Method, apparatus, and chemical composition for selectively coating fiber-based food containers

Abstract

To provide a method and an apparatus for applying vacuum forming and subsequent topical coating to a fiber-based food container.SOLUTION: The slurry includes one or more of an embedded moisture barrier, vapor barrier, and oil barrier, and the topical coating includes one or more of a vapor barrier, moisture barrier, oil barrier, and oxygen barrier. For food containers having deep sidewalls, the spray coating system includes a first nozzle for applying a full cone spray pattern to the bottom surface of the container and a second nozzle for applying a hollow cone spray pattern to the inner surface of the sidewall.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 15 / 220,371, filed July 26, 2016. No. 60 / 699,999, filed on Oct. 1, 2004, which is a continuation-in-part of, and claims priority to, the entire contents of which are incorporated herein by reference. be absorbed.

[0002] The present invention generally relates to a spray container for use with vacuum-formed, molded fiber food containers. More specifically, the coating provides the desired oil, water, vapor, and / or oxygen barrier. Selective combination of slurry chemistry and surface coating to produce do. [Background technology]

[0003] Contamination caused by single-use plastic containers and packaging materials is prevalent. are damaging global landscapes and threatening delicate ecosystems and the life forms that inhabit them. Single-use containers are packaged in Styrofoam and Expanded Polystyrene (EPS) packaging, take-out packaging, in the form of containers, bottles, membrane bags, and photodegraded plastic pellets They migrate along waterways to the ocean in this state.

[0004] This marine debris is made up of highly concentrated islands of plastic located in each of our ocean eddies. Sunlight and waves break floating plastic into smaller and smaller particles. However, they do not disappear completely or biodegrade. The sticky particles act as a sponge for water-soluble contaminants such as pesticides. and even whales eat plastic objects that make them sick or kill them. Smaller marine animals may ingest microscopic plastic particles and But they come to us when we eat seafood.

[0005] Sustainable solutions to reduce plastic pollution are gaining momentum. However, continued adoption will require these solutions to be environmentally friendly as well as offering performance and cost benefits. The present invention aims to improve the performance of the product by reducing the cost and time required to compete with plastics. It involves replacing plastics with innovative technologies of molded fibres without damaging the ecological Providing a competitive cost structure within an academically responsible framework.

[0006] As a brief background, molded paper pulp (molded fiber) has been used since the 1930s to make containers, trays, and and other packaging, but after the introduction of plastic foam packaging, Pulp and paper are made from old newsprint, cardboard boxes, and It can also be made from other plant fibers. Today, molded pulp packaging is used in a wide range of applications, including electronic components, household goods, and more. , automotive parts, and medical products, as well as for electronic and other fragile components. Widely used as edge / corner pads or pallet trays for shipping. , which is formed as a mirror image of the finished package, with the screen attached to its surface. A vacuum is drawn across the screen causing the fiber particles to accumulate into the finished product shape.

[0007] The two most common types of molded pulp are classified as Type 1 and Type 2. Type 1 has walls between 3 / 16" (4.7mm) and 1 / 2" (12.7mm). Type 1 molded pulp production is also known as "dry" pulp production, which is commonly used for support packaging applications. Also known as manufactured, it is made from crushed newsprint, kraft paper, or paper dissolved in water. A fiber slurry made from other fibers is used. The substrate is dipped or submerged in the slurry and a vacuum is applied to the generally convex backside. The slurry is pulled onto a mold to form the shape of the package. While under vacuum, the mold , is removed from the slurry tank and the water is allowed to drain from the pulp. Air is blown through the tool to push out the shaped fiber pieces. Typically, the material is deposited on a conveyor within a drying oven.

[0008] Type 2 molded pulp production, also known as "wet" production, typically involves 0. Electrode with a container having walls between 0.02 inches (0.5 mm) and 0.06 inches (1.5 mm) Used for packaging of electronic devices, mobile phones, and household goods. Type 2 molded pulp is Use the same materials as in Type 1 production up to the point where the vacuum pulls the slurry onto the mold, and The same basic process is followed. After this step, the transfer mold is mated with the fabric wrap and formed The "wet part" is transferred to a hot press, which compresses and dries the fibrous material, increasing its density. provides a smooth exterior surface finish. solutions / additive-manufacturing / tooling / molded-fiber, keiding.com / molded-fiber / ma nufacturing-process / , published on April 11, 2007, titled Improved Molded Fiber Manufacturing”Gre nidea Technologies PTE Ltd. European Patent Publication No. EP14 No. 92926B1, and afpackaging.com / thermoformed -fiber-molded-pulp / . All of the above content in its entirety is This is incorporated herein by reference.

[0009] Fiber-based packaging products are biodegradable, compostable, and, unlike plastics, do not migrate to the ocean. However, currently known fiber technologies are widely used in meat and poultry, prepared foods, agricultural products, and For use with produce, microwaveable foods, or as a lid for hot coffee or other beverage containers In particular, they are not well suited for use in the presence of one or more of oil, water, steam, and / or oxygen vapors. Selectively integrating the rear into the slurry and / or completing one or more barrier layers. Selective application to all or part of the surface of a packaged product is laborious and time consuming. This can be costly and expensive.

[0010] Therefore, methods, apparatus, spray systems, and chemical formulations that overcome the limitations of the prior art are provided. Things are needed.

[0011] Various features and characteristics are also described in detail below in conjunction with the accompanying drawings and this Background section. This will become apparent from the detailed description and the appended claims. Summary of the Invention

[0012] Various embodiments of the present invention are directed to the manufacture and use of vacuum-formed, fiber-based packaging and container products. a method for selectively applying a barrier coating to selected surfaces thereof, the chemical formula , spray systems, and nozzle configurations, including, among other things: i) new features that promote structural rigidity; meat, produce, horticulture, and utility containers that embody standard geometric features; ii) buried Meat with embedded and / or localized moisture, oil, oxygen, and / or vapor barriers , produce, and horticultural containers; iii) embedded and / or topical moisture, oil, and acid and / or vapor permeation barrier, and / or chemical bonds within the fiber matrix. Microwaveable and oven-heated, incorporating a yield enhancer to improve Frozen meals, ready-to-eat meals, yogurt, salads, prepared meals, macaroni and cheese, and other containers; and iv) maintain structural integrity over extended shelf life. and meat containers that embody a moisture / vapor barrier.

[0013] The various inventions described herein are intended to be used in the context of conventional slurry-based vacuum forming processes. It should be noted that the present invention is illustrated by, but not limited to, the following examples. The present invention relates to a drying method that may or may not involve vacuum forming, including 3D printing techniques. It will be understood that any fiber-based manufacturing method may be contemplated, including fiber or fluffing processes. There will be.

