U.S. patent application number 10/339129 was filed with the patent office on 2003-09-18 for biodegradable cotton composites.
Invention is credited to Wadsworth, Larry C..
Application Number | 20030176136 10/339129 |
Document ID | / |
Family ID | 23366377 |
Filed Date | 2003-09-18 |
United States Patent
Application |
20030176136 |
Kind Code |
A1 |
Wadsworth, Larry C. |
September 18, 2003 |
Biodegradable cotton composites
Abstract
A non-woven composite is disclosed, comprising a first layer,
further comprising a biodegradable component; and a second layer,
further comprising a biodegradation enhancement component, the
second layer being bonded to the first layer. As each of these two
layers has a biodegradable component, overall biodegrading is
enhanced. It is emphasized that this abstract is provided to comply
with the rules requiring an abstract which will allow a searcher or
other reader to quickly ascertain the subject matter of the
technical disclosure. It is submitted with the understanding that
it will not be used to interpret or limit the scope or meaning of
the claims.
Inventors: |
Wadsworth, Larry C.;
(Knoxville, TN) |
Correspondence
Address: |
Gary R. Maze
Duane Morris LLP
Suite 500
One Greenway Plaza
Houston
TX
77046
US
|
Family ID: |
23366377 |
Appl. No.: |
10/339129 |
Filed: |
January 9, 2003 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60348033 |
Jan 10, 2002 |
|
|
|
Current U.S.
Class: |
442/401 ;
442/327 |
Current CPC
Class: |
D04H 1/559 20130101;
Y10T 442/681 20150401; A61F 13/15252 20130101; B32B 5/26 20130101;
D04H 1/55 20130101; Y10T 442/60 20150401; D04H 1/435 20130101; D04H
1/56 20130101 |
Class at
Publication: |
442/401 ;
442/327 |
International
Class: |
D04H 001/00; D04H
005/00; D04H 013/00 |
Claims
What is claimed is:
1. A method of producing a non-woven composite, comprising: a.
creating a first layer, the first layer comprising a first
biodegradable component; b. creating a second layer, the second
layer comprising a biodegradation enhancement component; and c.
bonding the first layer to the second layer.
2. The method of claim 1, wherein: a. the biodegradable component
comprises at least one of (i) a wetting agent or (ii) a hydrophilic
biodegradable material
3. The method of claim 1, further comprising: a. adding a
non-elastic thermoplastic component to the biodegradable component
in the first layer; and b. heat-stretching the non-elastic
thermoplastic component and the biodegradable component in the
machine direction.
4. The method of claim 1, further comprising: a. adding a
non-elastic thermoplastic component to the biodegradable component
in the first layer; and b. heat-stretching the non-elastic
thermoplastic component and biodegradable component in the
cross-machine direction.
5. The method of claim 1, wherein: a. the second layer further
comprises at least one of (i) a spunbond material or (ii) a
meltblown material.
6. The method of claim 5, wherein: a. a wetting agent is added
topically to the spunbond material.
7. The method of claim 1, further comprising: a. creating a third
layer, the third layer comprising a nonbiodegradable component; and
b. bonding the first layer to the third layer; c. wherein the third
layer is on a side of the first layer opposite the second
layer.
8. A non-woven composite, comprising: a. a first layer, further
comprising a biodegradable component; and b. a second layer,
further comprising a biodegradation enhancement component, the
second layer being bonded to the first layer.
9. The non-woven composite of claim 8, wherein: a. the
biodegradation enhancement component is at least one of (i) a
wetting agent or (ii) a hydrophilic biodegradable material.
10. The non-woven composite of claim 9, wherein: a. the wetting
agent makes the non-woven composite more wettable.
11. The non-woven composite of claim 8, wherein: a. the second
layer is bonded to the first layer using at least one of (i)
calender patterned bonding, (ii) ultrasonic patterned bonding,
(iii) infrared bonding, or (iv) hot air bonding.
12. The non-woven composite of claim 8, wherein: a. the second
layer comprises at least one of (i) a spunbond non-woven material
or (ii) a meltblown non-woven material.
13. The non-woven composite of claim 8, wherein: a. the first layer
further comprises a thermoplastic biodegradable fiber, the
thermoplastic biodegradable fiber further comprising at least one
of (i) EASTAR BIO, (ii) poly(lactide), (iii) polyvinyl alcohol,
(iv) other biodegradable fibers, or (v) a bicomponent fiber with
biodegradable components.
14. The non-woven composite of claim 8, further comprising: a. a
third layer; b. wherein: i. the second layer comprises a meltblown
layer bonded on a first outer surface of the first layer; and ii.
the third layer comprises a spunbond layer bonded to a second outer
surface of the first layer disposed opposite the first outer
surface.
15. The non-woven composite of claim 14, wherein: a. the first
layer further comprises a cellulosic fiber blended with a
thermoplastic fiber, the thermoplastic fiber further comprising at
least one of (i) polyethylene, (ii) polypropylene, (iii) polyester,
(iv) nylon, (v) low melting point fibers, or (vi) bicomponent
fibers; and b. at least one of the outer spunbond or meltblown
layers comprise a biodegradable polymer, the biodegradable polymer
further comprising at least one of (i) poly(lactide), (ii) EASTAR
BIO, (iii) polyvinyl alcohol, or (iv) other biodegradable polymers.
Description
PRIORITY DATA
[0001] This application claims benefit under 35 U.S.C. Section 119
of provisional application 60/348,033 filed Jan. 10, 2002.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of
composite materials and in particular non-woven fabrics which
contain biodegradable material such as cotton.
BACKGROUND OF THE INVENTION
[0003] Cellulosic fibers offer the advantage of biodegradability of
that component of the composite and render the composite more
comfortable for wear and more useful in hygienic personal care
products due to enhanced liquid absorption. The cotton-core and
cotton-surfaced composites of this invention have been further
enhanced by imparting elasticity, by incorporating more
biodegradable components in addition to cellulosic fibers and by
the addition of wetting agents to improve the wetting properties
and accessibility for enhanced biodegradability.
[0004] Thermally bonded non-woven laminates with spunbond
polypropylene on one side and a meltblown polypropylene web on the
other side have been shown to have greater wicking rate, water
absorptive capacity, and water retention capacity than a similar
construction with light weight meltblown polypropylene webs on both
sides. An example of such a laminate is disclosed in U.S. Pat. No.
5,683,794.
[0005] Inherent properties of fibers that can be produced from
different biodegradable polymers may be a factor in engineering
structures to produce the laminate with the required mechanical
strength, flexibility, barrier, filtration, absorbency properties
and other traits. For example, spunbond and meltblown non-woven
fabrics and staple fibers made from poly(lactide). Poly(lactide)
has tenacity and elongation-to-break properties similar to more
conventional polypropylene fibers and fabric. In fact,
poly(lactide) staple fibers can be readily processed through a
carding machine as 100% poly(lactide) or in blends with other
fibers such as cotton or rayon. However, the poly(lactide) fibers
and fabrics are more difficult to thermally bond by hot air, heated
calenders, ultrasonic and infrared bonding than polypropylene or
other material.
[0006] A problem with many laminates is that only portions of the
laminate are fully biodegradable, leaving other portions either
partially or non-biodegradable.
SUMMARY OF THE INVENTION
[0007] A non-woven composite having increased biodegradation
properties is disclosed and may be produced by creating a first
layer, the first layer comprising a first biodegradable component;
creating a second layer, the second layer comprising a
biodegradation enhancement component; and bonding the first layer
to the second layer. The biodegradable component may comprise a
wetting agent, a hydrophilic biodegradable material, or the
like.
[0008] In an embodiment, a third layer may also be created, the
third layer comprising a nonbiodegradable component, where the
third layer is also bonded to the first layer.
[0009] The scope of protection is not limited by the summary of an
exemplary embodiments set out above, but is only limited by the
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a planar schematic view of a process line for
preparation of thermally point-bonded Cotton-Core Non-wovens on
spunbond line by laminating cotton and meltblown webs onto the
spunbond web;
[0011] FIG. 2 is a planar schematic view of a process line for
preparation of thermally point-bonded Cotton-Surfaced Non-wovens on
the spunbond line by introducing a carded cotton/polypropylene web
on one or both sides of the spunbond web;
[0012] FIG. 3 is a planar schematic illustration of lamination and
Infrared bonding of CCN non-wovens consisting of a supporting web
of spunbonded web and a core of carded cotton/polypropylene web and
a top layer of meltblown polypropylene or meltblown EASTAR BIO
non-wovens;
[0013] FIG. 3a is a planar schematic illustration of ultrasonic
bonding of CCN non-wovens consisting of a supporting web of
spunbonded web and a core of carded cotton/polypropylene web and a
top layer of meltblown polypropylene or meltblown EASTAR BIO
non-wovens;
[0014] FIG. 4 illustrates the effect of percentage of Cotton in
Cotton/polypropylene core content on Tenacity;
[0015] FIG. 5 illustrates the effect of meltblown weight on
Tenacity with core of 75% Cotton/25% PP;
[0016] FIG. 6 illustrates the effect of meltblown weight on Tearing
Strength with core of 75% Cotton/25% PP;
[0017] FIG. 7 illustrates the effect of Cotton/polypropylene core
content and meltblown Weight on Tenacity;
[0018] FIG. 8 illustrates the effect of Cotton/polypropylene core
content and meltblown Weight on Tearing Strength;
[0019] FIG. 9 illustrates absorption versus time curves (meltblown
side) for laminates containing meltblown EASTAR BIO GP Copolyester
webs;
[0020] FIG. 10 illustrates absorption versus time curves (spunbond
side) for laminates containing meltblown EASTAR BIO GP copolyester
webs;
[0021] FIG. 11 illustrates directional Flow Rate/Orientation of
E-29-01-1 spunbond side;
[0022] FIG. 12 illustrates directional Flow Rate/Orientation of E
29-01-1 meltblown side;
[0023] FIG. 13 illustrates directional Flow Rate/Orientation of
E-29-01-3A on spunbond side;
[0024] FIG. 14 illustrates directional Flow Rate/Orientation of
E-29-01-3 HS On spunbond side; and
[0025] FIG. 15 illustrates directional Flow Rate/Orientation of
E-29-01-4A HS on spunbond side.
DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENTS
[0026] EASTAR BIO GP COPOLYESTER ("EASTAR BIO") is marketed by the
Eastman Chemical Company of Kingsport, Tenn..
Spunbond/Cotton/meltblown (SCM) Cotton-Core Non-wovens (CCNs)
comprising a biodegradable web, such as one comprising a totally
biodegradable polymer such as an EASTAR BIO meltblown web instead
of meltblown polypropylene webs, were produced and compared to CCNs
containing polypropylene in both the meltblown and spunbond
components. The absorbent cores had a weight of 1.5 oz/yd.sup.2 (51
g/m.sup.2) and consisted of carded 75/25 and 50/50
Cotton/polypropylene staple fiber blends. The laminates were all
infrared bonded and evaluated for tearing strength, tenacity, and
water absorption rate and maximum absorption. Use of EASTAR BIO
meltblown in place of meltblown polypropylene resulted in stronger
well-bonded laminates with exceptionally high absorbency on the
EASTAR BIO meltblown side as well as in the cotton core.
[0027] Cotton-based non-woven materials may include cotton-core
non-wovens (CCNs) and/or cotton-surfaced non-wovens (CSNs). CCN
laminates are typically a three-layered structure with cotton or
cotton/polypropylene webs in the center, or core, layer bonded with
spunbond ("SB") and meltblown ("MB") webs as top and bottom layers.
It has been discovered that a cotton composite with enhanced
biodegradable properties occurs when a meltblown polypropylene
("PP") web is replaced with a totally biodegradable meltblown web,
such as one made using EASTAR BIO.
[0028] Although meltblown and spunbond webs have been produced with
100% EASTAR BIO, and may be laminated on both sides of a
cotton-core web, to produce a totally biodegradable SCM CCN
laminate, it has been discovered that better thermal bonding of
cotton core fibers to each other and to the outer spunbond or
meltblown fabrics may be achieved by blending thermoplastic staple
fibers with the cotton fibers. However, the staple fibers should be
essentially biodegradable in order for the entire CCN to be
biodegradable. This may be achieved by producing a bicomponent
staple fiber with a core of biodegradable poly(lactide) (PLA), e.g.
to achieve the desired mechanical strength and moderate to low
elasticity for carding, and a sheath of a biodegradable material
such as EASTAR BIO for the desired ease of thermal bonding, good
adhesion, and good wetability. Although the core/sheath bicomponent
fiber geometry may be a preferred geometry, numerous other
bicomponent fiber geometries may also be suitable such as
side-by-side, segmented, and islands-in-the-sea. The types of
degradable CCNs that may be produced comprise:
[0029] 1. 100% meltblown EASTAR BIO outer layer/100% Cotton
Core/100% meltblown EASTAR BIO outer layer
[0030] 2. 100% spunbond EASTAR BIO outer layer/100% Cotton
Core/100% spunbond EASTAR BIO outer layer
[0031] 3. 100% spunbond EASTAR BIO outer layer/100% Cotton
Core/100% meltblown EASTAR BIO outer layer
[0032] 4. 1, 2 and 3 above except the core cotton-based web has a
blend of cotton (or any cellulose fiber) with EASTAR BIO staple
fibers for improved thermal bonding
[0033] 5. 1, 2, 3 and 4 in which the EASTAR BIO webs may be
replaced with poly(lactide) webs on one or both sides of the
cotton-based core web.
[0034] 6. MELTBLOWN or spunbond bicomponent fiber webs, preferably
with a core of poly(lactide) and a sheath of EASTAR BIO, but with
any of the possible bicomponent fiber geometries, may replace any
of the meltblown or spunbond outer webs in the above
constructions.
[0035] Since the meltblown polypropylene in the above CCNs was
successfully replaced with a totally biodegradable polymer,
numerous other biodegradable polymers such as poly(lactide) may
also be candidates for replacing the meltblown polypropylene or
EASTAR BIO. Further, the polypropylene in the spunbond web of the
CCNs may be replaced with biodegradable polymers such as EASTAR
BIO, poly(lactide), polyvinyl alcohol, and copolymers of
polyhydroxybutyrate (PHB)-polyhydroxyvalerate (PHV). Furthermore,
the thermoplastic staple fibers such as polypropylene, which may be
blended with the cotton fibers in the center "core" layer to
improve the thermal bonding of the CCN laminate, may be replaced
with biodegradable fibers such as those noted above, as well as
others.
[0036] Additionally, biodegradable Cotton-Surfaced Non-wovens
(CSNs) may be produced. Among the possible embodiments for
producing biodegradable CSNs are the following constructions:
[0037] a. Base supporting web of spunbond poly(lactide) and top web
of cotton (or any cellulose fiber) blended with staple
poly(lactide) fibers with is subsequently thermally calendered, or
bonded by hot through-air, ultrasonic or infrared thermal bonding
methods.
[0038] b. Structure "a" above in which cotton fibers are blended
with bicomponent core/sheath (or any possible bicomponent fiber
geometry) with a core of poly(lactide) and a sheath of EASTAR
BIO.
[0039] Structures "a" and "b" above in which cotton webs blended
with poly(lactide) or with bicomponent fiber (preferably a core of
poly(lactide) and a sheath of EASTAR BIO.
[0040] Furthermore, the CSN constructions above may be
heat-stretched in one direction to produce elasticity in the CSN in
the direction perpendicular to the direction of stretch (or biased
to the direction of stretch) and to induce wetting and wicking in
the direction of stretch.
[0041] Referring now to FIG. 1, a non-woven composite may comprise
a plurality of layers. In a first exemplary embodiment, a first
layer, further comprising a biodegradable component is bonded to a
second layer, further comprising a biodegradation enhancement
component. The first layer may further comprise a thermoplastic
biodegradable fiber where the thermoplastic biodegradable fiber may
further comprise at least one of EASTAR BIO, poly(lactide),
polyvinyl alcohol, other biodegradable fibers, or bicomponent
fibers with biodegradable components, or the like, or a combination
thereof. The second layer may comprise a spunbond non-woven
material, a meltblown non-woven material, or the like.
[0042] In a further exemplary embodiment, the non-woven composite
may further comprise additional layers. For example, the non-woven
composite may comprise a third layer. In such an embodiment, the
second layer may comprise a meltblown layer bonded on a first outer
surface of the first layer and the third layer may comprise a
spunbond layer bonded to a second outer surface of the first layer
disposed opposite the first outer surface.
[0043] The first layer may further comprise a cellulosic fiber
blended with a thermoplastic fiber, the thermoplastic fiber further
comprising polyethylene, polypropylene, polyester, nylon, a low
melting point fiber, a bicomponent fiber, or the like, or a
combination thereof. At least one of the outer spunbond or
meltblown layers may comprise a biodegradable polymer, the
biodegradable polymer further comprising poly(lactide), EASTAR BIO,
polyvinyl alcohol, other biodegradable polymers, or the like, or a
combination thereof.
[0044] Bonding may be accomplished by calender patterned bonding,
ultrasonic patterned bonding, infrared bonding, hot air bonding, or
the like, or a combination thereof.
[0045] The biodegradation enhancement component may be a wetting
agent or a hydrophilic biodegradable material or the like, or a
combination thereof. The wetting agent makes the non-woven
composite more wettable.
[0046] Referring still to FIG. 1, CCNs may be produced by
sandwiching a cotton web between outer layers of a meltblown and/or
a spunbond web such as by using a thermal calendaring process. In
an exemplary embodiment, a bleached cotton web is introduced into a
production line after extrusion and laying of spunbond
polypropylene, and a meltblown polypropylene web may be introduced
into a production zone after the cotton web so as to develop a
three layered structure in which one or more cotton webs is bonded
in between a spunbond layer and a meltblown layer. A spunbond
polypropylene web and a meltblown polypropylene web may act as
binder fibers in the thermal bonding and may be engineered to
transport liquid into a highly absorbent cotton core from its dry
surfaces. The absorbent core and the dry surfaces make CCNs highly
suitable for diaper components, feminine hygiene products, baby
wipes, sponges, bandages, surgical gowns and other industrial and
consumer applications.
[0047] Heat-stretching the CCNs may impart instantaneous elastic
recoveries of up to 70%-80% from an extension of 50%.
Heat-stretching in one direction imparts elasticity to the laminate
in the other direction. For example, if a non-woven composite
laminate is heat-stretched in the machine direction, as that term
is understood by those of ordinary skill in the art, then it will
be elastic in the cross-machine direction, as that term is
understood by those of ordinary skill in the art. Elastic
non-wovens such as a laminate possess excellent comfort and fit
properties useful in applications such as inexpensive elastic leg
cuffs and waist bands for disposable diapers. Elastic CCNs have
improved wicking properties, in addition to stretchability, due to
the greater orientation of cotton and polypropylene fibers in the
machine direction which makes them ideal for protective apparel,
face masks, bandages, wound dressings, feminine hygiene products
and diapers.
[0048] Referring now to FIG. 2, Cotton-Surfaced Non-wovens (CSNs)
have been developed with cotton on one or both sides of a base
structure, generally a spunbonded polypropylene web, in which the
cotton content varies from 20-70% of the fabric weight. As shown in
FIG. 2, CSNs may be made by placing a carded cotton/polypropylene
web on one or both sides of spunbond polypropylene filament webs
prior to calendaring rollers. The thermally bonded two or three
layered laminates are soft but strong and have excellent wetting,
wicking, water absorption, and water retention properties. They are
ideally suited as cotton-surfaced outer fabrics for diapers,
acquisition layers in diapers and feminine hygiene products,
disposable bed linens and textile interfacings. A post-treatment
process enhances the extensibility of the fabrics produced with
instantaneous elastic recoveries of 83%-93% from an extension of
50%.
