Note: Descriptions are shown in the official language in which they were submitted.
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
SEPARATION OF MATERIALS COMPRISING SUPER ABSORBENT
POLYMERS USING REDUCED WATER
CROSS REFERENCE
100011 None
FIELD OF THE INVENTION
100021 The invention relates to methods of separating products containing
super absorbent
polymers into their constituent parts, including a plastic component, super
absorbent
polymers, and cellulosic fibers, and further refinement of said constituent
parts.
Examples of such products include absorbent sanitary products, for example
diapers.
BACKGROUND
100031 As used herein, absorbent sanitary paper products include, for
example, but not
limited to, disposable diapers, incontinence products, feminine hygiene
products,
bedpads and other related absorbent and adsorbent products ("products" or
"material"). These products typically consist of (i) a non-woven sheet formed
from a
liquid permeable material, for example a liquid permeable membrane formed from
polypropylene, polyethylene, or woven products formed from cotton or rayon,
(ii) a
liquid impermeable back sheet formed from, for example, polyethylene,
polypropylene, starch based degradable plastic films, woven cloth or rubber,
and (iii)
an adsorbent or absorbent core of air laid wood pulp fluff, commonly referred
to as
air felt, and/or synthetic pulp including polypropylene or polyethylene
filaments that
may be bonded or unbonded, hemp or other adsorbent fibrous material. The core
is
typically wrapped or encased in a creped envelope of wet strength tissue paper
or a
material with similar characteristics. The wrapping on the core may or may not
be
breathable, biodegradable, odour degradable or degradable or dissolvable by
other
means. The core usually also contains a super absorbent polymer (SAP)
material,
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
which is typically a polyacrylate, polyacrylamide, crosslinked starch or other
hydrophilic component, which may be synthetic, and may be in granular, fibrous
or
laminate form, possessing the ability to bond with water, urine or other body
fluids or
retain them without substantial release or discharge from the absorbent
portion.
Diapers and incontinence products typically utilize pressure sensitive
adhesives or
refastenable tape tabs or similar closure mechanisms. Feminine hygiene pads
and
incontinence products often use pressure sensitive adhesives for glue lines to
attach
the pad or liner to the user's undergarments. Diaper and incontinence products
typically utilize elastic, polyurethane, puckering and welding or adhesives to
create
close fitting cuffs around the leg and waist openings to provide a more
leakproof fit.
100041 Absorbent sanitary paper products are normally disposed of along
with garbage
generated by households, institutions, hotels and the like, by incineration or
in landfill
disposal sites. Incineration tends to result in air or other pollution being
generated.
Landfill disposal results in an accumulation of such products.
Thus, the
consequences of the convenience or necessity of use of absorbent sanitary
paper
products include problems relating to disposal of such products. In addition,
use of
either incineration or landfill disposal results in loss or destruction of the
components
of the absorbent sanitary paper products, rather than recycling some or all of
those
components to the same or other end-uses. The disposal problems are of ever
increasing concern to environmental and governmental authorities, and means
are
required for effective disposal and utilization of used absorbent sanitary
products.
Additionally the disposal of the scraps and defective product post industrial
diapers
puts a burden on manufacturers and wastes valuable resources.
SUMMARY OF THE INVENTION
- 2 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
(0005) Embodiments of this disclosure include a method for separating the
component parts
of a material comprising a super absorbent polymer (SAP), a fiber component
and a
plastic component. In certain embodiments, this method comprises shredding the
material, adding a salt to the material and agitating the material, wherein
the material
does not comprise a slurry. Other embodiments include heating the material. In
some embodiments, the heating comprises heating with steam.
(0006) In some embodiments of this disclosure, the material is pressurized
and then
depressurized. In further embodiments, the heating, pressurizing and agitating
are
performed in an autoclave. In certain embodiments, the salt comprises aluminum
sulfate. In other embodiments, the salt comprises a salt solution.
(0007) In some embodiments of this disclosure, less than 10% water by
weight of material is
added to the material. In other embodiments, less 200 liters of water per ton
of
material is added to the material. In still other embodiments, the material
comprises
substantially no free water. I certain embodiments, using a dry process, the
material
is separated into a fiber and SAP component, and a plastic component.
100081 Some embodiments of this disclosure include a method for separating
the component
parts of a material comprising a super absorbent polymer (SAP), a fiber
component
and a plastic component, the method comprising heating the material and
pressurizing
the material. Other embodiments include shredding the material. Still further
embodiments include agitating the material.
Some embodiments include
depressurizing the material. In certain embodiments, the heating,
pressurizing,
depressurizing and agitating are performed in an autoclave.
(0009) Some embodiments of this disclosure include further separating the
material into a
fiber and SAP component, and a plastic component.
DESCRIPTION OF THE FIGURES
(0010) FIG. 1 depicts a flow diagram of one embodiment of the methods
described herein for
separating a product containing a super absorbent polymer (SAP), a fiber and a
plastic
into its component parts; and
- 3 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
1001 n FIG. 2 depicts a flow diagram of one embodiment of the methods
described herein for
separating a product containing a super absorbent polymer (SAP), a fiber and a
plastic
into its component parts, and highlighting yet another embodiment of the
methods
herein for deactivating any SAP remaining in a plastics component (circled
portion).
100121 FIG. 3 depicts a flow diagram of one embodiment of the methods
described herein for
separating a product containing a super absorbent polymer (SAP), a fiber and a
plastic
into its component parts using an autoclave and salt.
[0013] FIG. 4 depicts a flow diagram of one embodiment of the methods
described herein for
separating a product containing a super absorbent polymer (SAP), a fiber and a
plastic
into its component parts using an autoclave, but without adding salt in the
autoclave.
DETAILED DESCRIPTION
100141 Numbers in the present disclosure are rounded to the nearest
significant figure using
conventional rounding techniques. Ranges of numbers contained herein are
understood to contain the numbers on the upper and lower limits, unless
otherwise
indicated. For instance, a range "from 1 to 10" is understood to include a
range
including the number"!," and up to and including the number "10."