[0014] Various other embodiments, aspects, and features are described in more detail below. [Brief explanation of the drawings]

[0015] Exemplary embodiments are described below in conjunction with the accompanying drawings, in which like numerals refer to like elements, and in which: means. [Figure 1] FIG. 1 is a schematic block diagram of an exemplary vacuum forming process using a fiber-based slurry, according to various embodiments. [Figure 2]FIG. 1 is a schematic block diagram of an exemplary closed-loop slurry system for controlling the chemical composition of a slurry, according to various embodiments. [Figure 3] FIG. 1 is a perspective view of the bottom of an exemplary meat tray, according to various embodiments. [Figure 4] FIG. 4 is a side elevational view of the meat tray of FIG. 3 according to various embodiments. [Figure 5] 5 is a top plan view of the meat tray of FIGS. 3 and 4 in accordance with various embodiments. FIG. [Figure 6] FIG. 6 is an end view of the meat tray of FIG. 5 according to various embodiments. [Figure 7] 1 is a schematic perspective view of a spray coating system for meat trays according to various embodiments; FIG. [Figure 8] FIG. 1 is a schematic perspective view of a spray coating system using a full-cone and hollow-cone dual nozzle system for use with microwave ovens, frozen foods, ready-to-eat meals, and other food containers with deep sidewalls, according to various embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE INVENTION The following detailed description of the invention is merely exemplary in nature and is not intended to limit the scope of the invention or its applications. Furthermore, the foregoing background or the following detailed description are not intended to limit the scope and use of the present invention. The present invention is not intended to be bound by any theory presented herein.

[0017] Various embodiments of the present invention are useful within and outside the food and beverage industry. As a non-limiting example, the present disclosure relates to fiber-based or pulp-based products for use in both. It acts as an oil barrier, moisture barrier, vapor barrier, water vapor barrier, oxygen barrier, strength additive, and and retention aids, tailored to address the unique challenges facing the food industry. The lack of these is related to the specific chemical formulation of the chemistry and topical film or coating. It can effectively replace single-use plastic containers in the food industry. has limited the range of textile-based products. Novel slurry chemistries and surface coating technologies (e.g. By combining the above methods (e.g., spray coating, dipping), the textile product can be Frozen, refrigerated and non-refrigerated foods, medical, pharmaceutical and biological uses, microwave ovens Dessicable and oven-safe food containers, drinking cups and lids, edible and non-edible liquids, storage Substances that liberate water, oil, and / or water vapor during shipping, handling, and preparation (e.g., cooking) , consumable and horticultural uses including landscape / garden plants, flowers, herbs, shrubs, and trees; Chemical storage and dispensing equipment (e.g., paint trays), human and animal feed (e.g., fruits and vegetables) Packaging and lids for produce (including food products), salads, prepared meals, meat, poultry, and fish , cups, bottles, guides and separators for the processing and display of the aforementioned, electronic equipment, Edges and edges for packaging, storage and shipping of mirrors, artwork, and other fragile components Corner pieces, buckets, tubes, gaskets, spacers, seals, cushions and the like automotive, marine, aerospace and military components, as well as the manufacturers of the above components. Associated molds, wire mesh forms, recipes, spray systems for manufacturing Spray nozzle configuration and process, chemical formulas, tools, slurry distribution, chemical monitoring , chemical injection, and related systems, devices, methods, and techniques. This allows them to replace plastic equivalents in applications.

[0018] Various embodiments of the spray coating technique involve spraying water and / or oil onto the tray surface. To combat the phenomenon of meat piercing and peeling off after freezing, an oil barrier and / or steam A barrier surrounds the microwave bowl as well as the meat tray. The coating may be applied to the lid of a beverage to mitigate unwanted staining (e.g., lipstick). It may have applicability to:

[0019] In some embodiments, the microwave bowl, steamer, or tray has an inner surface In some embodiments, only the inner and outer surfaces are spray coated, while in other embodiments, both the inner and outer surfaces are spray coated. For spray applications, the spray nozzle is Spray patterns that approximate the surface being sprayed (e.g., circular, annular, rectangular, and similar) ) may be configured to apply

[0020] Various spray, dip, or other coating formats can be applied to achieve the desired performance in the finished product. Various chemical formulations are used to create properties that are compatible with polyester. When mixed with the emulsion and heated (e.g., using a microwave or conventional oven), applied to the surface of a container to mitigate water vapor transmission through the container wall (e.g., bottom surface). Various chemical formulations are also used to coat the surface of the coating, including alginates (e.g., algae derivatives). It may also contain a calcium carbonate component to promote bonding of the fiber-based container to the surface. In this application, the coating also effectively mitigates oil penetration.

[0021] These coating chemistries are TG81, as described elsewhere herein. Used instead of (or in addition to) incorporating fluorochemicals into the slurry In some embodiments, the surface coating provides a primary vapor barrier and / or a water In addition to the barrier properties, the oil barrier component may have secondary oil barrier properties, but still It may be desirable to embed the

[0022] Various surface coating embodiments vary in chemical as well as process aspects (e.g., composition, The process involves applying the compound to a surface to achieve the desired coverage. Considerations include, but are not limited to, spray droplet size, atomizer configuration, and orientation, spray geometry, and whether the container (e.g., yogurt) is coated. The "fill and transfer" process is performed by filling the container with the lubricating compound and then rapidly emptying it to create a film on the inside surface. Examples of such technologies include "motion" technology.

[0023] In this regard, steaming (e.g., to prevent frozen food from drying out during freezing) is not permitted. The air barrier and oxygen barrier (to maintain freshness and shelf life during freezing) are typically Typically, complete (e.g., 100%) coverage of the protective surface is required, while For example, to prevent meat from sticking to meat trays after one or more freeze / thaw cycles, or moisture (e.g., water) to prevent starch from sticking to the microwave bowl Barrier coatings can be effective at less than substantially complete surface coverage.

[0024] In various embodiments, spray and other coating processes are used to vacuum form the container. In addition to incorporating one or more barrier chemicals into the slurry used to Instead, the surface of the finished container is coated with a steam, oxygen, moisture, and / or oil barrier. In a preferred embodiment, for example, only the inner surface is coated. When coated (e.g., in the case of a non-sticky barrier), the moisture barrier component The oil and / or vapor barrier is then applied to the formed container.

[0025] Spray coating applications include microwave bowls, frozen foods, and meat coatings, among others. Depending on the application, the tray may have one or more of the following barriers: water, steam, oil, and oxygen. Spray coating may be desirable. For microwave bowls, 100% coverage may not necessarily be required as long as the product has a shelf life. The technique can be used to apply a water and / or vapor barrier, but also to prevent meat from being frozen. After one or more cycles of freezing / thawing, the paper fibers are pulled out when removed from the tray in a frozen state. It is also used to prevent cracking (100% coverage is not required) and to prevent "sticking." Yogurt and other applications may require spray coating for water vapor and oxygen barrier. Coating is used, which typically requires nearly 100% coverage.

[0026] Spray coating use cases generally involve: i) the chemical formulation of the coating to be applied; ii) thermophysical, rheological, and viscoelastic properties; iii) coatings on containers, packaging, for application to one or more surfaces (or portions of surfaces) of a coating or other workpiece equipment, and iv) process parameters such as drying time and temperature.

