KR20240152854A - Rigid compartmental pressware plate with high baffles - Google Patents

Abstract

A compartmentalized pressware paper plate (10) having one or more elevated partitions (22, 24, 26) adjacent a plate bottom (14) that transition to the partition side surfaces, each having a pair of partition side surfaces, wherein the one or more elevated partitions have a partition height DH greater than 0.714375 cm and a flange (20) having a height H at an apex thereof and an outer flange downturn (54) extending downward a distance V with respect to the flange apex, the ratio of V:H being from about 0.1 to about 0.75, and preferably including a transition having a variable radius of curvature VR between the adjacent surfaces of the bottom surface and the partition side surfaces, the variable radius of curvature varying from a first value proximate the transition between the two surfaces to a second value greater than the first value at the transition proximate the intersection of the three surfaces.

Description

Rigid compartmental pressware plate with high baffles

Cross-reference to related applications

This application is based upon U.S. Provisional Patent Application No. 63/316,482, filed March 4, 2022, which is incorporated herein by reference in its entirety.

Technical field

The present invention relates to a pressware paper plate having tall dividers formed therein to define a plurality of serving compartments for food.

Many consumers prefer to separate different foods from each other on their plates when eating. Without a divider, food and liquids can mix or spill over during a meal, making it difficult to maintain separation between different foods. Various types of compartmentalized disposable plates have been available for many years. Some of these are described in more detail below.

Pulp-formed paper, foamed and solid plastic compartmented plates can be readily manufactured with high partitions between the compartments because of their respective manufacturing methods. Pulp-formed plates are manufactured by dipping a mold into a fiber slurry to distribute the fibers throughout the surface of the plate and the compartmented compartments. Solid and foamed plastic compartmented plates are produced by forming the material into a plate mold by thermoforming, heat softening and vacuum stretching. See U.S. Patent No. 6,440,509 to Littlejohn et al . These products are relatively expensive compared to pressed paper plates because of the cost of the materials and/or manufacturing methods for the products. Additionally, there is increasing awareness and pressure regarding these products due to environmental concerns (e.g., perfluorooctanoic acid (PFOA) in pulp-formed plates and disposable plastic products) compared to renewable, recyclable and compostable paper alternatives.

Manufacturers have successfully produced and sold press-paper compartmented plates. These commercially available press-paper compartmented plates have poor product rigidity and poor food loading capacity due to their low baffle heights (less than 5/16") and/or poor profiles without an outer downturn (i.e., flat flange). Taller height (greater than 7/16") compartmented pressware plates that have been available so far have been constructed with flat flanges without an outer downturn. A square compartmented pressware plate is shown in U.S. Patent No. 5,236,119 to Chu .

Applicants previously commercially sold a nominal 10", 3 compartment plate with outside downturn (Dixie® Kids™) which utilized a 4 radius profile, but had divider heights of only 9/32"(0.281"). Applicants previously also commercially sold a nominal 9", 3 compartment plate with outside downturn (Krazy Kritters™) which also utilized a 4 radius profile, but had divider heights of only 0.25". The 4 radius profile is described in U.S. Patent No. 5,088,640 to Littlejohn . Pactiv recently introduced its EarthChoice® brand of 3 compartment pressed paper plates with divider heights of 3/16"(0.188"). All of these pressware plates have lower divider heights than pulp molded and foamed plastic/solid plastic products which typically have divider heights of 1/2" or greater. Lower baffle heights can barely prevent foods/liquids from mixing with each other.

Pactiv also sold a three-compartment, 7-3/8" diameter pressed paper plate called ZooPals with 5/8"(0.625") divider height, but this plate had no exterior downturn and was of relatively low strength. The two additional compartments were smaller and located outside the center portion of the plate, each holding about a 1-ounce serving of condiment such as ketchup. See U.S. Patent No. 7,484,344 to Schiltz et al .

Press-type containers, unlike pulp-formed plates, can easily have a continuous functional coating applied to the paperboard prior to forming, which improves performance for hot and moist foods, but forming structural features for press-type paper plates is much more difficult than for pulp-formed plates or plastic plates. The various techniques for forming plates, namely pulp-formed, paperboard press-formed, and thermoforming, are not interchangeable, especially given the significant physical differences in the way plates are formed in these processes. In particular, the need to form strong pleats imposes serious limitations on the forming of press-type paperboard plates that other formatting techniques do not. When a paperboard blank is pressed to form a container, the flat blank must be distorted and deformed into shape and area in order to form the blank into the desired three-dimensional shape. This necessary distortion results in folds or creases in the sidewalls and edges, which are areas that are pulled toward the center of the container during the press-formed process, and this occurs because the formed container has a reduced perimeter compared to the blank. If not given due care during the pressing process, these folds or creases can become weak points in the material in the sidewall and rim areas, and such containers tend to buckle more easily than containers without creases in the sidewalls and rim. Forming high baffles into pressware plates introduces additional complications, including wrinkle formation in undesirable areas, hinging of the product, and tearing of the cardboard at the three-dimensional edges, particularly between the bottom, plate sidewalls, and baffle sidewalls.

Through various features, it has been found that strong and rigid pressware plates with high baffles can be manufactured while minimizing forming and lamination problems. The plates of the present invention have remarkable rigidity and strength.

In a first aspect of the present invention, a rigid compartmentalized press paper plate is provided having external downturns and high partition heights, the partition heights preferably being greater than 9/32", 7/16" or 1/2". The compartmentalized plate with high partitions of the present invention separates food/liquid from one another and can hold greater than 1 b of food without warping or breaking when held in one hand. The plates of the present invention typically have a FPI geometric mean plate stiffness (MD*CD)^0.5 of greater than or equal to about 100 grams. "FPI" stands for the Foodservice Packaging Institute, which provides a stiffness tester for plates, described below. Additionally, the plates of the present invention exhibit a "one-handed grip" (laboratory test) of greater than or equal to about 1 lb in the large compartments, which simulates the maximum capacity of the plate to support a food load while being held in one hand.

As can be seen in the examples below, the external downturn provides the product with remarkable stiffness and strength.

In a second aspect of the present invention, in addition to the compartmentalized press-laminated paper plate as described in the first aspect mentioned above, a variable radius along the length(s) is provided along the junction of the compartmentalized sidewall(s) and the bottom(s) to blend in 3D edges where localized excessive stretching may cause the paper to tear. The variable radius may optionally occur in separate areas as illustrated in the accompanying drawings and described herein. The variable fillet around the plate addresses forming issues, particularly the problem of paper tearing due to excessive stress on the paperboard during manufacturing. Although the fillet results in some reduction in compartment volume, its impact is minimized by confining the fillet to the 3D edge.

In a third aspect of the present invention, in addition to the compartmentalized press paper plate as described in the first aspect mentioned above, a localized height drop ("dip-down") is further provided at the ends of the dividers where the dividers meet the folding side walls to assist in gripping the paperboard material and/or to prevent localized material wrinkling/webbing that could cause stack stability issues/tilting, and/or to provide the dividers between the two smaller compartments and the one larger compartment in a cross-aligned three-compartment plate to reduce the hinge tendency of the dividers when the plate flexes in the machine direction, thereby increasing product strength (+6% per FEA computer modeling). For typical food loads up to about 1 pound, the plate will flex, but not break. Preferably the height drop or dip down is 1/8" or greater.

In a fourth aspect of the present invention, in addition to the compartmentalized press paper plate as described in the first aspect mentioned above, additional material downturn length lobes (“dog-ears”) are provided at the ends of the partitions(s) to provide locally enhanced strength and further reduce the tendency of the partitions to hinge when bent. The lobes align with one another in the stack and are aesthetically pleasing so that no post-forming trimming is required. Since the paperboard at the ends of the partitions does not need to be pulled into the die set as much as other locations between the partitions, the lobes are formed during the forming process so that the lobes extend downward more than the adjacent areas of the flanges of the plate. As mentioned above, the lobes may be post-trimmed after forming, but it has been found that this does not interfere with the stacking and unexpectedly provides a small increase in strength to the product.

