Note: Descriptions are shown in the official language in which they were submitted.
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S
FOOD CONTAINER HAVING SUBSTRATE
IMPREGNATED WITH PARTICULATE MATERIAL
FIELD OF THE INVENTION
The present invention relates to food containers, and more particularly to
food containers having a user facing surface which provides improved cut
resistance.
BACKGROUND OF THE INVENTION
Disposable food containers are well known in the art. Disposable food
containers include common paper plates, bowls, clam shells, trays, cutting
boards, etc.
The art has paid considerable attention to making, molding, and deforming
these food containers out of a single plane. In this latter process a blank is
provided. The blank is inserted between mating platens and pressed. The
periphery of the blank may have radial grooves. The radial grooves provide for
accumulation of the material deformed by the platens. Exemplary art includes
U.S. Patents 3,033,434, issued May 8, 1962 to Carson; 4,026,458, issued
May 31, 1977 to Morris et al., the disclosures of which are incorporated
herein by
reference; 4,606,496, issued August 19, 1986 to Marx et al.; 4,609,140, issued
September 2, 1986 to van Handel et al.; 4,721,500, issued Jan. 26, 1988 to van
Handel et al.; 5,230.939, issued July 27, 1993 to Baum; and 5,326,020, issued
July 5. 1994 to Cheshire et al.
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However, these attempts in the art suffer from several drawbacks. As
illustrated by the plethora of attempts to improve the rigidity and stability
of the
food containers, the prior art attempts do not provide food containers of
sufficient
strength. This lack of strength leads to spillage of food when the food
container
becomes overloaded, or, alternatively, unduly constrains the amount of foods
which can be placed on the food container at a given time.
There have been several attempts in the art to improve the rigidity of such
food containers. For example, food containers having a bottom wall, a side
wall
disposed radially outwardly of and circumjacent the bottom wall, and a rim
disposed radially outwardly of and circumjacent the side wall are known in the
art. Food containers with densified regions in the side wall have been
attempted
in the art. Likewise, containers having densified circumferentially spaced
regions
extending radially through annular portions of the rim are known. Such
attempts
in the art are alleged to provide resistance to bending throughout the entire
structure. Illustrative of such attempts are U.S. Pat. nos. 4,606,496 issued
Aug.
19, 1986 to Marx et al, and 4,609,140 issued Sept. 2, 1986 to Van Handel et
al.
Food containers according to the prior art have been coated to improve
resistance to penetration by liquids, such as grease, etc. Coatings have also
been used to attempt to provide cut resistance in the finished product, gloss,
ink
receptivity, etc. An example of such attempts is U.S. 5,776,619 issued July 7,
1998 to Shanton. Shanton teaches a coated paper board having two coatings, a
base coat and a top coat. Each coating consists of a polymer latex and a
particulate pigment. The top coat has a blend of about 90 parts kaolin clay,
having approximately 80% of the particles less than two microns in size.
Furthermore, U.S. 5,709,913 issued Jan. 20, 1998 to Andersen et al. discloses,
in Example 112, inorganically filled paper plates which are allegedly more
rigid
than conventional paper plates.
Another attempt in the art is illustrated by U.S. 5,635,279 issued June 3,
1997 to Ma et al. Ma et al. discloses paperboard having a polymer
matrixlwax/pigment mixture applied as an aqueous formation and suited for
corrugated box constructions. The coating consists of pigments, including
natural and synthetic silicates, bentonite, clay, etc. U.S. 5,494,716 issued
Feb.
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27, 1996 to Seung et al. discloses a food tray having an aqueous coating with
a
styrene/acrylic latex and other agents. U.S. 5,334,449 issued Aug. 2, 1994 to
' Bergmann discloses a paper having a prime coat and a mixture of kaolin,
calcium carbonate, casien and butadiene-styrene latex. U.S. 5,100,472 issued
Mar. 31, 1992 to Fugitt et al. discloses a paper coating containing dionized
clay
or calcium carbonate.
Similar attempts have been made in nonanalogous art to utilize particulates
for abrasion resistance. For example, U.S. 5,558,906 issued Sept. 24, 1996 to
Albrinck et al. discloses a decorative laminate having an abrasion resistant
material including alumina particles having particle sizes of about 25 microns
and
at about 3 microns in a 2-1 ratio.
Additionally, mineral pigments such as titanium dioxide, and water and
particulate fillers such as kaolin clay have been used as opacifying agents in
nonanalogous arts, such as tissue. Examples include commonly assigned U.S.