[0027] A typical use case involving spray coating is meat adhering to a fiber tray after freezing. To help prevent this, a moisture barrier surrounds the coating on the meat tray. To reduce the degree to which the meat sticks to the tray after freezing, a top (surface) coating is applied. The coating may also be applied (via spray or otherwise) to, for example, meat. and while the secretions are placed in the tray in the refrigerator, the strength and This helps maintain stiffness.

[0028] An exemplary method for producing spray-coated meat trays is to use up to 100% OC C, or any desired combination of OCC and double-lined kraft (DLK) paper Alternatively, one may start with an aqueous fiber-based slurry. (Alternatively, various slurry bases described herein may be used.) The slurry base may contain a mixture of recycled and virgin fibers, or the slurry base may be , as discussed below in conjunction with microwave bowls, 100% virgin fiber (e.g. , hardwood, softwood, or a combination thereof).

[0029] Water / moisture barrier (e.g., 2-5%, preferably about 4% AKD), dry strength additives ( For example, 0.5 to 4.5%, preferably about 4%, of starch, Hercobond 695 0 or modified starch), and wet strength additives (e.g., Kymene) are added to the slurry. After the tray is vacuum formed (e.g., dried in a heat press for about 55 seconds), After the trays are transferred to the stacker, the stack of trays is spray coated The nested items are then transferred to a station where they are de-nested and placed in their respective positions on the conveyor. The coating is then applied in either a serial or parallel fashion. Either one is applied to each tray.

[0030] In various embodiments, the auxiliary coating is performed by two fixed nozzles disposed above the tray. The coating may be applied using a system including nozzles, each of which may be positioned on a wall or produces a spray pattern in the form of a curtain (very similar to an air knife). Thus, each nozzle (or combination of nozzles) is preferably aligned with the direction of travel of the workpiece. In one embodiment, one nozzle generates a spray pattern that terminates in a line that is perpendicular to the nozzle. The sieve allows for full coating of sloping sidewalls, structural ribs, and any other geometric features. It may be angled forward (towards the direction of tray travel) to ensure proper alignment. , while other nozzles may be angled backward.

[0031] Alternatively, a substantially flat tray with limited sidewall depth or a thickness that is too thin for the film uniformity to be achieved. For less critical applications, a single curtain-type spray configuration is used. Good too.

[0032] Whether the tray is receiving sufficient coverage (e.g., is it sufficiently coated) One metric to assess whether the coating is effective is the weight of the tray before and after coating. to determine whether the weight of coating material applied to the tray exceeds a predetermined threshold (or range). Alternatively or additionally, the thickness of the applied film may be determined by: To determine whether the coating thickness meets a predetermined threshold (or range of values) can be measured.

[0033] In some embodiments, the uniformity of the applied coating is also measured to aid in future Process parameters are adjusted as needed to promote uniformity of application to the tray. In this respect, uniformity depends on at least two considerations: i) local point or whether the membrane layer in the area is too thin and therefore does not form an effective barrier; and ii) The film layer is too thick at a local point or area, causing the finished tray at that point The film may not dry completely (the top layer of the film slides off or otherwise peels off from the film) and may stain or or peeling.

[0034] The coated trays are then heated at 70 to 180°C, preferably at about 80 to 110°C. , most preferably in an oven in the range of about 95°C for about one (1) minute to remove the film layer. Remove moisture and cure as appropriate by other means. An infrared (IR) sensor detects the appropriate cure temperature. The temperature of the meat tray is measured at one or more points to ensure that the desired temperature is achieved. It can be used to check the degree.

[0035] For meat trays, the coating composition contains 25% acrylic and 75% water. Acrylics are available from DOW Chemical Corporation. Possible binders include acrylic copolymer latexes such as Rhobarr 110 or similar. In this context, the coating may be applied to the frozen meat once it has been removed from the tray. When the meat tray is opened, it acts as an anti-stick layer to prevent the top layer from peeling off.

[0036] In some embodiments, the opposite side of the tray (including the bottom surface and / or exterior sidewall) Some or all of the may also be coated. When stored at room temperature, secretions may form around the seal between the tray and the outer plastic wrap. If it leaks, frozen secretions from the meat (e.g., blood, oil, water) will adhere to the outside of the tray. This reduces the possibility of this happening to some extent.

[0037] Meat trays typically do not require a separate oil barrier, but may be subject to steam and / or The anti-corrosion barrier can also effectively inhibit oil penetration.

[0038] Pea emulsion and alginate as an alternative to or in addition to acrylic Also used for meat trays, microwave bowls, and / or other packaging components. It can be used.

[0039] After drying, the trays are stacked, boxed, and shipped.

[0040] The term "ready to eat" (RTE) trays refers to trays that contain salads, fruits, cooked meals, and other foods are packaged using a plastic film sealed around the perimeter of the tray. RTE trays are containers that are often stored in refrigerators to ensure freshness and shelf life. It may be coated to provide an oxygen barrier to improve durability.

[0041] RTE trays without a local membrane barrier are suitable for 30-100% OCC / DLK and 0-70 % virgin pulp, and preferably about 100% OCC / DLK. / DLK slurry contains i) 1 to 5%, preferably about 4%, Daikin 8111 ii) an oil barrier, ii) a moisture / water barrier containing 2-5%, preferably about 3.5%, AKD, and and iii) by adding a strengthening ingredient containing 3% starch, such as Hercobond. It can be produced by

[0042] RTE trays with local membrane barriers are fabricated in substantially the same manner as described above. (However, omitting the 8111 oil barrier and / or increasing the AKD to 4%) potential), and topical oxygen barriers containing acrylic in aqueous solution (e.g., 25% Ro bar 110 and 75% water) may be added. RTE trays and containers (e.g. For example, a yogurt cup, the membrane ensures more complete (e.g., 100%) coverage. To accommodate this, they are typically thicker than those described above in the context of meat trays.

[0043] Uncoated microwave bowls are made from up to 100% virgin fiber (softwood) , hardwood, or a combination thereof. In this state, the slurry base is about 45% bleached hardwood, about 35% bleached softwood, and about 25% The slurry also contains an oil barrier (e.g., 2.5% 8111), a water barrier, ria (e.g., 3% AKD), dry strength additives (e.g., 2.5% starch), yield Additives (e.g., 0.15% Nalco), and desorption to remove entrained air. A foam component (eg, 1.5% Expair) may also be included.

[0044] Coated microwave bowls are safe to use in conjunction with uncoated microwave bowls. It is made using a substantially virgin fiber slurry base as described above in connection with the urethane foam. and further comprising about 3% water barrier (AKD) and about 2.5% starch. but does not include oil barriers, retention additives, and defoamers. The solution may contain approximately 27.5% solids. The 27.5% solids may be comprised of the following five (5) components: Sometimes referred to as WP formulation): i) 25% acrylate, ii) 1.8% rice bran wax (may reduce stickiness), iii) 0.4% pectin (forms a vapor barrier) and may reduce stickiness to facilitate de-nesting of stacked bowls. ), iv) 0.3% pea protein (which can facilitate the emulsion of rice bran wax), and and v) 0.2% liquid acrylate to adjust the pH and thereby accelerate acrylate cure. ammonium or other additives, do.

