U.S. patent application number 10/169681 was filed with the patent office on 2003-11-06 for nonwoven laminate wiping product and proces for its manufacture.
Invention is credited to Annis, Vaughn, Gosavi, Nataraj, Gryskiewicz, Linda M, Gryskiewicz, Stanley M.
Application Number | 20030207636 10/169681 |
Document ID | / |
Family ID | 29269967 |
Filed Date | 2003-11-06 |
United States Patent
Application |
20030207636 |
Kind Code |
A1 |
Gosavi, Nataraj ; et
al. |
November 6, 2003 |
Nonwoven laminate wiping product and proces for its manufacture
Abstract
A nonwoven laminate product comprising a fine denier base web of
thermoplastic material joined to a bulk layer and method of
manufacture thereof. The bulk layer is preferably cellulosic
material and more preferably wood pulp. The nonwoven laminate
product has improved properties of strength, softner and
drapability compared to conventional nonwoven laminate
products.
Inventors: |
Gosavi, Nataraj; (South
Windsor, CT) ; Annis, Vaughn; (South Windsor, CT)
; Gryskiewicz, Stanley M; (Windsor, CT) ;
Gryskiewicz, Linda M; (Windsor, CT) |
Correspondence
Address: |
ALIX YALE & RISTAS LLP
750 MAIN STREET
SUITE 1400
HARTFORD
CT
06103
US
|
Family ID: |
29269967 |
Appl. No.: |
10/169681 |
Filed: |
July 5, 2002 |
PCT Filed: |
January 5, 2001 |
PCT NO: |
PCT/US01/00386 |
Current U.S.
Class: |
442/327 |
Current CPC
Class: |
Y10T 442/60 20150401;
D04H 1/498 20130101; A45D 2200/1018 20130101; D04H 3/016 20130101;
D04H 1/425 20130101; B32B 5/26 20130101; D04H 1/492 20130101; A45D
34/04 20130101 |
Class at
Publication: |
442/327 |
International
Class: |
D04H 005/00 |
Claims
What is claimed is:
1. A composite nonwoven material of enhanced tensile strength
including a nonwoven base web comprising thermoplastic fibers
having a maximum denier of 1.5 and an additional layer overlying a
surface of the base web and intimately entangled with the base
web.
2. The material of claim 1, wherein the thermoplastic fibers have a
denier within the range of 0.5 to 1.2.
3. The material of claim 1, wherein the thermoplastic fibers are
comprised of a material selected from at least one of the group
consisting of polyolefin, propylene, polyester,
polyethylene/polypropylene and polyethylene/polyester.
4. The material of claim 1, wherein the thermoplastic fibers are
substantially continuous spun filaments comprised of a material
selected from at least one of the group consisting of polyolefin,
polyester, polyethylene/polypropylene and
polyethylene/polyester.
5. The material of claim 1 wherein said additional layer is a bulk
layer.
6. The material of claim 1, wherein said additional layer is a bulk
layer comprised of cellulose material.
7. The material of claim 1, wherein said additional layer is a bulk
layer comprised of wood pulp.
8. The material of claim 1 having a basis weight wherein said base
web comprises 20 to 60 percent of the basis weight.
9. The material of claim 1 having a basis weight of less than 100
grams per square meter.
10. The material of claim 1 having a basis weight within the range
of 35 to 75 grams per square meter.
11. The material of claim 1, wherein the base web has a basis
weight of less than 25 grams per square meter.
12. The material of claim 1, wherein the base web has a basis
weight within the range of 9 to 20 grams per square meter.
13. A method of manufacturing a composite nonwoven material having
enhanced tensile and burst strength comprising: providing a
nonwoven base web comprising thermoplastic fibers having a maximum
denier of 1.5; providing a layer adjacent the base web; and
entangling said adjacent layer with said base web to form the
composite nonwoven material.
14. The method of claim 13, wherein said adjacent layer is provided
in substantially dry form.
15. The method of claim 13, wherein said adjacent layer is provided
as a predefined layer of nonwoven cellulose web material.
16. The method of claim 13, wherein said step of entangling
comprises hydroentangling and further including a step of drying
said hydroentangled composite nonwoven material.
17. The method of claim 13 further comprising the step of
compacting the base web and the adjacent layer.
18. The method of claim 13, wherein the step of providing a
nonwoven base web comprises spunbonding a thermoplastic
material.