4,952,278 issued Aug. 28, 1990 to Gregory et al.; U.S. 5,611,890 issued Mar.
18,
1997 to Vinson et al.; and 5,672,249 issued Sept. 30, 1997 to Vinson et al.,
the
disclosures of which are incorporated herein by reference. Additionally,
fillers
and cationic starch have been taught in nonanalogous arts such as the
production of news print as found in U.S. 5,670,021 issued Sept. 23, 1997 to
Owens.
Accordingly, this invention provides a food container having a cut resistance
surface which is simpler in execution and consumer preferred over the surfaces
provided by the attempts in the prior art. Particularly, this invention
provides a
food container having a cut resistance surface which not only improves
resistance to inadvertent cutting and to penetration by liquid such as grease,
but
also provides a preferred tactile feel, when using common eating utensils such
as
. silverware.
' SUMMARY OF THE INVENTION
This invention comprises a food container. The food container has a first
user-facing surface and a second surface opposed to the first surface. The
food
container has a cut-resistant particulate material impregnated into the
substrate.
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The food container may have an optional external facing with particulate
material
as well. The particulate material has a Mohs hardness of at least 3 and
preferably at least 7.
The particulate material has a particle size of at least 5 microns, and
preferably at least 10 microns.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of a food container according to the present
invention.
Fig. 2 is a fragmentary sectional view taken along the lines 2-2 of Fig. 1.
Fig. 3 is a fragmentary sectional view similar to that of Fig. 2 and showing a
food container having an intermediate facing.
DETAILED DESCRIPTION OF THE INVENTION
Referring to Figs 1-2, the food container 10 according to the present
invention may comprise a plate, bowl, tray, clam shell, cutting board, or any
other
configuration known in the art.
Typically the food container 10 according to the present invention has a
concave first surface 11 and a convex second surface 12. The concave first
surface 11 of the food container 10 is that side which typically faces the
user
while in use. The convex side of the food container 10 typically faces away
from
the user in use and may rest upon a horizontal surface such as a table.
The food container 10 thus comprises a first user-facing surface and a
second surface 12 opposed to the first surface 11. The food container 10
further
has a cut-resistant external facing 32 juxtaposed with, and preferably
coincident,
the first surface 11. The cut-resistant external facing 32 comprises
particulate
material 34 disposed in a single stratum. Particulate material 34 of the cut-
resistant external facing 32 is disposed on and carried by a substrate 30.
The food container 10 comprises a central region 14 and a circumjacent
periphery 16. The central region 14 and periphery 16 are preferably disposed
in
two different planes, although a flat food container 10 is contemplated as a
less
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preferred embodiment. A flat food container 10, may, for example, have utility
as
a food tray or cutting board.
The central region 14 defines the XY plane of the food container 10. The Z
direction of the food container 10 lies perpendicular to the XY plane. The
food
5 container 10 has a transition region 20 from the central region 14 to the
periphery
16. The periphery 16 may be spaced apart in the Z-direction from the central
region 14, or the food container 10 may be flat, as described above. In normal
use, the periphery 16 is raised relative to the central region 14. The central
region 14 of the food container 10 defines a first portion of the food
container 10.
Likewise, the periphery 16 of the food container 10 defines a second portion
of
the food container 10.
Thus, the food container 10 is preferably multi-planar. By multi-planar, it is
meant that the different portions of the food container 10 lie in different
planes.
An example of the multi-planarity of the food container 10 of the present
invention is illustrated by the central region 14 and periphery 16 of the food
container 10. The central region 14 and periphery 16 of the food container 10
are spaced apart in the Z-direction, thus rendering the food container 10
multi-
planar.
It may be necessary to accommodate the accumulation of material which
occurs when the food container 10 is formed. Pleats or gathers are often used
for this purpose, as is known in the art. Pleats and gathers, particularly
accumulation pleats having a radial orientation, are contemplated.
It is not necessary that either the central region 14 or the periphery 16 be
parallel to the XY plane or generally planar. For example, bowls having a
generally concave shaped bottom will be suitable for use with the present
invention. The Z-direction distance from the bottom surface of the central
region
. 14 (taken while the food container 10 is in its normal in use and generally
horizontal position) to the top surface of the periphery 16 as referred to as
the Z
direction depth 19 of the food container 10. If there are different depths at
different portions of the food container 10, the Z-direction depth is taken as
that
greatest Z-direction distance.
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The boundary and shape of the periphery 16 are defined by the edge 18 of
the food container 10. It is to be recognized that the dimensions and relative
proportions of the periphery 16 and central region 14 of the food container 10
will
vary according to the exact size and intended use of the food container 10.