[0045] Curtains terminating in lines for bowls and other packaging components with deep sidewalls To address this issue, the inventors have developed a hollow Two nozzle spray with cone spray pattern and combined full cone spray pattern A paradigm was developed that both sprays the bottom surface without overspraying the bottom surface. as well as providing adequate coverage for sidewall features.

[0046] In a preferred embodiment, the coating is applied through a spray coating station. The microwave uses a two-nozzle system positioned above a conveyor that carries the bowls. The first "full cone" nozzle is positioned to cover the center (bottom) of each bowl. and a second "hollow cone" nozzle is configured to cover the inner sidewall of each bowl. The full-cone and hollow-cone spray patterns are such that the full-cone pattern overlaps with the hollow-cone pattern. Preferably, the thickness is adjusted to ensure complete coverage while minimizing excess film thickness in other areas. It is properly configured.

[0047] In a preferred embodiment, bowls or other packaging components travel along a conveyor. At the same time, the nozzle system also travels along the same path for a given period of time, so that the nozzle or The nozzles do not translate relative to the bowl during spraying. It can remain "stationary" for each bowl without compromising its performance.

[0048] Coated yogurt cups are best used with uncoated microwaveable bowls. Made using a substantially virgin fiber slurry base as described above in connection with the and further comprising about 4% water barrier (AKD) and 3% starch. Alternatively (or in addition) to the spray method, the localized oxygen barrier layer can be applied by: i) placing the cup in a The plate is then immersed in a pool of coating solution, thereby coating both the inner and outer surfaces. or ii) a complete immersion process in which the coating solution is poured into the cup until it is full. The "fill and discard" process involves the filling of the cup with a coating of the inner surface of the cup, which is then discarded. In this context, the DWP formulations mentioned above may be applied using any of the "disposal" techniques. The same or more diluted (lower acrylate concentration) versions may be used. Additionally, the injected solution may be delivered in an open or closed loop to reduce waste. It can be recycled in the system.

[0049] The coated cups are then dried in an oven at about 95°C for about 1 minute. The laminated sheets may then be stacked, boxed, and shipped.

[0050] In a traditional bowl of mac and cheese, the pasta is dry. The cheeses are typically packaged separately in plastic or foil envelopes, so An oxygen barrier layer may or may not be required to prevent this. If desired, for example, the full immersion or pour-in and pour-out techniques described above (or both) may be used. If an oxygen layer is not required, the above-described method may be used. So, an anti-stick coating can be applied.

[0051] An alternative version of the DWP formula contains 0.3% pea protein (which is a powder). and to perform substantially the same function as emulsifying rice wax. This involves using .05% Tween 80 (an emulsifier).

[0052] Additionally, instead of using powdered pectin, we use a water-based version that is easy to mix. Use.

[0053] The formulation for the topical coating may include: [Table 1] [Table 2] [Table 3]

[0054] Generally, DWP spray coatings have a total solids content in the range of 15-40% by weight, preferably in the range of 25-30% by weight, most preferably about 27.5% by weight, One component in the formulation, upon hardening, provides the desired moisture, oil, and / or or an acrylic polymer that crosslinks and polymerizes to promote the formation of an oxygen barrier layer. The formulation also provides non-stick properties and a non-glossy surface finish to the coated surface. It contains rice bran wax to provide a stable aqueous dispersion. The formulation is also emulsified with pea protein to reduce hydrophobicity during spray coating. Contains pectin as a viscosity modifier for optimum adhesion to fibrous surfaces. is about 9.0 with the addition of ammonia to maintain solubility of the acrylic polymer.

[0055] An exemplary method for preparing a solution to be applied as a topical coating is will be explained in the context of a seventy-five (75) gallon batch using RBW: Rice bran wax PP: Pea protein Pec: pectin G: Gallon L: Liter kg: kilogram

[0056] Heat 35.6 gallons of water to at least 185°F until the wax pellets are completely dissolved. Add 5.1 kg of RBW and mix at high speed for approximately 12 minutes until the solution temperature returns to 185°F. Add 0.85 kg of PP to the mixture over approximately 1 minute. No lumps are visible. Mix PP for another 10 minutes or more until 1.14 kg of Pec is mixed in. Add the ingredients and mix the contents for an additional 15 minutes or more until no lumps are visible. Continue mixing on low speed to bring the batch temperature to approximately 120°F. While mixing, add 37.5 gallons Add 2.15g of Rhobarr 110 to the batch and continue mixing for 10 minutes. Slowly pour in L of 4% ammonia and continue mixing for an additional 10 min.

[0057] Referring now to FIG. 1, an exemplary vacuum forming system using a fiber-based slurry and The process 100 involves forming a mold (not shown for clarity) that is a mirror image of the product to be produced. ) is wrapped in a thin wire mesh form 102 to conform to the contours of the mold. A supply 104 of fiber-based slurry 104 is supplied at pressure (P1) 106 (typically The pressure (P2) 108 is maintained inside the mold. The slurry is drawn through the mesh form, capturing the fiber particles in the shape of the mold. The excess slurry 110 is then drained and recycled back into the system.

[0058] Continuing to refer to FIG. 1, the second step 103 is to form a mold around the periphery of the wire mesh. This involves building up a layer of fiber 130. When the layer 130 reaches the desired thickness, the mold The wet curing process then enters a third stage 105 for either wet curing or dry curing. In this process, the formed part is transferred to a heated press (not shown) and the layers 130 are compressed. and dried to the desired thickness, thereby providing a smooth exterior surface finish for the finished part. In the dry-cure process, heated air passes directly over the layer 130. This removes moisture from the carton, leaving it with a more textured finish, much like a traditional egg carton. This causes problems.

[0059] According to various embodiments, the vacuum forming process is carried out by removing unused slurry from the molded article. It operates as a closed loop system in that the liquid is recirculated to the reservoir. Some of the chemical additives (discussed in more detail in) are absorbed into the individual fibers, and some of the additives Some remain in the aqueous solution. During vacuum forming, only the fibers (which have absorbed some of the additives) The remaining additive is recycled to the tank. The additives are recirculated with the slurry in solution, so that only the additives trapped within the molded part are As described below, the system is configured to contain a slurry. Maintain a steady state chemistry in the vacuum tank at a predetermined volumetric ratio of components.

[0060] Referring now to FIG. 2, a closed loop slurry system for controlling the chemical composition of a slurry is shown. In the illustrated embodiment, a tank 202 contains a particular desired chemical. The mold is then filled with a fiber-based slurry 204 having a thickness of 100 μm, and a vacuum forming mold 206 is then formed to form the molded part. After the molded part has been formed to the desired thickness, it is immersed in a bath of slurry. Subsequent processing 208 (e.g., forming, heating, drying, top coating, and the like) Therefore, the mold 206 is removed.