19. A nonwoven wipe material suited for wet use having a nonwoven
base web comprising thermoplastic fibers having a maximum denier of
1.5 and cellulosic material intimately entangled with the base web,
wherein the nonwoven wipe material has a tensile strength at least
1.5 times greater than a similar nonwoven wipe material having a
base web comprised of filaments with a higher denier.
20. The wet wipe material of claim 19 having a wet tensile strength
at least 2 times greater than a similar nonwoven wipe material
having a base web comprised of filaments with a higher denier.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to nonwoven laminate
products. More particularly, the present invention relates to
nonwoven laminate products having a base web with a fine denier per
filament.
[0002] As used herein, the term "nonwoven laminate product"
comprises a multilayer product having a nonwoven "base" layer
comprised of polymer fibers or filaments produced by an extrusion
process and a nonwoven "bulk" layer, preferably of cellulosic
material, joined thereto. As used herein, the term "nonwoven
laminate product" excludes multiphase materials such as those
described in U.S. Pat. No. 2,414,833, wherein both of the phases or
layers are deposited onto a foraminous member from a
dispersion.
[0003] The inventive nonwoven laminate product may be cut into
individual wiping sheets. While the sheets may be used dry, more
typically the individual sheets are saturated with a chemical
solution suited for the intended end use, stacked and wrapped in a
liquid tight package for subsequent dispensing. The chemical
solution often includes bactericides and other biological control
agents as well as emulsifiers, pH buffers, perfumes and the like.
The liquid tight packaging maintains the saturated condition of the
wiping sheet.
[0004] Such wiping sheets, also called wet wipes or simply, wipes,
are commonly used by consumers for cleaning or wiping, particularly
when wash water is not readily available or cannot be conveniently
used.
[0005] Travelers and parents of small children find such wipes
especially convenient. These wipes have been used for applying or
removing makeup, cleansing parts of the body and as a substitute
for conventional dry toilet paper. The wipes are also useful for
household and industrial cleaning.
[0006] Current nonwoven laminate products have allowed the
marketability to consumers of various desirable properties such as
strength, softness, lotion distribution, cleanability and purity
(i.e., lack of binder) in product applications such as baby wipes.
As will be appreciated, these premoistened wipes must also have
sufficient wet strength to resist tearing and puncturing during
vigorous use in the moistened state. While the existing products
have been well received by consumers, there is a desire to improve
the strength, softness and thickness of such current products.
[0007] Definitions
[0008] Bicomponent fibers--Fibers that have been formed from at
least two polymers extruded from separate extruders through a
single spinneret hole to form a single filament. The polymers are
arranged in substantially constantly positioned distinct zones
across the cross-section of the bicomponent fibers and extend
continuously along the length of the bicomponent fibers. The
configuration of such a bicomponent fiber may be, for example, a
sheath/core arrangement wherein one polymer is surrounded by
another or a side by side arrangement.
[0009] Biconstituent fibers--Fibers that have been formed from a
mixture of two or more polymers extruded from the same spinneret.
Biconstituent fibers do not have the various polymer components
arranged in relatively constantly positioned distinct zones across
the cross-sectional area of the fiber and the various polymers are
usually not continuous along the entire length of the fiber,
instead usually forming fibrils which start and end at random.
Biconstituent fibers are sometimes also referred to as
multiconstituent fibers.
[0010] Cellulose fibers--Cellulosic fibers from natural sources
such as woody and non-woody plants. Woody plants include, for
example, deciduous and coniferous trees. Non-woody plants include,
for example, cotton, flax, esparto grass, sisal, abaca, milkweed,
straw, jute, hemp, and bagasse.
[0011] Cross machine direction (CD)--The direction perpendicular to
the machine direction.
[0012] Denier--A unit used to indicate the fineness of a filament.
The unit expresses the mass of a filament divided by its length. A
filament of 1 denier has a mass of 1 gram for 9000 meters of
length.
[0013] Machine direction (MD)--The direction of travel of the
forming surface onto which fibers are deposited during formation of
a nonwoven web.
[0014] Meltblown fibers--Fibers formed by extruding a molten
thermoplastic material as filaments from a plurality of fine,
usually circular, die capillaries into a high velocity gas (e.g.,
air) stream which attenuates the filaments of molten thermoplastic
material to reduce their diameter. Thereafter, the meltblown fibers
are carried by the high velocity gas stream and are deposited on a
collecting surface to form a web of randomly dispersed meltblown
fibers. Meltblown fibers are generally discontinuous. The meltblown
process includes the meltspray process.