While
a round food container 10 is contemplated, one of ordinary skill will
recognize
that any suitable shape and depth of food container 10 may be selected for use
with the present invention and the invention is not so limited. Other suitable
shapes include squares, rectangles, ovals, various polygons, etc.
The substrate 30 of the food container 10 may be comprised of at least two
plies, a first ply and a second ply. The second ply may be smaller that the
first
ply, so that at least part of the food container 10 is free from the second
ply. The
second ply and the first ply may be concentric. It is to be recognized that an
alternative embodiment (not shown) of the food container 10 may comprise three
or more plies.
In a particularly preferred embodiment, the food container 10 comprises a
single piy of a rigid material, particularly a material which provides for
carrying the
cut-resistant external facing 32 in juxtaposition and preferably coincident
with the
user-facing surface of the food container 10. Suitable rigid materials include
foam, plastic and various other synthetic materials. The food container 10 is
preferably made of cellulose and may be made of kraft, solid bleached sulfite
(SBS), or layers of various paper fibers including recycled cellulose. The
food
container 10 may be molded from a pulp slurry or pressed from a blank between
mating platens. Both methods of manufacture are well known in the art.
The external facing 32 provides resistance to penetration of hot greasy
foods into the substrate 30 of the food container 10. Also, the external
facing 32
provides a tactile sensation which is not unpleasant when the user touches the
first surface 11 of the food container 10, or cuts food thereon with an eating
utensil such as a knife.
One of ordinary skill will recognize that a particulate material 34 is
particularly preferred for the external facing 32. A material having discrete
and
separate particles allows the facing to be hard and cut resistant without
being
brittle. This combination allows the food container 10 to be handled, shipped,
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etc., during normal transportation and use - without breaking, spalling,
delamination or chipping of the external facing 32 surface.
It is important that the first surface 11 of the food container 10 be hard yet
flexible - rather than hard and brittle. This arrangement further allows the
first
surface 11 of the food container 10 to be cut-resistant. As used herein, a
surface
is considered to be "cut-resistant' if the surface allows the user to exert
normal
pressures while eating cooked and other prepared foods without ordinarily
penetrating through the substrate 30 of the food container 10. It is further
important that the first surface 11 provides the proper tactile sensation
directly to
the fingertips and as transmitted through various eating utensils.
It is preferred that the particulate material 34 comprising the external
facing
32 have a Mohs hardness of at least 3, preferably at least 7, and even
approaching or greater than 9. A Mohs hardness between 6.5 and 7.5 has been
found suitable for use with the food container 10 of the claimed invention.
The
Mohs hardness scale (measured on a 1 to 10 talc to diamond scale) of the
particulate materials 34 of the external facing 32 are well documented in
reference handbooks such as pages 4-132 to 4-139, 12-93 to 12-97, and 12-205
to 12-206 of The Handbook of Chemistry and Physics, 78t" Edition, 1997-1998
incorporated herein by reference. Of course, the hardness of the particulate
material 34 comprising the external facing 32 is determined prior to
incorporating
the particulate material 34 into or disposing the particulate material 34 on
the
substrate 30 of the food container 10.
By providing a particulate material 34 of the aforementioned hardness, a
food container 10 having the proper and preferred tactile sensation is
attainable.
Such a hardness allows the user to cut foods on the food container 10 with a
sharp knife, without experiencing the unpleasant occurrence when the knife
cuts
through the food container 10, allowing gravy, au jus, etc., to leak through
the
food container 10.
Furthermore, it has been unexpectedly found that the particulate material
34 has a preferred particle size. The preferred particle size is necessary to
impart the tactile sensation of toughness without being unpleasant to the
touch.
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The, user will not be afraid to cut food disposed on such a food container 10
with
a sharp knife or other eating utensil.
r
The particulate material 34 comprising external the facing 32 has a particle
size of at least 5 microns, and preferably 10 microns. The particulate
material 34
may range in size from 20 to 200 microns, and possibly range from 50 to 200
microns. Particle size is measured using an l_3P Sonic Sifter Separator, ATM
available from VWR Scientific Products Corp., catalog number 57353-035.