[0049] These elastic fabrics also exhibit minimal Tinting
characteristics and would be suitable as isolation gowns, or drapes
and gowns (if fluorochemical finished), physical therapy pants,
head covers and shoe covers, bed sheets, pillow cases and for
consumer applications such as disposable underwear, towels, wipers
and personal hygiene products.
[0050] A cotton web may comprise a bleached cotton staple used for
the initial stage of fabric development such as a premium medical
grade with excellent absorbency, entanglement potential and comfort
characteristics. Additionally, additional grades of cotton may be
incorporated into CSN and CCN composites with similar results as
well.
[0051] Referring now to FIGS. 3 and 3a, CCNs may be bonded using
infrared bonding, ultrasonic bonding, or the like.
[0052] In the operation of an exemplary embodiment, a non-woven
composite may be produced by creating a first layer which comprises
a first biodegradable component, e.g. cotton or another cellulosic
fiber. A second layer may be created, the second layer comprising a
biodegradation enhancement component such as a wetting agent or a
hydrophilic biodegradable material. In a preferred embodiment, a
wetting agent may be added topically to a layer comprising spunbond
material.
[0053] The first layer may then be bonded to the second layer. The
second layer may further comprise a spunbond material, a meltblown
material, or the like, or a combination thereof.
[0054] A non-elastic thermoplastic component may be added to the
biodegradable component in the first layer. Further, the
non-elastic thermoplastic component and the biodegradable component
may be heat-stretched in either the machine or cross-machine
direction.
[0055] Additionally, a laminate having a third layer may be created
where the third layer comprises a nonbiodegradable component. The
third layer may be bonded to the first layer, e.g. the
biodegradable, such that the third layer is on a side of the first
layer opposite the second layer.
[0056] In a first exemplary method of preparation, an spunbond
polypropylene comprising polypropylene 3155, 35 MFR, marketed by
ExxonMobil Chemical Company of Houston, Tex., with basis weights of
11 and 17 g/m.sup.2 were first produced on a 1-meter Reicofil 2
spunbond Line. Next, carded webs with a weight of 51 g/m.sup.2 (1.5
oz/yd.sup.2) at a width of 28 inches in compositions of 50% cotton
(VERATEC EASY STREET)/50% staple polypropylene (FiberVisions T-156,
2.2 denier.times.1.5 in.), and 75% cotton/25% staple polypropylene
were deposited from the card onto the 11 and 17 g/m.sup.2 spunbond
polypropylene webs. Rolls of unbonded carded web/SB polypropylene
laminates were laminated to meltblown webs as shown in FIG. 3a. Two
laminates, Sample 1 (E-29-01-1) and Sample 2 (E-29-01-2),
illustrated in Table 1, were produced by adding a 34 g/m.sup.2
meltblown EASTAR BIO web instead of meltblown polypropylene with
two-ply combinations of 11 g/m.sup.2 spunbond polypropylene and
carded cotton/polypropylene webs consisting of 75% cotton/25%
polypropylene and 50% cotton/50% polypropylene. The remaining
samples illustrated in Table 1 were prepared by laminating the
carded cotton/polypropylene and spunbond polypropylene combinations
with 30-inch meltblown polypropylene webs with basis weights of 12
and 16 g/m.sup.2.
1TABLE 1 Description of Biodegradable Cotton-Core Non-wovens
(CCN's) Web Wt. Sample Core Content* (G/m.sup.2) IR Bonded #/Descr.
Laminate C/polypropylene SB MB T/FPM 1 E-29-01-1 75/25 11 34**
164F/34 2 E-29-01-2 50/50 11 34** 164F/34 3 E-29-01-3A 75/25 11 12
200F/38 4 E-29-01-4 50/50 11 16 200F/38 5 E-29-01-5 50/50 11 12
200F/38 6 E-29-01-6A 75/25 11 12 200F/38 7 E-29-01-7A 75/25 11 16
200F/38 8 E-29-01-3 HS*** 75/25 11 12 200F/38 9 E-29-01-4A HS***
75/25 11 -- 200F/38 10 E-29-01-5A HS*** 50/50 11 16 200F/38 Note:
Laminates 1 and 2 were bonded with spunbond polypropylene on top
(height of IR unit 8"). Laminates 3-7 were first bonded with
spunbond on top (line speed 45 ft/min) and were turned over and
then were bonded a second time with meltblown on top (line speed 38
ft/min, nip roller temperature 200.degree. F., height of IR unit
7"). *Composition of center carded web of cotton/polypropylene
staple fiber. **meltblown Web consisting of 34 gsm EASTAR BIO; all
other meltblown and spunbond Components consisted of 100%
polypropylene. ***As-Bonded laminate heat-stretched in oven at
290-300F with a draw ratio of 1.9
[0057] The 34 g/m.sup.2 meltblown EASTAR BIO was produced on a
20-inch ACCURATE PRODUCTS meltblown line. The web was collected on
release paper. Alternatively, water spray quench may be utilized
between the die and collector in order to avoid the use of release
paper to prevent the web from sticking to the collector. Although
thermal calendaring may be used to bond the webs as depicted in the
preparation of CCNs in FIG. 1, CCN laminates may also be bonded
utilizing infrared (IR) bonding.
[0058] Laminates 1 and 2 were bonded by placing the spunbond
polypropylene side on top for impingement of the infrared radiation
with the infrared heater 8 inches above the spunbond polypropylene.
The line speed was 34 feet/min and a nip roller after the IR heater
was heated to 164.degree. F. with a nip pressure of 80 psi. These
conditions were sufficient to bond the spunbond polypropylene to
the cotton/polypropylene webs and also resulted in excellent
bonding of the EASTAR BIO and spunbond polypropylene to the carded
cotton/polypropylene center webs. Laminates 3 through 7 illustrated
in Table 1 were first bonded using infrared bonding under the same
conditions as samples 1 and 2, except meltblown polypropylene webs
were placed on the bottom and the line was increased to 45
feet/min. It was later found that the meltblown polypropylene webs
were not well-bonded and Samples 3-7 were bonded using infrared
bonding a second time with the meltblown polypropylene webs on top
and exposed to the infrared bonding unit and the height of the
infrared bonding unit was reduced to 7 inches. Also, the nip roller
was heated to 200.degree. F. with a nip pressure of 80 psi and the
line speed was 38 feet/minute.
[0059] Also as noted in Table 1, approximately 20-meter lengths of
laminates 3, 4 and 5 were heat-stretched (laminates 8, 9 and 10
respectively) through a 6-ft forced hot air oven at a temperature
of 300.degree. F. The first pair of nip rolls had a surface speed
of 3.8 m/min and the second pair of nip rolls had a speed of 7.2
m/min, resulting in a draw ratio of 1.9.
[0060] In a second exemplary embodiment, ultrasonic bonding (UB),
like infrared bonding described in the previous section a bonding
technique which does not compress a laminate as much as thermal
point-bonding in a calendar, was utilized.
[0061] Thermoplastic polyurethanes have been developed in recent
years, which have the elasticity of thermoset cross-linked rubber
or SPANDEX, but do not have to be solvent spun like SPANDEX, for
example. The thermoplastic polyurethanes can be spun into fibers by
more environmentally friendly melt spinning process and the
addition of cotton to the surface of meltblown thermoplastic
polyurethanes and spunbond thermoplastic polyurethane fabrics will
made them even more suitable with the comfort and biodegradability
afforded by the cotton component. Furthermore, thermoplastic
polyurethanes can possess hydrophilic backbone chemistry and be
breathable. During preliminary meltblown trials it was observed
that the thermoplastic polyurethane filaments were often traveling
horizontally from meltblown die only a few inches or more,
depending on air flow rates, before dropping vertically towards the
floor. This observation coupled with the fact that relatively large
diameter meltblown fibers were being produced led the inventor to
believe that efforts had been going in the wrong direction with
respect to spinneret hole diameter and air knife gap. With many
high melt viscosity polymers such as polyesters and nylons, a large
hole die (0.018 inch hole diameter compared to the standard hole
diameter of 0.0145 in.) and larger air knife gap of 0.090 inches
actually results in finer fibers and softer webs. However, based on
observations described above, the standard die tip with 0.0145 in.
diameter holes and with an LID of 8.5/1 and a hole density of 25
holes/inch was used. Also, the air knife gap on both sides of the
nose tip was reduced to 0.030 in. and the die tip setback to 0.030
in. These innovations enabled us to produce uniform meltblown
thermoplastic polyurethane webs with fiber diameters of 5
micrometers, well in the microfiber range (data not shown).
[0062] In an effort to successfully produce spunbond thermoplastic
polyurethane, which would enable the production of cotton-surfaced
spunbond thermoplastic polyurethane, Two resins, 58283-045 and
X-4981-045, were obtained from Noveon, Inc. of Cleveland, Ohio.
These resins were re-extruded to lower molecular weight and a
filler was added to both resins to minimize sticking of the
extruded filaments before quenching.
[0063] In a third exemplary embodiment, additional carded webs of
Barnhardt bleached raw cotton were prepared at a basis weights of
13 grams/square-meter ("gsm") for the preparation of CSNs and at
weights of 40-51 gsm for the preparation of CCNs. Also, since the
bicomponent core/sheath (c/s) staple fibers with a core of
poly(lactide) (for strength and low elongation for good carding)
and a sheath of EASTAR BIO (for good thermal bonding and
biodegradability) were not be available, a bicomponent C/S
polypropylene/EASTAR BIO staple fiber was selected for blending
with cotton fiber to form carded webs for the preparation of CCNs
and CSNs. Replacement of the polypropylene with poly(lactide) in
the bicomponent binder core/sheath fiber will make the bicomponent
fiber completely biodegradable.
[0064] Wicking and absorption properties (to distilled water) of
all the samples were evaluated using an ATS-600 Absorbency Testing
System which is a table top instrument that measures the absorption
and desorption rate and total capacity of absorbent materials. The
desorption of these samples was not determined. All samples were
cut from the sheets into 2-inch squares and placed on the table
oriented in the same direction. Results were corrected for sample
weight and appear in grams/gram. The Cotton-Core samples were
tested on the spunbond (SB) side, except the laminates with
meltblown EASTAR BIO were also tested on the meltblown side. Tests
were run for a period of time, usually 100-300 seconds, to ensure
that absorption had tapered off, and the differential fluid head
was set approximately at zero.