100151 The present disclosure includes methods of separating a product
including a super
absorbent polymer (SAP), a fiber and a plastic into components thereof. This
disclosure also includes methods of deactivating SAP in a plastic recovered
from a
product including SAP. in addition, this disclosure includes methods of
producing
reusable plastic and SAP from the treatment of a product including SAP.
Further, this
disclosure includes methods of treatment of a wet SAP such that the SAP is
reusable
and/or does not comprise alum. As used herein, "alum" refers to KAI(SO4)2.
Other
names for alum include kalinite (the mineral form), potash alum, potassium
alum
dodecahydrate or KA1(SO4)2-12H20. Aluminum sulfate (Al2(SO4)3 or A12012S3)
is sometimes incorrectly referred to as alum, however, under the definition of
alum
herein, alum does not include aluminum sulfate. Finally, this disclosure
includes
methods of recycling SAP for use as an agglomerating agent.
-4-
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
(0016) Previous methods of separating absorbent sanitary paper products
continue to produce
byproducts having their own disposal issues. US Patent 5,558,745, incorporated
by
reference herein, describes one such method. This method includes shredding
the
products and adding a crosslinking agent to harden the SAP. The hardened SAP
is
then separated from the plastic and fiber. The process uses rotating multi-
shell drums
and centrifugal cleaners to achieve separation. While the process may achieve
separation, there are disadvantages to the separated components. The plastic
component, for example, still contains SAP and cellulosic material. The
recovered
SAP, in it's hardened, granulated state, no longer retains its super absorbent
function.
This function may possibly be recovered by the addition of large amounts of
NaOH
(at a pH of 11, for example), for example, but the necessary processing makes
the
SAP much more expensive than virgin SAP. The granulated SAP is also unsuitable
for agricultural and landfill applications, since the crosslinking salts that
remain with
the SAP, especially alum, are environmentally unfriendly and detrimental to
plant
growth. Additionally, if Alum is used as the crosslinking agent, any
byproducts from
this process may be environmentally unfriendly as alum may have a negative
impact
on plant and animal life.
100171 The benefits of the methods of the present disclosure include cost
savings due to
reduced use of chemicals, for example, alum. In addition, any residual SAP in
the
plastic stream is deactivated, making the plastic more attractive as a
recycled
material. Any composted fiber and/or alum resulting from this process may be
more
desirable due to reduced or eliminated alum content. And finally, because alum
may
not be used on the bulk of the SAP, the SAP may have increased options for
recycling
and increased market value.
100181 Absorbent sanitary paper products ("products" or "material")
typically consist of (i) a
non-woven sheet formed from a liquid permeable material, for example a liquid
permeable membrane formed from polypropylene, polyethylene, or woven products
formed from cotton or rayon, (ii) a liquid impermeable back sheet formed from
for
example polyethylene, polypropylene, starch based degradable plastic films,
woven
cloth or rubber, and (iii) an adsorbent or absorbent core of air laid wood
pulp fluff,
- 5 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
commonly referred to as air felt, and/or synthetic pulp including
polypropylene or
polyethylene filaments that may be bonded or unbonded, hemp or other adsorbent
fibrous material ("fiber component"). Components (i) and (ii), typically both
made of
a thermoplastic, may be referred to herein as the "plastic component." The
core is
typically wrapped or encased in a creped envelope of wet strength tissue paper
or a
material with similar characteristics. The wrapping on the core may or may not
be
breathable, biodegradable, odour degradable or degradable or dissolvable by
other
means. The core usually also contains a super absorbent polymer (SAP)
material,
which is typically a polyacrylate, polyacrylamide, crosslinked starch or other
hydrophilic component, which may be synthetic, and may be in granular, fibrous
or
laminate form, possessing the ability to bond with water, urine or other body
fluids or
retain them without substantial release or discharge from the absorbent
portion.
Diapers and incontinence products typically utilize pressure sensitive
adhesives for
refastenable tape tabs or similar closure mechanisms. Feminine hygiene pads
and
incontinence products often use pressure sensitive adhesives for glue lines to
attach
the pad or liner to the user's undergarments. Diaper and incontinence products
typically utilize elastic, polyurethane, puckering and welding or adhesives to
create
close fitting cuffs around the leg and waist openings to provide a more
leakproof fit.
100191 Absorbent sanitary paper products are usually fabricated using SAPs.
Such polymers
facilitate wetting and wicking properties of the products, especially the
cellulosic core
usually present in the products, and in particular increase the liquid
retention capacity
of the absorbent sanitary paper products. Super-absorbent polymers tend to be
acrylic
polymers and starch-based polymers. At least SAP's made from acrylic polymers
are
usually cross-linked in the manufacturing process in order to give them
compressive
and tensile strength along with their super absorbent properties. Further
cross-linking
may occur in steps in embodiments of the methods of the present disclosure.
100201 As a result of the inherent water absorption properties of SAP, SAP
tends to swell on
contact with aqueous solutions. Products containing SAP may swell to 2-5 times
or
more its dry (feed) volume on contact with an aqueous solution. Chemical steps
including cross-linking of the SAP in situ or adding agents that reduce the
swelling of
- 6 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
SAP and/or change the shape and specific gravity of particles of SAP may
reduce
swelling. In some instances, reduction of swelling, i.e. shrinkage, of SAP
should be
carried out prior to, or substantially simultaneously with cross-linking of
the SAP if
cross-linking is desired. Water-soluble alkali and alkaline earth metal
compounds are
believed to cause shrinkage of the SAP whereas the aluminum, copper, iron and
zinc
compounds, for example, alum, are believed to cause cross-linking. The
treatment of
the SAP should be carried out in acidic or substantially neutral solutions,
especially at
a pH of about 3-8, which limits the alkali and alkaline earth metal compounds
that
may be used. Examples of chemical compounds that may be added, usually in the
form of mixtures, to effect cross-linking of SAP, especially SAP formed from
acrylic
polymers, include soluble salts of at least one of an alkali metal, an
alkaline earth
metal, aluminum, copper (II), iron (III), and zinc. Examples of such salts
include
calcium chloride, calcium nitrate, calcium sulphate, magnesium chloride,
magnesium
nitrate, magnesium sulphate, disodium phosphate, barium chloride, sodium
carbonate
and bicarbonate, trisodium phosphate, sodium silicate, potassium sulphide,
aluminum
sulphate, sodium bisulphate, zinc sulphate, aluminum chloride, sodium sulphate
and
alum. Aluminum salts e.g. sulphate and chloride, are preferred.
