Protective member for a cut edge of a fiber-based molded article

Abstract

A fiber-based article having a raw edge with an applied barrier film portion selected to provide barrier properties to this specific area after cutting or trimming. The film portion or sleeve member is generally dimensioned and positioned adjacent with the cut edge in an initial perpendicular alignment and wrapped around the cut edge through an application of heat for securing on both a top edge and a bottom edge of the article to be protected.

Description

PROTECTIVE MEMBER FOR A CUT EDGE OF A FIBER-BASED MOLDEDARTICLETECHNICAL FIELD

[0001] This disclosure is related to a protective member in the form of a film or film portion to be applied to a cut edge of a fiber or fiber-based molded article. More particularly, this disclosure is related to a sleeve member having shrink properties to allow the sleeve member to conform to the cut edge of the fiber or fiber-based article to generally provide protection and barrier properties to this sensitive area after cutting and forming.BACKGROUND

[0002] It has become increasingly desirable to design packaging structures that are more sustainable. Increased sustainability may be in the form of using raw materials that are renewably resourced, such as paper or other fiberbased materials. One such sustainable packaging structure is a fiber or fiberbased molded article having a dimensional profile with a thickness that can generally encompass articles having a three-dimensional appearance. A majority of fiber-based articles are comprised of cellulose fibers. Cellulose fibers, when untreated, are generally hydrophilic as a result of polar hydroxyl groups present on the fiber surface that have an affinity for bonding with water molecules. This affinity for water is generally undesirable as moisture from the contents within the package or the environment can seep into or be absorbed by the package structure resulting in softening, failure, and overall package degradation. Therefore, packages using cellulose and other fiber-based materials that may be exposed to moisture are often constructed withadditional treatments, coatings, or modifications to the fiber to reduce this moisture affinity and impart additional characteristics to the fiber that is not inherent to its natural structure.

[0003] These fiber molded articles, such as placards, flat boards, trays, plates, bowls, or cups are often molded from a dry or wet fiber agglomeration via a dimensioned mold with heat and pressure to compress and bind the fibers into a final shape during manufacturing. Depending upon the end use of a given article, the article may be chemically modified prior to entry into or after molding and / or may have a film or films or a coating(s) added to a surface of the article prior to or after molding. One such process is the addition of an overwrap, or a thin vacuum and / or over-pressure applied skin film to form a barrier on an exterior surface(s) of the molded article. When applied and adhered to the fiber-based article, overwraps and liner or skin films, due to the elastic properties of certain polymers in these films and overwraps, may generate a compressive force upon the article that can be strong enough to deform or damage the article resulting in an unsightly package or one that does not meet quality specifications.

[0004] Still further, in some or all of these above-mentioned general processes, the final and dimensioned fiber-based article is often cut and trimmed to remove excess material along the article edges. These cut or trimmed edges are often particularly susceptible to moisture intrusion as the cutting and trimming process exposes raw fiber portions that accentuate the hydrophilic nature of the cellulose or other fiber. As these freshly cut or trimmed edges are particularly susceptible to moisture intrusion, it is common to utilize a finishing process in an attempt to lessen this intrusion. Thesecommon processes are typically mechanically based, wherein this cut or trimmed edge is often rolled or compressed in an attempt to protect this area. Although useful, these mechanical and surface treatments are problematic for certain container types and manufacturing process. Therefore, there is a need within the art for additional solutions to provide barrier properties to the exposed and sensitive edge area of a freshly cut or trimmed fiber-based molded article.SUMMARY

[0005] The developments described herein include the application of a film portion or a sleeve member to a cut edge of a dimensioned fiber or fiberbased article to provide barrier properties to this specific area after cutting or trimming. The film portion or sleeve member is generally dimensioned and positioned adjacent with the cut edge in an initial perpendicular alignment and wrapped around the cut edge for securing on both sides adjacent the cut edge of the article to be protected. Accordingly, this sleeve member or film portion may generally be referred to as a band that is capable of application onto the cut edge and secured in position through an increase in temperature to impart a dimensional shrinking to the band or film portion for adhering around the cut edge and without generating the compressive force associated with a traditional overwrap or liner film arranged over the entire article.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The disclosure may be more completely understood in consideration of the following detailed description of various embodiments of the disclosure in connection with the accompanying drawings, in which:

[0007] FIG. 1 is a cross-sectional view of a fiber article having a cut / trimmed edge with a protective member in positional alignment with the edge prior to application;

[0008] FIG. 2 is a cross-sectional view of the fiber article having a cut / trimmed edge with the protective member affixed to the edge in a preferred position;

[0009] FIG. 3 is a cross-sectional view of the fiber article having a cut / trimmed edge with the protective member affixed to the edge in a preferred position and covered with an additional protective film encompassing a portion of the surface of the article; and

[0010] FIG. 4 is a cross-sectional view of the fiber article of FIG. 3 including an exploded portion identified as Section “A” with the article having a cut / trimmed edge with the protective member affixed to the edge in a preferred position and covered with an additional protective film encompassing a portion of the surface of the article.

[0011] The drawings show some but not all embodiments. The elements depicted in the drawings are illustrative and not necessarily to scale, and the same (or similar) reference numbers denote the same (or similar) features throughout the drawings.DETAILED DESCRIPTION

[0012] The following detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments, which are also referred to herein as “examples,” are described in enough detail to enable those skilled in the art to practice the invention. The embodiments may be combined, otherembodiments may be utilized, or structural, and logical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. Before the present invention is described in such detail, however, it is to be understood that this invention is not limited to particular variations set forth and may, of course, vary.