[0065] FIG. 4 illustrates the effect of the percentage of cotton in
a cotton/polypropylene core on tenacity.
[0066] FIGS. 5 and 6 illustrate that an increase in the basis
weight of meltblown web in the CCN laminate also had minimal effect
on the tenacity and tearing strength.
[0067] FIG. 7 illustrates that the machine direction tenacity
values of the heat-stretched laminates are greater than that of
As-Bonded laminates. Heat-stretching increased the fabric
orientation and compactness of the fabric, which helped in
increasing the strength of the fabric and tenacity of the fabric.
The machine-direction/cross-machine-di- rection ratio of tenacity
values for all the laminates is >2.5.
[0068] Referring now to FIG. 8, there are no clear trends in
tearing strength in the heat-stretched samples in either machine or
cross-machine directions when compared to the As-Bonded
laminates.
[0069] Referring now to FIG. 9, a graph of absorption versus time
curves on a meltblown side for laminates containing a meltblown
EASTER BIO web, the sample with 50% cotton in the core, E 29-1-2,
had slightly lower absorption than the sample containing 75% cotton
in the core, E 29-1-1.
[0070] Referring now to FIG. 10, in which the above samples E
29-1-1 and E-29-1-2 were wetted from the spunbond polypropylene
side instead of the meltblown side, as above, both laminates
absorbed nearly as much water with time from the spunbond
polypropylene side as from the meltblown EASTAR BIO side as
illustrated in FIG. 9.
[0071] The maximum absorption values are expectedly slightly lower
when tested from the spunbond side at 6.4 grams/gram and 6.1
grams/gram respectively for the CCNs containing 75 and 50% cotton
in the cotton/polypropylene cores.
[0072] In a further embodiment, a laminate, E 29-1-3 HS, containing
higher cotton content (75%) had a greater absorption amount and a
second laminate, E 29-1-5A, containing 50% cotton, had the second
highest absorption amount. The maximum absorption values for three
laminates E 29-1-3, E 29-1-5A HS, and E 29-1-4A, were 9.6
grams/gram, 9.4 grams/gram, and 8.0 grams/gram respectively.
Comparing the maximum absorption amount values of the
Heat-Stretched laminates with the As-Bonded laminates, for the
laminates containing higher cotton content, Heat-Stretching
produced minimal changes in the absorption properties. After the
Heat-Stretching the laminates were oriented in the machine
direction and their directional absorption properties were
prominent in the machine direction. Directional flow rates of
As-Bonded samples containing 75% Cotton/polypropylene and 50%
Cotton/polypropylene in the cotton based cores and the
corresponding Heat-Stretched CCNs are illustrated in FIGS. 12-15.
As is illustrated in FIGS. 12-15, the As-Bonded CCNs have a more
circular wetting pattern and the CCN webs with 50%
cotton/polypropylene in the core had a smaller wetting area and a
slower wicking rate. The Heat-Stretched samples exhibited greater
directional flow in that the machine direction/CD rates were
greater.
[0073] In a further embodiment, in order to improved the
wettability of CSNs and CCNs for hygienic products and for other
products such as wound dressings and absorbents in the packaging of
meats, as well as to improve water absorption to better facilitate
the biodegradation processes of the degradable components of CCNs
and CSNs, a study was made to determine the best method of adding
wetting agents to spunbond polypropylene.
[0074] Additional follow-up in determining the most cost-effective
method for producing acceptable wettability and rewettability in
spunbond polypropylene led to the evaluation of two new
fluorosurfactant (FS) type wettable concentrates, S-1242, a
monomer-based fluorosurfactant, and S-1243, a polymer-based
fluorosurfactant, both available from Polyvel Inc. of Hammonton,
N.J. It was found that both fluorosurfactant concentrates improved
the wetting performance of cotton composites containing spunbond
polypropylene. It was further found that of the two, the
polymer-based fluorosurfactant gave better wetting properties than
the monomer-based fluorosurfactant.
[0075] In a further embodiment, in an effort to determine if lower
grades of less expensive cotton other than bleached first quality
cotton could be used to produce CCNs and CSNs, three 75-lb bags,
each of two grades of greige re-ginned cotton motes (Grade 1H50 and
Grade 1, with a slightly lower quality having more trash content)
were obtained from T. J. Beall Company, West Point, Ga. for the
preparation of two weights of carded webs in a 50/50 blend with
FiberVisions Type 196 polypropylene staple fiber with a hydrophilic
spin finish. Both the 13 g/m2 (gsm) and the 36-40 gsm carded webs
described above were rolled up with tissue paper during the carding
work for the preparation of CCNs and CSNs.
[0076] In yet a further embodiment, for preliminary work in the
preparation of CSNs with wettable spunbond polypropylene on an
spunbond line 100 pounds of wettable concentrate, S-1180, a
concentrate with 7% silica, 15% surfactant, and 78% polypropylene,
were obtained from Polymer Applications Inc., Lawrenceville, N.J.
The wettable concentrate was mixed at 4% and 6% (weight %) levels
with 35 MFR polypropylene before spunbond extrusion. For a
comparison of the wettability of the base spunbond polypropylene
webs, 200-meter rolls of 12 g/m2 (gsm) spunbond polypropylene with
no wetting agent and rolls with 4% and 6% wettable concentrate were
produced. Three 200-meter rolls of 17 gsm spunbond polypropylene
with 6% wettable concentrate were also prepared for the preparation
of CCNs.
[0077] In yet a further embodiment, EASTAR BIO was meltblown to
produce meltblown EASTAR BIO web with a weight of 27 gsm for the
subsequent preparation of mostly biodegradable CCNs.
[0078] Also, 50 lbs of bicomponent core/sheath (c/s) staple fiber
with a core of polypropylene and a sheath of EASTAR BIO were
obtained with the following specifications: 50% polypropylene
core/50% EASTAR BIO; 4 denier/filament; 1.4 inch staple length; and
9.4 crimps/inch. This bicomponent fiber was then mixed and carded
in blends of 60% bleached cotton/40% bicomponent and 70% bleached
cotton/30% bicomponent to produce carded webs with weights of 11
gsm, 22 gsm, 25 gsm and 36-40 gsm and rolled with tissue paper for
subsequent unwinding to laminate for other webs to produce SCNs and
CCNs as specified in this document.
[0079] In addition, 30 yards of 20 gsm spunbond poly(lactide) at a
width of 15 inches was also obtained from Cargill Dow for
preparation of CSNs and CCNs.
[0080] CSNs were prepared on a 1.0 meter Reicofil 2 spunbond line
in which 13 gsm carded bleached cotton/polypropylene staple fiber
webs (50/50 cotton/polypropylene and 60/40 cotton/polypropylene)
were thermally bonded to 12 gsm spunbond polypropylene webs with 4%
and 6% wettable concentrate. Bonding of the CSNs produced with the
wettable concentrate appeared to be much better than had
here-to-fore been produced with spunbond polypropylene not
containing wetting agent. CSNs were also prepared with spunbond
base webs containing 6% wettable concentrate in which carded webs
of greige reginned cotton motes formed the surface layer.
[0081] CSNs were prepared with spunbond base webs containing 6%
wettable concentrate in which carded webs of greige Cotton Gin
Motes formed the surface layer. Carded 10 gsm re-ginned cotton
motes consisting of 50% Gray Beall Grade 1/50% polypropylene staple
and 50% Greige Bealls Grade lH50/50% staple polypropylene were
unrolled onto the 12 gsm spunbond polypropylene (6% wettable
concentrate). Also, a 36 gsm carded web of 50% Greige Bealls 1H50
and staple polypropylene was laid onto the wettable 12 gsm spunbond
polypropylene web and thermally point bonded on the spunbond line.
It was anticipated that the natural waxy coating on the greige
cotton fiber would adversely affect bonding to the spunbond
polypropylene. Nevertheless, excellent bonding of the greige
re-ginned cotton mote/staple polypropylene blend was obtained to
the wettable spunbond polypropylene, as was obtained with the CSNs
containing bleached cotton blend surface webs. The spunbond run
conditions for the preparation of the above samples on the 1.0 m
spunbond line were as follows and it should be noted that in the
preparation of all CSNs on the spunbond line in this study, the top
heated calender roller had a raised diamond pattern with a bonding
area of 14.7% and the bottom heated calender roller was smooth
steel:
[0082] A. Preparation of 12 gsm spunbond polypropylene controls
with no S-1180 and with 4 and 6% S-1180:
[0083] 1) Die Zones 4.1 and 4.7: 445 F. (229.degree. C.)
[0084] 2) Melt temp: Die 1-384 F.(195.6.degree. F.); Die 2:
422.degree. F. (216.7.degree. C.)
[0085] 3) Thru-put of 0.15 gram/spinneret hole/min (g/h/m)
[0086] 4) Quench Air Temp of 64.degree. F.; Cooling Air Fan at 1586
RPM
[0087] 5) Suction Fan at 1469 RPM
[0088] 6) Belt Speed of 59.4 m/min
[0089] 7) Calender Speed of 62 meter/min (m/m)
[0090] 8) Winder Speed of 64 m/m
[0091] 9) Calendering Conditions: 265.degree. F. Top/261.degree. F.
(Bottom); 141 PLI (lbs/linear inch) Nip Pressure.
[0092] B. Preparation of CSNs with 4 and 6% S-1180:
[0093] 1) Increase Calender Temps to 290.degree. F. Top/285.degree.
F. Bottom
[0094] 2) Increase PLI to 618 PLI
[0095] 3) Unwind unbonded carded cotton-blend webs (while removing
the tissue paper used to roll up the carded webs) onto unbonded
spunbond filament web prior to the thermal calender section
[0096] 4) Other line conditions same as "A" above without cotton
lamination
[0097] Similar CSNs were then also made onto 12 gsm containing 5%
S-1242 fluorosurfactant and 5% S-1243 fluorosurfactant. The run
conditions for the 12 gsm spunbond polypropylene without and with
5% S-1242 and 5% S-1243 are as follows:
[0098] A. Preparation of 12 gsm spunbond polypropylene with no
wetting agent and with 5% S-1242 and 5% S-1243:
[0099] 1) Die Zones 4.1 and 4.7: 445.degree. F. (229.degree.
