Patent Application
20250027276
Pollution caused by single use plastic containers and packaging materials is now a recognized worldwide problem. Replacing single use packaging with biodegradable and compostable materials is proposed as one way to reduce plastic pollution. However, for a new environmentally-friendly replacement to be successful, it must be competitive in both cost and performance to the incumbent plastic technologies it is to replace.
By way of brief background, molded paper pulp (also referred to as molded fiber) has been used since the 1930s to make containers, trays and other packages. Paper pulp can be produced from recycled materials such as old newsprint and corrugated boxes or directly from tree and other plant fibers. Today, molded pulp packaging is widely used for electronics, household goods, automotive parts and medical products.
Molds are made by machining a metal tool in the shape of a mirror image, if you will, of the finished part. Holes are drilled through the tool and then a screen is attached to its surface. The vacuum is drawn through the holes while the screen prevents the pulp from clogging the holes. To make the molded fiber part, the mold is immersed into a slurry of fiber and a pressure gradient is applied and water is drawn through the holes in the mold. Fiber from the slurry is collected on the screen and, after the fiber layer is formed to a desired thickness, the mold with the molded fiber part is removed from the slurry. The molded fiber part is then disengaged from the mold and may be subjected to subsequent processing (e.g., forming, heating, drying, top coating, and the like).
The two most common types of molded pulp are classified as Type 1 and Type 2. Type 1 is commonly used for support packaging applications with 3/16 inch (4.7 mm) to ½ inch (12.7 mm) walls. Type 1 molded pulp manufacturing, also known as “dry” manufacturing, uses a fiber slurry made from ground newsprint, kraft paper, or other fibers dissolved in water. A mold mounted on a platen is dipped or submerged in the slurry and a vacuum is applied to the generally convex backside. The vacuum pulls the slurry onto the mold to form the shape of the package. While still under the vacuum, the mold is removed from the slurry tank, allowing the water to drain from the pulp. Air is then blown through the tool to eject the molded fiber piece. The part is typically deposited on a conveyor that moves through a drying oven.
Type 2 molded pulp manufacturing, also known as “wet” manufacturing, is typically used for packaging electronic equipment, cellular phones and household items with containers that have 0.02 inch (0.5 mm) to 0.06 inch (1.5 mm) walls. Type 2 molded pulp uses the same materials. The molding process differs from Type I manufacturing in that after the initial part (referred to as the “wet part”) is made, the wet part is subjected to a pressing step that compresses and dries the fiber material to increase density and provide a smooth external surface finish.
Less common types of molded fiber include Type 3 and Type 4. Type 3 molded fiber products may also be called “thermoformed” products. The products are manufactured using multiple heated molds with a product wall thickness of about 3/32 to 5/32 inches (2 mm to 4 mm). Surfaces are smooth and forms are well-detailed with minimal draft angles. Products are dried in the mold and no oven curing is needed. Due to the hot mold pressing process, the walls are somewhat denser. Type 3 thermoformed fiber, products closely resemble Thermoformed plastic material.
Type 4 refers to products that require some type of secondary or special treatment other than molding and curing such as die-cutting, secondary pressing, coating, and/or printing operations.
Molded fiber packaging products can be biodegradable and compostable. However, presently known fiber technologies are not well suited for use in food packaging where the food can come into contact with the packaging, particularly meat and poultry containers, prepared food, produce, microwavable food containers, and lids and cups for beverage containers.
The present disclosure relates to molded fiber formulations suitable for the automated, efficient, high-speed production of fiber-based containers, particularly for containers for use with produce such as apples. Fiber compositions are created as slurries to be used in the manufacture of molded fiber products. Embodiments of the fiber composition include a fiber base mixture of pulp and water, with some amount of a fiber substitute additive that is chemically compatible with the product to be stored in contact with the final molded fiber product. In an embodiment, apple pomace is a compatible fiber substitute for use in an apple container in that it is compatible with apples. Pomace is the pulp residue remaining after processing of fruit to extract its juice, e.g., by crushing, pressing. Pomace includes the processed residue of seeds, stems, skin and core material of the fruit in addition to at least some residue of the fruit juice itself as it is typically not possible to extract all the juice in a processing operation. Pomace may be added to the base fiber as a dried pulp, a wet pulp, or a rehydrated pulp (i.e., the pomace was dried and then rehydrated with water) or any combination of the preceding. Other types of fruit pomace may be used for handling other types of fruit, e.g., orange pumace for use in an orange container, peach pumace for use in a peach container, etc.
The following drawing figures, which form a part of this application, are illustrative of described technology and are not meant to limit the scope of the disclosure as claimed in any manner, which scope shall be based on the claims appended hereto.
Before the molder fiber compositions are disclosed and described, it is to be understood that this disclosure is not limited to the particular structures, process steps, or materials disclosed herein, but is extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for the purpose of describing particular embodiments of the pod dispensers only and is not intended to be limiting. It must be noted that, as used in this specification, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a step” may include multiple steps, and reference to “producing” or “products” of a step or action should not be taken to be all of the products.