A particularly preferred embodiment of the present invention combines the various features mentioned above. Accordingly, in accordance with the present invention, there is provided a compartmentalized pressware paper plate having tall dividers formed from a cardboard blank including a plate bottom defining a bottom surface transitioning adjacent plate sidewalls extending around a plate bottom and projecting outwardly and upwardly therefrom, the plate sidewalls adjacent flanges defining the plate sidewall surfaces and flaring outwardly from the sidewalls, the plate further comprising at least one tall divider adjacent the plate bottom transitioning to the divider sidewall surfaces, each of the at least one tall divider characterized in that a divider height (DH) from the plate bottom is greater than 9/32", the at least one tall divider extending from the sidewalls toward a central portion of the plate bottom and configured to divide the plate bottom into a plurality of serving compartments. The flange is characterized in that it has an outer flange downturn extending downwardly from the plate bottom a distance (V) from the plate apex to the apex of the flange and a height (H) of the plate apex, wherein the ratio of V:H is from about 0.1 to about 0.75. The transition between the adjacent surfaces of the bottom surface and the baffle side wall surfaces is characterized by a variable radius of curvature, wherein the variable radius of curvature changes from a first value near the transition between the two surfaces to a second value greater than the first value near the intersection of the three surfaces, the change being gradual over intermediate distances so as not to disturb the smoothness of the fillet region of the plate surface. The baffle is adjacent the side wall of the plate at a height (SDH) less than the DH (hence defining the baffle as "deep down"), and the flange is optionally provided with a reinforced downturn near the junction of one or more of the baffles and the side wall, said reinforced downturn having a lobe extending further downwards than the adjacent portion of the flange.

The rigid press paper compartmentalized round plates of the invention described (and exemplified) herein have an exterior downturn and a taller divider (greater than 7/16") to provide the consumer with a functional press paper and a less expensive option. The nominal 10" diameter round plates described in connection with FIGS. 1-15 have a diameter profile of 10-1/4" and a divider height of ½", which is based on the profile described in U.S. Patent No. 6,715,630 to Littlejohn et al ., entitled "DISPOSABLE FOOD CONTAINER WITH A LINEAR SIDEWALL PROFILE AND AN ARCUATE OUTER FLANGE." This plate requires an 11.562" diameter blank, which is slightly larger than the 11.094" diameter blank used to form a similar plate without compartments due to the additional material length to form the compartments, which can be formed in four sections on a 57" wide press forming system, or in five or six sections on a 70" wide press forming system. The blanks used to make the illustrated compartmented product have (48) radial scores for the corrugations, each measuring 1.422" in length. Ideally, scores would also be used at the compartment joints to control material gathering, but with a circular blank that can be rotated after blanking prior to forming, the exact location of these scores cannot be determined at the time of forming, so the centrally located scores are omitted in the case of the circular plates.

For polygonal containers or plates, a score positioned centrally on the blank may be used to facilitate forming.

Additional details and advantages are described below with reference to the attached drawings.

The present invention is described in detail below with reference to the drawings in which like reference numerals represent like parts.
Figure 1 is an isometric plan view of a compartmental pressware paper plate of the present invention.
Figure 1a is an isometric plan view of the compartmental pressware paper plate of Figure 1, showing the wrinkles around the plate sidewalls and the flange of the plate.
Figure 2 is a plan view of the compartmental pressware paper plate of Figure 1, identifying three-dimensional edges that may tear during forming.
Figure 3 is a plan view of the compartmental pressware paper plate of Figure 1, identifying the locations of the variable fillets.
Figure 4 is a top schematic drawing of the compartmental pressware paper plate of Figure 1, illustrating a roving protrusion downwardly of the rim associated with the plate's dividers.
Figure 5 is a schematic diagram illustrating the profile of the compartmental pressware paper plate of Figure 1.
Figure 6 is a schematic diagram illustrating the side wall and flange profiles of the compartmentalized paper plate of Figure 1, with the partitions omitted for illustration purposes.
Figure 7 is a plan view of the compartmental pressware paper plate of Figure 1, illustrating the geometric structure of the central joint of the compartment dividers.
FIG. 8 and FIG. 8a are schematic diagrams illustrating cross-sectional dimensions of the partitions of the compartmental pressware paper plate of FIG. 1.
FIG. 9 is a schematic diagram illustrating profile dimensions according to the partitions of the compartmental pressware paper plate of FIG. 1.
FIG. 10 is a schematic diagram illustrating the profile dimensions of the joint with the plate side wall and the deep down of the partition of the compartmental pressware paper plate of FIG. 1.
FIGS. 11 to 13 are enlarged partial plan views of the compartmental pressware paper plate of FIG. 1, illustrating an optional variable radius of curvature between the side walls of the dividers and the central joint of the plate having the bottom of the compartmental paper plate of FIG. 1.
The bold lines in Figures 11 to 13 represent the boundaries of fillets that can be observed with the naked eye, and the transition between the bottom of the plate and the side walls of the plate or baffle.
FIG. 14 is a plan view of a compartmental pressware plate including various features of the plates of FIGS. 1 to 13, illustrating the arcuate trajectory of the longer ribs from the center baffle joint of the plate to the side walls of the plate.
Fig. 15 is another plan view of the compartmental pressware plate of Fig. 14.
Figure 16 is a schematic diagram illustrating FPI stiffness measurements on a pressware plate.
Figure 17 is a schematic diagram illustrating failure measurements for loads on a pressware plate.
FIG. 18 is an isometric plan view of an octagonal paper pressware plate of the present invention incorporating various features described in connection with FIGS. 1 through 15.
Figure 19 is a plan view of the octagonal paper pressware plate of Figure 18, illustrating the arched trajectory of the longer ribs from the center baffle joint of the plate to the side walls of the plate.
Figure 20 is a plan view of a scored cardboard blank for manufacturing the octagonal paper pressware plates of Figures 18 and 19, illustrating the arched trajectory of the longer ribs from the center baffle joint of the plate to the side walls of the plate.

The present invention is described in detail below with reference to the drawings for illustrative purposes only. The invention is defined in the appended claims. Unless otherwise specified, terms and symbols used herein are to be given their ordinary meanings consistent with the exemplary definitions set forth immediately below, for example, terms following a numerical value such as "in." or " represent inches, # represents pounds, ft2 or fts represent square feet, etc.

The center of a circular plate is a point equidistant from the circumference. For a plate of regular polygonal shape, the center is a point equidistant from each vertex or edge. It is also the center of the inscribed and circumscribed circles of the regular polygon. When the plate is of an irregular polygonal shape, or of another shape such as an ovoid, an ellipse, or a combination of shapes, the term center as used herein means the city center (center of area) resulting from considering the surface of the shape as having a constant density.

The terms central portion of the plate bottom, central joint of the plate where the high baffles meet, and similar terms refer to the structure near the center of a pressware plate.

The terms "characteristic diameter", "plate diameter" and similar terms mean the diameter of a circular plate, or, for another shape, equal to 2X √A/π (or alternatively (4 A/π) ^½ ), where A is the projected area of the finished plate. In a preferred embodiment, the characteristic diameter of the plate of the present invention is about 8" to 12".

Fillet characteristic radius of curvature is the maximum radius of curvature between the side walls of the fillet and the bottom of the plate.

FPI stiffness and single-handed load to failure tests are performed as described below. Additionally, FPI stiffness can be calculated by finite element analysis (FEA) for design evaluation purposes.

“Proximity”, “nearby”, etc. mean that the distance between the cited elements is generally no more than 0.35 times the characteristic diameter of the plate, the distance between the cited elements is typically no more than 0.25 times the characteristic diameter of the plate, and in most cases, the distance between the cited elements is no more than 0.1 times the characteristic diameter of the plate.

Pressware board plates are a preferred option for disposable plates, as the board stock can typically be impregnated with starch and coated on one side with a layer consisting of a water-based coating applied by pressure over a water-resistant layer or an inorganic pigment that is usually applied to the board during the manufacturing process. If desired, carboxylated styrene-butadiene resins can be used with or without fillers. Additionally, for aesthetic reasons, the board stock can often be printed first before being coated with an overcoat layer. As an example of a typical coating material, a first layer of a latex coating can be applied over the printed board, and a second layer of an acrylic coating can be applied over the first layer. These coatings can be applied using a conventional printing press used to apply decorative printing, or they can be applied using some other form of conventional press coater. The coating may include two pigmented (clay) bearing layers containing about 6 lbs/3,000 ft ² ream of binder, followed by two acrylic layers of about 0.5 to 1 lbs/3,000 ft ² ream. The clay bearing layers are applied first during board manufacture, and the acrylic layers are then applied by a press coating method, such as gravure, coil coating, flexographic processing, or the like, rather than extrusion or film laminating methods which are expensive and may require off-line processing and large amounts of coating material. For example, an extruded film may require 25 lbs/3,000 ft ² ream.