C.)
[0100] 2) Melt temp: Die 1-379 F. (192.8.degree. C.); Die
2-421.degree. F. (216.degree. C.)
[0101] 3) Thru-put of 0.15 g/h/m
[0102] 4) Quench Air Temp of 64.degree. F.; Cooling Air Blower at
1586 RPM
[0103] 5) Suction Fan at 1469 RPM
[0104] 6) Belt Speed of 59 m/min (mpm)
[0105] 7) Calender Speed of 61 mpm
[0106] 8) Winder Speed of 64 mpm
[0107] 9) Calendering Conditions: 265.degree. F. Top/262.degree. F.
(Bottom); 200 PLI Nip Pressure
[0108] B. Preparation of CSNs with 5% S-1242 and with 5%
S-1243:
[0109] 1) Increase Calender Temps to 290.degree. F. Top/286.degree.
F. Bottom
[0110] 2) Increase PLI to 618
[0111] 3) Unwind unbonded carded cotton-blend webs onto unbonded
spunbond filament web prior to calender
[0112] 4) Other conditions same as "A" above with run of no cotton
with S-1242 and S-1243 in spunbond polypropylene.
[0113] In all of the above runs, the belt speed, calender speed and
winder speeds were simply reduced to produce 17 gsm spunbond
polypropylene with and without 4% and 6% S-1180 and 5% S-1242 and
S-1243 for subsequent preparation of CCNs and SCNs for thermal
bonding and ultrasonic bonding.
[0114] The spunbond EASTAR BIO was produced on a 1.0 m Reicofil 2
spunbond line. First, two 200-meter rolls comprising 25 and 48 gsm
spunbond EASTAR BIO were produced without the application of
cotton-blended surface webs. Then, carded 11 and 25 gsm webs of 70%
bleached cotton/30% bicomponent staple consisting of a core of
polypropylene and a sheath of EASTAR BIO were unwound onto a 48 gsm
and 25 gsm EASTAR BIO spunbond web just before the calendaring
component of the spunbond line. Excellent bonding of the cotton
blended webs to the spunbond EASTAR BIO webs has been achieved and
these essentially biodegradable CSNs are highly absorbent and are
elastic in all directions with good strength and dimensional
stability. If complete biodegradability is desired, the
polypropylene in the bicomponent fiber may be replaced with an
inelastic biodegradable fiber such as poly(lactide). The spunbond
conditions on the 1.0 m spunbond line for the preparation of 25 gsm
spunbond EASTAR BIO were as follows:
[0115] A. Preparation of 25 gsm spunbond EASTAR BIO without cotton
web addition:
[0116] 1) Extruder: Zone 1.1-332.degree. F. (166.7.degree. C.);
Zone 1.4-378.degree. F. (192.degree. C.)
[0117] 2) Die Zones: Die 4.1-405.degree. F. (207.degree. C.); Die
4.4-384.degree. F. (195.6.degree. C.); Die 4.7-404.degree. F.
[0118] 3) Melt temp: Die 1-365.degree. F. (185.degree. C.); Die
2-389.degree. F. (198.degree. C.)
[0119] 4) Thru-put of 0.15 g/h/m
[0120] 5) Quench Air Temp of 46.degree. F.; Cooling Air Blower at
1859 RPM
[0121] 6) Suction Fan at 1652 RPM
[0122] 7) Belt Speed of 41 meters/min. (mpm)
[0123] 8) Calender speed of 53 mpm
[0124] 9) Winder Speed of 55 mpm
[0125] 10) Calendering Conditions: Top Roll-171.degree. F.; Bottom
Roll-167.degree. F.; 53 PLI Nip
[0126] B. Preparation of CSNs on 25 gsm spunbond EASTAR BIO:
[0127] 1) Increase calender nip to 544 PLI and leave all of the
above "A" conditions the same
[0128] 2) Unwind the carded cotton-blend webs onto the unbonded 25
gsm EASTAR BIO filament web prior to the thermal calender.
[0129] The spunbond runs conditions for the 48 gsm EASTAR BIO were
as follows:
[0130] A. Preparation of 48 gsm spunbond EASTAR BIO without cotton
web addition:
[0131] 1) Extruder: Zone 1.1-330.degree. F. (165.6.degree. C.);
Zone 1.4-377.degree. F. (191.7.degree. C.)
[0132] 2) Die Zones: Die 4.1-405.degree. F. (207 C.); Die
4.4-377.degree. F. (191.7.degree. C.); Die 4.7-405.degree. F.
[0133] 3) Melt temp: Die 1-365.degree. F. (185.degree. C.); Die
2-389.degree. F. (198.degree. C.)
[0134] 4) Thru-put of 0.15 g/h/m
[0135] 5) Quench Air Temp of 40.degree. F.; Cooling Air Blower at
1865 RPM
[0136] 6) Suction Fan at 1652 RPM
[0137] 7) Belt Speed of 41 meters/min. (mpm)
[0138] 8) Calender speed of 26 mpm
[0139] 9) Winder Speed of 28 mpm
[0140] 10) Calendering Conditions: Top Roll-171.degree. F.; Bottom
Roll-167.degree. F.; 52 PLI Nip
[0141] B. Preparation of CSNs on 48 gsm spunbond EASTAR BIO:
[0142] 1) Increase calender nip to 544 PLI and leave all of the
above "A" conditions the same
[0143] 2) Unwind the carded cotton-blend webs onto the unbonded 48
gsm EASTAR BIO spunbond filament web prior to the thermal
calender
[0144] In a further embodiment, thermally-point bonded CCNs may be
thermally-point bonded using the same calendering conditions as
described herein above. CCNs to be thermally-point bonded may be
prepared by depositing a carded cotton blend web of the appropriate
weight, composition, and width onto a predetermined spunbond
polypropylene, e.g. 17 gsm, with the specified wetting agent. Then
a meltblown polypropylene web, e.g. 12 gsm, may be laid onto the
laminate on the side opposite from the spunbond web. Un-bonded CCN
may then be unrolled such as onto a 1.0 m Reicofil 2 spunbond line,
e.g. without the spunbond extrusion die in operation, and run
through a thermal calender with the meltblown side positioned
against a patterning device, e.g. a heated raised diamond patterned
(14.7% bonding area) steel roller, and the spunbond polypropylene
web positioned against a second device, e.g. a heated bottom smooth
steel roller. In an embodiment, the patterned roller temperature
was 266.degree. F., the bottom smooth roller was 261.degree. F.,
the nip pressure was 500 PLI, and the calender surface speed was 20
meters/min.
[0145] In a further embodiment, CCN and CSN laminates may be
ultrasonically bonded, such as using a Branson 184V 20 kHz
laboratory unit. In an embodiment, one of two 10-inch wide
ultrasonic horns was engaged on the laboratory unit. The setting on
the laboratory unit was 60 with a 20 load factor and the gap was 15
mils. The fabric speed through the unit was 2 meters/min.
[0146] When CCN or SCN were ultrasonically bonded, the highly
elastic meltblown or spunbond EASTAR BIO webs could not be on the
side next to the ultrasonic horn, but had to be placed on the side
against the patterned roller since the vibrating horn would
otherwise pinch up under the elastic web causing it to tear.
[0147] In certain embodiments, in order to improve the
biodegradability of cotton-based non-wovens, different types of
wetting agents were added to the non-biodegradable spunbond
polypropylene layer of CSNs and CCNs to better enable water to
better penetrate into the structures and enhance the biodegradation
process of cotton and other naturally degradable components.
Wetting agents were also added to improve the absorption and
wicking performance of CSNs and CCNs for personal hygiene
applications such as baby diapers, sanitary napkins, panty liners
and pre-wetted wipes, as well as for wound dressings and absorbent
pads in meat packaging.
[0148] As shown in Table 2, CSN "o" consists of a 2-layer thermally
point bonded laminate with a carded 13 g/m2 (gsm) web of 50%
bleached (Ed Hall) cotton/50% staple polypropylene (FiberVisions
T-196) with a hydrophilic finish on top of a 12 gsm spunbond
polypropylene substrate containing 6% Polyvel S-1180 wettable
concentrate, as mixed in pellet with Exxon 35 MFR polypropylene
3155 pellets prior to the spunbond process. The concentration of
silicone-based wetting agent in the S-1100 was 15%, resulting in a
net active add-on of wetting agent of 0.9%. CSN "s" only differed
from "o" in that the top 13 gsm carded web consisted of a blend of
60% bleached cotton and 40% staple polypropylene T-196. The target
weight of both of these samples was 25 gsm and as can be seen in
Table 2, the actual weights of "o" and "s" were very close at 24.1
and 25.9 gsm, respectively, and the thickness measurements were
0.31 and 0.31 mm. Both samples also have excellent air
permeability, an important attribute for thermal comfort for items
worn on or near the body. However, Sample "o", which had the lower
cotton content of 50% exhibited very poor wettability, in that no
uptake of water resulted during testing with the ATS-600 unit when
the spunbond polypropylene side with 6% S-1100 was subjected to the
initial pulse of water to start the test cycle. When the
cotton/polypropylene blend side was turned down and subjected the
wetting challenge, a small maximum absorption of 2.9 grams of water
per gram of sample resulted. Sample "s", which had 60% cotton
allowed some wetting to occur on the spunbond polypropylene side
(3.4 g/g) and had a slightly higher absorption of 4.4 g/g from the
cotton side. The apparently improved wettability of the spunbond
polypropylene side with the higher cotton content on the opposite
side may be explained by the fact that these are comparatively thin
samples with the cotton and spunbond polypropylene fibers being
intermingled at the interface and a greater number of cotton fibers
would be in a position to wick water through the sample to the
cotton-based side.