The particulate material 34 comprising the external facing 32 may be a
mixture of or several mixtures of mineral and other types of particulates
known in
the art and commercially available. For example, various particulates
comprising
alumina, silica, carbonate, oxides, carbides, nitrides, bromides, hard metals,
hard
alloys, hard elements. If carbides are selected, suitable carbides include
tantalum carbide, tungsten carbide, zirconium carbide, beryllium carbide or
silicone carbide (carborundum). If a boride is selected, suitable borides
include
aluminum boride, tantalum boride, zirconium boride, and titanium boride. Boron
may also be used. If a nitride is selected, suitable nitrides include aluminum
nitride, zirconium nitride and titanium nitride. Metals, including hard metal
alloys,
such as iron, steel and chromium may be used for the particulate material 34.
Ceramics, such as stoneware and particularly porcelain type ceramic
particulate
materials 34 have been found suitable. More particularly, aluminum oxide
(corundum), silicone dioxide (quartz), calcium carbonate, potassium aluminum
silicate and feldspar are suitable. Silicone dioxide, calcium carbonate, and
aluminum oxide are available from the J.T. Baker Company, a division of
Mallincroft Baker, Inc., of Phillipsburg, NJ, under catalog numbers JT3405,
JT1301, and JT0536, respectively.
The particulate material 34 may further comprise clay. A kaolin clay has
been found particularly well suited. Suitable kaolin clay is available from
the J.T.
Baker Company of Phillipsburg, NJ under catalog number JT2242.
A suitable mixture for the external facing 32 has been found to be 80%
kaolin clay and 20% aluminum oxide. Another suitable mixture has been found
to be 80% kaolin clay and 20% calcium carbonate. All percentages described
herein are weight percentages, unless otherwise specified.
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The particulate material 34, including any optional clay, may be added to a
water-based resin to form a coating. An acrylic resin is particularly
preferred. A
suitable coating may have 50 to 90% resin with 10 to 50% particulate material
34
mixed therein.
A suitable add-on level for the particulate material 34 comprising the
external facing 32 of first surface 11 of the food container 10 is from about
0.5 to
100 grams per square meter, and preferably from about 1 to 50 grams per
square meter. A round food container 10 having a finished diameter of about
22.9 centimeters and 0.1 to 2 grams of particulate material 34 comprising the
external facing 32 has been found suitable.
It is desired. that the particulate material 34, including any resin or other
carrier used therewith, be applied to the substrate 30 of the food container
10 as
a single stratum. The single stratum provides the benefits over the dual
strata
teachings of the prior art of more precise control of the add-on levels, a
single
application operation, and is accommodated by a commercial drying operation.
In contrast, the dual strata teachings of the prior art require double the
inventory
of raw materials and double the machinery to apply the particulate material 34
to
the substrate 30.
The coating, which ultimately comprises the external facing 32, may be
applied to the substrate 30 of the food container 10 after it is formed. The
coating comprising the particulate material 34 may be applied by blade
coating,
printing, or spraying as are known in the art. If blade coating is used, the
hardness of the blade must be at least as hard as the particulate material 34.
Preferably, an air knife coating process is used to apply the particulate
mixture to
the substrate 30. Preferably, the substrate 30 of the food container 10 is not
dipped into the coating - so that the second surface 12 of the food container
10
remains uncoated.
One of ordinary skill will recognize that many variations are feasible. For
example, the particulate material 34 may be applied in a gradient. The
gradient
preferably has a greater add-on level near the center of the food container 10
where more cutting typically occurs in use. Less of the particulate material
34
may be applied to the exposed sides and periphery 16 of the food, which
typically
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function to hold the food within the periphery 16 of food container 10. This
allows for conservation of the particulate material 34 as well as
concentrating the
particulate material 34 in the area which typically receives the greatest wear
in
use. Such an arrangement provides a Z-direction gradient, with concentration
5 increasing as the center of the food container 10 is approached and
decreasing
as the edge of the food container 10 is approached.
Alternatively, the particulate material 34 may vary in an XY pattern between
regions of the first surface 11 having the particulate material 34 and regions
free
of the particulate material 34. The particulate material 34 may, for example,
be
10 applied in a checkerboard pattern or in stripes. Suitable patterns of
stripes
include concentric rings, radial lines (either straight or spiral), parallel
lines, etc.
This arrangement provided the benefit that the food container 10 is flexible
in the
regions not having the particulate material 34 and yet hard in the regions
having
the particulate material 34. Thus a food container 10 which has a cut
resistant
external facing 32 will still result.
Optionally, the external facing 32 may be provided with at least one
overcoat (not shown). The overcoat serves to protect the particulate material
34
and the external facing 32 from becoming dislodged from the substrate of the
food container 10. Additionally, the overcoat defines and provides a
relatively
smoother first surface 11. Preferably, the overcoat does not provide a first
surface 11 which is too smooth, otherwise the proper tactile sensation may not
result.
