sample and the control sample at a given force and
force direction is calculated from the data recorded in the MTS
Test Works 4.12 F software. [0138] n) Steps a) through n) are
repeated for the transverse direction A (or cross-direction) and
each of the opposing "45.degree." diagonal directions D.sub.45 (as
illustrated in FIG. 8).
[0139] Stretchability Test.sub.z--Test to measure displacement of
layer of material under force F along the z-axis (or direction) of
the layer of material.
[0140] The Stretchability Test.sub.z is modeled after the ASTM
D3787-16, Standard Test Method for Bursting Strength of Textiles
(ASTM International, West Conshohocken, Pa., 2016). The ASTM
D3787-16 procedure was slightly modified and performed as follows:
a sample is clamped between two grooved, circular plates. A second
piece, a ball attachment, is secured to the load cell in order to
apply compression by means of the constant-rate-of-traverse testing
machine. The force is exerted against the specimen by a polished,
hardened, steel ball until rupture occurs in the non-woven portion
of the material. Testing of materials was performed to show
displacements under load at specific ranges. Both non-woven and
non-woven with laminates were tested. The test is conducted at
23.degree. C. and 50% relative humidity.
[0141] A. Apparatus:
[0142] The testing apparatus used is Instru-Met & Instron 1122
& 5543 (Instru-Met Corporation, Union, N.J. 07083) with an ASTM
D3787 Burst Fixture, including 44.5 mm ID ring clamp and 25.4 mm
spherical plunger. The throat of the Burst Fixture was modified by
extending it from its original length of 2.5'' to a length of
3.75'' and the springs under the clamping screws are removed to
ensure clamping forces.
[0143] B. Procedure: [0144] a) Test samples (samples with material
free slit pattern units) are prepared by cutting the layer material
into 33/4 diameter circle shaped cutouts. [0145] i. The layer of
material used in preparing the samples is a bilayer substrate
comprised of: [0146] A nonwoven layer manufactured from 100% PET
fibers having a fiber length about 38 mm by passing the fibers
through a dry-laid carding process to form a blanket roll which is
then passed through a needle punching process. The nonwoven has a
weight of 3.7 oz/square yard. [0147] A layer of nonstick, HDPE net
is heat laminated onto the nonwoven substrate. The net has the
following properties: [0148] Thickness=102-127 microns [0149] Boss
Count: longitudinal direction: 22-28 bosses/inch/transverse 27-33
bosses/inch [0150] Aperture (hole) size 300 .mu.m [0151] Basis
weight=0.48-0.59 oz/sq yd [0152] Geometry=hexagonal [0153] Such
HDPE nets are available from Delnet Technologies (Del.) under
Delnet.RTM. AC530WHT net. The above described bilayer material can
be obtained from Delstar Technologies, DEL under the name
Stratex.TM. 3.7NPET-E (which incorporates Delnet.RTM. AC530WHT
net). [0154] ii. The slit pattern units formed into the layer of
material are incorporated using a 90 watt CO.sub.2 laser (Full
Spectrum Laser [NV], Model P2012) having a laser thickness of 406
.mu.m such that the slit pattern units are arranged as parallel
rows of slit pattern units having the following the measurements:
[0155] Slit pattern units provide a surface density of slit pattern
units of 12 slit pattern units/in.sup.2 (counting only complete
pattern units) [0156] Slit pattern units cover 100% surface area of
layer of material. [0157] b) Control samples (i.e. samples not
having slits [or material free regions]) were prepared by cutting a
layer material without the slits into 5 inch by 1 inch strips
[0158] i. The layer of material used for this step is the same as
the layer of material of step a). [0159] c) The test and control
cut samples are conditioned by leaving them in a room which is
23.+-.1.degree. C. and 50.+-.2% relative humidity for a period of
twenty-four hours. [0160] d) A sample to be tested is placed into
the ring clamps of testing apparatus, and fastened securely; [0161]
e) There should be no tension in the sample. [0162] f) A force is
applied to the sample in the z direction (i.e., perpendicular to xy
plane of the sample) with the spherical plunger at a constant rate
of speed as specified in the internal test standard (25.4 mm/min)
and then the speed was reduced to 5.08 mm/min. [0163] g)
Application of the force is continued until the sample yielded
(i.e., there is a rupture anywhere in the sample). [0164] h) The
applied force at displacements (or extensions) of length of the
sample (along the z-direction of force) of 1 mm, 2 mm, 3 mm, 4 mm,
5 mm, 6 mm, 8 mm, 10 mm, 15 mm, and 20 mm. was recorded (as kgf)
into an MTS Test Works 4.12 F software application (Instru-Met
Corporation, N.J.) [0165] i) A test sample is tested in accordance
with steps d) through h). [0166] j) The above steps d) through i)
are repeated two additional times using different test and control
samples, respectively. [0167] k) The data recorded into the MTS
Test Works 4.12 F software at the 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6
mm, 8 mm, 10 mm, 15 mm, and 20 mm displacement increments are then
averaged and recorded.