2TABLE 2 Weight, Thickness, Air Permeability and Maximum Amount of
Water Absorbed and Absorption Rate of Thermally Bonded (TB) CSNs
Containing 12 gsm spunbond polypropylene Substrate with
Silicone-based Wettable Concentrate Maximum Air Absorption
Absorption Permeability (g/g) & Sec Rate-1.sup.st 60 Sample
Weight Thickness (cm.sup.3/ in Test sec (g/g/s) No. Description
(gsm) (mm) cm.sup.2/s) C-up/C-dn C-up/C-dn "o" 13 gsm 50/50 24.1
0.31 222.8 nw 2.9 nw 0.04 C/polypropylene (64) 12 gsm spunbond
polypropylene/6% S-1180 (Silicone) "s" 13 gsm 60/40 25.9 0.32 277.9
3.4 4.4 0.05 0.07 C/polypropylene (180) (58) 12 gsm spunbond
polypropylene/6% S-1180 (Silicone) Notes: C-up - cotton side up and
polypropylene side down and exposed directly to water challenge.
C-dn - cotton side down and exposed directly to wetting challenge.
Time of wetting test is in seconds and in parenthesis. nw - sample
does not wet from that side.
[0149] Given the less than anticipated wetting performance with the
S-1180 silicone-based wetting concentrate in the spunbond
polypropylene, two fluorosurfactant based wetting agents were
obtained from Polyvel, Inc. of Hammonton, N.J. The fluorosurfactant
wetting agents are comparatively more expensive than silicone-based
compounds, but may be more effective in enhancing polypropylene
wetting performance. The two fluorosurfactant concentrates
evaluated were S-1242, a monomer-based fluorosurfactant, and
S-1243, a polymer-based fluorosurfactant. Both concentrates were
mixed with Exxon polypropylene 3155 pellets at a level of 5%,
resulting in a calculated add-on of 0.5% of the fluorosurfactant
wetting agent on the spunbond fabric. As shown in Table 3, the
first two identical samples in Table 3, D3PP1 and D3PP2, which had
a 5% addition of S-1242, the monomer-based fluorosurfactant, to the
spunbond polypropylene did not take up any water from either the
50/50 cotton/staple polypropylene side or the spunbond
polypropylene side during testing on the ATS-600 unit. However, as
with the 6% addition of S-1180 to the spunbond polypropylene, the
CSNs with 5% S-1242 in spunbond polypropylene and with a top web of
60% cotton/40% staple polypropylene (D4aPP and D4bPP) exhibited
some uptake of water. On the other hand, CSNs with 5% addition of
the polymer-based fluorosurfactant, S-1243, with both the 50/50
cotton/polypropylene and 60/40 cotton/polypropylene, top webs
generally exhibited notably high maximum absorption values and
absorption rates. It is believed that the polymer-based
fluorosurfactant (S-1243) is less likely to be volatilized off or
decomposed by the heat of the spunbond extrusion process and that
the polymer molecules will be slower in migrating from the interior
of the spunbond polypropylene filaments to the surface, where the
fluorosurfactant can be volatized or can be readily washed off.
Nevertheless, the cotton/polypropylene side of these CSNs had
appreciably higher maximum absorption and absorption rates than did
the very wettable spunbond polypropylene side. Sample H1PP, which
had 5% S-1243 in the spunbond polypropylene only absorbed a small
amount of water on both sides; however, the gray cotton was not
scoured or bleached in the top 36 gsm web of 50% Bealls Grade 1
reginned cotton motes/50% polypropylene staple, was very
non-absorbent since the natural pectins and waxes were still on the
fiber.
3TABLE 3 Weight, Thickness, Air Permeability and Maximum Amount of
Water Absorbed and Absorption Rate of TB CSNs Containing 12 gsm
spunbond polypropylene Substrate with 5% of Two Fluorosurfactant
(FS) Concentrates Maximum Air Absorption Absorption Permeability
(g/g) & Sec Rate-1.sup.st 60 Sample Weight Thickness (cm.sup.3/
in Test sec (g/g/s) No. Description (gsm) (mm) cm.sup.2/s)
C-up/C-dn C-up/C-dn D3PP1 13 gsm 50/50 26.0 0.33 334 nw nw nw nw
C/polypropylene 12 gsm spunbond polypropylene/5% S-1242
fluorosurfactant D3PP2 Same as D3PP1 27.3 0.26 277.0 nw nw nw nw
D4aPP 13 gsm 60/40 24.7 0.31 328.5 3.3 4.0 0.04 0.07
C/polypropylene (180) (180) 12 gsm spunbond polypropylene/5% S-1242
fluorosurfactant D4bPP Same as D4aPP 29.6 0.30 288.7 6.4 0.14 (200)
G2aPP 13 gsm 50/50 26.6 0.31 170.3 C/polypropylene 12 gsm spunbond
polypropylene/5% S-1243 fluorosurfactant G2bPP Same as G2aPP 27.0
0.30 295.2 7.3 15.9 0.05 0.15 (250) (298) G3aPP 13 gsm 60/40 24.8
0.28 311.6 nw 12.2 nw 0.11 C/polypropylene (252) 12 gsm spunbond
polypropylene/5% S-1243 fluorosurfactant G3bPP Same as G3aPP 24.5
0.28 321.2 G3cPP Same as G3aPP 27.5 0.34 295.8 8.3 13.5 0.20 0.35
(180) (100) H1PP 36 gsm 50/50 64.8 0.66 167.4 0.9 0.4 0.04 0.02
Bealls Gr 1 Gin (20) (20) (1.sup.st Motes/ 20 polypropylene sec 12
gsm spunbond for polypropylene/5% both) S-1243 fluorosurfactant
[0150] Table 4 illustrates weight, thickness, air permeability and
absorption properties for CSNs with a carded cotton blend web on 25
and 48 gsm spunbond EASTAR BIO. The CSNs in Table 4 have air
permeability values comparable to similarly constructed CSNs in
Table 1 and 2 even though both EASTAR BIO spunbond fabrics are much
heavier than 12 gsm spunbond polypropylene. Samples D1E and D3E
have top carded webs with weights of 12.5 and 22.6 gsm consisting
of 70% bleached cotton and 30% bicomponent (bico) staple fiber with
a core of polypropylene and a sheath of EASTAR BIO, on a 25 gsm
spunbond EASTAR BIO. Except for the polypropylene component used in
the blend with cotton, these samples are biodegradable. The
polypropylene in the bicomponent fiber can be replaced with a
biodegradable fiber such as poly(lactide), which also had the high
modulus required for carding, and thereby make the CSN completely
biodegradable. Samples D1E and D3E have maximum absorption values
and absorption rates comparable to the CSNs in Table 2 with 5% of
the polymer-based fluorosurfactant (S-1243) in spunbond
polypropylene. Sample "ah", which had a 25 gsm carded 70%
cotton/30% bicomponent polypropylene/EASTAR BIO on a 48 gsm
spunbond EASTAR BIO, had similar absorbency to Samples D1E and D3E,
when tested with the cotton blend side up, but when the cotton side
was down and subjected to the wetting charge on the ATS-600 unit,
the sample transported the water in a manner that resulted in water
being left on the testing table in puddles and possibly
contributing to an error in absorbency testing.
4TABLE 4 Weight, Thickness, Air Permeability and Maximum Amount of
water Absorbed and Absorption Rate of TB CSNs Containing 25 gsm and
48 gsm spunbond EASTAR BIO Substrates Maximum Air Absorption
Absorption Permeability (g/g) & Sec Rate-1.sup.st 60 Sample
Weight Thickness (cm.sup.3/ in Test sec (g/g/s) No. Description
(gsm) (mm) cm.sup.2/s) C-up/C-dn C-up/C-dn D1E 12.5 gsm 70 C/30
42.0 0.37 310.6 11.5 15.6 0.09 0.21 Bico (219) (94) polypropylene/
Eastar 25 gsm spunbond EASTAR BIO D3E 22.6 gsm 70 C/30 56.8 0.52
184.9 11.3 11.8 0.18 0.19 Bico 80) (70) polypropylene/ Eastar 25
gsm spunbond Eastar Bio E1E 13 gsm 60/40 35.4 0.30 327.2
C/polypropylene 25 gsm spunbond Eastar Bio E4E 40 gsm 50 Beals 97.2
1.12 197.1 Grade 1 Cotton Reginned Motes/ 50 polypropylene 25 gsm
spunbond Eastar Bio "ah" 25 gsm 70 C/30 74.7 0.48 115.8 10 pdl
0.163 pdl Bico (86) polypropylene/ Eastar 48 gsm spunbond Eastar
Bio Pdl - water quickly taken up and puddles on testing table
[0151] The effects of silicone-based and fluorosurfactant wettable
concentrates in the spunbond components of thermally point-bonded
CCN samples are shown in Table 5. CCN Sample 9/12D had a 12 gsm
meltblown polypropylene on the top against the diamond patterned
heated calendar roll during thermal bonding of the laminate, a
center core of 40 gsm carded 50% Bealls Grade 1 unbleached reginned
cotton motes/50% staple polypropylene, and a 17 gsm spunbond
polypropylene web containing 6% silicone based S-1100 against the
bottom heated smooth steel calendar roll The fact that the reginned
cotton motes had not been scoured and bleached likely contributed
to the lack of absorbency of this sample. However, Sample 9/12C
which ad a similar construction, except the 51 gsm core had 60%
scoured and bleached cotton and 40% staple polypropylene, had
notable absorbency when tested from the wettable spunbond side. The
meltblown side of the CCNs would not be expected to readily absorb
water since the meltblown webs were not treated with wetting agents
(although it is feasible to do so) and since the meltblown webs
have very fine microfibers with high cover factor compared to
spunbond webs. Nevertheless, CCN Sample 9/12D, which had the same
construction as 9/12C, except that 5% S-1243 fluorosurfactant was
added to the spunbond side, had some absorbency on the meltblown
side.