[0015] Non-thermoplastic--Any material which does not fall within
the definition of thermoplastic material.
[0016] Nonwoven fabric or web--A web having a structure of
individual fibers which are interlaid, but not in an identifiable
manner as in a knitted fabric. Nonwoven fabrics or webs have been
formed from many processes such as for example, meltblowing
processes, spunbonding processes, and wet or dry laying processes.
The basis weight of nonwoven fabrics is usually expressed in grams
per square meter (gsm) and the fiber fineness is measured in
denier.
[0017] Polymer--Generally includes, for example, homopolymers,
copolymers, such as, for example, block, graft, random and
alternating copolymers, terpolymers, etc, and blends and
modifications thereof. Furthermore, unless otherwise specifically
limited, the term "polymer" includes all possible geometrical
configurations of a material. These configurations include for
example, isotactic, syndiotactic and random symmetries.
[0018] Spun filaments or fibers--Filaments formed by extruding
molten thermoplastic materials from a plurality of fine, usually
circular, capillaries of a spinneret. The diameter of the extruded
filaments is then rapidly reduced as by, for example, eductive
drawing and/or other well-known mechanisms. Spun filaments are
generally continuous and have a denier range up to about 5 or
more.
[0019] Thermoplastic--A polymer that is fusible, softening when
exposed to heat and returning generally to its unsoftened state
when cooled to room temperature. Thermoplastic materials include,
for example, polyvinyl chlorides, some polyesters, polyamides,
polyfluorocarbons, polyolefins, some polyurethanes, polystyrenes,
polyvinyl alcohol, caprolactams, copolymers of ethylene and at
least one vinyl monomer (e.g., poly (ethylene vinyl acetates)), and
acrylic resins.
SUMMARY OF THE INVENTION
[0020] Briefly stated, one aspect of the invention in preferred
form is a nonwoven laminate or composite product including a bulk
layer comprised predominately of cellulosic fibers or pulp joined
to a base web comprised of extruded fine denier fibers. The layers
are preferably joined by hydroentanglement. The "fine denier" base
web fibers have a denier of 1.5 or less, a preferred denier of 1.2
or less and a more preferred denier in the range of 0.5 to 1.2. The
basis weight for the inventive nonwoven laminate product is
preferably less than 100 gsm and more preferably in the range of 35
to 75 gsm.
[0021] The base web fibers are comprised of extruded materials such
as, for example, polyolefins (such as polyethylene or
polypropylene), polyester, rayon, lyocell, acetate and acrylic. The
base web fibers are preferably extruded from a thermoplastic
polymer. The base web is more preferably comprised of a layer of
spunlaid and bonded substantially continuous filaments preferably
selected from at least one of the group consisting of polyolefin,
polyester, and bicomponent polyethylene/polypropylene and
bicomponent polyethylene/polyester. Bicomponent filaments are
preferably in a lower melting point sheath/higher melting point
core arrangement.
[0022] The base web has a preferred basis weight of less than 25
gsm and a more preferred basis weight in the range of 9 to 20 gsm.
The base web preferably comprises between 20 and 60 percent of the
resulting laminate product basis weight.
[0023] The bulk layer may be comprised of cellulosic fibers,
cellulosic pulp, synthetic or other manmade fibers or mixtures of
the above. The bulk layer is preferably comprised of cellulose
fibers and more preferably wood pulp.
[0024] The bulk layer preferably comprises between 40 and 80
percent of the resulting nonwoven laminate product basis
weight.
[0025] Another aspect of the invention is a preferred method for
producing the inventive nonwoven laminate product, comprising
providing a base web of fine denier fibers on a forming wire or
conveyor. The base web is preferably preformed and placed over the
conveyor. Alternatively, the base web may be extruded directly onto
the conveyor. The bulk layer is deposited over the base web. The
bulk layer may be deposited by, for example, wet laying or air
laying processes. It is also possible to deposit the bulk layer as
a preformed tissue. The resulting fine denier base web with
overlying bulk layer may optionally be passed below a compacting
roll. The base web/bulk layer composite, with or without
compacting, is entangled, preferably by passage under a series of
hydroentangling nozzles. Water jets emitted from the nozzles
impinge on the combined web material to hydraulically entangle the
bulk layer fibers or pulp into the base web. The hydroentangled wet
laminate material is placed under vacuum to remove a majority of
water. The semi-dry laminate sheet material is preferably subjected
to additional heated drying operations to further remove remaining
water, after which the finished nonwoven laminate product may be
wound into a roll for subsequent handling.