The layer comprising latex may contain any suitable latex known in the art. For example, suitable latexes include styrene-acrylic copolymers, acrylonitrile styrene-acrylic copolymers, polyvinyl alcohol polymers, acrylic acid polymers, ethylene vinyl alcohol copolymers, ethylene-vinyl chloride copolymers, ethylene vinyl acetate copolymers, vinyl acetate acrylic copolymers, styrene-butadiene copolymers, and acetate ethylene copolymers. The layer comprising latex may include, but is not limited to, one or more of a styrene-acrylic copolymer, a styrene-butadiene copolymer, or a vinyl acetate-acrylic copolymer. In some embodiments, the layer comprising latex may include a vinyl acetate ethylene copolymer. The layer comprising latex may include a latex that is pigmented. Pigmenting the latex increases the coating weight of the layer comprising latex, thereby reducing runnability problems when coating a substrate using a blade coater. Pigmenting the latex also improves the final quality of the print that can be applied to the coated paperboard. Suitable pigments or fillers include kaolin clay, delaminated clay, structured clay, calcined clay, alumina, silica, aluminosilicates, talc, calcium sulfate, ground calcium carbonate and precipitated calcium carbonate. The pigments can include kaolin clay and conventional delaminated coating clays. The layer comprising the latex may also contain other additives known in the art to improve the properties of the coated paperboard. For example, suitable additives include dispersants, lubricants, defoamer, film formers, defoamers and/or crosslinking agents.

Typically, board for pressware containers can contain up to about 6 lbs/3,000 ft ² of starch, but significantly improved stiffness can be achieved by using board having from about 9 lbs/3,000 ft ² to about 12 lbs/3,000 ft ² of starch, as further described in U.S. Patent Nos. 5,938,112 and 5,326,020, the disclosures of which are incorporated herein by reference.

The plate of the present invention is prepared from a substantially flat cardboard blank that is wetted, starch impregnated, and scored prior to insertion and forming in a segmented pressware die set. The blank can have from about 35 to 65 scores around its perimeter to form a border about 1.25" to 1.75" long. Further details are provided in U.S. Patent No. 8,584,929 to Littlejohn et al. , U.S. Patent No. 8,047,834 to Sofronie et al. , and U.S. Patent No. 6,783,720 to Johns et al. , as well as in U.S. Patent Application Publication No. 2017/0065110.

When forming the compartmental pressware of the present invention, it is preferred to form the partitions to full height or substantially full height before final pressing of the container rim to reduce tearing of the blank during processing. "Substantially full height" may be between 75% and 100% of the full height of the partitions in the finished product.

Referring to FIGS. 1 through 15, a circular compartmental pressware dish (10) is illustrated having a dish bottom (12) defining a dish bottom surface (14) (which may be flat or slightly crowned) that transitions adjacent a dish sidewall (16) extending about the bottom (12) and projecting upwardly and outwardly therefrom. The dish sidewall defines a dish sidewall surface (18) adjacent a flange (20) that flares outwardly from the sidewall (16). The dish (10) defines three tall partitions (22, 24, 26), as shown, the partitions (22) being shorter in length between compartments (28, 30) and the partitions (24, 26) being longer in length between compartments (30, 32) and 28, 32. The pressware plate of the present invention is manufactured from a scored cardboard blank as mentioned above and has a plurality of wrinkles (P) as shown in Fig. 1a. In other drawings, the wrinkles are omitted for illustrative purposes.

As can be seen from FIG. 2, the plate (10) has a plurality of three-dimensional edges (34) where three surfaces intersect, i.e., a side wall surface, a high baffle side wall surface and a plate bottom surface, or where two baffle side wall surfaces intersect a bottom surface. Due to the geometrical demands on the paperboard, when making plates with high baffles, tearing may occur in these areas during forming of the pressware plate (10).

To improve tearing at the three-dimensional edge (34), a first plurality of variable fillets (36), optionally a second plurality of variable fillets (38) and a third plurality of fillets (40) are provided, as shown in FIG. 3 and described later.

Another feature that alleviates the forming problems of high baffles and provides an area to collect excess material is a "dip down" or height reduction section of the baffle where it meets the side wall of the plate.

Referring to FIGS. 4 and 5, it can be seen that the plate (10) has three baffle height reducing portions or "deep downs" (42, 44, 46) adjacent the side walls of the plate (10), as well as lobes (48, 50, 52) radially aligned relative to the height reducing portions (42, 44, 46), i.e., they are present in their respective vicinity around the flange (20).

FIG. 5 is a schematic diagram illustrating the profile of a plate (10) extending between compartments (28, 30) along a baffle (22). The plate is characterized by a diameter passing through the center of the plate of a length D of about 10.25", a flange height H at a apex of about 0.8" from the plate bottom (12), a baffle height DH of about 0.5" from the plate bottom, and an intersection of the baffle (22) and the sidewall (16) at a lower height SDH of about 0.3" to about 0.4" from the plate bottom (12). The lobes (48, 50, 52) extend an additional distance L downwardly of about 0.05" to 0.25" further than adjacent portions of the flange, as can be seen in FIGS. 5 and 6.

The "deep down" and lobes, as described below, allow for layering of the plate and provide some strength enhancement.

Figure 6 schematically illustrates the overall profile of the plate (10) (the baffles are not shown). The values of the various dimensions are given in Table 1 below. R = ½ D.

[Table 1]

From FIGS. 5 and 6, it can be seen that the flange (20) has a significant downturn (54) on its outer periphery, and the downturn (54) extends downwards by a distance V of about 50% of the height H from the peak near the partition (the highest point of the flange). The V:H ratio is suitably between 0.1 and 0.75.

The dimensions in Table 1 are the molding die set values corresponding to the dimensions of the molded plate (10). For this purpose, the transition characterized by the radius of curvature R1 is considered to be part of both the plate bottom (12) and the plate sidewall (16).

Referring to FIG. 7, a plan view of a plate (10) is illustrated, wherein it can be seen that a central joint (56) defined by the baffles (22, 24, 26) is formed near the center (58) of the plate (10) at the intersection of two plate diameters D. The central joint (56) is radially offset from the center (58) by a distance (60) of about 0.6". That is, the central joint (56) is formed by the intersection of the baffles (22, 24, 26), and this intersection is located at a center that is slightly offset from the center (58) of the plate (10).

The baffles (22) are aligned along the diameter, while the baffles (24, 26) are aligned in a direction offset from the diameter by an angle of 15° as shown. Each baffle has a terminal portion (62, 64, 66) on the plate sidewall (16) and a middle portion (68, 70, 72) between the three-dimensional edges. The three tall baffles are configured in a Y configuration with a sweeping direction change characterized by a radius of curvature R4, which is suitably 0.75" to 1.5" long, such as 1.062" or 1.281" or 1.438" for a nominal 10" diameter plate.

In a preferred embodiment, the end portions (62, 64, 66) and the middle portions (68, 70, 72) of the partitions (22, 24, 26) have structures further described below with respect to FIGS. 8, 8a, 9 and 10.

FIG. 8 is a cross-sectional view of a middle portion (68) of a baffle (22), wherein the baffle has a linear side wall portion (74) that forms a 30° angle with the vertical from the plate bottom. The baffle (22) transitions from the plate bottom (12) with a radius of curvature R5 and has a curved upper portion (76) that defines the radius of curvature R6. Both R6 and R5 can be 0.188" in length. The baffle, as shown, has a pair of baffle side walls (22A, 22B), as well as a height DH of 0.5", as noted above.

FIG. 8a is a plan view of the end portion (62) of the partition (22), wherein the upper portion (76) of the partition has a smaller radius of curvature R7 of about 0.06" at the end of the partition, i.e., where the reduction in the partition height begins.

FIG. 9 is another profile of the plate (10) along the baffle (22). The distal portion (62) of the baffle (22) transitions downwardly with a radius of curvature R8 into a linear section (78A) (FIG. 10) which extends downwardly with a radius of curvature R9 and transitions outwardly toward the sidewall (16) having a height drop (78) of 0.125" or 0.188" forming a "dip down" or baffle height reduction in the sidewall. The linear section forms a 60° angle with the horizontal as shown.

FIG. 10 is an enlarged view showing the geometry of the height reduction portion in the side wall of the distal portion (62). The linear section (78A) forms an angle of 30° with the vertical direction as shown. The lengths of the radii of curvature R8 and R9 are in the range of 0.09" to 0.16", typically 0.125".

Figures 11, 12, and 13 are enlarged details showing the variable radius of curvature between the plate bottom and the high baffle, as well as the optional variable fillets (36, 38, 40).

Figure 11 illustrates the compartment (28) and the partitions (22, 24), as well as optional fillets (36, 38). A variable radius of curvature VR is depicted in the drawing. It can be seen that the radius of curvature between the bottom of the plate and the side walls is constant along the middle portion (70) of the partition (24) and varies substantially at the optional fillets (36, 38).

Figure 12 illustrates the variable radius of curvature between the high baffle and the plate bottom around an optional variable fillet (38) near the central junction (56) of the high baffles (22, 24, 26).