100211 The present disclosure includes methods of separating products that
include a super
absorbent polymer (SAP), a fiber and a plastic. Figure 1 depicts one
embodiment of
this method. This embodiment includes first shredding the products. in
addition to
shredding, this may also be accomplished by otherwise releasing the SAP and
fiber
component from the nonwoven and plastic layers by some form of cutting or
tearing.
All separation processes will be referred to herein as "shredding."
100221 Next, water, an aqueous solution, or another solvent is added to the
shredded product,
causing the SAP to swell. The product is then moved to a press. Enough water
must
be added such that separation of the components is maximized in the press,
while at
the same time attempting to minimize the total amount of water needed.
Preferably,
this amount includes not more than enough water to saturate the SAP. In some
embodiments, water is added in about a 10 to 1 ratio of water to dry product
by
weight. In other embodiments, the water is added in a range of about from 10:1
to
- 7 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
20:1 water to dry product by weight. Caustic aqueous solution may speed the
absorption process, making this portion of the method faster.
100231 The press may include, for example, but not limited to, a screw
press. One example
of such a press is the Model SP-23-2 (HDS Dewatering Corp., Montreal, Quebec,
Canada). Other types of presses may include, for example, but not limited to,
hydraulic presses, for example, a ram press (MD/A, Sweden), pneumatic presses,
magnetic presses, knuckle-joint presses, rolling presses and centrifuges.
[0024] Once inside the press, the method includes pressing the product
against a screen. The
press applies pressure by pressing the wet product and forcing the product
against a
screen. As used herein, the term "pressing" means to act upon through force,
for
example pushing or thrusting force, or to move by means of pressure. As used
herein,
the term "screen" means a body having at least one opening against which the
press
forces the wet product. Examples of a screen include, but are not limited to,
a plate
with holes, a sieve, wire mesh, a screen cylinder, and a "basket." The
openings in the
screen may include perforations, holes, slots, grating, mesh, or the like.
Preferably,
the openings include holes between 0.049 inches and 0.25 inches in diameter.
More
preferably, the openings are between 0.0625 inches and 0.125 inches. Most
preferably, the openings are about 1/16 inch. In general, the openings are big
enough
such that the SAP and some of the fiber is pressed through the openings.
Preferably,
the openings are small enough such that the majority or substantially all of
the plastic
component remains in the press. In the end, the press separates the product
into a
plastics component (plastics component) remaining in the press and a SAP and
fiber
component (SAP and fiber component) pushed out of the press. Up to about 50%
of
the fiber content may exit the press in the SAP and fiber component. The
remaining
fiber remains in the press with the plastic, in addition to any residual SAP.
In a screw
press, for example, the press applies pressure via a screw flight, forcing the
wet
product against a screen cylinder or "basket." This forces the SAP through the
screen
plate openings, while the plastic remains in the press.
- 8 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
100251 The benefits of this particular method of separation involving a
press is that no salt is
required. Salts may be harmful or at least undesirable to the environment.
When
certain components of the products are used in the environment, for example as
compost, salts included in those components may have deleterious effects such
as
changing the pH of the water in the surrounding ecosystem, and/or killing,
injuring or
disrupting plant and animal life. Alum, a salt commonly used in separation of
SAP
from these products, is particularly undesirable in the environment.
Therefore, in the
methods involving the use of a press, the products preferably do not include a
salt,
and the steps of adding water and pressing does not include the addition of a
salt. In
particular, the products and these steps do not include a material that cross-
links SAP.
Preferably, the products do not include alum and these steps do not include
the
addition of alum.
100261 The plastics component that remains in the press includes
substantially plastic, but
also includes some SAP and fiber. Plastic products made from this plastic
component
may still swell, form a gel, and/or retain water when exposed to water due to
the
residual amounts of SAP. This result is particularly disadvantageous for
recycled
products including the plastic component, such as, for example, plastic
lumber, which
will likely be exposed to water. This result (gelling of residual SAP) may
occur even
after the plastic/SAP is melted and extruded into a finished product. Thus, it
is
preferable to remove as much SAP as possible from the plastic component, and
deactivate any remaining SAP in the plastic before recycling the plastic
composition.
As used herein, "deactivate" refers to rendering the SAP substantially unable
to swell
or retain water. This may be accomplished by either crosslinking the SAP to
the
point where swelling is minimized or eliminated, or exposing the SAP to a
substance
that breaks the existing crosslinks. In one embodiment of this disclosure, the
method
further includes adding a composition that substantially deactivates SA .P to
the
plastics component. In another embodiment, the method further includes
substantially separating the remaining SAP from the plastics component. In
still
further embodiments, the method further comprises both adding a composition
that
substantially deactivates SAP to the plastics component and substantially
separating
the remaining SAP from the plastics component. Any combination of these steps
- 9 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
yields a purified plastics component and a secondary component which may
include
water, fiber and SAP. As used herein, a purified plastics component is
substantially
comprised of plastic, and any remaining SAP in the purified plastics component
is
substantially deactivated.
100271 In a preferred embodiment, a composition comprising alum is added to
the plastics
component and then water, fiber and SAP is removed to yield a purified
plastics
component and a secondary component including the water, fiber and SAP. One of
the benefits of the embodiments of the present disclosure is that the alum is
only
added after the plastic has been substantially separated from the other
components,
for example by a press as described above. This may require the use of less
alum
than other prior art methods. In some embodiments, the amount of alum measured
in
dry weight added to the plastics component is about equivalent to the dry
weight of
SAP remaining in the plastics component.
100281 The alum composition may also include additional water. The alum may
serve two
purposes when used after pressing. First, the alum may act as a washing agent
to
break the bonds between the SAP and the surrounding solids after the pressing
adheres them. Second, the alum acts as an agent to sequester the SAP by
dewatering,
densifying and deactivating the SAP. The alum crosslinks the SAP to a point
where
swelling and water retention is minimized or substantially eliminated. Then,
any
secondary components such as water, loose solids such as SAP particles, and
fiber
(secondary component) are separated from the purified plastics component. The
separation can be accomplished using a pulper and a washer, as is known in the
art.