[0061] In a typical wet pressing process, the hot pressing temperature range is approximately 150-250°C. The hot press pressure range is approximately 140 to 170 kg / cm 2 The density of the final product is , about 0.5~1.5g / cm 3 and most likely about 0.9-1.1 g / cm m 3 The thickness of the final product is about 0.3 to 1.5 mm, preferably about 0.5 to 0.8 mm. m.

[0062] Continuing to refer to FIG. 2, the fiber-based slurry containing pulp and water is added to the slurry feed 2 10 into tank 202. In various embodiments, a grinder is used to grind the pulp fibers. One or more additional components or chemical additives may be added to the surface of the material to break down the fibers and create additional bond sites. The slurry can be supplied at each input 212-214. Additional particles can be added as needed. The mixture may be recirculated using a closed loop conduit 218, which may be used to add slurries and / or water. To maintain a steady state balance of the chemical additives, the sampling module 216 The components of the slurry are measured or otherwise monitored and each charge 212-214 By controlling the Typically, the slurry concentration is about 0.1 to 1%, and most ideally about In one embodiment, the content is 0.3 to 0.5%, and preferably about 0.4 to 0.5%. The various chemical components are maintained at predetermined desired volume percentages; alternatively, the chemicals may be mixed by weight. It may be maintained based on a percentage or any other desired manner of control.

[0063] The pulp fibers used in 202 also improve interfiber bonding and provide chemical protection to the fibers. To improve the bonding of the material, it can also be mechanically crushed. The fiber undergoes a modification process that changes the freeness or drainage rate of the fiber material. modifies the fibers to make them fibrillated and more flexible for better bonding. The modification process can also increase the tensile strength and burst strength of the final product. In various embodiments, freeness is related to the surface condition and swelling of the fiber. f) is preferably between 200 and 300°C for many of the processes and products described herein. 700, preferably in the range of about 350 to 550.

[0064] Various chemical formulations (sometimes referred to herein as "chemicals"), spray coatings, dipping and dipping systems and nozzle configurations for various fiber-based packaging and containers The product configurations and various methods for applying the topical coating are shown in Figures 3-8. will be further explained in conjunction with.

[0065] FIG. 3 illustrates the underside of the bottom surface 302 and the outer surface of the sidewalls 304 of the meat tray 30. This is an oblique view of 0.

[0066] FIG. 4 is a side elevational view of the meat tray 402 of FIG.

[0067] FIG. 5 shows the top surface 502 of the bottom region of the tray, as well as the respective side walls 504 and 505. 5 is a top plan view of the meat tray of FIGS. 3 and 4 illustrating 06.

[0068] FIG. 6 is an end view of the meat tray 602 of FIG.

[0069] FIG. 7 illustrates a spray coating useful for applying a spray coating to meat trays, according to various embodiments. FIG. 7 is a schematic perspective view of a spray coating system 700.

[0070] More specifically, the system 700 moves the tray along the direction indicated by the arrow 730. The trays include a conveyor 708 having pockets 710 for holding the trays as they are transported. The tray includes a bottom panel 704 having structural features (e.g., ribs) 706 and sidewalls Surrounded by 702.

[0071] With continued reference to FIG. 7, the illustrated spray system includes a first spray The nozzle 712 is provided at the side edge 71 and a second spray nozzle 718. 4 and terminates at a line 716 that is substantially perpendicular to the direction 730. The nozzle 718 is configured to deliver a substantially planar spray pattern 715. A line 716 bounded by a side edge 720 and substantially perpendicular to a direction 722 The spray nozzle 720 is configured to dispense a substantially planar spray pattern 721 that terminates at a tray. As the spray passes under the spray nozzle, the spray lines 716 and 722 contact the bottom surface 7 704 and / or the inner surface of the sidewall 702. Apply the following.

[0072] FIG. 8 illustrates a full-cone nozzle 810 configured to deliver a full-cone spray pattern; and a medium configured to deliver an annular (or "donut") shaped spray pattern. FIG. 8 is a schematic perspective view of a spray coating system 800 including an empty cone nozzle 814. In particular, the system 800 applies a full cone spray to the inside bottom surface 802 of the workpiece (bowl). The system 800 is configured to apply a hollow cone spray pattern 812. It is further configured to apply turns 816 to the inner surface of the workpiece sidewall 804 .

[0073] With continued reference to FIG. 8, conveyor 806 moves in the direction defined by arrow 830 ( 8) along the conveyor 806. 830, thereby lowering the platen 820 from the stationary platen 820. The nozzles 810, 814 may be configured to position successive trays under the stationary nozzles 810, 814. In this position, the right bowl is spray coated on the sidewall while the left bowl is spray coated. The bottom of the spray-coated roll can be indexed to the next position, after which the previously The bowl that was under nozzle 810 is then placed under nozzle 814, etc. .

[0074] In an alternative embodiment, the total workpiece throughput is This can be increased by operating the conveyor 806 in a continuous (proportionally) manner. Positional registration between the nozzle system and the underlying workpiece during coating application To maintain this spacing, platen 820 advances to the right along with conveyor 830 to maintain the spacing between the nozzles. The relative motion is temporarily interrupted and the nozzle is then moved to the next set of workpieces to be coated. The image may be configured to shift left to align with the image source.

[0075] FIG. 8 shows two workpieces and one each of a full-cone and hollow-cone nozzle. Although one nozzle is illustrated, those skilled in the art will appreciate that the system may be configured to operate with any number of nozzles per reciprocating motion of the platen 820. It will be appreciated that the dimensions may be scaled to accommodate the tube and workpiece.

[0076] As briefly mentioned above, the present invention provides a method for manufacturing a vacuum-formed container using a variety of vacuum forming techniques. The chemistry is engineered to impart desired performance characteristics tailored for each specific product application. The base fiber comprises a fiber-based mixture of pulp and water to which a component is added. Materials: Softwood (SW), bagasse, bamboo, old corrugated cartons (OCC), and newsprint (NP). Alternatively, the base fiber may comprise any one or combination of: Selection may be made according to the following resources, the entire contents of which are incorporated herein by this reference: Incorporated: Mohamed Naceur Belgacem and Antonio Edited by Pizzi (Scrivener Publishing, LLC) © 2016 Google, and https: / / books.google.co m / books?id=jTL8CwAAQBAJ&printsec=frontco Available from ver#v=onepage&q&f=false "Lignocell ulosic Fibers and Wood Handbook: Renewable e Materials for Today's Environment,” Af At the American Pulp and Paper Week on October 8, 2002 Published at tappsa.co.za / archive / APPW2002 / Title / Efficient_use_of_fluorescent_w / efficient Liisa, available at t_use_of_fluorescent_w.html "Efficient Us" by Ohlsson and Robert Federe e of Flourescent Whitening Agents and Sh adding Colorants in the Production of Whi te Paper and Board”, Woodhead Publishing © 2009 by books.google.com / book s?id=xO2iAgAAQBAJ&printsec=frontcover#v= Available on onepage&q&f=false, J.F. Kennedy, G.O. Phillips, Cellulosic, edited by P.A. Williams Pulps, Fibers and Materials: Cellucon '98 Proceedings, and U.S. Patent No. 5,169,497A, entitled "A pplication of Enzymes and Flocculants fo r Enhancing the Freeness of Paper Making Pulp”.