FIG. 13 illustrates a variable radius of curvature VR at a fillet (40) at the end portion (62) of the plate between the plate bottom and the baffle (22). It can be seen in FIG. 13 that the VR length substantially decreases to the outer portion of the baffle (22). In FIGS. 11 and 13, it can be seen that the variable fillet (36) is aligned with the middle portion (70) of the baffle (24) along the direction (24A), while the variable fillet (40) is aligned with the junction of the baffle (22) with the side wall of the plate at the end portion (62) along the direction (62B).

The variable curvature radius values shown in FIGS. 11, 12 and 13 are commonly applied to the transition between the baffles (22, 24, 26) and the plate bottom (12), as can be seen from FIGS. 1, 2 and 3 and the preceding description.

FIGS. 14 and 15 illustrate a plate substantially identical to the plates of FIGS. 1 to 13 except that the baffles meet at a central junction (56AT) in a Y configuration, wherein the two layer baffles (24AT, 26AT) project outwardly from the central junction (56AT) toward the side walls (16) in an arcuate trajectory, as shown. Note the offset from the center indicated by the dashed line.

The baffles (22, 24AT, 26AT) transition about the central joint (56AT) at the arcuate change in direction (R4, described above), while the baffles (24AT, 26AT) define a radius of curvature R10 as they protrude into the side walls (16). R10 is suitably 10.188", and may optionally be a value of 8" to 11" in the designs shown. In some designs, R10 may be between 0.5 and 1.5 times the characteristic plate diameter, preferably between 0.75 and 1.25 times the characteristic plate diameter.

FPI stiffness is expressed in grams per 0.5" deflection and is measured on a Foodservice Packaging Institute Rigidity Tester available from or through the Foodservice Packaging Institute, Inc., Falls Church, Va., 22043 (www.fpi.org). This test is designed to measure the stiffness (i.e., resistance to buckling and bending) of paper and plastic plates, bowls, plates, and trays by measuring the force required to deflect the rim of these products a distance of 0.5" while the product is supported at its geometric center. Specifically, a plate specimen is secured by an adjustable bar on one end and supported at the center. The rim or flange end opposite the secured end is deflected 0.5" by a motorized cam assembly equipped with a load cell and the force (in grams) is recorded. This test simulates in many respects the ability of a container to support the weight of its contents when held in the hand of a consumer. A higher FPI value is desirable because it indicates a stiffer product.

FIG. 16 is a schematic isometric drawing of a Foodservice Packaging Institute Rigidity Tester for measuring FPI rigidity including a test stand generally designated by the reference numeral 100. A plate, such as a compartmented pressware plate (10), is secured to the test stand using clamping members (110), as shown, and is centered by posts (120, 130, 140, 150), with a shorter baffle (22) aligned with a force transducer probe (160) and the clamping members (110). The posts (140, 150) are removed prior to measuring force. This direction is considered the machine direction (MD). The force transducer measures the force to deflect the flange of the plate 0.5". To measure FPI rigidity in the cross direction (CD), the plate is rotated 90°.

The FPI stiffness can also be estimated via finite element analysis (FEA) in both MD and CD.

FIG. 17 is a schematic perspective view of a test apparatus for measuring the load to breaking capacity of a paper plate. The test stand, generally designated by reference numeral 100(a), includes a clamping assembly (110(a)) and a support member (150(a)). As illustrated, a plate, such as a plate (10), is positioned in a partition (22) such that a flange of the plate is secured to the assembly (110(a)) and supported below the middle portion of the partition (22) by a member (150(a)) beneath the plate, such that the largest compartment (32) is positioned opposite the clamping assembly (110(a)) so that the plate is positioned in the weakest orientation for testing. A 1/4 lb. weight is incrementally added to the compartments (32) until the plate buckles under the load. Therefore, the test provides a simulation of the "one hand hold maximum" of the plate (10), which is denoted in the following examples as "One Hand Hold-Maximum-Bean Bags".

Example

A series of 10.25" round pressware plates were prepared and tested for FPI stiffness and failure load (maximum one-hand grip). The plates were fabricated from cardboard blanks having basis weights of 163 lbs/3000 ft ² and 180 lbs/3000 ft ² . The plates tested in Tables 2 and 3 had outer flange downturn, variable radii of curvature between the plate bottom and the baffle sidewalls, a "dip down" at the end of the high baffle in the plate sidewalls, and the reinforced downturn described above. All plates were identical and had the configuration illustrated in FIGS. 1 through 13 , except for the following: (a) the plates in Tables 4 and 5 had no outer downturn around the flange; (b) the plates in Tables 6 and 7 had no reinforced downturn lobes ("dog ears"); and Tables 8 and 9 show the plates in FIGS. 1 through 13 and FIG. 1 Compare with the plates of Figs. 14 and 15 which are substantially identical, but which include two baffles with arched external trajectories instead of the straight baffles as in Fig. 13.

Details and results of the tests are given in Tables 2 to 7 and Tables 8 and 9.

10-1/4" Round Sectional Plate FPI Stiffness and One-Handed Maximum Comparison

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

Comparing Tables 2 and 3 with Tables 4 and 5, it can be seen that the external downturn around the flange has a dramatic, indeed surprising, effect on both the FPI stiffness and the maximum one-hand grip or failure load. The plates in Tables 4 and 5 without external downturn had geometric mean FPI stiffnesses more than 50% lower than the corresponding plates in Tables 2 and 3. The plates in Tables 4 and 5 also had failure load values that were 20% to 25% lower than the plates in Tables 2 and 3, which is also dramatic.

The plates in Tables 6 and 7 without the reinforced downturn lobes also had lower FPI stiffness than the corresponding plates in Tables 2 and 3, exhibiting 7% lower GM FPI stiffness and 13% lower GM FPI stiffness, respectively. The difference in failure load peak load was not readily detectable, i.e., within the same 14 lb load increment measured.

Tables 8 and 9 below show that the arched outer trajectory of the larger baffles provides significant improvements to the FPI stiffness and maximum one-handed grip of the plate.

[Table 8]

[Table 9]

FEA Analysis

A plate having the features of FIGS. 1-13, including the baffle height reduction in the sidewall or "dip down" (no crease), was modeled and analyzed using finite element analysis FEA (0.014" thickness, 300,000 psi elastic modulus, 0.29 Poisson's ratio) and yielded an FPI stiffness value of 141 g. The same plate without the baffle height reduction or "dip down", when modeled and analyzed using FEA, yielded an FPI stiffness value of 133 g, or 6% lower than the plate with the "dip down", all other things being equal.

FPI stiffness measurements, failure load tests, and FEA analyses consistently show that the pressware plates of the present invention are unexpectedly superior to plates without the salient features of the compartmental pressware plates of the present invention.

From the above data, it will be appreciated that the compartmentalized pressware plates of the present invention, fabricated from cardboard blanks having a basis weight greater than about 120 or 150 lbs/3000 ft ² (up to about 300 lbs/3000 ft ² ), exhibit (a) a maximum one-hand grippable weight of at least 1 lb, or, in most cases, at least 1.25 lbs, and (b) a FPI-GM stiffness greater than 75 g, more preferably at least 100 g, at least 110 g, at least 115 g or at least 120 g.

While the above has been described in detail and evaluated for stiffness and strength with respect to a circular pressware plate, the plate of the present invention may be manufactured in a variety of shapes including square plates, polygonal plates, oval plates, etc. FIG. 16 is an isometric plan view of an octagonal, nominally 10 inch paper pressware plate of the present invention having various features described with respect to FIGS. 1-13, and FIG. 17 is a plan view of the octagonal pressware plate of FIG. 16 illustrating the arcuate trajectory of the long rib from the center baffle joint of the plate to the side walls of the plate. Corresponding features are indicated by numbers 200 larger than in FIGS. 1-13.

Referring to FIGS. 18 and 19, an octagonal sectioned pressware plate (210) is illustrated having a plate bottom (212) defining a plate bottom surface (214) that transitions adjacent a plate sidewall (216) extending about the plate bottom (212) and projecting upwardly and outwardly therefrom. The plate profile is based on that disclosed in U.S. Pat. No. 8,177,119 to Littlejohn entitled "Pressed paperboard servingware with arched bottom panel and sharp brim transition." The plate sidewall defines a plate sidewall surface (218) adjacent a flange (220) that flares outwardly from the sidewall (216). The plate (210) defines three tall baffles (222, 224, 226), with the baffle (222) being shorter in length between the compartments (228, 230) and the baffles (224, 226) being longer in length between the compartments (230, 232 and 228, 232). A central joint (256) is formed by the intersection of the baffles (222, 224, 226). The baffles (224, 226) extend from the central joint (256) to the side walls along an arcuate trajectory, as illustrated. The pressware plate (210) includes the optional variable transition radius and fillet features noted with respect to the previously described circular pressware plate (10).