[0168] Moreover, the above-described sigmoidal slit pattern units
15 also provide dressing 10 which readily conform to or drape upon
the tissue contacted or covered by dressing 10, permitting dressing
10 to move with the tissue, yet maintain skin and/or wound coverage
or contact.
Releasable Layer
[0169] In certain embodiments, the dressing 10 (optionally,
including any additional layers 20 [as discussed in more detail
below]) also comprises a releasable layer 17 releasably disposed on
(or in contact with): i) the layer of material 11; or ii) the
dressing 10 comprising the layer of material 11. In certain
embodiments, the releasable layer 17 releasably contacts and covers
any adhesive that may be disposed on the layer of material 11. In
some embodiments, the releasable layer 17 contacts (or, is
releasably attached to) the layer of material 11 or the dressing 10
while (or when) the material free regions 15 are in the closed
position. In some embodiments, the releasable layer 17 releasably
contacts (or is releasably attached to) the layer of material 11 or
the dressing 10 such that material free regions 15 are releasably
retained in the closed position until such time as the releasable
layer 17 is removed from the layer of material 11 or the dressing
10, thereby permitting the material free regions 15 to freely open
upon the application of a force F as described above (and,
correspondingly. close upon termination of such force F). In
certain embodiments, the releasable layer 17 can comprise or be
made of polyethylene, polypropylene, kraft papers, polyester or
composites of any of these materials.
Optional Components
[0170] In certain embodiments, dressing 10 further incorporates on
at least one of surfaces 12 and/or 13 an adhesive (not shown) and
disposed between the releasable layer and the layer of material to
provide adherence of the dressing 10 to the skin and/or wound. When
incorporated onto dressing 10, the adhesive is applied so as not
restrict or inhibit the freeness of the distinct material free
regions freely opening and closing. In general, any of a variety of
pressure-sensitive adhesives can be utilized as the adhesive. In
particular, pressure-sensitive adhesives that are biocompatible
with human skin are typically utilized. In some embodiments, an
adhesive of the present invention may also be either generally
water soluble or generally insoluble, or dispersible in an aqueous
environment. For instance, commercially available dispersible
pressure-sensitive adhesive is sold under the trade name of
HL-9415-X and is available from H.B. Fuller Company. Another
suitable adhesive includes about 10-75% by weight of a
polyalkyloxazoline polymer, 10-75% by weight of a functional
diluent comprising a hydroxy compound or a carboxylic acid
compound, and 5-50% by weight of a tackifier.
[0171] The adhesive may comprise hydrocolloids. The hydrocolloid
element used may be any substance that has a good performance in
this utilization, as for example, sodium carboxymethylcellulose,
pectin, xanthan gum, polysaccharides, sodium or calcium alginates,
chitosan, seaweed extract (carrageenan), polyaspartic acid,
polyglutamic acid, hyaluronic acid or salts and derivatives
thereof, among others.
[0172] Hydrocolloids, just as sodium carboxymethylcellulose and
pectin, among others, are agents that form gels as soon as they
come into contact with the bodily fluids from the wound. When used
in adhesive bandages, these hydrocolloids are combined with
elastomers and/or adhesives. Preferably, the adhesive bandage
should provide a humid environment but without saturation or
cicatrisation, which is a situation suitable for acceleration of
the healing,
[0173] The adhesive may be any conventional adhesive known for such
use, as for example pressure acrylic adhesives, among others.