[0077] With respect to vacuum-formed product containers manufactured using either wet or dry pressing, A fiber system of CC or OCC / DLK and NP may be used, the OCC / DLK component being 50% to 100%, preferably about 70% OCC / DLK and 30% NP or VNP in the range of 1 to 10% by weight, preferably about 1.5% to 4% by weight, most preferably In a preferred embodiment, the moisture / water barrier has about 4% by weight of added moisture / water repellent. fobchem.com / html_products / Alkyl-Ketene -Dimer%EF%BC%88AKD-WAX%EF%BC%89.html#.V0 FOBCHEM in zozvkrKUk, and yztianchengchem. com / en / index.php?m=content&c=index&a=sho w&catid=38&id=124&gclid=CPbn65aUg80CFRCO Yanzhou Tiancheng Chemical in aQod0JUGRg Alkyl ketene dimers (AKD) (e.g., He The copolymer may contain olefins such as olefins of the formula (e.g., ...

[0078] Cationic dyes or fiber reactions to produce specific colors for molded pulp products Fiber reactive dyes, such as Procion MX, can be added to the pulp. It bonds with the cellulose at a molecular level and becomes chemically part of the dough. Increasing the pulp temperature and / or the pulp temperature will help the absorbed dye to become more confined within the fabric. It helps prevent color bleeding and improve color depth.

[0079] To improve structural rigidity, a starch component may be added, e.g., Topcat® L98 Cationic Additive (or Hercobo available from Solenis LLC) nd 6950), Hercobond, and Topcat® L95 catio Affinity additives (Penford Products, Cedar Rapids, Iowa) Liquid starch, commercially available as Starch Starch (available from Starch Starch, Inc.), can be added to the slurry. Alternatively, the liquid starch may also contain Penbond® cationic additive and PAF 9137 BR cationic additive (Penford Products Co. (also available from Cedar Rapids, Iowa) It can also be combined with any low charge liquid cationic starch.

[0080] For dry pressing process, Topcat L95 or Hercobond 69 50 is in the range of 0.5% to 10% by weight, preferably about 1% to 7% by weight, particularly For products that need to maintain strength in high humidity environments, most preferably about 6.5% by weight Otherwise, it is most preferably added in the range of about 1.5 to 2.0% by weight. Regarding the press process, both hydrogen and ionic bonds are formed with the fibers and particulates. , made from modified polyamines, Topcat L95 or Hercobond 6 950. The dry strength additives are used to increase dry strength, and aids in drainage and retention, and provides anionic, hydrophobic and sizing agents to textiles. These additives are also effective in fixing the stabilizer. Of these, it is preferably added in an amount of about 1% to 6% by weight, most preferably about 3.5% by weight. Additionally, both wet and dry processes may utilize wet strength additives such as Kymene 9 Polyamide-epichlorohydrin (PAE) resins such as 20A or 1500, or Ashland Specialty at ashland.com / products Add a similarly formulated solution available from Chemical Products. In a preferred embodiment, Kymene 920A or 1500 is in the range of 0.5% to 10% by volume, preferably about 1% to 4% by volume, most preferably about 1% to 4% by volume. Preferably, it is added at about 2% by volume or an amount equivalent to the dose of a dry strength additive. 920A or 1500 has an average of two or more amino groups and / or quaternary groups per molecule. These are a class of polycationic materials containing ammonium salt groups. The amino groups tend to protonate in acidic solution to produce cationic species. Other examples of cationic materials include Hercosett 57 and Hercules. and Ciba-Geigy Catalyst 3774. Amino-containing polyamines, such as those prepared from dipic acid and dimethylene triamine Examples of polymers include those derived by modifying ethylenediamine with epichlorohydrin.

[0081] The inventors have proposed that molded fiber containers may be used by embedding barrier chemicals in the slurry or by providing a vacuum Microwave ovens, convection ovens, or by adding a topical coating to the forming container, or both. and as a single-use food container suitable for use in a conventional oven. In particular, the slurry and / or topical coating chemistry The quality is advantageously measured by the following three performance metrics: i) moisture barrier; ii) oil barrier; and iii) A hot container is placed in a lower temperature than the container, corresponding to one or more of the water vapor (condensation) barriers. Condensation caused by placement on hot surfaces should be avoided.

[0082] In this context, the degree to which water vapor penetrates the container is related to the porosity of the container, which is the basis of the present invention. That is, the container is effectively impermeable to oil and water. Even if water vapor is present, it can condense on cold surfaces, leaving behind a moisture ring. If water vapor penetrates the container, it can detract from the user's experience. Condensation issues are inherently more prevalent in fiber-based applications because they do not penetrate plastic barriers. He further judged that.

[0083] Thus, with respect to microwaveable containers, the present invention provides a water barrier, an oil barrier, and Fiber or pulp based slurry containing a water vapor barrier and optional retention aids In one embodiment, the softening point is in the range of about 10% to 90%, preferably in a ratio of about 7:3. A fiber base of timber (SW) / bagasse can be used. As a moisture barrier, AKD is about 0 Use in the range of 0.5% to 10%, preferably about 1.5% to 4%, most preferably about 3.5% As an oil barrier, grease and oil repellent additives are often used by Daikin or worldofchemicals.com / chemicals / chemical- World in properties / unidyne-tg-8111.html UNIDYNE TG 8111 or U, available from Fluoropolymer compositions such as NIDYNE TG-8731 or other fluorine-containing polymers It is a water-based emulsion of fluorine containing material. Slurry (or topical coating) oil barrier The component is present in a weight percentage range of 0.5% to 10% by weight, preferably about It may be present in an amount of 1% to 4% by weight, most preferably about 2.5% by weight. Nal, available from Nalco Company, Naperville, Ill. The organic compound such as CO 7527 is in the range of 0.1% by volume to 1% by volume, preferably about 0 Finally, dry strength additives such as inorganic salts can be used to strengthen the finished product. Additives (e.g., solenis.com / en / industries / tissue- towel / innovations / hercobond-dry-strength Hercobond 6950, available at -additives / , also available at sfm.st ate.or.us / CR2K_SubDB / MSDS / HERCOBOND_6950 See .PDF) is in the range of 0.5% to 10% by weight, preferably about 1.5% by weight It may be used in amounts of 100% to 5% by weight, most preferably about 4% by weight.

[0084] As mentioned above, vapor barrier performance is directly affected by the porosity of the fiber tray. The reduction in porosity of the fiber tray, and therefore the improvement in vapor barrier performance, is due to at least two factors: This can be achieved using several approaches. One is to crush the fibers. The second method is to improve the freeness of the material. By topical spray coating using Daikin S2066, a sintered material. The pre-coating is in the range of about 0.1% to 3% by weight, preferably about 0.2% by weight. It may be implemented using up to 1.5% by weight, most preferably about 1% by weight.