In one embodiment, the plastic with some contamination is ground into smaller
pieces
using a single rotor plastics grinder that reduces the plastic to less than
about 20 mm
diameter pieces. The material exits the grinder and drops into a pulper or
agitator
tank containing an impeller for separating the components in a slurry.
[0029] In an embodiment including a pulper and a washer, the salt, for
example, alum, is
introduced to the plastics component and agitated. The salt can be added in
liquid
solution or granulated form. The liquid alum is pumped in at a controlled rate
to
- 10 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
match approximately equal to the dry weight of SAP in the incoming solids. In
one
embodiment, the dosing pump includes a positive displacement gear pump. Water
may also added to the mix until the suspension is about 1-5% solids by weight.
100301 The plastic and remaining SAP, paper fiber and waste (plastics
component) are sent
to a coarse screen with openings of about 1-6mm such as a "friction washer"
similar
to a FW-560/3000-SP type (REKO Technologies, Pufte, Belgium). The mixture is
drained and agitated, removing more of the paper fiber, SAP, and waste. The
remaining plastic may travel through a washer to flush with clean water
further
removing impurities, for example an IW 1004-SP type intensive washer (REKO
Technologies, Putte, Belgium). After exiting the washer the plastic may go to
a screw
press for removal of some of the water bringing the solids to about 20-60%
solids by
mass. For example, a suitable press may include a dewatering screw press type
AKUPRESS A 200 (Andritz Kufferath GmbH, Dueren, Germany). In one
embodiment, the press may include 3rnrri screen openings.
100311 After separating the secondary component (fiber, SAP, waste) from
the plastic
component, the plastic component may be recycled. In some embodiments, the
plastic component is dried before being recycled into another product.
[0032] The secondary component may be further separated using a sidehill
screen, for
example. Water and any accompanying small particles of fiber (water and fiber
component) is separated from any SAP and larger sized fiber particles (SAP and
fiber
component) by the sidehill screen, for example a 24 inch inclined screen with
about
0.25mm slotted screen surface with about a 380 liters per minute flow rate
(GIAV,
Montreal, Quebec, Canada). The result of this separation is the water and
fiber
component and the SAP and fiber component.
100331 The water and fiber component may be further subjected to dissolved
air filtration.
Dissolved air flotation (DAF) is a water treatment process that clarifies
wastewaters
(or other waters) by the removal of suspended matter such as oil or solids, or
in this
instance, fiber and/or SAP. The removal is achieved by dissolving air in the
water or
wastewater under pressure and then releasing the air at atmospheric pressure
in a
-11-
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
flotation tank or basin. The released air forms tiny bubbles which adhere to
the
suspended matter, causing the suspended matter to float to the surface of the
water
where it may then be removed by a skimming device. In general, any wastewaters
from the methods of the present disclosure may be subjected to DAF.
[00341 The SAP and fiber component may also be further separated by a
press, a centrifugal
drum, or other means into a substantially water component (water component)
and a
fiber sludge component (fiber sludge component) including any remaining SAP
and
fiber. The water component may be subjected to DAF or other wastewater
treatment
techniques. The fiber sludge component may be disposed in a landfill or used
as
compost or any other suitable use. The fiber sludge component may be combined
with the super absorbent polymer and fiber component from the initial press
operation
(the component that exited the press) before being disposed, landfilled,
composted,
disposed in some other manner, or recycled as another product.
100351 The SAP and fiber component that leaves the press during the initial
pressing
operation (described above) may be recycled in that form, or it may be further
processed and/or separated. In certain embodiments, the SAP and fiber may be
subjected to a further separation step, including separating the SAP and fiber
component into a SAP component (SAP component), which may include
substantially SAP, and a fiber component (fiber component), which may include
substantially fiber.
100361 In some embodiments, the SAP may be dried, either as part of the SAP
and fiber
component, or after being separated into the SAP component. These methods
include
drying the SAP component or SAP and fiber component by salt assisted
dehydration.
The SAP and fiber component may also be used for compost, or recycled for
other
products.
100371 One of the products that the SAP and fiber component may be used for
is a seeding or
reseeding composition for growing vegetation on freshly excavated or fire-
damaged
ground. In this embodiment, the human waste may or may not be removed from the
SAP and fiber component. If it is retained, the human waste may be sanitized
by
- 12-
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
techniques known in the art, for example, but not limited to., radiation,
autoclaving
and/or pasteurization. Seeds may be added to the SAP and fiber component, and
the
mixture is distributed on the ground. The seeds sprout into new vegetation.
The SAP
holds water and slowly releases it, providing a time-release source of water
for the
seeds. This effect is especially beneficial in arid climates or in fire-
damaged areas.
In addition, the SAP and fiber remains near the surface of the soil allowing
oxidation
and sunlight degradation, allowing the SAP to decompose while at the same time
establishing ground cover. The fiber in the mixture typically and preferably
includes
long strings of fiber that interweave. Typically, the fibers are about 1-3 min
long and
50 microns in diameter. The interlaced fibers prevent migration of the SAP,
seeds,
and underlying soil. This may be especially beneficial in fire-damaged ground
or on
hillsides. Finally, the waste, if present, may act as a fertilizer.
Additionally, any
beneficial salts such as potassium salts that remain from the salt assisted
dehydration
may act as fertilizers. Additional fertilizers known in the art may also be
added to the
seeding composition.
WM In another embodiment, SAP recovered from the methods described in
this disclosure
may be used in fire prevention. The SAP may be wet and sprayed onto houses,
barns,
fuel tanks and other structures in the face of an oncoming fire. The wet SAP
may
provide protection from nearby heat and flames.
100391 In yet another embodiment, SAP with or without fiber may be used for
the
sequestering/collection/removal of toxic waste, hazardous chemicals and heavy
metals from water and soil. In one embodiment, dehydrated or partially
hydrated
SAP is spread across an area of soil. Water and contaminants may be absorbed
into
the SAP gel, preventing the water from penetrating into the ground water until
the
material can be moved as a solid. Retention in the SAP may also eliminate the
hazard
of dripping water and contaminants until the now contaminated SAP is moved to
safe
location for disposal. Wet SAP in a "gel" state also has a blocking property.