Additionally, such an adhesive may contain a resin for increasing
adhesion, a cohesion increasing agent, an absorption agent
(preferably a polyacrylate superabsorbent, a polyacrylate salt
superabsorbent or a mixture thereof), a plasticizer and optionally
a pigment. The adhesive may further be configured in discontinuous
patterns, arranged in lines, screen, spray or any other which a
person skilled in the art understands as discontinuous, composed by
an elastomeric base.
[0174] Optionally, one or more additional layer(s) (or substrate
layer(s)) 20 comprising a single or multiple layers (or substrate
layers) is disposed on the layer of material 11, either on the
surface side of the layer of material 11 which is opposite the
releasable layer 17 or disposed between the layer of material 11
and releasable layer 17. In such embodiments, the layer of material
11 is not attached to any additional layer 20 such that additional
layer 20 would significantly restrict or inhibit the opening or
closing of the material free regions 15. In certain embodiments,
the additional layer 20 may or may not incorporate the material
free regions 15. In embodiments where the additional layer 20
incorporates the material free regions 15, the material free
regions 15 in the additional layer 20 form the same or similar
pattern units as the pattern units formed by the material free
regions 15 in the layer of material 11; in certain of such
embodiments, the pattern units of the additional layer 20 are also
aligned with the pattern units of the layer of material 11. The
additional layer 20, in the form of a single or multiple layer, may
be incorporated to act as a protective backing layer for layer of
material 11 as shown in FIG. 7. Or, such additional layer 20 may
act as, or include, a pad layer, as shown in FIG. 6, providing
absorbent and/or swelling properties. In certain embodiments, the
additional layer 20 comprises the material free regions 15
(optionally, in the form of slitted patterns) of the present
invention. In certain embodiments, the additional layer 20 is free
of or substantially free of the material free regions of the
present invention; in one such embodiment the additional layer 20
acts as a protective non-stick layer (with or without apertures)
disposed on the surface of the layer of material 11 facing the skin
of a user (and/or wound on such skin).
[0175] In certain embodiments, when additional layer 20 acts as a
pad layer, additional layer 20 includes a first surface facing a
first side of the layer of material 11, and that has a first
surface area, and a second surface opposite the first surface and
facing the skin, and that has a second surface area. The pad layer
can be formed from open work, porous, natural or synthetic fibrous
material, such as material used to form gauze. Suitable pad layer
material include, but are not limited to, fibrous PET. The pad
layer typically contacts the skin surface and/or wound to absorb
wound exudate or excretions. In certain embodiments, when the
additional layer 20 acts as a pad layer, the additional layer 20
can be affixed either directly or indirectly layer of material 11
so that it will not become separated from layer of material 11
during normal use.
[0176] When used as a backing layer, additional layer 20 may have
various shapes, including but not limited to, rectangular, oval,
ovoid, or oblong. In such an embodiment, the shape of the bandage
and tape 10 defined by the shape of additional layer 20. In some
such embodiments, additional layer 20 may be thin, highly flexible
or deformable, water-impervious, and clear or opaque. General, in
some such embodiments, the thickness of additional layer 20 is
between about 0.05 to 0.2 millimeter ("mm") to achieve the forming
and flexing characteristics desired.
[0177] In certain such embodiments, where additional layer 20 acts
as a backing layer, the material used in forming the additional
layer 20 should be both conformable to the contours of the body and
flexible so as to permit free movement of the body part wearing the
product. In certain embodiments, it can be a a film or a foam.
Polymeric materials useful in forming backing layers include
polyolefin (such as polyethylene), polyurethane, and
polyvinylchloride. Other examples of backings include, but are not
limited to, nonwoven, woven, or knitted fabrics such as cotton,
polyester, polyurethane, rayon and the like.