FIG. 20 illustrates a flat cardboard blank (300) including a plurality of perimeter scores (P) arranged in clusters around the edges of the blank and the central span (310, 320) of the blank to facilitate plating in corresponding areas when the plate is formed. A plurality of center scores (CP) spaced apart within the perimeter of the blank (and the formed plate) are also provided to accommodate wrinkling about the central joint of the plate and the baffle when the pressware is formed. Note that the center scores are arranged in an arcuate trajectory from the center of the Y configuration of CP scores on the blank toward the edge where the sidewall is formed.

The blank (300) is also shaped to accommodate gathering of the cardboard around the central joint and dividers more than other areas of the blank. In this regard, the blank has a first span (314) that is slightly shorter than the second span (316). For a nominal 10" plate, the blank transition between the different edge areas via fillets is shown, characterized by a radius of curvature R11 of about 3" and an angle of 3°, although for other sized plates, different transitions may be used.

Exemplary embodiment

Accordingly, various embodiments of the present invention are provided, embodiment 1 being a compartmentalized pressware paper plate having tall dividers formed from a cardboard blank, the plate bottom adjacent the plate sidewalls extending around the plate bottom and protruding outwardly and upwardly toward a flange flared outwardly from the sidewalls, at least one tall divider adjacent the plate bottom and characterized by a height DH of the divider from the plate bottom greater than 9/32", the at least one tall divider extending from the sidewalls to a central portion of the plate bottom and configured to divide the plate bottom into a plurality of serving compartments, the flange characterized by a height H from the plate bottom to a vertex, and an outer flange downturn extending downward a distance V relative to the vertex of the flange, the ratio of V:H being about 0.1 to 0.75.

Embodiment 2 is a compartmentalized pressware paper plate having tall dividers formed from a cardboard blank, the plate bottom defining a bottom surface transitioning adjacent to plate sidewalls extending around the plate bottom and projecting outwardly and upwardly therefrom, and a plate sidewall adjacent a flange flared outwardly from the sidewalls, the plate further comprising one or more tall dividers adjacent the plate bottom each having a pair of divider sidewall surfaces and transitioning to the divider sidewall surfaces, wherein the one or more tall dividers are characterized by a divider height DH from the plate bottom greater than 9/32", the one or more tall dividers extending from the sidewalls toward a central portion of the plate bottom and configured to divide the plate bottom into a plurality of serving compartments, the flange being characterized by a height H from the plate bottom to a vertex and an outer flange downturn extending downward a distance V relative to the vertex of the flange, wherein the ratio of V:H is from about 0.1 to about 0.75, and the plate bottom surface and the dividers The transition between adjacent surfaces between the sidewall surfaces is characterized by a variable radius of curvature that varies from a first value near the transition between the two surfaces to a second value higher than the first value near the intersection between the three surfaces.

Embodiment 3 is a compartmentalized pressware plate according to Embodiment 2, wherein a ratio of a second value of the variable radius of curvature proximate the intersection of the three surfaces to a first value of the transition proximate the transition between the two surfaces is 1.25 to 2.5.

Embodiment 4 is a compartmentalized pressware plate according to Embodiment 3, wherein a ratio of a second value of the variable radius of curvature proximate the intersection of the three surfaces to a first value of the transition proximate the transition between the two surfaces is from 1.3 to 2.25.

Embodiment 5 is a compartmentalized pressware plate according to Embodiment 4, wherein a ratio of a second value of the variable radius of curvature proximate the intersection of the three surfaces to a first value of the transition proximate the transition between the two surfaces is 1.35 to 2.1.

Embodiment 6 is a compartmentalized pressware plate according to Embodiments 2 to 5, wherein the at least one high baffle has a middle portion between the intersections of three surfaces, and a side wall surface of the at least one high baffle transitions from a bottom surface of the plate with a constant middle transition radius of curvature.

Embodiment 7 is a compartmental pressware plate according to embodiment 6, wherein the intermediate transition radius of curvature is 0.15" to 0.4" or 0.225".

Embodiment 8 is a compartmentalized pressware plate according to embodiments 2 to 7, characterized in that at least one region of the plate proximate the intersection of the three surfaces has a filleted structure having a second value of radius of curvature of 0.25" to 0.5" between the plate bottom and the partition sidewall(s).

Embodiment 9 is a compartmentalized pressware paper plate having tall dividers formed from a cardboard blank, the plate bottom defining a bottom surface transitioning adjacent to plate sidewalls extending around the plate bottom and projecting outwardly and upwardly therefrom, and a plate sidewall adjacent a flange flared outwardly from the sidewalls defining the plate sidewall surfaces, the plate further comprising one or more tall dividers adjacent the plate bottom each having a pair of divider sidewall surfaces and transitioning to the divider sidewall surfaces, wherein the one or more tall dividers are characterized in that a divider height DH from the plate bottom is greater than 9/32", the one or more tall dividers extending from the sidewalls toward a central portion of the plate bottom and configured to divide the plate bottom into a plurality of serving compartments, the one or more tall dividers having an outer end portion proximate the sidewalls and an intermediate portion between the end portions of the one or more tall dividers and the central portion of the plate, the sidewall surfaces of the one or more tall dividers having a constant intermediate transition from the plate bottom surface to the intermediate portion. The outer end portions of the one or more high baffles have a fillet structure having a variable radius of curvature, including a fillet characteristic radius of curvature between the baffle side walls and the bottom of the dish being greater than a middle radius of curvature of a middle portion of the one or more high baffles, the flange further characterized by an outer flange downturn having a height H from the bottom of the dish to a vertex and extending downward a distance V relative to the vertex of the flange, wherein the ratio of V:H is from about 0.1 to about 0.75.

Embodiment 10 is a compartmental pressware plate according to embodiment 9, wherein the intermediate transition radius of curvature is from 0.15" to 0.4" or from 0.15" to 0.225".

Embodiment 11 is a compartmentalized pressware plate according to embodiment 8 or embodiment 9, wherein the fillet structure of the outer end portion of the high partition comprises a first fillet pair aligned with a middle portion of at least one high partition along a side wall surface of the high partition.

Embodiment 12 is a compartmentalized pressware plate according to Embodiment 11, wherein the fillet structure of the outer end portion of the high baffle includes a second fillet pair aligned with the outer end portion of one or more of the high baffle sidewall surfaces.

Embodiment 13 is a compartmental pressware plate according to any one of Embodiments 8 to 12, wherein a ratio of the fillet characteristic radius of curvature to the intermediate radius of curvature is 1.25 to 2.5.

Embodiment 14 is a compartmental pressware plate according to Embodiment 13, wherein the ratio of the fillet characteristic radius of curvature to the intermediate radius of curvature is 1.3 to 2.25.

Embodiment 15 is a compartmental pressware plate according to Embodiment 14, wherein a ratio of the fillet characteristic radius of curvature to the intermediate radius of curvature is 1.35 to 2.1.

Embodiment 16 is a compartmental pressware plate according to any one of Embodiments 8 to 15, wherein the fillet characteristic radius of curvature is from 0.25" to 0.5".

Embodiment 17 is a compartmentalized pressware paper plate having tall dividers formed from a cardboard blank, the plate bottom protruding outwardly and upwardly from the plate sidewall toward a flange extending around the plate bottom and flared outwardly from the sidewall, and at least one tall divider adjacent the plate bottom and characterized by a divider height DH from the plate bottom greater than 9/32", the at least one tall divider extending from the sidewall to a central portion of the plate bottom and configured to divide the plate bottom into a plurality of serving compartments, the flange characterized by a height H from the plate bottom to the apex, and an outer flange downturn extending downward a distance V relative to the apex of the flange, the ratio of V:H being from about 0.1 to 0.75, the at least one divider also being adjacent the plate sidewall at a height SDH less than DH, wherein the flange is optionally provided with a reinforced downturn near the junction of the sidewall and the at least one divider, the reinforced downturn being adjacent the flange. It has lobes that extend more downward than the portion.

Embodiment 18 is a compartmental pressware plate according to Embodiment 17, wherein the ratio of SDH to DH is from 0.15 to 0.75.

Embodiment 19 is a compartmental pressware plate according to Embodiment 18, wherein the ratio of SDH to DH is from 0.25 to 0.65.

Embodiment 20 is a compartmental pressware according to embodiments 17, 18, or 19, having lobes extending downward a distance of from 0.05" to 0.4" beyond an adjacent portion of the flange.

Embodiment 21 is a compartmental pressware according to embodiments 17 to 20, wherein the lobes extend downward a distance of 0.1" to 0.35" further than an adjacent portion of the flange.