Wet
SAP swells to block the passage of water and other fluids. This "blocking" is
prevented in diapers, for example, by mixing the SAP with fibers that provide
a liquid
passageway. When there is no passageway, however, SAP can effectively block
- 13-
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
liquid flow. Thus, a layer of SAP on contaminated ground may prevent more
water
falling onto the soil and getting contaminated. In another embodiment, SAP may
be
added to a leaking vessel containing a contaminant. If the SAP settles in the
leak, it
would block further leakage.
100401 Salt assisted dehydration is a method for drying SAP, or in this
case, an SAP and
fiber component. This method is much faster than air-drying, and uses less
energy
than using heat alone to dry the SAP. The method first includes contacting wet
or dry
super absorbent polymer with a salt or aqueous salt solution. Preferably, the
salt used
does not cause further crosslinking of the SAP. The salt serves to draw water
out of
the wet SAP. This method also includes decanting at least a portion of the
salt water
and water extracted from the wet super absorbent polymer. The remaining
portion of
the salt water and water extracted from the wet super absorbent polymer may be
evaporated. As the water evaporates, the salt remains on the surface of the
SAP,
drawing even more water out of the SAP particles. Finally, the dried salt may
be
removed from the super absorbent polymer.
100411 In some embodiments, about 2 grams of salt by dry weight may be
added for every
gram of SAP dry weight. The initial dewatering is driven by concentration of
salt,
and therefore more salt will increase water removal before evaporation starts.
Once
the salt water initially removed from the SAP is decanted, the remaining
process will
evaporate the water and reach an equilibrium with the salt concentrated on the
surface
of the SAP. Salt concentration may be adjusted depending on whether a faster
dehydration is desired, or whether less salt is used to reduce cost.
100421 In certain embodiments, removing the dried salt from the SAP
comprises placing the
super absorbent polymer and salt in a dry state into a rotating drum. The
inside of the
drum may include a screen, or may have holes, slots or other openings or
apertures.
The openings are large enough that the salt particles can pass through, but
small
enough so that substantially all of the SAP and fiber, if present, remain in
the drum.
The SAP may include particles from 1/10 to 1/2mm. Consequently, it is
preferred
that the holes in the drum are about 0.Imm, or 0.0039 inches. The salts used
for salt
- 14 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
assisted dehydration may include, for example, but not limited to, NaC1, sea
salt,
calcium chloride, and potassium salts. The potassium salts may include, for
example,
but not limited to Potassium Chloride, Potassium Nitrate and potassium
carbonate.
100431 Potassium salts are preferable because unlike other salts, potassium
salts may actually
be beneficial to plants. Indeed, potassium salts are a component of some
fertilizers.
Thus, when potassium salts are included in a component including SAP that is
used
as compost or some other agricultural product, the potassium salts may benefit
the
environment. Further, the decanted water from the salt assisted dehydration
product
may be used as a liquid fertilizer because of its potassium salt content.
Finally, it is
preferred that the salt used in salt assisted dehydration does not include
alum, or any
other salt that causes further crosslinking or irreversible contraction of the
SAP, or is
environmentally unfriendly.
100441 The methods of the present disclosure also provide a method of
producing both a
reusable plastic and a reusable SAP from separation of a product containing
SAP, a
fiber and a plastic into its component parts. Examples of this method is
described
above using a press and the embodiment depicted in Figure 1. In these methods,
the
products are first separated into components including a plastics component
including
substantially plastic, but also some SAP and fiber (plastic component), and an
SAP
and fiber component (SAP and fiber component) including substantially SAP,
waste
and fiber, but also some plastic. In these methods, water may be removed
SAP/fiber
component with a method comprising salt assisted dehydration, yielding a
reusable
SAP. Salt assisted dehydration is described, above. The method may further
include
treating the plastics component with a composition comprising alum in order to
remove or deactivate any residual alum in the plastic. In these methods, the
initial
separation step may include shredding the product, adding water to the
product, and
pressing the product against a screen as described above. The press separates
the
products into components including a plastics component, and a super absorbent
polymer and fiber component. In these methods, treating the plastics component
further with a composition including alum includes adding a composition
including
alum to the plastic component as described above. One of the benefits of the
methods
- 15 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
described in this disclosure is that any water recovered may be used in a
composting
and biogas facility to adjust the moisture of incoming materials.
100451 Further embodiments of this disclosure include methods of
deactivating super
absorbent polymer in a plastic component as part of the separation of a
product
comprising a super absorbent polymer, a fiber and a plastic. One of these
embodiments is depicted in Figure 2. Initially, separating the products
including a
super absorbent polymer may be achieved in a substantially dry environment,
unlike
the method described above using a press.
100461 One dry separation method uses a drum type filter separator, for
example, the Model
FS-75 fluff separator (Ibis Company, Hoschton, GA, USA). This device uses a
rotating filter with air blowers and a vacuum system to draw the paper fiber
away
from the plastic after they have been run through a shredder and a "buster
fan" that
loosens and separates the diaper scraps. Air cyclones can further separate the
larger
SAP particles from the fluff fiber using the different densities and geometry
to
separate SAP and fiber. These devices will only remove a percentage of the
SAP.
None of the separated components have purity.
[00471 This process may yield a substantially dry super absorbent polymer
component, and a
substantially dry fiber component, and a substantially dry plastic component.
Alum
or a similar salt can be introduced to these streams to condition either the
fiber stream
with small amounts of SAP still carried with the paper fiber, or to condition
the
plastics stream which also may include residual SAP.
100481 The fiber may be sent to an agitator tank and combined with water
and alum. Low
levels of alum can be used to reflect the low levels of SAP in the remaining
fiber
stream. The fiber stream can now be partially &watered to isolate the salt and
water.