[0178] Polyethylene film may be optional used to form additional
layer 20 where additional layer 20 acts as a backing layer 20, and,
in such instances, particularly effective results can be achieved
with stretchable, elastomeric films formed of polyurethane, which
has the further advantage of gas (including water vapor)
transmissibility. It is to be understood, however, that, in such
instances, other flexible, water insoluble polymeric films known in
the art may be used. Furthermore, where additional layer 20 is used
as a backing layer, additional layer 20 may be formed from
closed-cell polymeric foam, particularly one with an integral skin
covering the side of the closed-cell polymeric foam facing away
from the skin of the user. In certain such embodiments, foam layers
formed of polyurethane or polyethylenes are suitable, while other
polymeric foams having similar properties may be used. In other
embodiments, where additional layer 20 is used as a backing layer,
additional layer 20 may be made from other polyolefins, vinyl
polyethylene acetate, textile non-woven fabrics, rubber, or other
materials known in the adhesive article art. In certain
embodiments, polymers used to form additional layer 20 where
additional layer 20 acts as a backing layer generally have
viscosity of from about 500 to 500,000 centipoises at temperatures
of about 190.degree. C., or from about 1,000 to 30,000 centipoises
at temperatures of about 190.degree. C., or from about 3,000 to
15,000 centipoises at temperatures of about 190.degree. C.
[0179] In certain embodiments, where additional layer 20 acts as a
backing layer, additional layer 20 may be impermeable to liquid,
but permeable to gas, which allows the wound and the skin to which
the bandage and tape 10 of the present invention is adhered to
breathe. In one embodiment, where additional layer 20 acts as a
backing layer, additional layer 20 may have pores of such a size
that will allow only the passage of gases, which have molecules of
extremely small size.
[0180] Finally, where additional layer 20 acts as a backing layer,
additional layer 20 may be perforated for still further ventilation
of the skin. In certain such embodiments, perforations may be
circular in area and have a range of diameters, such as from about
0.1 to about 0.8 millimeters. In certain other embodiments,
however, where additional layer 20 acts as a backing layer,
additional layer 20 may, when necessary, be totally impermeable to
gases.
The present invention is further described by the following example
which is presented for purposes of illustration and comparison:
EXAMPLES
Comparative Example 1
[0181] Extension Displacement of Layer of Material with Slit
Pattern Units of FIG. 9 Under Force Along the Various Directions of
in Xy-Plane.
[0182] Test and Control samples were prepared and measured in
accordance with the Stretchability Test.sub.xy to determine %
difference in the extensibility along a given direction at a force
F between samples with the slits of the present of the present
invention (Test sample) and samples without slits (Control sample).
The Test samples incorporated the slit pattern units of FIG. 9. The
longitudinal, transverse and diagonal directions D.sub.45 and D'45
are illustrated as longitudinal, transverse and 45.degree. diagonal
directions (B, A, D.sub.45 and D'.sub.45) at FIG. 8. The data is
summarized as extensibility or elongation data and the calculated %
difference (i.e.,
[ Test Sample at force F Control Sample at force F .times. 100 ] -
100 ) ##EQU00001##
for the various directions of elongation or stretch in Tables 1-4
and 1a-4a, respectively.
TABLE-US-00001 TABLE 1 Extensibility (mm) in the Longitudinal
Direction at Force F Force F (kgf) 0.1 0.2 0.3 0.4 Test Sample 1.51
3.09 7.25 13.80 Control Sample 1.01 1.37 1.65 1.9
TABLE-US-00002 TABLE 1a % Difference (versus Control) in
Longitudinal Extensibility at Force F Force F (kgf) 0.1 0.2 0.3 0.4
Test Sample 49% 126% 339% 626% Control Sample -- -- -- --
TABLE-US-00003 TABLE 2 Extensibility (mm) in the Transverse
Direction at Force F Force F (kgf) 0.1 0.2 0.3 0.4 Test Sample 2.10
4.68 14.92 21.96 Control Sample 1.46 2.2 2.92 3.63
TABLE-US-00004 TABLE 2a % Difference (versus Control) in Transverse
Extensibility at Force Force F (kgf) 0.1 0.2 0.3 0.4 Test Sample
44% 112% 412% 504% Control Sample -- -- -- --
TABLE-US-00005 TABLE 3 Extensibility (mm) in the Diagonal Direction
D'.sub.45 at Force F Force F (kgf) 0.1 0.2 0.3 0.4 Test Sample 3.52
13.65 28.03 34.49 Control Sample 0.71 1.13 1.55 2.00
TABLE-US-00006 TABLE 3a % Difference (versus Control) in Diagonal
Direction D'.sub.45 Extensibility at Force Force F (kgf) 0.1 0.2
0.3 0.4 Test Sample 395% 1108% 1708% 1625% Control Sample -- -- --
--
TABLE-US-00007 TABLE 4 Extensibility (mm) in the Diagonal Direction
D.sub.45 at Force F Force F 0.1 0.2 0.3 0.4 Test Sample 2.99 7.60
14.07 19.55 Control Sample 1.30 1.78 2.23 2.69
TABLE-US-00008 TABLE 4a % Difference (versus Control) in Diagonal
Direction D.sub.45 Extensibility at Force Force F (kgf) 0.1 0.2 0.3
0.4 Test Sample 130% 327% 531% 627% Control Sample -- -- -- --
Tables 1a, 2a, 3a and 4a show that the Slit Pattern Units of FIG. 9
provide some degree of the extensibility of the layer of material
beyond the extensibility of that layer of material without any
slits.