Embodiment 22 is a compartmental pressware according to Embodiment 21, wherein the lobes extend downward a distance of from 0.1" to 0.25" further than an adjacent portion of the flange.

Embodiment 23 is a compartmentalized pressware paper plate having tall dividers formed from a cardboard blank, the plate bottom defining a bottom surface transitioning adjacent to plate sidewalls extending around the plate bottom and projecting outwardly and upwardly therefrom, and a plate sidewall adjacent a flange flared outwardly from the sidewalls, the plate further comprising one or more tall dividers adjacent the plate bottom each having a pair of divider sidewall surfaces and transitioning to the divider sidewall surfaces, wherein the one or more tall dividers are characterized by a divider height DH from the plate bottom greater than 9/32", the one or more tall dividers extending from the sidewalls toward a central portion of the plate bottom and configured to divide the plate bottom into a plurality of serving compartments, the flange being characterized by a height H from the plate bottom to a vertex and an outer flange downturn extending downward a distance V relative to the vertex of the flange, wherein the ratio of V:H is from about 0.1 to about 0.75, and the plate bottom surface and the A transition between adjacent surfaces between the baffle side wall surfaces is characterized by a variable radius of curvature, which varies from a first value proximate the transition between the two surfaces to a second value higher than the first value at the transition proximate the intersection between the three surfaces, wherein the one or more baffles are also abutting the side wall of the dish at a height SDH lower than DH, wherein the flange is optionally provided with a reinforced downturn proximate the junction of the one or more baffles and the side wall, the reinforced downturn having a lobe extending further downward than the adjacent portion of the flange.

Embodiment 24 is a compartmentalized pressware plate according to embodiment 23, wherein a ratio of a second value of the variable radius of curvature proximate the intersection of the three surfaces to a first value of the transition proximate the transition between the two surfaces is from 1.25 to 2.5.

Embodiment 25 is a compartmental pressware plate according to embodiment 24, wherein a ratio of a second value of the variable radius of curvature proximate the intersection of the three surfaces to a first value of the transition proximate the transition between the two surfaces is from 1.3 to 2.25.

Embodiment 26 is a compartmentalized pressware plate according to embodiment 25, wherein a ratio of a second value of the variable radius of curvature proximate the intersection of the three surfaces to a first value of the transition proximate the transition between the two surfaces is from 1.35 to 2.1.

Embodiment 27 is a compartmentalized pressware plate according to embodiments 23 to 26, wherein the at least one high baffle has a middle portion between the intersections of three surfaces, and a side wall surface of the at least one high baffle transitions from a bottom surface of the plate with a constant middle transition radius of curvature.

Embodiment 28 is a compartmental pressware plate according to Embodiment 27, wherein the intermediate transition radius of curvature is from 0.15" to 0.4".

Embodiment 29 is a compartmentalized pressware plate according to embodiments 23 to 28, wherein at least one region of the plate proximate the intersection of the three surfaces is characterized by a fillet structure having a fillet characteristic radius of curvature of from 0.25" to 0.5".

Embodiment 30 is a compartmental pressware plate according to Embodiments 23 to 29, wherein the ratio of SDH to DH is 0.15 to 0.75.

Embodiment 31 is a compartmental pressware plate according to Embodiment 30, wherein the ratio of SDH to DH is 0.25 to 0.65 or 0.4.

Embodiment 32 is a compartmental pressware plate according to embodiments 23 to 31, having lobes extending downward a distance of from 0.05" to 0.4" beyond an adjacent portion of the flange.

Embodiment 33 is a compartmental pressware plate according to embodiment 32, wherein the lobes extend downward a distance of from 0.1" to 0.35" further than the adjacent portion of the flange.

Embodiment 34 is a compartmental pressware plate according to embodiment 33, wherein the lobes extend downward a distance of from 0.1" to 0.25" further than adjacent portions of the flanges.

Embodiment 35 is a compartmental pressware plate according to any one of the embodiments described above, wherein the plate has at least two high partitions.

Embodiment 36 is a compartmental pressware plate according to embodiment 35, wherein the plate has three tall baffles in a Y configuration at the central joint of the plate.

Embodiment 37 is a compartmental pressware plate according to embodiment 36, wherein the center joint transitions between baffles having a radius of curvature of from 0.75" to 1.5".

Embodiment 38 is a compartmental pressware plate according to embodiment 36 or embodiment 37, wherein at least two high baffles are arcuate trajectories from a central joint of the plate to a side wall of the plate. The outwardly protruding baffles define a radius of curvature when they protrude into the side wall. A suitable radius of curvature for the outward trajectory can be between 0.5 and 1.5 times the characteristic plate diameter, preferably between 0.75 and 1.25 times the characteristic plate diameter.

Embodiment 39 is a compartmentalized pressware plate according to any one of the preceding embodiments, wherein the high baffles have a baffle height DH of at most 3/4".

Embodiment 40 is a compartmentalized pressware plate according to embodiment 39, wherein the high baffles have a baffle height DH of about 0.3" to 0.75".

Embodiment 41 is a compartmentalized pressware plate according to embodiment 39, wherein the high baffles have a baffle height DH of about 0.475" to 0.625".

Embodiment 42 is a compartmental pressware plate according to any one of the embodiments described above, wherein the ratio of V:H is from 0.15 to 0.75.

Embodiment 43 is a compartmental pressware plate according to any one of the aforementioned embodiments, wherein the ratio of V:H is from 0.2 to 0.75.

Embodiment 44 is a compartmental pressware plate according to any one of the embodiments described above, wherein the ratio of V:H is from 0.3 to 0.65.

Embodiment 45 is a compartmental pressware plate according to Embodiment 44, wherein the ratio of V:H is 0.35 to 0.6.

Embodiment 46 is a compartmental pressware plate according to any one of the embodiments described above, wherein the compartmental pressware plate is circular.

Embodiment 47 is a compartmental pressware plate according to any one of Embodiments 1 to 45, wherein the compartmental pressware plate is polygonal.

Embodiment 48 is a compartmental pressware plate according to embodiment 47, wherein the compartmental pressware plate is octagonal.

Embodiment 49 is a compartmental pressware plate according to embodiments 46, 47, or 48, wherein the compartmental pressware plate has a characteristic diameter of from 8" to 12".

Embodiment 50 is a compartmental pressware plate according to embodiment 49, wherein the compartmental pressware plate has a characteristic diameter of from 8-1/2" to 11".

Embodiment 51 is a compartmental pressware plate according to embodiment 50, wherein the compartmental pressware plate has a characteristic diameter of from 9" to 10-1/2".

Embodiment 52 is a compartmental pressware plate according to any one of the preceding embodiments, wherein the compartmental pressware plate is manufactured from a paperboard blank having a basis weight of from 80 lbs/3000 ft ² to 300 lbs/3000 ft ² .

Embodiment 53 is a compartmental pressware plate according to embodiment 52, wherein the compartmental pressware plate is manufactured from a paperboard blank having a basis weight of from 145 lbs/3000 ft ² to 240 lbs/3000 ft ² .

Embodiment 54 is a compartmental pressware plate according to embodiment 53, wherein the compartmental pressware plate is manufactured from a paperboard blank having a basis weight of from 155 lbs/3000 ft ² to 190 lbs/3000 ft ² .

Embodiment 55 is a compartmentalized pressware paper plate having a partition formed from a cardboard blank, the plate bottom defining a bottom surface transitioning adjacent a plate sidewall extending around the plate bottom and projecting outwardly and upwardly therefrom, and a plate sidewall adjacent a flange flared outwardly from the sidewall defining the plate sidewall surfaces, the plate further comprising at least one partition adjacent the plate bottom transitioning to the partition sidewall surfaces, each partition characterized by a partition height DH from the plate bottom, the at least one partition extending from the sidewall toward a central portion of the plate bottom and configured to divide the plate bottom into a plurality of serving compartments, the transition between the adjacent surface of the plate bottom surface and the partition sidewall surface being characterized by a variable radius of curvature, the variable radius of curvature varying from a first value proximate the transition between two surfaces to a second value higher than the first value at the transition proximate the intersection between three surfaces.

Embodiment 56 is a compartmentalized pressware plate according to embodiment 55, wherein a ratio of a second value of the variable radius of curvature proximate the intersection of the three surfaces to a first value of the transition proximate the transition between the two surfaces is from 1.25 to 2.5.

Embodiment 57 is a compartmentalized pressware plate according to embodiment 56, wherein a ratio of a second value of the variable radius of curvature proximate the intersection of the three surfaces to a first value of the transition proximate the transition between the two surfaces is from 1.3 to 2.25.