The overcoats) may comprise an acrylic resin. Preferably, the acrylic resin
is relatively transparent or translucent, so that an aesthetically pleasing
first
surface 11 will result. The overcoat may be applied by printing, spraying,
dipping, blade coating, air knife coating, etc. as known in the art.
One of ordinary skill will recognize that the external facing 32 may comprise
one stratum or plural strata. The external facing 32 may have one or more
binder materials 36. Binder materials 36 include clay, resin, and other
particulate
matter which may or may not have a Mohs hardness greater than 3, but serve to
bind the particulate material 34 into a matrix comprising the external facing
32.
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Thus, the external facing 32 will be free of clay, free of resin, or free of
both while
still containing the particulate material 34.
If multiple strata are used for the external facing 32, one stratum may be
free of resin while the other stratum may be free of clay. One stratum may be
free of both resin and clay.
Of course, one of ordinary skill will recognize that at the interface between
the strata, there may be some slight intermingling of the clay and the resin
binder
materials. Likewise, such intermingling may occur between the external facing
32 and the substrate 30 of the food container 10. However, such intermingling
does not prevent either stratum of the external facing 32 from consisting
essentially of a particulate material 34 and a single binder material 36.
Intermingling at the interface may occur due to migration of the various
binder
materials 36 between the plural strata of the external facing 32.
The external facing 32 is disposed on the substrate 30. The condition of
being "disposed on" includes configurations where the external facing 32
resides
directly upon the substrate 30 as we(I as configurations where the external
facing
32 is connected to the substrate 30 through an intermediate member, such as an
intermediate facing 40. The intermediate facing 40 may have the same
composition as the external facing 32.
Referring to Figure 3, preferably, however, the intermediate facing 40 and
the external facing 32 have different compositions. This allows one to tailor
the
intermediate facing 40 and external facing 32 to the particular desired
properties.
For example, one of the external facing 32 and intermediate facing 40 may be
free of resin. The other of the external facing 32 and intermediate facing 40
may
be free of clay. One of the external facing 32 and intermediate facing 40 may
be
free of both resin and clay. The other may contain clay or resin.
Alternatively, the external facing 32 may contain only a single binder
material 36 while the intermediate facing 40 contains both (or a single)
binder
material 36. All such variations are contemplated and within the scope of the
claimed invention.
In a particularly preferred embodiment, the intermediate facing 40 is
disposed on the substrate 30. The intermediate facing 40 comprises both
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particulate material 34 and a clay binder material 36. An external facing 32
is
disposed on the intermediate facing 40. The external facing 32 comprises resin
binder material 36 as well as particulate material 32. This arrangement
provides
the advantage that the intermediate facing 40 has clay therein, which adheres
well to a cellulosic substrate 30. The external facing 32 has resin therein
which
provides a less gritty tactile sensation.
The particulate material 34 is impregnated into the substrate 30. By
"impregnated" it is meant that the particulate material 34 may be in direct
contact
with the substrate 30 or, alternatively, the particulate material 34 may be
placed
on a carrier (not shown) which is joined to the substrate 30.
The carrier may be a generally planar sheet of material capable of existing
independently from the substrate 30. The particulate material 34 is
incorporated
into the carrier which is then joined, adhesively, or by other means known in
the
art to the substrate 30. The carrier need not be capable of holding the
desired
shape illustrated in the figures, but only needs to be capable of being joined
to
the substrate 30 and substantially conforming thereto.
For example, the carrier may be a sheet of tissue or another grade of a light
weight paper which is subsequently joined to a single ply SBS substrate 30.
The
tissue or other grade of fight weight paper carrier has the particulate
material 34
impregnated therein prior to being joined to the SBS or other substrate 30.
The
sheet of tissue or other light weight grade carrier may be made according to
any
of the teachings well known in the art as, for example, illustrated by the
commonly assigned patents incorporated herein below.
Alternatively, the carrier may be a single ply of liner board having the
particulate material impregnated therein. The single ply of liner board may be
joined to the corrugated medium of a single face corrugated substrate 30. The
liner board carrier having the particulate material 34 impregnated therein
then
becomes one of the external faces of a multi-ply corrugated medium as is known
in the art.
More preferably, the particulate material 34 is directly incorporated into and
impregnated in the substrate 30 during manufacture of the substrate 30. The
substrate 30 is preferably formed by a wet laying process as is well known in
the
,.