Various embodiments of the technology described below relate to the manufacture of fiber-based or pulp-based products for use both within and outside of the food and beverage industry. The embodiments described herein have been optimized for use with fruit products, particularly apples. However, any embodiments described herein are suitable for use in any situation in which fruit contact with the molded fiber is anticipated.
By way of non-limiting example, the present disclosure relates to the automated, efficient, high-speed production of fiber-based containers. The fiber-based products are adapted replace their plastic counterparts in a wide variety of applications such as, for example: frozen, refrigerated, and non-refrigerated foods; medical, pharmaceutical, and biological applications; microwavable food containers; beverages; comestible and non-comestible liquids; substances which liberate water, oil, and/or water vapor during storage, shipment, and preparation (e.g., cooking); horticultural applications including consumable and landscaping/gardening plants, flowers, herbs, shrubs, and trees; single-use or disposable storage and dispensing apparatuses (e.g., paint trays, food trays, brush handles, protective covers for shipping); produce (including human and animal foodstuffs such as fruits and vegetables); salads; prepared foods; packaging for meat, poultry, and fish; lids; cups; bottles; guides and separators for processing and displaying the foregoing; edge and corner pieces for packing, storing, and shipping electronics, mirrors, fine art, and other fragile components; buckets; tubes; industrial, automotive, marine, aerospace and military components such as gaskets, spacers, seals, cushions, and the like; and associated molds, wire mesh forms, recipes, processes, chemical formulae, tooling, slurry distribution, chemical monitoring, chemical infusion, and related systems, apparatus, methods, and techniques for manufacturing the foregoing components.
Embodiments of the fiber composition are created as slurries to be used in the manufacture of molded fiber products as described above. The following embodiments describe the compositions in the form of a fiber slurry feed and not in the form of the final fiber product, however, it is anticipated that the final fiber product (after forming, pressing, drying, etc.) will be very close to the same composition as that in the slurry, with the one major variation being the differences in water content between the slurry and the finished fiber product.
Embodiments of the fiber composition include a fiber base mixture of pulp and water, with added chemical components to impart desired performance characteristics tuned to each particular product application. The water may be tap water, distilled water, or filtered water from any suitable source. The base fiber may include any one or combination of at least the following materials: softwood (SW), hardwood (HW), bagasse, bamboo, old corrugated containers (OCC), and newsprint (NP). The base fibers may be bleached or unbleached.
Two common base fibers used in the industry are northern bleached softwood Kraft (NBSK) and northern bleached hardwood kraft (NBHK). NBSK is produced from softwood trees mainly found in Canada, the Nordic countries and Russia (specifically, Siberia). The most common species are pine and spruce. NBSK pulps typically have long fibers, and their inclusion in the paper furnish is often for structure. NBHK pulp is produced from hardwood trees and the classification ‘northern’ is used to designate the region from which the trees come (in this case Canada, Nordic regions and Russia). Species are primarily maple, birch, beech and ash. The primary use of NBHK is to provide sheen and quality in the production of printing and writing papers, as well as tissue.
In one embodiment, the base fiber composition is 100% a mixture of NBSK and NBHK (all percentages given in this document are by weight of the total amount of dry base fiber in the slurry). The mixture of NBSK and NBHK may be between 10% to 90% NBSK with the remainder NBHK. Alternatively, the mixture of NBSK and NBHK may be 25% to 80% NBSK, 35% to 75% NBSK, 45% to 70% NBSK, 55% to 70% NBSK, 60% to 70% NBSK or even 62.5% to 68% NBSK (all with the remainder NBHK). For example, in one embodiment created and tested, the fiber base is 66.5% NBSK and 33.5% NBHK. In another embodiment, the fiber base is 40-60% SW with balance being a mixture of HW and bamboo. In yet another embodiment, the fiber base is 20-70% SW with balance being one of HW, bamboo, OCC, or NP. All combinations of the above are contemplated as embodiments of the disclosed grease-resistant slurry composition.
In an alternative embodiment, the base fiber composition is one or more base fibers selected from any one or more of the fiber bases listed above. For example, in one embodiment the base fiber may be entirely bagasse.
In addition to the fiber base, the embodiments of the fiber composition include some amount of each of the following added components: a fiber substitute additive that is chemically compatible with the product being stored in contact with the final product; and sizing additive that improves the water resistance of the final product (sometimes also referred to as a “water sizing” component). Each of these will be discussed in turn below.