Inventive Example 2
[0183] Extension Displacement of Layer of Material with Slit
Pattern Units of FIG. 2 Under Force Along the Various Directions of
in Xy-Plane.
[0184] Test and Control samples were prepared and measured in
accordance with the Stretchability Test.sub.xy to determine %
difference in the extensibility along a given direction at a force
F between samples with the slits of the present of the present
invention (Test sample) and samples without slits (Control sample).
The Test samples incorporated the slit pattern units of FIG. 2. The
longitudinal, transverse and diagonal directions D.sub.45 and
D'.sub.45 are illustrated as longitudinal, transverse and
45.degree. diagonal directions (B, A, D.sub.45 and D'.sub.45) at
FIG. 8. The data is summarized as extensibility or elongation data
and the calculated % difference for the various directions of
elongation or stretch in Tables 5-8 and 5a-8a, respectively.
TABLE-US-00009 TABLE 5 Extensibility (mm) in the Longitudinal
Direction at Force F Force F (kgf) 0.1 0.2 0.3 0.4 Test Sample 6.07
13.34 19.13 23.94 Control Sample 1.01 1.37 1.65 1.9
TABLE-US-00010 TABLE 5a % Difference (versus Control) in
Longitudinal Extensibility at Force F Force F (kgf) 0.1 0.2 0.3 0.4
Test Sample 498% 874% 1059% 1160% Control Sample -- -- -- --
TABLE-US-00011 TABLE 6 Extensibility (mm) in the Transverse
Direction at Force F Force F (kgf) 0.1 0.2 0.3 0.4 Test Sample 4.32
10.87 16.26 21.11 Control Sample 1.46 2.2 2.92 3.63
TABLE-US-00012 TABLE 6a % Difference (versus Control) in Transverse
Extensibility at Force Force F (kgf) 0.1 0.2 0.3 0.4 Test Sample
196% 394% 458% 481% Control Sample -- -- -- --
TABLE-US-00013 TABLE 7 Extensibility (mm) in the Diagonal Direction
D'.sub.45 at Force F Force F (kgf) 0.1 0.2 0.3 0.4 Test Sample
17.78 30.53 38.17 45.3 Control Sample 0.71 1.13 1.55 2.00
TABLE-US-00014 TABLE 7a % Difference (versus Control) in Diagonal
Direction D'.sub.45 Extensibility at Force Force F (kgf) 0.1 0.2
0.3 0.4 Test Sample 2404% 2602% 2363% 2165% Control Sample -- -- --
--
TABLE-US-00015 TABLE 8 Extensibility (mm) in the Diagonal Direction
D.sub.45 at Force F Force F 0.1 0.2 0.3 0.4 Test Sample 1.55 2.62
3.88 5.37 Control Sample 1.30 1.78 2.23 2.69
TABLE-US-00016 TABLE 8a % Difference (versus Control) in Diagonal
Direction D.sub.45 Extensibility at Force Force F (kgf) 0.1 0.2 0.3
0.4 Test Sample 19% 47% 74% 100% Control Sample -- -- -- --
When compared with Tables 1a and 2a of Comparative Example 1,
Tables 5a and 6a, respectively, of Inventive Example 2 show that
the layer of material having the Slit Pattern Units of FIG. 2
provides greater extension in at least one of the longitudinal or
transverse directions than the layer of material having the Slit
Pattern Units of FIG. 9 at forces 0.1-0.4 kgf and in the other (or
remaining) longitudinal or transverse direction at forces 0.1-0.3
kgf. Additionally, Table 7a compared with Table 3a shows the
following for the two patterns with respect to extensibility in at
least one of the 45.degree. diagonal directions: [0185] Table 7a
shows that the Slit Pattern Units of FIG. 2 provides greater
extension in at least one of the 45.degree. diagonal directions
than the layer of material having the Slit Pattern Units of FIG. 9
at forces 0.1-0.4 (as shown in Table 3a); and
Example 3
[0186] To compare the extensibility in the z-direction of the
prepared Test and Control samples of the Slit Pattern Units of FIG.