[0026] The inventive nonwoven laminate product provides perceptible
benefits. The fine denier spunbonded base web functions to provide
a softer and more drapable nonwoven laminate product with a
smoother surface than conventional nonwoven laminate products using
higher denier base webs. The improved softness, drape and surface
smoothness of the inventive nonwoven laminate products provides
distinct advantages in the end-use marketplace. Additionally, the
plastic content provided by the base web functions to enhance
subsequent embossing of an image onto the end product, thereby
improving its consumer appeal.
[0027] Despite providing increased softness and smoothness, the
inventive nonwoven laminate products have surprisingly enhanced
tensile and burst strengths when compared to conventional nonwoven
laminate products of similar basis weights but having higher denier
base webs. The enhanced strength of the inventive laminate product
is beneficial in subsequent manufacturing steps; during dispensing
of a finished end-product, such as a baby wipe, from a storage
container; and during usage of the wipe wherein the enhanced burst
strength significantly reduces the "poke-through" associated with
some conventional nonwoven laminate wiping materials during usage.
The bulk layer provides a surface that is very useful during an end
use such as cleaning and helps lower manufacturing costs by
substituting less expensive cellulose fiber or pulp in place of
more expensive synthetic fibers. Additionally, the preferred wood
pulp material, especially when airlaid, provides enhanced thickness
to the resulting nonwoven laminate product.
[0028] An object of the invention is to provide a nonwoven laminate
product that has enhanced properties of strength and softness.
[0029] Another object of the invention is to provide a nonwoven
laminate product that has higher tensile and burst strengths than
conventional nonwoven laminate products.
[0030] A further object of the invention is to provide a method of
manufacture for improved nonwoven laminate products having
increased tensile and burst strength as compared to conventional
nonwoven laminate products.
[0031] A better understanding of the invention will be obtained
from the following detailed disclosure of the article and the
desired features, properties, characteristics and the relation of
the elements as well as the process steps, one with respect to each
of the others, as set forth and exemplified in the description and
illustrated embodiments.
DESCRIPTION OF A PREFERRED EMBODIMENT
[0032] One preferred embodiment of the present invention comprises
a nonwoven base web comprised of fine denier fibers joined to a
bulk layer to form an inventive nonwoven laminate product. The
invention does not exclude additional layers. The basis weight for
the resulting inventive nonwoven laminate product is preferably
less than 100 gsm and more preferably about 35-75 gsm.
[0033] The nonwoven base web is comprised of extruded and bonded
fine denier fibers. As used herein a "fine" denier filament or
fiber has a denier of 1.5 or less, more preferably a denier of 1.2
or less and most preferably a denier within the range of 0.5 to
1.2. The nonwoven base web fibers are comprised of extruded
materials such as, for example, polyolefins (such as polyethylene
or polypropylene), polyester, rayon, lyocell, acetate and acrylic.
The base web fibers are preferably extruded from a thermoplastic
polymer.
[0034] The base web is more preferably comprised of substantially
continuous spunlaid and bonded filaments. The base web filaments
are comprised of a material preferably selected from at least one
of the group consisting of polyolefin, polyester, and bicomponent
polyethylene/polypropylene and bicomponent polyethylene/polyester.
Bicomponent filaments, if present, are preferably in the form of a
lower melting point sheath and a higher melting point core.
[0035] The type of bor ding of the base web material is not
believed to be critical and may include, for example, solvent,
adhesive, needle, hydroentanglement or thermal bonding. The base
web component preferably has a basis weight of less than 25 gsm.
More preferably the base web has a basis weight in the range of
9-20 gsm. The base web component preferably comprises between 20%
and 60% of the resulting nonwoven laminate product basis
weight.