A compatible fiber substitute is a pulp fiber that is deemed compatible with the product to be contained in the packaging produced from the fiber. In an embodiment, apple pomace is a compatible fiber substitute for use in an apple container in that it is compatible with apples. Pomace is the pulp residue remaining after processing of fruit to extract its juice, e.g., by crushing, pressing. Pomace includes the processed residue of seeds, stems, skin and core material of the fruit in addition to at least some residue of the fruit juice itself as it is typically not possible to extract all the juice in a processing operation. Pomace may be added to the base fiber as a dried pulp, a wet pulp, or a rehydrated pulp (i.e., the pomace was dried and then rehydrated with water) or any combination of the preceding. In addition to apple pumace, the pumace of other fruits, such as peaches, oranges, bananas, grapes, strawberries, watermelons, pineapples, mangoes, kiwis, blueberries, pears, cherries, plums, lemons, grapefruits, raspberries, and avocados may be used for fruit containers and specifically for containers wherein the type of pumace used in the fiber slurry matches that of the fruit packaged in the container.
In an embodiment, the compatible fiber substitute for an apple container is an apple pomace. The apple pomace can be from 5% to 60% of the total base fiber by dry pulp with the remainder being the base pulp described above. Further embodiments can be from 10% to 40%, from 15% to 35%, from 17.5% to 30% and even from 20% to 25% apple pomace.
Without being bound to any particular theory, it is believed that the sugar content of the pomace acts as a natural water protector that reduces the amount of moisture absorbed by the final product. In addition, the pomace's chemical signature includes the chemical formula of the sugars. By being the same as that of the apples being held in the container, using apple pomace in apple packaging may reduce the amount of diffusion or osmosis of water and chemicals from the fruit to the container and vice versa.
It is believed that these effects from using compatible fiber substitutes are what allow the reduced the amount of water sizing component and the elimination of many other chemical additives used in traditional molded fiber (e.g., mold release additives, grease and oil sizing component, dry and wet strength sizing additives to name but a few typically used in molded fiber manufacture) while still creating a sufficiently strong and water resistant container suitable for use in commerce.
The water sizing component is added in the range of 0.01%-2% by weight of the total dry base fiber. Examples of suitable water sixing components include alkylketene dimer (AKD) (also known generically as AKD WAX and having CAS NO.: 84989-41-3) and/or long chain diketenes, available from FOB Chemical Co., Ltd., or Yanzhou Tiancheng Chemical Co., Ltd. Further examples include Hercon 79™ and Precis 3000™ sold by Hercules, Inc. Smaller ranges are also contemplated including ranges starting from 0.01%, from 0.025%, from 0.05%, from 0.075%, from 0.08%, from 0.085%, from 0.09%, from 0.091%, from 0.092%, or even from 0.093% 1 at the low end to 0.094%, 0.095%, 0.0975%, 0.1%, 0.15%, 0.2%, 0.3%, 0.4%, 0.5%, 0.75%, 1.0%, or even 2%, at the high end of the range. All range combinations of the preceding low and high ends of the range are contemplated. For example, in a particular embodiment a range of from 0.092% to 0.095% may be used. In another embodiment, a range of from 0.05% to 1.0% is used. In yet another embodiment, a range of from 0.075% to 1% is used. In yet another embodiment, a range of from 0.08% to 2% is used. In yet another embodiment, a range of from 0.093% to 1% is used.
The fiber composition above is mixed with a suitable amount of water, which can be tap water, filtered water, or distilled water, to obtain a fiber slurry. Additional adjustments to the slurry (or the water before mixing with the fiber composition) may be made before passing the slurry through a mold to deposit the fiber composition on the surface of the mold. These adjustments may include varying the temperature, pH, dissolved oxygen, total dissolved solids and metal content of the water and/or slurry. For example, in an embodiment, the pH of the fiber slurry may be maintained between 5.0 and 9.0 during the forming process using any know pH adjusting additive such as NaOH, NaHCO3, KOH, HCl, CO2, HNO3, NH4OH, or Ca(OH)2, to name but a few common pH adjusting additives. Other pH ranges may also be used such as between 5 and 6, between 6 and 9, between 7 and 8, between 6.5 and 7.5, between 8 and 9, and between 6 and 7. Likewise, the temperature of the slurry may also be maintained between 10 and 50 degrees C.
Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the technology are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
It will be clear that the systems and methods described herein are well adapted to attain the ends and advantages mentioned as well as those inherent therein. Those skilled in the art will recognize that the methods and systems within this specification may be implemented in many manners and as such are not to be limited by the foregoing exemplified embodiments and examples. In this regard, any number of the features of the different embodiments described herein may be combined into one single embodiment and alternate embodiments having fewer than or more than all of the features herein described are possible.
While various embodiments have been described for purposes of this disclosure, various changes and modifications may be made which are well within the scope contemplated by the present disclosure. Numerous other changes may be made which will readily suggest themselves to those skilled in the art and which are encompassed in the spirit of the disclosure.
This application claims the benefit of U.S. Provisional Application No. 63/513,971, filed Jul. 17, 2023, which application is hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63513971 | Jul 2023 | US |