2, Test and Control samples were prepared and measured at forces
0.1 kgf and 0.5 kgf in accordance with the Stretchability Testy.
The results are summarized in Tables 9 and 9a, respectively.
TABLE-US-00017 TABLE 9 z-Directional Extensibility (mm) at Force of
0.1 kgf 1 2 3 4 5 6 8 10 15 20 Test Yes Yes Yes Yes No No No No No
No Sample Control Yes No No No No No No No No No Sample
Table 9 shows that the layer of material with Slit Pattern Units of
FIG. 2 permits a greater degree of movement in the z direction (or
along the z-axis) at a force of 0.1 kgf than the layer of material
without any slits at the same force.
TABLE-US-00018 TABLE 9a z-Directional Extensibility (mm) at Force
of 0.5 kgf 1 2 3 4 5 6 8 10 15 20 Test Yes Yes Yes Yes Yes Yes Yes
No No No Sample Control Yes Yes Yes No No No No No No No Sample
Table 9a shows that the layer of material with Slit Pattern Units
of FIG. 2 permits a greater degree of movement in the z direction
(or along the z-axis) at a force of 0.5 kgf than the layer of
material without any slits at the same force.
[0187] It will be appreciated by those skilled in the art that
changes could be made to the exemplary embodiments shown and
described above without departing from the broad inventive concept
thereof. It is understood, therefore, that this invention is not
limited to the exemplary embodiments shown and described, but it is
intended to cover modifications within the spirit and scope of the
present invention as defined by the claims. For example, specific
features of the exemplary embodiments may or may not be part of the
claimed invention and features of the disclosed embodiments may be
combined.
[0188] It is to be understood that at least some of the figures and
descriptions of the invention have been simplified to focus on
elements that are relevant for a clear understanding of the
invention.
[0189] Further, to the extent that any method does not rely on the
particular order of steps set forth herein, the particular order of
the steps should not be construed as limitation on the claims. The
claims directed to any such method of the present invention should
not be limited to the performance of their steps in the order
written, and one skilled in the art can readily appreciate that the
steps may be varied and still remain within the spirit and scope of
the present invention.
EMBODIMENTS OF THE PRESENT INVENTION
[0190] 1. A dressing comprising: [0191] a. a layer of non-swellable
material, the layer having at least two material free regions
wherein the material free regions are in the form of curvilinear
sigmoidal patterns, wherein the patterns are non-intersecting and
arranged adjacent to one another such that, upon application of a
force to the dressing, after the dressing is applied to a wound,
the material free regions freely open from a closed position to an
open position to facilitate stretching of the layer of material
from a first position to a second position in the direction of the
force and wherein once the force is no longer applied, the material
free regions freely close to the closed position to facilitate
movement of the layer of material back to the first position from
the second position; and [0192] b. a releasable layer releasably
contacting the layer of material while the material free regions
are in the closed position. [0193] 2. The dressing of embodiment 1
further comprising an adhesive disposed between the releasable
layer and the layer of material. [0194] 3. The dressing of
embodiment 1 and/or 2, wherein the material free regions are slits
in the layer of material. [0195] 4. The dressing of any one or
combination of embodiments 1-3, wherein the sigmoidal pattern has a
top and further wherein the bottom of any sigmoidal pattern in a
row is aligned with the top and bottom of the other sigmoidal
patterns that row. [0196] 5. The dressing of any one or combination
of embodiments 1-4, wherein the non-swellable material forming the
layer of material is selected from polyurethanes, polyethylene,
polyisobutylene, polyamides, polyesters, polyether polyesters,
non-hydrophilic polyether-polyamides, plasticised polyvinyl
chloride, styrene-butadiene block copolymers, styrene-isoprene
block copolymer, polyacrylates, methacrylic copolymers,
polypropylene, rayon, rayon/polyester blends and mixtures thereof
[0197] 6. The dressing of any one or combination of embodiments
1-5, wherein the material forming the layer of material is
polyester. [0198] 7. The dressing of any one or combination of
embodiments 1-6, wherein the sigmoidal patterns have a length l
and, optionally, wherein the length l of at least one sigmoidal
pattern is oriented perpendicular to the length l of an adjacent
sigmoidal pattern. [0199] 8. The dressing of any one or combination
of embodiments 1-7, wherein the lengths of each sigmoidal pattern
in a row is oriented perpendicular to the length l of its adjacent
sigmoidal pattern in that row. [0200] 9. The dressing of any one or
combination of embodiments 1-8, wherein the sigmoidal patterns have
a width w and further wherein the length l of the sigmoidal pattern
is from about 1 to about 6 times the width w of sigmoidal pattern.