[0085] such as those used in grocery store displays for poultry, beef, pork, and seafood Currently known meat trays are typically made primarily for their excellent moisture barrier properties. Generally, the device is made from plastic-based materials such as polystyrene and styrofoam. The inventors have found that variations of the aforementioned chemicals used for microwaveable containers are particularly effective as moisture barriers. It was determined that the product could be adapted for use in meat trays (oil and porous burrs). (This is typically not as important in meat trays as it is in microwave containers.)

[0086] Thus, with respect to meat containers, the present invention includes a water barrier and an optional oil barrier. In one embodiment, the range is about 10% to 90%. Preferably, the fiber base is softwood (SW) / bagasse and / or bamboo / bagasse in a ratio of about 7:3. As a moisture / water barrier, AKD can be used in the range of about 0.5% to 10%. , preferably about 1% to 4%, most preferably about 4%. emulsion, UNIDYNE TG 8111 or UNIDYNE TG-8731, etc. The oil barrier component of the slurry (or topical coating) may be used in a weight percentage As a sachet, the range is 0.5% to 10% by weight, preferably about 1% to 4% by weight, and most preferably about 1% to 4% by weight. Preferably, about 1.5% by weight of Herco is also included to strengthen the finished product. A dry strength additive such as Bond 6950 is preferably present in the range of 0.5% to 10% by weight. Alternatively, it may be used at about 1.5% to 4% by weight, most preferably at about 4% by weight.

[0087] As discussed above in relation to produce containers, slurry chemicals and / or spray The tray coating chemicals, combined with structural features, prevent moisture / water from penetrating the tray. Preventing this can provide long-term stiffness over time.

[0088] Therefore, a method for manufacturing meat trays is provided, the method comprising the steps of: Provides wire mesh moulds similar to old corrugated boxes (OCC) and double lined preparing an aqueous fiber-based slurry containing at least one of: and adding an embedded moisture barrier to the slurry and immersing the mold in the slurry. and allowing the mold to settle in the slurry until the desired thickness of fiber particles accumulates on the mold surface. and removing the accumulated particles from the mold and pressing the press. drying and pressing the particles accumulated within to thereby form a meat tray; Transferring meat trays from the press to the coating station and coating the trays and applying a supplemental moisture barrier layer to the surface of the meat tray at the station.

[0089] In one embodiment, the embedded moisture barrier comprises 2% to 5% alkyl ketene dimer ( AKD).

[0090] In one embodiment, the method further comprises adding a dry strength additive to the slurry.

[0091] In one embodiment the dry strength additive comprises 0.5% to 4.5% starch.

[0092] In one embodiment, the coating station comprises a spray system and a coating station for advancing the meat trays. a conveyor configured to move along the row direction to engage the spray system; Equipped with.

[0093] In one embodiment, the spray system applies a first predetermined spray pattern onto the meat tray. a first nozzle configured to dispense the

[0094] In one embodiment, the first predetermined spray pattern terminates in a line on the meat tray. The line includes a substantially vertical curtain having a predetermined thickness and running in the direction of travel. They are oriented qualitatively orthogonal.

[0095] In one embodiment, the spray system applies a second predetermined spray pattern onto the meat tray. and a second nozzle configured to discharge the first spray pattern in a forward direction. The first spray pattern is angled towards the direction of travel and the second spray pattern is angled away from the direction of travel. It will be done.

[0096] In one embodiment, the auxiliary moisture barrier layer comprises an acrylic copolymer latex in an aqueous solution. nothing.

[0097] In one embodiment, the auxiliary moisture barrier layer comprises a solution of about 1:3 acrylic and water.

[0098] The method also includes forming a substantially flat circular bottom region bounded by a circumferential sidewall. The method is provided for producing a microwave bowl of the type characterized by the steps of: Providing a wire mesh mold that approximates the shape of a bowl and using hardwood virgin fibers and preparing an aqueous fiber-based slurry comprising at least one of virgin softwood fibers and virgin softwood fibers; adding an embedded moisture barrier to the slurry; and dipping a mold into the slurry. and stirring the slurry on the mold until the desired thickness of fiber particles accumulates on the mold surface. A vacuum is applied across the mold to remove the accumulated particles and press the mold. drying and pressing the accumulated particles to form a bowl; and from the press to a coating station; and applying a topical oil barrier layer to at least a portion of the bowl.

[0099] In one embodiment, the embedded moisture barrier comprises 2% to 5% alkyl ketene dimer ( AKD).

[0100] In one embodiment, the method further comprises adding a dry strength additive to the slurry; Dry strength additives include 0.5% to 4.5% starch.

[0101] In one embodiment, the topical oil barrier layer comprises about 27.5% solids in an aqueous solution.

[0102] In one embodiment, the solids include acrylates, rice bran wax, pectin, and endo. Contains protein.

[0103] In one embodiment, the coating station comprises a spray system and a and a conveyor configured to move the bowl along a travel direction beneath the tray.

[0104] In one embodiment, the spray system provides a full cone spray pattern over the bottom region of the bowl. a first nozzle configured to discharge a hollow cone spray pattern into the inner periphery of the circumferential sidewall; and a second nozzle configured to eject onto the side surface.

[0105] In one embodiment, the method includes moving the spray system along a direction of travel. The method further includes: i) a first nozzle disposed above the bowl; a second nozzle positioned above the bowl; and remains stationary relative to the bowl for a second predetermined period of time.

[0106] In one embodiment, the first period is: i) greater than the second period; ii) equal to the second period; and iii) less than a second period.

[0107] The method includes a type including a substantially circular bottom portion bounded by a sloped circumferential sidewall. The method is provided for producing a fiber-based microwave bowl of the present invention. A process that provides a wire mesh mold that resembles a water-based preparing a fiber-based slurry and adding an embedded moisture barrier to the slurry; dipping a mold into the slurry and allowing fiber particles of a desired thickness to accumulate on the surface of the mold; and drawing a vacuum across the mold within the slurry until the accumulated particles are removed from the mold. and drying and pressing the accumulated particles in a press, thereby removing the ball. forming the bowl and transferring the bowl from the press to a coating station and applying an acrylic oil barrier layer to the surface of the bowl at a coating station. and

[0108] In one embodiment, the embedded moisture barrier comprises 2% to 5% alkyl ketene dimer ( AKD).

[0109] In one embodiment, the oil barrier layer is made of calcium carbonate to promote bonding to the bowl surface. Contains ingredients.

[0110] In one embodiment, the oil barrier layer comprises a pea emulsion.

[0111] In one embodiment, the oil barrier layer comprises an alginate.

[0112] In one embodiment, the oil barrier layer is formed by mixing an aqueous solution containing about 25% acrylate with a tack-reducing agent. and a first accessory component configured to:

[0113] In one embodiment, the first adjunct component comprises about 1.8% rice bran wax.

[0114] In one embodiment, the first accessory ingredient comprises about 0.4% pectin.