[0036] The bulk layer is generally comprised of cellulosic
material. More preferably, the bulk layer is cellulosic pulp and
most preferably the bulk layer is wood pulp. Mixtures of various
cellulose fibers and pulp may also be used. The bulk layer may
include up to 25% synthetic or other manmade materials, for
example, rayon, lyocell, polyester, polyolefin, polyamide, and
bicomponent materials depending on the desired resultant bulk layer
properties. The bulk layer preferably has a basis weight of less
than 75 gsm and more preferably a basis weight in the range of 25
to 60 gsm. The bulk layer preferably comprises between 40% and 80%
of the resulting nonwoven laminate product basis weight.
[0037] A preferred method for producing the inventive nonwoven
laminate product comprises providing a spunbond web of a
substantially continuous fine denier filaments on a foraminous
conveyor. The fine denier spunbond base web is preferably
preformed, although thermally processing the filaments directly
onto the conveyor is within the scope of the invention. Cellulosic
material is deposited on top of the fine denier base web to form
the bulk layer. The cellulosic material may be deposited over the
base web either dispersed in fluid (wetlaid) or in air (airlaid).
It is also possible to deposit the bulk layer as a preformed tissue
over the base web. It should be noted that deposition of the
cellulosic material onto a conveyor or papermaking machine and
placement of the spunbond base web over the cellulosic bulk layer
is fully comprehended by the invention. Optionally, the base web
with deposited bulk layer is passed below a compacting roll.
[0038] The base web with deposited bulk layer is hydroentangled to
provide a resulting laminate sheet with desired tactile, absorption
and strength characteristics. Preferably the hydroentanglement step
is performed prior to a drying operation. Typically, the
hydroentangling operation is a low to medium pressure
hydroentangling operation as set forth in U.S. Pat. No. 5,151,320
to Homonoff et al, the disclosure of which is incorporated by
reference herein. While the Homonoff patent relates to a different
nonwoven web material than the present invention, the
hydroentangling operation described therein can efficaciously be
employed with the present invention. Briefly, the hydroentanglement
process preferably impinges a plurality of fluid jets onto the
fibers of the bulk layer with sufficient force to cause a portion
of the fibers therein to be propelled into and entangled with the
base web layer. The fluid jets are preferably jets of an aqueous
liquid. The entanglement process can be carried out on the conveyor
using total energy input of about 0.1 to 0.4 horsepower-hours per
pound of web (Hp-hr/lb). It should be understood that energy inputs
greater than 0.4 Hp-hr/lb can be used in the practice of the
invention.
[0039] The resultant hydroentangled wet laminate material is placed
under vacuum to remove the majority of water. The semi-dried
laminate sheet is further subjected to conventional heated drying
operations, for example over heated dryer cans, to remove
additional water. The drying process and temperature is controlled
to achieve a desired level of fusion of the thermoplastic fibers.
As an example, the drying temperature for nonwoven laminate
products comprising a polyolefin base web is about 100.degree. C.
After drying the finished nonwoven laminate product may be wound
into a roll for subsequent handling, shipment and manufacture of
end products.
[0040] The inventive nonwoven laminate product exhibits
surprisingly increased tensile strength, in both the wet and dry
condition, compared to conventional web materials of similar basis
weight comprising higher denier base webs. As used herein tensile
testing is conducted on a 1 inch (approximately 25 mm) wide by 5
inch long sample. The sample is placed in the jaw's of a tensile
testing instrument. Suitable tensile testing instruments are
available from Instron and Zwick. The tensile testing instrument
applies a constant rate of extension of 5 inches per minute until
the test sample breaks. A load cell is used to measure the force
imposed on the sample at breakage. The force required to break the
test sample is reported in grams per 25 mm (gm/25 mm). For wet
tensile testing the sample is soaked in room temperature water.
After soaking, the sample is blotted on a cotton blotter to remove
excess water. Tensile strength may also be reported as total
tensile strength, which is the sum of the MD and CD tensile
strengths.
[0041] The inventive nonwoven laminate product further exhibits
surprisingly increased burst strength, especially in the wet
condition, compared to conventional web materials of similar basis
weight comprising larger denier base webs. As used herein burst
strength testing is conducted according to ASTM D3786.
[0042] Having generally described the invention, the following
examples are included for purposes of illustration so that the
invention may be more readily understood and are in no way intended
to limit the scope of the invention unless otherwise specifically
indicated. All parts are given by dry weight unless otherwise
specified.