[0201] 10. The dressing of any one or combination of embodiments
1-9, wherein the surface density of pattern units per square inch
of the surface of the layer of material is from about 10 pattern
units/in.sup.2 to about 14 pattern units/in.sup.2 of the surface of
the layer of material. [0202] 11. The dressing of any one or
combination of embodiments 1-10, wherein the layer of material
extends in at least one of the longitudinal or transverse
directions at least about 100% more than the same layer of material
without material free regions, as measured by the Stretchability
Test.sub.xy described in the Specification, when applying a force
of from about 0.1 kgf along such longitudinal or transverse
direction of the layer of material. [0203] 12. The dressing of any
one or combination of embodiments 1-11, wherein the layer of
material extends in at least one of the longitudinal or transverse
directions at least about 150% more than the same layer of material
without material free regions, as measured by the Stretchability
Test.sub.xy described in the Specification, when applying a force
of from about 0.2 kgf along such longitudinal or transverse
direction of the layer of material. [0204] 13. The dressing of any
one or combination of embodiments 1-12, wherein the layer of
material extends in at least one of the longitudinal or transverse
directions at least about 425% more than the same layer of material
without material free regions, as measured by the Stretchability
Test.sub.xy described in the Specification, when applying a force
of from about 0.3 kgf along such longitudinal or transverse
direction of the layer of material. [0205] 14. The dressing of any
one or combination of embodiments 11-13, wherein the layer of
material extends in the other longitudinal or transverse direction
at least about 75% more than the same layer of material without
material free regions, as measured by the Stretchability Test
described in the Specification, when applying a force of from about
0.1 kgf along such other longitudinal or transverse direction of
the layer of material. [0206] 15. The dressing of any one or
combination of embodiments 11-13, wherein the layer of material
extends in the other longitudinal or transverse directions at least
about 150% more than the same layer of material without material
free regions, as measured by the Stretchability Test.sub.xy
described in the Specification, when applying a force of from about
0.2 kgf along such other longitudinal or transverse direction of
the layer of material. [0207] 16. The dressing of any one or
combination of embodiments 1-15, wherein the layer of material
extends in at least one of the 45.degree. diagonal directions at
least about 425% more than the same layer of material without
material free regions, as measured by the Stretchability
Test.sub.xy described in the Specification, when applying a force
of from about 0.1 kgf along such 45.degree. diagonal direction of
the layer of material. [0208] 17. The dressing of any one or
combination of embodiments 1-16, wherein the layer of material
extends in at least one of the 45.degree. diagonal directions at
least about 1125% more than the same layer of material without
material free regions, as measured by the Stretchability
Test.sub.xy described in the Specification, when applying a force
of from about 0.2 kgf along such 45.degree. diagonal direction of
the layer of material. [0209] 18. The dressing of any one or
combination of embodiments 1-17, wherein the layer of material
extends in the z direction at least about 1 mm to about 8 mm away
from the xy-plane of the layer of material, as measured by the
Stretchability Test.sub.z described in the Specification, when
applying a force of about 0.5 kgf along the z direction of the
layer of material. [0210] 19. The dressing of any one or
combination of embodiments 1-18, wherein the releasable layer
comprises polyethylene, polypropylene, kraft papers, polyester or
composites thereof.
* * * * *