5TABLE 5 Weight, Thickness, Air Permeability and Maximum Amount of
Water Absorbed and Absorption Rate of Thermally Bonded (TB) CCNs
Containing 12 gsm spunbond polypropylene with Silicone-based and
Fluorosurfactant (FS) Wettable Concentrates Maximum Air Absorption
Absorption Permeability (g/g) & Sec Rate-1.sup.st 60 Sample
Weight Thickness (cm.sup.3/ in Test sec (g/g/s) No. Description
(gsm) (mm) cm.sup.2/s) S-up/S-dn S-up/S-dn TB Top Web- 106.4 0.76
22.1 nw nw Nw nw CCN 12 gsm MB 9/12A polypropylene (against diamond
roll) Core - 40 gsm 50% Bealls Gr 1/50% polypropylene Bottom Web-
17 gsm spunbond polypropylene w 6% S- 1180(Silicone) TB Top Web-
79.2 0.622 20.4 nw 5.6 Nw 0.10 CCN 12 gsm MB (59.7) 9/12C
polypropylene (against diamond roll) Core - 51 gsm 60% Cotton/40%
polypropylene Bottom Web- 17 gsm spunbond polypropylene w 6% S-1180
(Silicone) TB Top Web- 81.23 0.63 19.3 3.5 4.9 0.03 0.09 CCN 12 gsm
MB (169) (57.8) 9/12D polypropylene (against diamond roll) Core -
51 gsm 60% Cotton/40% polypropylene Bottom Web- 17 gsm spunbond
polypropylene w 5% S-1243 fluorosurfactant S-up - Spunbond side up
and MB side down and exposed directly to water challenge. S-dn -
Spunbond (SB) side down and exposed directly to wetting
challenge
[0152] Furthermore, another highly effective wetting agent, CIBA
IRGASURF HL 560, has been reported in the product literature of
Ciba Specialty Chemicals of Tarrytown, N.Y. It may be mixed as a
concentrate in pellet form with 35 MMR polypropylene pellets before
melt extrusion in the spunbond or meltblown processes.
[0153] Ultrasonic bonding, like infrared bonding described in the
previous section, is a bonding technique which does not compress a
laminate as much as thermal point-bonding in a calendar. Thus
ultrasonic bonding was investigated as a technique for thermally
point-bonding CCN and CSN laminates for sufficient strength for
possible use in hygienic applications, while maintaining high loft
(greater bulk) in the structure for absorbing and holding liquid.
All of the ultrasonically bonded CCNs in Table 6 have high
thickness ranging from 1.0-1.5 mm and high maximum absorption when
tested from either the meltblown EASTAR BIO sides or on the
spunbond sides. All of these samples had very rapid absorption
rates when tested from both sides, especially CCN 9/23A-PLA, which
had a spunbond poly(lactide) web on the top side against the
ultrasonic horn, a 44 gsm core of 70% bleached cotton and 30%
bicomponent polypropylene/EASTAR BIO staple binder fiber and a
bottom web of meltblown EASTAR BIO against the patterned roller
during ultrasonic bonding. However, EASTAR BIO is very hydrophilic
in both staple fiber and meltblown components. No difference in the
absorption properties were seen between UB CCN 9/23B, which had a
17 gsm spunbond polypropylene web with 6% silicone based S-1180 on
top against the horn, and Sample 9/23C, which had a 17 gsm spunbond
polypropylene with 5% polymer-based fluorosurfactant 1243. Both of
these samples also had a heavy (51 gsm) core of 60% cotton/40%
staple polypropylene and a bottom 27 gsm meltblown EASTAR BIO web
against the patterned roller. It was not possible to bond any of
the samples in Table 6 when the meltblown EASTAR BIO web was placed
on top next to the ultrasonic horn because the vibrating horn would
pinch the elastic EASTAR BIO web and after accumulating some
material under the horn tore holes in the web. On the other hand,
when the inelastic webs such as spunbond polypropylene or spunbond
poly(lactide) were placed on top against the ultrasonic horn, the
laminates were easily ultrasonically bonded without tearing.
6TABLE 6 Weight, Thickness, Air Permeability and Maximum Amount of
Water Absorbed and Absorption Rate of Ultrasonically Bonded (UB)
CCNs Containing Wettable spunbond polypropylene Webs and MB and
spunbond Eastar Bio Webs Maximum Air Absorption Absorption
Permeability (g/g) & Sec Rate-1.sup.st 60 Sample Weight
Thickness (cm.sup.3/ in Test sec (g/g/s) No. Description (gsm) (mm)
cm.sup.2/s) S-up/S-dn S-up/S-dn UB Top Web-17 92.2 1.0 119.9 9.5
8.8 0.16 0.12 CCN gsm spunbond (81.3) (150) 9/23B polypropylene w
6% S-1180 (Silicone) against Horn Core - 51 gsm 60% C/40%
polypropylene Bottom Web-27 gsm MB Eastar Bio UB Top Web-17 96.1
1.1 118.9 9.6 8.8 0.16 0.12 CCN gsm spunbond (77) (151.7) 9/23C
polypropylene w 5% S-1243 (Fluorosurfactant) against Horn Core - 51
gsm 60% C/40% polypropylene Bottom Web-27 gsm MB Eastar Bio UB Top
Web-20 124.3 1.5 85.6 10.8 9.82 0.18 0.29 CCN gsm spunbond (69.7)
(33.7) (1.sup.st 9/23A- poly(lactide) 33.7 s) PLA against Horn Core
- 44 gsm 70% C/30% Bico polypropylene Core/Eastar Bio Sheath Bottom
Web-27 gsm MB Eastar Bio S-up - spunbond side up and MB Eastar side
down and exposed directly to water challenge. S-dn - Spunbond (SB)
side down and exposed directly to wetting challenge
[0154] The effects of ultrasonically bonding CSNs are illustrated
in Table 7. As with the meltblown EASTAR BIO webs above, it was
necessary to place the elastic spunbond EASTAR BIO webs on the
bottom against the patterned roller to avoid tearing of the Eastar
web. With CSN Samples 9/23E and 9/23F, the 48 gsm carded 60/40
cotton/polypropylene webs were placed on top against the horn and
UB proceeded with no problem. CSN Sample 9/23B-PLA also bonded well
with the spunbond poly(lactide) web on top. All of these samples
had comparatively good bulk and air permeability. Samples 9/23E and
9/23F demonstrated excellent maximum absorbency and absorption rate
on the when tested on the spunbond side (cotton side up), but the
problem with puddles being observed on the ATS-600 testing table,
which could cause errors in absorbency determinations, occurred
when all three of the samples in Table 7 were tested on the cotton
side. CSN Sample 9/23B-PLA, however, did not appear to wet when
tested from the spunbond poly(lactide) side.
7TABLE 7 Weight, Thickness, Air Permeability and Maximum Amount of
Water Absorbed and Absorption Rate of Ultrasonically Bonded (UB)
CSNs Containing Wettable spunbond Webs and spunbond Eastar Bio Webs
Maximum Air Absorption Absorption Permeability (g/g) & Sec
Rate-1.sup.st 60 Sample Weight Thickness (cm.sup.3/ in Test sec
(g/g/s) No. Description (gsm) (mm) cm.sup.2/s) C-up/C-dn C-up/C-dn
UB Top Web - 48 88.7 0.85 138.5 13.1 pdl 0.21 pdl CSN gsm 60%
(90.7) 9/23E C/40% polypropylene (against Horn) Bottom Web- 25 gsm
spunbond Eastar Bio UB Top Web - 48 69.8 0.92 221.6 21.9 pdl 0.34
pdl CSN gsm 60% (101) 9/23F C/40% polypropylene (against Horn)
Bottom Web- 25 gsm spunbond Eastar Bio UB Top Web-20 36.7 0.50
225.3 Nw pdl nw pdl CSN gsm spunbond 9/23B- poly(lactide) PLA
(against Horn) Botton Web- 11 gsm 70% C/30% Bico polypropylene
Core/Eastar Bio Sheath C-up - Cotton side up and spunbond side down
and exposed directly to water challenge. C-dn - Cotton side down
and exposed directly to wetting challenge nw - side did not wet pdl
- water quickly taken up and puddles on testing table
[0155] As illustrated in Table 8, the calender point-bonded CSN
Samples "o" and "s" had good strength properties with the
cross-machine direction ("CD") tearing strength values being about
40% greater than the machine direction ("MD") values.
8TABLE 8 Strength Properties of TB CSNs Containing 12 gsm spunbond
polypropylene Substrate with Silicone-based Wettable Concentrate
Tearing Breaking Strength Sample Load Breaking (KG) No. Description
(KG) Elongation (%) MD CD "o" 13 gsm 50/50 1.58 53.0 0.16 0.23
C/polypropylene 12 gsm spunbond polypropylene/6% S-1180 (Silicone)
"s" 13 gsm 60/40 1.87 37.7 0.13 0.19 C/polypropylene 12 gsm
spunbond polypropylene/6% S-1180 (Silicone)
[0156] Likewise, the calender point-bonded CSNs in Table 9 had
excellent tearing strength with the cross-machine direction values
again being much higher. On the other hand, machine direction
breaking load values were more than twice the cross-machine
direction values. However, breaking elongations were more similar
between meltblown and cross-machine direction, with these values
ranging from 51-82%, even without elastomeric components such as
meltblown or spunbond EASTAR BIO, are highly extensible.