Embodiment 58 is a compartmental pressware plate according to embodiment 57, wherein a ratio of a second value of the variable radius of curvature proximate the intersection of the three surfaces to a first value of the transition proximate the transition between the two surfaces is from 1.35 to 2.1.

Embodiment 59 is a compartmental pressware plate according to embodiments 55 to 58, wherein one or more of the partitions has a middle portion between the intersections of three surfaces, and a side wall surface of one or more of the partitions transitions from a bottom surface of the plate with a constant middle transition radius of curvature.

Embodiment 60 is a compartmental pressware plate according to embodiment 59, wherein the intermediate transition radius of curvature is from 0.15" to 0.4".

Embodiment 61 is a compartmentalized pressware plate according to embodiments 55 to 60, characterized in that at least one region of the plate proximate the intersection of the three surfaces has a fillet structure having a second value of radius of curvature of 0.25" to 0.5" between the plate bottom and the partition sidewall(s).

Embodiment 62 is a compartmentalized pressware plate according to embodiments 59 to 61, wherein one or more of the partitions is proximate to a side wall of the plate and has an outer end portion between the side wall of the plate and a middle portion of the partition, the outer end portion of the one or more partitions having a fillet structure having a variable radius of curvature, including a fillet characteristic radius of curvature between the partition side wall and the bottom of the plate that is greater than a middle radius of curvature of the middle portion of the one or more partitions.

Embodiment 63 is a compartmentalized pressware plate according to embodiment 62, wherein the fillet structure of the outer end portions of the partitions includes a first fillet pair aligned with a middle portion of one or more of the partitions along a high partition side wall surface.

Embodiment 64 is a compartmentalized pressware plate according to embodiment 63, wherein the fillet structure of the outer end portion of the partition comprises a second fillet pair aligned with the outer end portion of one or more partitions along the partition side wall surface.

Embodiment 65 is a compartmental pressware plate according to any one of embodiments 62 to 64, wherein a ratio of the fillet characteristic radius of curvature to the intermediate radius of curvature is 1.25 to 2.5.

Embodiment 66 is a compartmental pressware plate according to embodiment 65, wherein the ratio of the fillet characteristic radius of curvature to the intermediate radius of curvature is from 1.3 to 2.25.

Embodiment 67 is a compartmental pressware plate according to embodiment 66, wherein the ratio of the fillet characteristic radius of curvature to the intermediate radius of curvature is from 1.35 to 2.1.

Embodiment 68 is a compartmental pressware plate according to any one of Embodiments 62 to 67, wherein the fillet characteristic radius of curvature is from 0.25" to 0.5".

Embodiment 69 is a compartmentalized pressware dish according to any one of embodiments 55 to 68, wherein the one or more baffles are adjacent a side wall of the dish at a height SDH less than DH, the flange optionally having a reinforced downturn provided near the junction of the side wall and the one or more baffles, the reinforced downturn comprising a lobe extending further downwardly than an adjacent portion of the flange.

Embodiment 70 is a compartmental pressware plate according to embodiment 69, wherein the ratio of SDH to DH is from 0.15 to 0.75.

Embodiment 71 is a compartmental pressware plate according to embodiment 70, wherein the ratio of SDH to DH is 0.25 to 0.4 or 0.65.

Embodiment 72 is a compartmental pressware according to embodiments 69 to 71, having lobes extending downward a distance of 0.05" to 0.4" beyond an adjacent portion of the flange.

Embodiment 73 is a compartmental pressware according to embodiment 72, wherein the lobes extend downward a distance of from 0.1" to 0.35" further than an adjacent portion of the flange.

Embodiment 74 is a compartmental pressware according to embodiment 33, wherein the lobes extend downward a distance of from 0.1" to 0.25" further than an adjacent portion of the flange.

Embodiment 75 is a compartmentalized pressware paper plate having a divider formed from a cardboard blank, comprising: a plate bottom adjacent the plate sidewall extending around the plate bottom and protruding outwardly and upwardly toward a flange flared outwardly from the sidewall; and at least one divider adjacent the plate bottom and characterized by a divider height DH from the plate bottom, the at least one divider extending from the sidewall to a central portion of the plate bottom and configured to divide the plate bottom into a plurality of serving compartments, the at least one divider being adjacent the sidewall of the plate at a height SDH less than DH, wherein the flange is optionally provided with a reinforced downturn near the junction of the sidewall and the at least one divider, the reinforced downturn having a lobe extending further downwardly than an adjacent portion of the flange.

Embodiment 76 is a compartmental pressware plate according to Embodiment 75, wherein the ratio of SDH to DH is from 0.15 to 0.5.

Embodiment 77 is a compartmental pressware plate according to Embodiment 76, wherein the ratio of SDH to DH is from 0.25 to 0.4.

Embodiment 78 is a compartmental pressware plate according to embodiments 75, 76, or 79, having lobes extending downward a distance of from 0.05" to 0.4" beyond an adjacent portion of the flange.

Embodiment 79 is a compartmental pressware plate according to embodiments 75 to 78, wherein the lobes extend downward a distance of from 0.1" to 0.35" beyond an adjacent portion of the flange.

Embodiment 80 is a compartmental pressware plate according to embodiment 79, wherein the lobes extend downward a distance of from 0.1" to 0.25" further than adjacent portions of the flanges.

Embodiment 81 is a compartmental pressware plate according to any one of embodiments 55 to 80, wherein the plate has at least two partitions.

Embodiment 82 is a compartmental pressware plate according to embodiment 81, wherein the plate has three compartments in a Y configuration at a central joint of the plate.

Embodiment 83 is a compartmental pressware plate according to embodiment 82, wherein the center joint transitions between the baffles with a radius of curvature of from 0.75" to 1.5".

Embodiment 84 is a compartmental pressware plate according to embodiment 82 or embodiment 83, wherein at least two of the partitions are arcuate trajectories from a central joint of the plate to a side wall of the plate.

Embodiment 85 is a compartmentalized pressware plate according to any one of embodiments 55 to 84, wherein the partitions have a partition height DH of at most 3/4".

Embodiment 86 is a compartmentalized pressware plate according to embodiment 85, wherein the partitions have a partition height DH of about 0.3" to 0.75".

Embodiment 87 is a compartmentalized pressware plate according to embodiment 86, wherein the high baffles have a baffle height DH of about 0.475" to 0.625".

Embodiment 88 is a compartmental pressware plate according to any one of embodiments 55 to 87, wherein the compartmental pressware plate is circular.

Embodiment 89 is a compartmental pressware plate according to any one of embodiments 55 to 87, wherein the compartmental pressware plate is polygonal.

Embodiment 90 is a compartmental pressware plate according to embodiment 89, wherein the compartmental pressware plate is octagonal.

Embodiment 91 is a compartmental pressware plate according to embodiments 88, 89, or 90, wherein the compartmental pressware plate has a characteristic diameter of from 8" to 12".

Embodiment 92 is a compartmental pressware plate according to embodiment 91, wherein the compartmental pressware plate has a characteristic diameter of from 8-1/2" to 11".

Embodiment 93 is a compartmental pressware plate according to embodiment 92, wherein the compartmental pressware plate has a characteristic diameter of from 9" to 10-1/2".

Embodiment 94 is a compartmental pressware plate according to any one of embodiments 55 to 93, wherein the compartmental pressware plate is manufactured from a paperboard blank having a basis weight of from 80 lbs/3000 ft ² to 300 lbs/3000 ft ² .

Embodiment 95 is a compartmental pressware plate according to embodiment 94, wherein the compartmental pressware plate is manufactured from a paperboard blank having a basis weight of from 145 lbs/3000 ft ² to 240 lbs/3000 ft ² .

Embodiment 96 is a compartmental pressware plate according to embodiment 95, wherein the compartmental pressware plate is manufactured from a paperboard blank having a basis weight of from 155 lbs/3000 ft ² to 190 lbs/3000 ft ² .

While the present invention has been described in connection with numerous embodiments, those skilled in the art will appreciate that plates, bowls, oval plates, trays, and the like having various shapes and sizes may be developed to have the properties of the present invention. Some may be chamfered squares or rectangles, triangles, polygons, polygons, and similar shapes having the profiles and compartments described. Thus, instead of using a single layer of cardboard blank, a composite cardboard blank may be used. For example, the containers of the present invention may be formed from a composite cardboard material, wherein the containers are formed by laminating three individual layers of cardboard together in the shape of a container having the shapes described herein. The specific operating steps for forming a composite plate are described in more detail in U.S. Patent Nos. 6,039,682, 6,186,394, and 6,287,247. In view of the foregoing description, the knowledge of the relevant art, and the references referenced above in connection with the foregoing description, including the detailed description and background of the present invention, the entire disclosure of the present invention is incorporated herein by reference and no further description is deemed necessary. In addition, it should be understood from the foregoing description that aspects of the present invention and portions of the various embodiments may be combined or interchanged in whole or in part. Accordingly, the containers of the present invention provide not only increased FPI stiffness, but also improved load-bearing capabilities. Modifications to the specific embodiments described above within the spirit and scope of the present invention, as set forth in the appended claims, will be readily apparent to those skilled in the art.