The dewatered pulp with small amounts of deactivated SAP can be added to the
pulp
stream of a typical low end recycled paper mill without any further separation
being
required. The remaining SAP particles would be incorporated into the paper
without
seriously degrading the final product. Without the SAP deactivation step, the
expanding SAP in the pulp would stick to the surface of the paper machine
felts and
- 16 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
wires, plugging the surface and preventing water from draining. The active SAP
even
in small amounts would create spots in the paper commonly called "stickies" in
the
paper industry.
100491 In the case of the plastics stream, a composition including alum is
added to the plastic
component, as described above. This method includes adding a composition
comprising alum to the plastic component.
100501 Certain other embodiments of this disclosure include a plastic
product including the
plastic component of any of the methods described herein. Because any
remaining
SAP in the plastic is deactivated, the plastic may be suitable for recycling
into other
products including products that may be exposed to water. In certain
embodiments,
the plastic component is recycled into a plastic product including a product
selected
from the group consisting of plastic lumber and roofing shingles, or any other
suitable
plastic product. Other plastic products may be extruded, cast, or molded into
useful
articles. Another embodiment of this disclosure includes a method of making a
plastic product including using any of the plastic components described herein
to
make the plastic product.
100511 Certain other embodiments of the present disclosure include a method
of using
recycled super absorbent polymer as an agglomerating agent. This method may
include treating the super absorbent polymer with heat and/or a chemical in
order to
break the crosslinking bonds to form substantially uncrosslinked super
absorbent
polymer. This method may further include using the substantially uncrosslinked
super absorbent polymer as an agglomerating agent. The agglomerating agent may
be used in a dissolved air flotation (DAF) process.
[0052] In other embodiments of this disclosure, separation of a material
containing SAP, a
fiber component and a plastic component includes shredding the material,
adding a
salt to the material and agitating the material. In certain embodiments, the
material is
not a slurry, as discussed below. One embodiment demonstrating this process is
depicted in Figure 3. The material may be shredded before agitating, or the
material
may be shredded through the act of agitation itself. Shredding may occur
during
- 17-
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
agitation merely by the agitation of the material, or the shredding may occur
as a
result of physical contact with the apparatus that is performing the
agitation, for
example, but not limited to a rotating vessel. The rotating vessel may have
fins,
blades, or other components to assist in shredding the material.
(0053) As mentioned above, agitating the material may be accomplished by a
rotating vessel.
Agitating may also be accomplished by other methods, for example, but not
limited
to, shaking, vibrating, stirring, blowing and cycloning.
[0054] In some embodiments, the salt dries or removes water from the SAP
through salt-
assisted dehydration, as discussed above. Water removed from the SAP and fiber
is
removed from the material. Removal may occur by various methods, including
draining, decanting, pumping, and evaporating the water.
100551 In certain embodiments, no water or very little additional water is
added to the
material during salt-assisted dehydration aside from the water already
contained in
the material. In certain embodiments, less than 20% water by weight of the
material
is added. In other embodiments, less than 15% water by weight of the material
is
added. In still further embodiments, less than 10% water by weight of the
material is
added. And in other embodiments, less than 5% water by weight of the material
is
added.
(0056) In some embodiments, the material is heated during salt-assisted
dehydration. The
heat may serve to evaporate the water, such that it may be removed from the
material
as water vapor. This may help to dry the SAP and material faster. Evaporating
water
may increase the concentration of salt on the surface of the SAP, which serves
to
draw more water out of the SAP driven by the concentration gradient. In
certain
embodiments, the material is heated in a vessel that is heated by a jacket or
other heat
exchanger. In other embodiments, the material is heated by injecting steam
into a
vessel that contains the material. In some embodiments, the amount of water
added
as steam is from 1-10% by weight of the material. In other embodiments, water
added as steam is about 5% by weight or less of the material. In certain
embodiments, water added as steam is about 50 liters per ton of material or
less.
- 18 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
[0057] In some embodiments, the salt being added to the material may be in
aqueous form to
allow the use of dosing pumps to control the amount of salt being added. In
some
embodiments, the amount of salt solution added is from 1-10% by weight of the
material. In other embodiments, salt solution added is about 5% by weight or
less of
the material. In certain embodiments, salt solution added is about 50 liters
per ton of
material or less.
(0058) In certain embodiments, the combined amount of water added as steam
and as a salt
solution is less than 500 liters per ton of material. In other embodiments,
the
combined amount of water added as steam and as a salt solution is less than
250 liters
per ton of material. In some embodiments, the combined amount of water added
as
steam and as a salt solution is less than 100 liters per ton of material. In
other
embodiments, the amount of total water added is less than 75 liters per ton.
In still
other embodiments, the total amount of water added may be less than 50 liters
per ton
or 25 liters per ton of material. In some embodiments, substantially no
additional
water is added to the material.
100591 In some embodiments, the amount of water added to the material
before separating is
only as much as is required to heat the material with steam and/or add a salt
solution
to the material in metered doses. In these and other embodiments, the material
does
not form or comprise a slurry.
100601 A slurry may be described as "a thin, watery suspension..." Lewis,
Richard J.,
Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold Co. (12th Ed.,
1993). Another description is "a thin mixture of an insoluble substance..
.with a
liquid.. .to prepare a suspension of (a solid in a liquid)." Random House
Webster's
College Dictionary, Random House (2nd Ed., 1999). A slurry is also described
as a
suspension or a "soupy" material, possibly containing significant quantities
of
interstitial water between the particles of solid matter. A slurry may be
described as a
suspension of solids in a liquid. The solids in a slurry are enveloped in the
liquid
phase of the suspension. Suspended solid particles vary in size from very fine
colloidal particles to sedimentable coarse particles, with solid concentration
affecting
- 19 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
the viscosity. Usui, Hiromoto, Powder Technology Handbook, 299, CRC Press (3rd
Ed., 2006). Fluid behavior, however, is the hallmark of a slurry. Id. Thus, in
some
embodiments, less water is added to the material than would be required to
make it
flow or exhibit fluid behavior.
100611 In embodiments of this disclosure, the solids are not suspended in a
liquid. There is
little or no "free water" in the solids mass. In some embodiments where salt
is added
to the material, the salt requires the mechanical agitation to bring the salt
into direct
contact with the surface of the SAP gel.