[0115] In one embodiment, the oil barrier layer comprises a second oil-containing layer configured to promote emulsification of the first auxiliary ingredient. Contains 2 supplementary ingredients.

[0116] In one embodiment, the second accessory component comprises about 0.3% pea protein.

[0117] In one embodiment, the oil barrier layer adjusts the pH level of the oil barrier coating to and a third adjunct component configured to accelerate acrylate cure by

[0118] In one embodiment, the third adjunct component comprises about 0.2% liquid ammonium.

[0119] In one embodiment, the coating station includes a spray system and a bowl advancement system. a conveyor configured to move along the direction to engage the spray system. can.

[0120] In one embodiment, the spray system provides a full cone spray pattern on the bottom of the bowl. A first nozzle configured to dispense is provided.

[0121] In one embodiment, the spray system applies a hollow cone spray pattern to the interior surface of the sidewall. A second nozzle configured to dispense is provided.

[0122] In one embodiment, the oil barrier layer comprises a solution of about 1:3 acrylic and water.

[0123] The method also includes providing a substantially flat circular bottom region bounded by a circumferential sidewall. A microwave bowl is provided for manufacturing a type characterized by the shape of the bowl. providing a wire mesh mold that approximates the hardwood virgin fiber and the softwood virgin fiber; preparing an aqueous fiber-based slurry comprising at least one of the fibers; adding a moisture barrier to the slurry; immersing a mold in the slurry; and A vacuum is drawn across the mold within the slurry until a thickness of fiber particles accumulates on the surface of the mold. a step of removing the accumulated particles from the mold; and a step of removing the accumulated particles in the press. drying and pressing the mixture to form a bowl; and removing the bowl from the press. transferring the bowl to a coating station; and applying a topical oil barrier layer to at least a portion of the Contains approximately 27.5% solids in solution.

[0124] In one embodiment, the solids include acrylates, rice bran wax, pectin, and endo. Contains protein.

[0125] The microwave bowl may be manufactured using any of the methods described herein. .

[0126] While the present invention has been described in the context of the foregoing embodiments, it is understood that the invention should not be so limited. It will be understood that this is not intended to be a substitute for various spray systems and The nozzle configuration, slurry chemistry, and spray coat chemistry are based on the teachings of the present invention. and can be tailored to suit additional applications.

[0127] As used herein, the term "exemplary" means "one example" or "an example." Serves as an example, instance, or illustration "exemplary" means "to Any embodiment described herein should not necessarily be construed as preferred or advantageous over other embodiments. It should not be interpreted as a model that must be literally replicated. It is not intended to be.

[0128] The foregoing detailed description will provide a convenient road map for implementing various embodiments of the invention. While provided for those skilled in the art, the specific embodiments described above are merely examples and are not intended to limit the scope, applicability, or otherwise of the present invention. It should be understood that these examples are not intended to limit the capabilities or configurations of the To the contrary, modifications may be made in the function and arrangement of elements described without departing from the scope of the invention. Various modifications can be made to the

Claims

1. 1. A method of making meat trays, comprising: providing a wire mesh mold approximating the shape of the meat tray; At least one of old corrugated containers (OCC) and double lined kraft (DLK) paper preparing an aqueous fiber-based slurry comprising: adding an embedded moisture barrier to the slurry; immersing the mold in the slurry; The former is stirred in the slurry until a desired thickness of fiber particles accumulates on the surface of the former. drawing a vacuum across the mold; removing the accumulated particles from the mold; drying and pressing the accumulated particles in a press, thereby forming the meat tray; and forming transferring the meat trays from the press to a coating station; A supplemental moisture barrier layer is applied to the surface of the meat tray at the coating station. applying.

2. The embedded moisture barrier contains 2% to 5% alkyl ketene dimer (AKD). The method of claim 1 .

3. The method of claim 1 further comprising adding a dry strength additive to the slurry.

4. 4. The method of claim 3, wherein the dry strength additive comprises 0.5% to 4.5% starch. 。

5. the coating station A spray system; The meat tray is moved along a travel direction to engage the spray system. and a conveyor configured to:

6. The spray system delivers a first predetermined spray pattern onto the meat tray. The method of claim 5 , further comprising: a first nozzle configured to:

7. The first predetermined spray pattern is substantially uniform and terminates in a line on the meat tray. The line includes a substantially vertical curtain, the line having a predetermined thickness and substantially perpendicular to the direction of travel. The method of claim 6, wherein the layers are oriented qualitatively orthogonally.

8. The spray system delivers a second predetermined spray pattern onto the meat tray. a second nozzle configured to spray the first spray pattern in the advancing direction; the second spray pattern is angled toward the direction of travel, and the second spray pattern is angled away from the direction of travel. The method of claim 6, wherein the axial direction of ...

9. 10. The method of claim 1, wherein the auxiliary moisture barrier layer comprises an acrylic copolymer latex in an aqueous solution. The method described below.

10. 10. The method of claim 1, wherein the auxiliary moisture barrier layer comprises a solution of about 1:3 particulates and water. method.

11. characterized by a substantially flat circular bottom region bounded by a circumferential sidewall 1. A method for making a microwave bowl of the type comprising: providing a wire mesh mold approximating the shape of the bowl; A water-based fiber system comprising at least one of hardwood virgin fibers and softwood virgin fibers preparing a slurry; adding an embedded moisture barrier to the slurry; immersing the mold in the slurry; The former is stirred in the slurry until a desired thickness of fiber particles accumulates on the surface of the former. drawing a vacuum across the mold; removing the accumulated particles from the mold; The accumulated particles are dried and pressed in a press, thereby forming the bowl. and transferring the bowl from the press to a coating station; A localized oil barrier is applied to at least a portion of the bowl at the coating station. applying a layer.

12. The embedded moisture barrier contains 2% to 5% alkyl ketene dimer (AKD). The method of claim 11 .

13. further comprising adding a dry strength additive to the slurry, the dry strength additive comprising:

12. The method of claim 11, comprising 0.5% to 4.5% starch.

14. 12. The method of claim 11, wherein the topical oil barrier layer comprises about 27.5% solids in an aqueous solution. Law.

15. The method of claim 14, wherein the solid comprises a sticky component and an emulsifier.

16. the coating station A spray system; configured to move the bowl along a direction of travel beneath the spray system; and a conveyor.

17. the spray system comprising: a second nozzle configured to deliver a full conical spray pattern onto the bottom region of the bowl; One nozzle; a second nozzle configured to deliver a hollow cone spray pattern onto the inner surface of the circumferential sidewall; 20. The method of claim 16, further comprising:

18. further comprising the step of moving the spray system along the direction of travel, i) the first nozzle is disposed above the bowl and is in contact with the bowl ii) the second nozzle is positioned above the bowl and remains stationary for a predetermined period of time; 17. The method of claim 16, wherein the second predetermined period of time is a second predetermined period of time. The method described below.

19. The first period is i) greater than the second period, or ii) equal to the second period. and iii) less than the second period of time.

20. 18. A microwave bowl made from the method of claim 17.

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