9TABLE 9 Strength Properties of TB CSNs Containing 12 gsm spunbond
polypropylene Substrate with 5% of Two Different Fluorosurfactant
(FS) Concentrates Breaking Tearing Breaking Elongation Strength
Sample Load (KG) (%) (KG) No. Description MD CD MD CD MD CD D3PP1
13 gsm 50/50 C/polypropylene 1.46 0.77 61.8 74.3 0.34 0.40 12 gsm
spunbond polypropylene/5% S-1242 fluorosurfactant D3PP2 Same as
D3PP1 D4aPP 13 gsm 60/40 C/polypropylene 1.78 0.62 67.8 68.0 0.18
0.30 12 gsm spunbond polypropylene/5% S-1242 fluorosurfactant D4bPP
Same as D4aPP 1.68 0.61 62.9 67.6 0.23 0.51 G2aPP 13 gsm 50/50
C/polypropylene 12 gsm spunbond polypropylene/5% S-1243
fluorosurfactant G2bPP Same as G2aPP 1.71 0.58 63.6 65.1 0.21 0.31
G3aPP 13 gsm 60/40 C/polypropylene 1.71 0.73 51.3 73.2 0.20 0.27 12
gsm spunbond polypropylene/5% S-1243 fluorosurfactant G3bPP Same as
G3aPP 1.97 62.8 0.19 0.34 G3cPP Same as G3aPP 1.64 68.9 0.15 0.34
H1PP 36 gsm 50/50 Bealls Gr 1 Gin 1.72 0.71 72.7 82.5 0.30 0.41
Motes/polypropylene 12 gsm spunbond polypropylene/ 5% S-1243
fluorosurfactant
[0157] In Table 10, the strength and breaking elongation properties
of calender point-bonded CSNs with cotton-blend webs on 25 and 48
gsm spunbond EASTAR BIO are illustrated. As with the CSNs having 12
gsm wettable spunbond polypropylene as the substrate described
above, all of the samples in Table 10 had excellent breaking load
and tearing strength, and the machine direction breaking loads were
greater than the cross-machine direction values, and the
cross-machine direction tearing strength values were greater in the
cross-machine direction than in the machine direction. However, the
breaking elongations were much higher in both machine direction and
cross-machine direction directions with the elastic 25 and 48 gsm
spunbond EASTAR BIO substrates than with the relatively inelastic
12 gsm spunbond polypropylene webs.
10TABLE 10 Strength Properties of Thermally Bonded (TB) CSNs
Containing 25 gsm and 48 gsm spunbond EASTAR BIO Substrate Breaking
Tearing Breaking Elongation Strength Sample Load (KG) (%) (KG) No.
Description MD CD MD CD MD CD D1E 12.5 gsm 70 C/30 Bico 0.49 0.27
88.9 125.4 0.26 0.41 polypropylene/Eastar 25 gsm spunbond EASTAR
BIO D2aE 11 gsm 60 C/40 Bico 2.93 2.04 133.5 156.6 0.50 0.97
polypropylene/Eastar 25 gsm spunbond Eastar Bio D2bE Same as D2aE
0.40 0.32 84.7 114.5 0.21 0.43 D3E 22.6 gsm 70 C/30 Bico 0.50 0.29
68.4 119.4 0.21 0.40 polypropylene/Eastar 25 gsm spunbond Eastar
Bio E1E 13 gsm 60/40 C/polypropylene 0.59 0.34 60.5 61.7 0.20 0.34
25 gsm spunbond Eastar Bio E4E 40 gsm 50 Beals Grade 1 0.60 0.35
89.0 110.5 0.20 0.37 Cotton Reginned Motes/50 polypropylene 25 gsm
spunbond Eastar Bio "ah" 25 gsm 1.42 0.50 99.6 130.5 0.27 0.60 70
C/30 Bico polypropylene/Eastar 48 gsm spunbond Eastar Bio
[0158] Significant progress was also made in developing the
technology for the meltblown and spunbond processing of
thermoplastic polyurethanes. During preliminary meltblown trials it
was observed that the thermoplastic polyurethane filaments were
often traveling horizontally from meltblown die only a few inches
or more, depending on air flow rates, before dropping vertically
towards the floor. This observation coupled with the fact that
relatively large diameter meltblown fibers were being produced led
us to believe that we had been going in the wrong direction with
respect to spinneret hole diameter and air knife gap. With many
high melt viscosity polymers such as polyesters and nylons, a large
hole die (0.018 inch hole diameter compared to the standard hole
diameter of 0.0145 in.) and larger air knife gap of 0.090 inches
actually results in finer fibers and softer webs. However, based on
our observations described above, the standard die tip with 0.0145
in. diameter holes and with an L/D of 8.5/1 and a hole density of
25 holes/inch was used. Also, the air knife gap on both sides of
the nose tip was reduced to 0.030 in. and the die tip setback to
0.030 in. These innovations enabled us to produce uniform meltblown
thermoplastic polyurethane webs with fiber diameters of 5
micrometers, well in the microfiber range (data not shown).
[0159] In an effort to successfully produce spunbond thermoplastic
polyurethane, which would enable the production of cotton-surfaced
spunbond thermoplastic polyurethane, Noveon, Inc. of Cleveland,
Ohio designed two resins, 58283-045 and X-4981-045, which were
re-extruded to lower molecular weight, and a filler was added to
both resins to minimize sticking of the extruded filaments before
quenching.
[0160] Estane 58238-045 was first run on a 1.0 meter Reicofil 2
spunbond line. Although this thermoplastic polyurethane had a
higher melt index than Estane 58280, there were still problems with
pressure surges in the extruder and spunbond die at the same die
temperature of 380.degree. F. Nevertheless, some thermoplastic
polyurethane filaments were processed through the spunbond die to
produce some spunbond fabric. The filaments still stuck together
forming bundles of filaments, although the sticking problem was not
as pronounced as before.
[0161] Thermally-point bonded laminates of meltblown and spunbond
thermoplastic polyurethane webs produced strong, highly elastic
composites with excellent cover factor and barrier performance
being provided by the meltblown component with its microfibers.
Furthermore, cotton-based webs have been bonded in preliminary
trials by this inventor to meltblown thermoplastic polyurethane,
spunbond thermoplastic polyurethane and to meltblown/spunbond
laminated thermoplastic polyurethane webs to produce strong highly
elastic fabrics with cotton on one or both sides for enhanced wear
comfort, absorption, and biodegradability of the cotton
component.
[0162] Some properties of thermally or ultrasonically bonded CCNs
are illustrated in Tables 11-13.
11TABLE 11 Strength Properties of Thermally Bonded (TB) CCNs
Containing 12 gsm spunbond polypropylene Substrate with
Silicone-based and Fluorosurfactant (FS) Concentrates Breaking
Breaking Tearing Load Elongation Strength (KG) (%) (KG) Sample No.
Description MD CD MD CD MD CD TB CCN 9/12A Top Web- l2 gsm MB 2.86
41.9 0.31 0.44 polypropylene (against diamond roll) Core- 40 gsm
50% Bealls Gr 1/50% polypropylene Bottom Web- 17 gsm spunbond
polypropylene w 6% S-1180 (Silicone) TB CCN 9/12C Top Web- l2 gsm
MB 2.91 48.5 0.32 0.46 polypropylene (against diamond roll) Core-
51 gsm 60% Cotton/ 40% polypropylene Staple Bottom Web- 17 gsm
spunbond polypropylene w 6% S-1180 (Silicone) TB CCN 9/12D Top Web-
l2 gsm MB 1.72 49.9 0.43 0.68 polypropylene (against diamond roll)
Core- 51 gsm 60% Cotton/ 40% polypropylene Staple Bottom Web- 17
gsm spunbond polypropylene w 5% S-1243 fluorosurfactant
[0163]
12TABLE 12 Strength Properties of Ultrasonically Bonded (UB) CCNs
Containing Wettable spunbond Webs and spunbond EASTAR BIO Webs
Tearing Breaking Breaking Strength Sample Load Elongation (KG) No.
Description (KG) (%) MD CD UB Top Web- 17 gsm spunbond 3.27 73.3
0.29 0.50 CCN polypropylene w 6% S-1180 (Silicone) 9/23B against
Horn Core- 51 gsm 60% C/40% polypropylene Bottom Web- 27 gsm MB
EASTAR BIO UB Top Web- 17 gsm spunbond 0.99 73.5 0.59 0.77 CCN
polypropylene w 5% S-1243 9/23C (Fluorosurfactant) against Horn
Core- 51 gsm 60% C/40% polypropylene Bottom Web- 27 gsm MB EASTAR
BIO UB Top Web- 20 gsm spunbond poly(lactide) 0.54 34.1 0.40 0.71
CCN against Horn 9/23A- Core- `44 gsm 70% C/30% Bico PLA
polypropylene Core/EASTAR BIO Sheath Bottom Web- 27 gsm MB EASTAR
BIO
[0164]
13TABLE 13 Strength Properties of Ultrasonically Bonded (UB) CSNs
Containing Wettable spunbond Webs and spunbond EASTAR BIO Webs
Breaking Breaking Tearing Load Elongation Strength Sample (KG) (%)
(KG) No. Description MD CD MD CD MD CD UB Top Web- 48 gsm 60% C/40%
1.22 69.0 0.29 0.73 CSN polypropylene (against Horn) 9/23E Bottom
Web- 25 gsm spunbond EASTAR BIO UB Top Web- 48 gsm 60% C/40% 0.23
67.6 0.22 0.49 CSN polypropylene (against Horn) 9/23F Bottom Web-
25 gsm spunbond EASTAR BIO UB Top Web- 20 gsm spunbond 0.49 20.9
0.31 0.42 CSN poly(lactide) (against Horn) 9/23B- Botton Web- 11
gsm 70% C/30% Bico PLA polypropylene Core/EASTAR BIO Sheath
[0165] EASTAR BIO meltblown bonded better than did the meltblown
polypropylene webs in that the CCN laminates produced with
meltblown polypropylene and spunbond polypropylene webs had to be
run through the infrared bonding unit twice so that each side could
be exposed directly to the infrared radiation. The EASTAR BIO
meltblown web resulted in very well bonded laminate in one pass
through the infrared unit. In addition to having better infrared
thermal bonding performance than meltblown polypropylene and
spunbond polypropylene, EASTAR BIO meltblown web resulted in
exceptionally good wetting and wicking performance compared to the
polypropylene web. Further the EASTAR BIO is completely
biodegradable thereby making the composite more biodegradable.
Heat-Stretching resulted in higher tearing strength and tenacity of
laminates. Heat-Stretching produced webs of softer hand and a
greater directional wetting in the machine direction.
[0166] It will be understood that various changes in the details,
materials, and arrangements of the parts which have been described
and illustrated above in order to explain the nature of this
invention may be made by those skilled in the art without departing
from the principle and scope of the invention as recited in the
appended claims.
* * * * *