Claims (25)

A compartmentalized pressware paper plate having tall dividers formed from a cardboard blank, the pressware paper plate comprising: a dish bottom adjacent the dish sidewalls extending around the dish bottom and projecting outwardly and upwardly toward a flange flared outwardly from the sidewalls; one or more tall dividers adjacent the dish bottom and having a divider height DH from the dish bottom greater than 9/32", the one or more tall dividers extending from the sidewalls to a central portion of the dish bottom and configured to divide the dish bottom into a plurality of serving compartments, the flange characterized by a height H from the dish bottom to a vertex; and an outward flange downturn extending downward a distance V relative to the vertex of the flange, wherein the ratio of V:H is from about 0.1 to 0.75. A compartmentalized pressware paper plate having a high partition formed from a cardboard blank, wherein the high partition in the first aspect has a partition height DH of about 0.3" to 0.75". A compartmentalized pressware paper plate having high partitions formed from a cardboard blank, wherein the V:H ratio in claim 1 is from 0.3 to 0.65. A compartmentalized pressware paper plate having a tall partition formed from a cardboard blank, the paper plate comprising a plate bottom defining a bottom surface transitioning adjacent a plate sidewall extending around the plate bottom and projecting outwardly and upwardly therefrom, the plate sidewall defining a plate sidewall surface and adjacent a flange flared outwardly from the sidewall, the transition between the adjacent surface of the bottom surface and the partition sidewall surface being characterized by a variable radius of curvature, the variable radius of curvature varying from a first value proximate the transition between two surfaces to a second value greater than the first value at the transition proximate the intersection of three surfaces. A compartmentalized pressware paper plate having high partitions formed from a cardboard blank, wherein in the fourth paragraph, a ratio of said second value of the variable radius of curvature proximate the intersection of said three surfaces to said first value of the transition proximate the transition between the two surfaces is from 1.25 to 2.5. A compartmentalized pressware paper plate having high partitions formed from a cardboard blank, wherein in the fourth paragraph, a ratio of said second value of the variable radius of curvature proximate the intersection of said three surfaces to said first value of the transition proximate the transition between the two surfaces is from 1.35 to 2.1. A compartmentalized pressware paper plate having a high partition formed from a cardboard blank, wherein at least one region of the plate proximate the intersection of the three surfaces has a fillet structure having a second value of radius of curvature between the plate bottom and the partition sidewall(s) of from 0.25" to 0.5". A compartmentalized pressware paper plate having a high partition formed from a cardboard blank, wherein in the first aspect, the at least one high partition includes an outer end portion proximate the side wall and an intermediate portion between the end portion of the at least one high partition and the central portion of the plate, the side wall surface of the at least one high partition transitions from the bottom surface of the plate to the intermediate portion with a constant intermediate transition radius of curvature, and the outer end portion of the at least one high partition has a fillet structure having a variable radius of curvature, including that the fillet characteristic radius of curvature between the partition side wall and the plate bottom is larger than the intermediate radius of curvature of the intermediate portion of the at least one high partition. A compartmentalized pressware paper plate having high partitions formed from a cardboard blank, wherein the intermediate transition radius of curvature in the 8th paragraph is from 0.15" to 0.40". A compartmentalized pressware paper plate having a high partition formed from a cardboard blank, wherein the fillet structure of the outer end portion of the high partition comprises a first fillet pair aligned with a middle portion of the at least one high partition along a side wall surface of the high partition, in accordance with the eighth clause. A compartmentalized pressware paper plate having a high partition formed from a cardboard blank, wherein the fillet structure of the outer end portion of the high partition comprises a second fillet pair aligned with the outer end portion of the at least one high partition along the side wall surface of the high partition. A compartmentalized pressware paper plate having high partitions formed from a cardboard blank, wherein in the first aspect, said one or more partitions are adjacent a side wall of said plate at a height SDH lower than DH, said flange optionally having a reinforced downturn near the junction of said side wall and said one or more partitions, said reinforced downturn having a lob extending further downward than an adjacent portion of said flange. A compartmentalized pressware paper plate having high partitions formed from a cardboard blank, wherein the ratio of SDH to DH in claim 12 is from 0.15 to 0.75. A compartmentalized pressware paper plate having high partitions formed from a cardboard blank, wherein the ratio of SDH to DH in claim 13 is from 0.25 to 0.65. A compartmentalized pressware paper plate having a tall partition formed from a cardboard blank, wherein the lobe extends downward a distance of 0.1" to 0.35" beyond the adjacent portion of the flange in clause 12. A compartmentalized pressware paper plate having a high partition formed from a cardboard blank, wherein in the first aspect, a transition between an adjacent surface of the bottom surface and a surface of the partition side wall is characterized by a variable radius of curvature, the variable radius of curvature varying from a first value proximate the transition between two surfaces to a second value greater than the first value at a transition proximate the intersection of three surfaces, wherein the one or more partitions are also abutting the side wall of the plate at a height SDH less than DH, the flange optionally being provided with a reinforced downturn proximate the junction of the one or more partitions and the side wall, the reinforced downturn having a lobe extending further downwardly than an adjacent portion of the flange. A compartmentalized pressware paper plate having tall partitions formed from a cardboard blank, wherein the plate in the first aspect has three tall partitions in a Y configuration at the central joint on the plate. A compartmentalized pressware paper plate having tall partitions formed from a cardboard blank, wherein the central joint in claim 17 transitions between the partitions with a radius of curvature of 0.75" to 1.5". A compartmentalized pressware paper plate having tall partitions formed from a cardboard blank, wherein in claim 17, the plate has three tall partitions in a Y configuration at a central joint on the plate, two of which are longer than the third and extend outwardly in an arched trajectory from the central joint. A compartmentalized pressware paper plate having a tall partition formed from a cardboard blank, wherein the partition protruding outwardly in an arched trajectory defines a radius of curvature of 0.5 to 1.5 times the characteristic plate diameter when protruding into the side wall, in the 19th paragraph. A compartmentalized pressware paper plate having a tall partition formed from a cardboard blank, wherein the partition protruding outwardly in an arched trajectory defines a radius of curvature of 0.75 to 1.25 times the characteristic plate diameter when protruding into the side wall, in the 19th paragraph. A compartmentalized pressware paper plate having high partitions formed from a cardboard blank, the compartmentalized pressware paper plate having high partitions formed from a cardboard blank, wherein the compartmentalized pressware paper plate is formed from a polygonal cardboard blank, in accordance with claim 1. A compartmentalized pressware paper plate having a high partition formed from a cardboard blank, wherein the blank is provided with scores spaced from the edges of the central portion of the blank and positioned so as to facilitate partition forming in the plate. A compartmentalized pressware paper plate having partitions formed from a cardboard blank, the plate bottom defining a bottom surface transitioning adjacent a plate sidewall extending around the plate bottom and projecting outwardly and upwardly therefrom, and the plate sidewall defining a plate sidewall surface and adjacent a flange flared outwardly from the sidewall, the plate further comprising at least one partition adjacent the plate bottom, each partition having a pair of partition sidewall surfaces and transitioning to the partition sidewall surfaces, the at least one partition characterized by a partition height DH from the plate bottom, the at least one partition extending from the sidewall toward a central portion of the plate bottom and configured to divide the plate bottom into a plurality of serving compartments, the transition between the adjacent surface of the bottom surface and the partition sidewall surface being characterized by a variable radius of curvature, the variable radius of curvature varying from a first value proximate the transition between two surfaces to a second value greater than the first value at the transition proximate the intersection between three surfaces. Compartmental pressware paper plates with dividers formed from cardboard blanks. A compartmentalized pressware paper plate having a partition formed from a cardboard blank, the paper plate comprising: a plate bottom adjacent a plate side wall extending around a plate bottom and projecting outwardly and upwardly toward a flange flared outwardly from the side wall; and at least one partition adjacent the plate bottom and characterized by a partition height DH from the plate bottom, the at least one partition extending from the side wall to a central portion of the plate bottom and configured to divide the plate bottom into a plurality of serving compartments, the at least one partition being adjacent the side wall of the plate at a height SDH less than DH, the flange optionally having a reinforced downturn near the junction of the side wall and the at least one partition, the reinforced downturn having a lobe extending further downwardly than an adjacent portion of the flange.

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