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art. In the wet laying process, cellulosic, synthetic and other fibers are
deposited
from a headbox onto a forming screen by a liquid carrier. The liquid carrier
is
drained away and the resulting fibrous slurry is dried. The fibers may be
cellulose, synthetic, various combinations thereof.
The substrate 30 may be of constant basis weight or having regions of
multiple basis weights. A constant basis weight substrate 30 may be made
according to the teachings of commonly assigned U.S. Patents 3,994,771 issued
Nov. 30, 1976 to Morgan, Jr., et al., 4,225,382 issued Sept. 30, 1980 to
Kearney
et al. or 4,300,981 issued Nov. 17, 1981 to Carstens et al., the disclosures
of
which are incorporated herein by reference. A multiple basis weight substrate
30 may be made according to the teachings of commonly assigned U.S. Patents,
5,245,025 issued Sept. 14, 1993 to Trokhan et al., 5,503,715 issued April 2,
1996 to Trokhan et al., 5,534,326 issued July 9, 1996 to Trokhan et al., and
5,804,281 issued Sept. 18, 1998 to Phan et al., the disclosures of which are
incorporated herein by reference.
If desired, the substrate 30 may be air laid as is well known in the art. If
the
substrate 30 is air laid, the binder material 36 and/or the particulate
material 34
may be distributed in a gradient, as desired. Suitable apparatuses) for making
the air laid substrate 30 and providing such a distribution of the binder
material
36 and/or particulate material 34 are disclosed in commonly assigned in U.S.
Patent Nos. 5,445,777 issued Aug. 29, 1995 to Noel et al. and 5,558,832 issued
Sept. 24, 1996 to Noel et al., the disclosures of which are incorporated
herein by
reference. Preferably, the substrate 30 has a gradient therethrough, with a
greater concentration of the particulate material 34 oriented towards the
first
surface 11.
The particulate material 34 may be disposed in and deposited from the
headbox used in the wet laying operation. Such an arrangement will
prophetically produce a food container 10 having a substrate 30 with the
- particulate material impregnated therein and relatively homogeneously and
uniformly distributed throughout. However, in an undesirable execution, the
particulate material 34 may drain towards the bottom of the forming wire and
become juxtaposed with the second surface 12 of the food container 10. This
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arrangement yields a food container 10 having a Z-direction gradient with the
particulate material 34 having a lesser concentration at the first surface 11.
Such
an arrangement is undesirable, since the user desires more particulate
material
34, not less, to be juxtaposed with the first surface 11. ,
In order to overcome this predicament, a layered headbox may be utilized
for the wet laying operation. In a layered headbox, two or more channels of
different materials may be deposited onto the forming wire. The first channel
is
the channel closest to and deposits the fibers first to contact the forming
wire.
The second, third, or uppermost channel of the headbox may contain particulate
material 34, or, preferably, particulate material 34 disposed in a slurry of
fbers
and the liquid carrier. This arrangement provides the advantage over that
discussed above that the particulate material 34 is disposed in a gradient
having
a greater Z-direction concentration oriented towards the first surface 11.
Thus,
more of the particulate material 34 is juxtaposed with the first surface 11
and
improves cut resistance and provides a pleasing tactile sensation for the
user.
In an alternative embodiment, multiple single channel headboxes may be
utilized. In such an arrangement, preferably a first headbox deposits a
fibrous
slurry and a liquid carrier onto the forming wire. One or more subsequent
headboxes deposit particulate material 34 and/or a combination of particulate
material 34 and fibers onto the first fibrous slurry. This arrangement allows
the
fibers deposited from the first headbox occlude the flow of particulate
material 34
from the subsequent headbox(es), keeping the particulate material 34 disposed
near the surface of the resulting fibrous slurry. The fibrous slurry is
subsequently
dried by any means well known the art. The dried surface facing outwardly from
the forming wire becomes, of course, the first surface 11 of the food
container
10.
If desired, a substrate 30 manufactured according to the air laid process
may be layered as well. Layering the substrate 30 in an air laying process
provides the benefits that the particulate material 34 and/or binder material
36
may be disposed in a gradient having a heavier Z-direction concentration
juxtaposed towards the first surface 11.
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Apparatuses and processes suitable for incorporating the particulate
material 34 and/or the binder material 36 are disclosed in commonly assigned
U.S. Pat. Nos. 5,661,890 issued Mar. 18, 1997 to Vinson et al. and 5,672,249
issued Sept. 30, 1997 to Vinson et al., the disclosures of which are
incorporated
5 herein by reference.