EXAMPLE 1
[0043] Four nonwoven laminate products (samples 1-4) were produced
generally following the above-described method. In all of the
samples the base webs were comprised of spunlaid and bonded
substantially continuous filaments of polypropylene. In all of the
samples Korsnaes treated wood fluff pulp was airlaid onto the
respective base web. The resulting laminate materials were
hydroentangled and dried conventionally using vacuum and heat.
[0044] Samples 1 and 2 comprised conventional nonwoven laminate
products having a spunbonded base web wherein the filaments had an
average denier of about 2.2. Samples 3 and 4 comprised inventive
nonwoven laminate products having a fine denier spunbonded base web
wherein the filaments had an average denier of less than 1.2.
[0045] The base web of samples 3 and 4 comprised approximately 25%
of the resulting total laminate basis weight of 74 g/m.sup.2.
Sample 2 had a similar ratio of base web to wood pulp fiber to
samples 3 and 4, while the base web of sample 1 comprised somewhat
more wood pulp. The basis weight for the resulting laminate
products was somewhat higher for sample 2 than for samples 1, 3 and
4, which were similar. The samples were tested for dry and wet
tensile strengths in the machine direction (MD), the cross machine
direction (CD) and total tensile strength. The samples were also
tested for wet Mullen burst strength. The properties of samples 1-4
are summarized in TABLE 1.
1 TABLE 1 SAMPLE #1 SAMPLE #2 SAMPLE #3 SAMPLE #4 BULK LAYER
Composition wood pulp wood pulp wood pulp wood pulp % of total
product 85 74 76 73 BASE WEB Composition polypropylene
polypropylene polypropylene polypropylene % of total product 15 26
24 27 dpf 2.2 2.2 <1.2 <1.2 NONWOVEN LAMINATE PRODUCT
PROPERTIES Basis Weight g/m.sup.2 75 83 74 74 Dry Tensile MD 2022
1842 3556 3250 gm/25 mm Dry Tensile CD 641 829 1518 1444 gm/25 mm
Dry Tensile Total 2663 2671 5074 4694 gm/25 mm Wet Tensile MD 1389
1004 3081 2825 gm/25 mm Wet Tensile CD 315 568 1240 1396 gm/25 mm
Wet Tensile Total 1704 1572 4321 4221 gm/25 mm Wet Mullen Burst 802
1028 1513 1621 gm/cm.sup.2
[0046] The fine denier base webs of samples 3 and 4 were
perceptibly softer, smoother on the surface and more drapable than
the conventional higher denier base webs of samples 1 and 2. The
improved softness, surface smoothness and drapability of the fine
denier base webs functioned to provide the resultant inventive
nonwoven laminate products of samples 3 and 4 with increased
softness, drape, and surface smoothness as compared to the
conventional nonwoven laminate products typified by samples 1 and
2.
[0047] As can further be seen from Table 1, both inventive nonwoven
laminate products (samples 3 and 4) exhibited significantly
increased tensile strengths compared to conventional samples 1 and
2. The increases were achieved under both wet and dry conditions
and in both the machine direction (MD) and cross machine direction
(CD). Both inventive nonwoven laminate products (samples 3 and 4)
also exhibited considerably increased burst strengths compared to
conventional samples 1 and 2. The enhanced tensile and burst
strengths are surprising and counterintuitive given the fine denier
of the inventive base web fibers and the improved softness, drape
and surface smoothness of the resulting nonwoven laminate
products.
[0048] Additionally, both inventive nonwoven laminate products
(samples 3 and 4) had a higher surface area and higher web
uniformity as compared to the conventional nonwoven laminate
products of samples 1 and 2. The higher uniformity of both
inventive nonwoven laminate products (samples 3 and 4) was judged
to make them more appealing with regard to appearance as a wiping
product and to portray an image of higher quality as compared to
conventional nonwoven laminate products. It should be noted that
these advantages were obtained while maintaining substantially the
same or lower basis weights as the conventional products. In fact,
use of base webs having filaments with a denier of about 2.2 or
greater was found to result in some amount of undesirable
"splotchiness" in the final nonwoven laminate product.
[0049] While preferred embodiments of the foregoing invention have
been set forth for purposes of illustration, the foregoing
description should not be deemed a limitation of the invention
herein. Accordingly, various modifications, adaptations and
alternatives may occur to one skilled in the art without departing
from the spirit and scope of the present invention.
* * * * *