100621 In other embodiments, the material is not submerged or put in a bath
of water or
aqueous solution. In still other embodiments, the material is not saturated
by, or
immersed in, water or aqueous solution. In some embodiments, after adding
water or
aqueous solution, the material cannot be poured like a liquid, sludge or
slurry. In
some embodiments, the material does not comprise a slurry, sludge or
suspension
from the addition of any water to the material. In certain embodiments, the
amount of
water added to the material is less than what would be added to a washing
machine-
type device. These types of devices typically use a perforated basket or mesh
cage
inside, which may not be present in the vessels of certain embodiments herein.
In
certain embodiments, water or "free water" does not circulate through the
material
during agitation.
100631 In other embodiments, the material does not form or comprise a
sludge. A sludge
may be described as a "thick, viscous mass." Lewis, Richard J., Hawley's
Condensed
Chemical Dictionary, Van Nostrand Reinhold Co. (12th Ed., 1993).
[0064i In some embodiments, the range of salt concentration in the salt
solution added to the
material is from about 2% by weight to 15-20% by weight. In certain
embodiments,
the concentration depends on the quantity of SAP in the process, which can
vary. In
some embodiments, the amount of dry (non-aqueous) salt added to the material
in
either dry or aqueous form is roughly equal to the dry weight of the SAP. In
some
embodiments, the purity of the salt may be as low as 17% by weight of
industrial
grade granulated alum. In one embodiment, a weight of dry salt of about from
3% to
-20 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
5% of the weight of the material is added to the material in either dry form
or in a
solution. In another embodiment salt in the amount of about 5% by weight of
the
incoming material is added.
100651 In still further embodiments, the material may be pressurized during
salt-assisted
dehydration, with or without heat. The pressurization may occur naturally as a
result
of heat causing water to evaporate while contained in a pressure vessel. In
another
embodiment, the material may be pressurized in a pressure vessel using a
compressed
fluid, for example, steam.
100661 In some embodiments, the material undergoes salt-assisted
dehydration in an
autoclave. The autoclave may heat, pressurize, agitate and/or shred the
material. In
some embodiments, water is only removed from the autoclave at or near the end
of
the salt-assisted dehydration process. At this point, the pressure in the
autoclave is
released and existing water vapor escapes. Liquid water may also flash to
vapor
while pressure is being released. Remaining liquid water may be removed, as
described above, from the autoclave. In other embodiments, water vapor is
removed
from the autoclave while it is pressurized. In certain embodiments this is
done with a
vacuum pump system.
[0067] The temperature of the autoclave may depend on the final use of the
material. In
embodiments where the material needs to be sterilized, the material may be
held at
121 C for fifteen minutes. In other embodiments, the material is heated to a
temperature that allows for sterilization, and kept at that temperature for an
effective
amount of time. If sterilization is not required, the process may be operated
at
ambient temperatures, allowing the material to air-dry or vacuum dry. In some
embodiments, the autoclave should not heat the material to the melting point
of the
plastic. If the plastic melts, it can bind to the fiber and SAP making
separation more
difficult. In some embodiments, the autoclave heats the plastic to a
temperature less
than the melting point of the lowest-melting component of the material. In
other
embodiments, the autoclave heats the material up to from 125 C to I30 C.
- 21 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
10068] In some embodiments, the autoclave is operated at temperatures of
from 100 C to
130 C. In other embodiments, the autoclave is operated at temperatures of from
121 C to 125 C. in still other embodiments, the autoclave may be operated at a
temperature of about 121 C.
00691 In some embodiments, the autoclave is operated at pressures of from
atmospheric
pressure (about I bar) to over 4 bar. In other embodiments, the autoclave is
operated
at pressures of from 1-3 bar. In other embodiments, the autoclave is operated
at
pressures of from 2-2.3 bar. In still other embodiments, the autoclave may be
operated at a pressure of about 2.1 bar. In some embodiments, the pressure in
the
autoclave is generated by merely heating the material, which evaporates the
water in
the material. In other embodiments, the autoclave is heated and pressurized by
adding
steam. In certain embodiments, the steam may be at a pressure of 2.0-2.2 bar
and a
temperature of 121 C to 125 C.
100701 In some embodiments, the autoclave and/or salt-assisted dehydration
process removes
from 30-99% of the water from the SAP and other components of the material. In
other embodiments, the autoclave and/or salt-assisted dehydration process
removes
from 90-95% of the water from the SAP and other components of the material. In
still other embodiments, the autoclave and/or salt-assisted dehydration
process
removes at least about 95% of the water from the SAP and other components of
the
material.
100711 In some embodiments, the material is subjected to a separation
process after leaving
the autoclave. In some embodiments, the separating process separates the
material
into a component comprising mostly fiber and SAP with some plastic (fiber and
SAP
component), and a component comprising mostly plastic with some fiber and SAP
(plastic component). In some embodiments, the separation process is a dry
separation
process, meaning that the material separated by the process is not a slurry,
or meaning
that no additional water is added for the separation process. In one
embodiment, this
separation process includes a dry screen with approximately one inch openings.
In
other embodiments, the openings may range from 0.25"-2.0". The screen retains
- 22 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
most of the plastics with a small amount of fiber, waste and SAP ("plastic
component"). In some embodiments, the plastics are sent to a pulper/washer
with
approximately 0.06 inch openings, which adds water to the plastic component to
clean and further separate the material. In other embodiments, the openings
may
range from 0.004"-0.5". In some embodiments, the plastics may then be
recycled. In
still further embodiments, the plastic may be further reduced in size before
or after
washing. The reduced particle size may range from 0.25"-0.5".
100721 In certain embodiments, fiber, waste and SAP removed in the
pulper/washer ("fiber
and SAP component') is sent to a sidehill screen with 0.03 inch openings. In
other
embodiments, the openings may range from 0.10"-0.125". Wastewater from the
sidehill screen is subjected to dissolved air filtration in some embodiments.
In other
embodiments, the SAP, fiber and waste from the sidehill screen is pressed to
remove
additional water. The SAP, fiber and waste may then be recycled for use in
energy
production, incineration, landfill, or other use.
100731 In some embodiments, the SAP, fiber and waste that is separated from
the plastics
and passes through the dry screen may also be recycled for use in energy
production,
incineration, landfill, or other use. In other embodiments, this dry material
may be
used to make paper products.
100741 In some embodiments, the salt used in the process may be any salt
discussed in this
disclosure. In one embodiment, a salt that causes shrinkage or dehydration,
but no
cross-linking may be used. In other embodiments, a salt that causes cross-
linking
may used. In certain embodiments, aluminum sulfate is used in the autoclave.
One
benefit of using aluminum sulfate is that the SAP is deactivated so that the
fiber and
plastic may be recycled.
100751 Generally, the benefits of using this system where little to no
water is added are that
since the components are deactivated and separated in a substantially dry
manner, the
resulting separated components are lighter and require less energy to process,
dry and
ship. The process also consumes less water compared to a system using wet
pulping
and other wet separation methods involving liquid suspensions and/or slurries.
Even
- 23 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
when wet separation methods are used in these embodiments, they are used
further
downstream and use much less water than if water was added initially. In some
embodiments, other separation processes, including those described in this
specification, may be used to further separate and refme the material.
(00761 Figure 4 depicts an example of another embodiment of a dry
separation system. In
this embodiment, the material is shredded before being added to an autoclave
or by
the autoclave itself. The material is subject to heat, pressure and agitation,
but salt is
not added while the material is in the autoclave. In further embodiments, the
material
is depressurized after heating and agitating. In certain embodiments, the
material
does not comprise a slurry. In some embodiments, the dehydrated material is
separated by a dry screen as described above. In certain embodiments, the
plastic
from the dry screen with small amounts of fiber, SAP and waste is also
separated by a
pulper/washer. However, in these embodiments, salt may be added in addition to
water in the pulper/washer in order to deactivate the SAP.
100771 In certain of these embodiments, the SAP, fiber and waste from the
dry screen may be
composted or recycled in that form. In other embodiments, however, salt and/or
water may be added to the SAP, fiber and waste. In some embodiments, the salt
dehydrates the SAP, but does not deactivate it. This stream may be placed in
containers, pasteurized or dried. The SAP, fiber and waste may then be
recycled by
methods disclosed herein, for example, by combining with seed. In these
embodiments, the SAP is active for recycled materials where retaining water is
desired. This process has benefits similar to the ones described above, but
also may
use less salt. In some embodiments, other separation processes, including
those
described in this specification, may be used to further separate and refine
the material.
EXAMPLE I
100781 Figure 3 represents the process used in a pilot plant that has been
created to separate
material containing SAP, a fiber component and a plastic component. First, the
material is shredded. Then, the material is added to a rotating autoclave.
Aluminum
-24 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/062076
sulfate is added to the autoclave either in dry form or by a salt solution
using a dosing
pump. The salt helps to dehydrate and/or crosslink the SAP during the process.
100791 The material is heated during in the autoclave during agitation. The
heat disinfects
the material and also speeds up the dehydration of the SAP. The heat may also
serve
to evaporate the water, which is removed from the material as water vapor.
Evaporating water may increase the concentration of salt on the surface of the
SAP,
which serves to draw more water out of the SAP driven by the concentration
gradient.
The autoclave is heated by a jacket or other heat exchanger. In order to speed
up the
heating process, steam is sometimes injected into the autoclave. The water
added as
steam is about 50 liters per ton of material or less. When salt is added as a
solution,
the water making up the solution is about 50 liters per ton of material or
less. Thus,
the combined amount of water added as steam and as a salt solution is less
than 100
liters per ton of material.
100801 The amount of water added is such that the material does not form a
suspension,
slurry or sludge. The material is not agitated in a bath like a washing
machine.
Instead, the water inherent in the material is dried by the autoclave with
only minimal
addition of other water
(0081) The amount of dry (non-aqueous) salt added to the material in either
dry or aqueous
form can be roughly equal to the dry weight of the SAP, but mostly the weight
of dry
salt is about from 3% to 5% of the weight of the material is added to the
material in
either dry form or in a solution.
100821 The autoclave is pressurized while agitating. The pressurization
occurs from a
combination of the water native to the material evaporating and injected
steam.
When the agitation is complete, the pressure in the autoclave is released and
existing
water vapor escapes. Some liquid water also flashes to vapor while pressure is
being
released. Remaining liquid water, which is minimal, is removed from the
autoclave.
In the future, a vacuum pump will be installed to vent water vapor while the
autoclave
is under pressure.
- 25 -
CA 02854441 2014-05-02
WO 2013/077877 PCT/US2011/0620 76
[0083] The material is held at 121 C for at least fifteen minutes in the
autoclave. The
autoclave is operated at a pressure of about 2.1 bar. The steam is at a
pressure of
about 2.0-2.2 bar and a temperature of about 121 C to 125 C.
100841 The autoclave removes at least about 95% of the water from the SAP
and other
components of the material with the addition of only a minimal amount of water
in
the beginning of the process. Overall, this process uses significantly less
water than
"washing machine" style processes.
[0085] After leaving the autoclave, the material is subjected to a dry
separation process using
a dry screen with approximately one inch openings. The screen retains most of
the
plastics with a small amount of fiber, waste and SAP ("plastic component").
The
plastics are sent to a pulper/washer with approximately 0.06 inch openings.
The
plastics are then further reduced in size by a conventional shredder and then
recycled.
The final particle size of the plastic is about 0.25"-0.5".
100861 The fiber, waste and SAP removed in the pulper/washer ("fiber and
SAP
component") is sent to a sidehill screen with 0.03 inch openings. Wastewater
from
the sidehill screen is subjected to dissolved air filtration. The SAP, fiber
and waste
from the sidehill screen is pressed to remove additional water. The SAP, fiber
and
waste is then recycled.
(00871 The present invention may be embodied in other specific forms
without departing
from its essential characteristics. The described embodiments are to be
considered in
all respects only as illustrative and not as restrictive. The scope of the
present
invention is, therefore, indicated by the appended claims rather than by the
foregoing
description. All changes which come within the meaning and range of the
equivalence of the claims are to be embraced within their scope.
-26 -