[0013] Various changes may be made to the invention described and equivalents may be substituted without departing from the true spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process act(s) or step(s), to the objective(s), spirit or scope of the present invention. All such modifications are intended to be within the scope of the disclosure made herein.

[0014] Unless otherwise indicated, the words and phrases presented in this document have their ordinary meanings to one of skill in the art. Such ordinary meanings can be obtained by reference to their use in the art and by reference to general and scientific dictionaries.

[0015] References in the specification to “one embodiment” indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment.

[0016] Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, orcharacteristic in connection with other embodiments whether or not explicitly described.

[0017] The following explanations of certain terms are meant to be illustrative rather than exhaustive. These terms have their ordinary meanings given by usage in the art and in addition include the following explanations.

[0018] As used herein, the term “and / or” refers to any one of the items, any combination of the items, or all of the items with which this term is associated.

[0019] As used herein, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise.

[0020] As used herein, the terms “include,” “for example,” “such as,” and the like are used illustratively and are not intended to limit the present invention.

[0021] As used herein, the terms “preferred” and “preferably” refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances.

[0022] Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the invention.

[0023] As used herein, the term “coupled” means the joining of two members directly or indirectly to one another. Such joining may be stationary in nature or movable in nature and / or such joining may allow for the flow of fluids, gasses, vapors, or communication between two members. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body withone another or with the two members or the two members and any additional intermediate members being attached to one another.

[0024] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the teachings of the disclosure.

[0025] There is a need for more sustainable fiber and / or fiber-based dimensioned articles for use in packaging containers such as, but not limited to, placards, flat boards, trays, plates, bowls, clamshell-style containers, and cups. When formed in traditional fiber manufacturing processes these containers are often molded and dimensioned to a final size through trimming or cutting. Due to this cutting and trimming process, an edge is created that is particularly susceptible to the ingress of moisture into the container. Often this trimmed or cut edge is called a “raw” edge as the cutting and trimming exposes a raw portion of the fiber, such as a portion of a cellulose fiber. The solutions presented here provide for a protective material and method of application to the raw edge of a fiber-based container or article for preventing the ingress of moisture and degradation of the structure. The solution is particularly desirable for packages utilizing additional treatments or film structures, as the protective material may be provided in a position and assembly which can be hidden or sandwiched within and between these additional treatments or film structures. The positional assembly of the protective material in combination with the additional treatments or filmstructures may allow for easy removal of the protective material and film structures to advance recycling, such as, but not limited to, repulping or composting of the fiber or fiber-based component.

[0026] Referring now to FIGS. 1 -4, several cross-sectional views of a fiberbased container in the form of a tray 100 and method of manufacture are shown. The tray 100 is a fiber-based container having a first surface 101, a second surface 102, a distance between the first surface 101 and the second surface 102 defining a thickness 103, and an edge 104 positioned along an outermost side of the tray 100 and encompassing the first surface 101 , the second surface 102, and the thickness 103. As used herein, the term fiber or fiber-based may include, but not be limited to, cellulose and / or cellulose- based fibers including virgin cellulose-based fibers, recycled fibers including materials like paper fibers and craft papers, textiles, non-wovens, wood-based fibers, cotton, linen, hemp, sugar cane or sorghum commonly known as bagasse fibers, or grains. These fibers may be untreated and / or treated to provide enhancements or improvements to their inherent properties. These fibers may be provided in a plurality of dimensions / lengths including micro and nano fibrillated types, such as, but not limited to, microfibrillated and / or nanofibrillated cellulose. Further, these fibers for a fiber-based article may contain fluff pulp and / or another fiber type and may be provided in a roll, bale, blank or sheet form, continuous web, and / or may be formed from an airlaid process, and / or may be provided in a slurry for forming in a wet molding process. Further, the use of fiber or fiber-based materials may provide a multitude of end of use options for the tray 100, wherein the tray 100 may berecycled, compostable, biodegradable, repulpable, or be considered responsibly disposable.

[0027] The first surface 101 may be an innermost surface of the tray 100, wherein it may be an interior surface of a package should the tray 100 be sealed with a lidding. The second surface 102 is opposed the first surface 101 and generally corresponds to an outermost and exterior side of the tray 100. The distance between the first surface 101 and the second surface 102 defines the thickness 103 of the tray 100, wherein this thickness 103 generally corresponds to the bulk or amount of the fiber and / or fiber-based material, often called the basis weight. The basis weight of the embodiments of the tray 100 and method of manufacture can vary widely based upon need and be provided in a range of about 250 to 1500 grams per square meter (gsm). Accordingly, when the tray 100 is comprised of a single fiber-based material or blank, the thickness 103 generally corresponds to the bulk of the fiberbased composition of the tray 100 with the bulk and amount of fiber adjusted to conform to a given use of the tray 100. Alternately, the tray 100 may be provided in a layered assembly, wherein the first surface 101 , second surface 102, and / or the thickness 103 comprise multiple fiber-based layers in an assembly.

[0028] In a general process of manufacture, the tray 100 is formed via a dimensioned mold receiving a fiber-based blank, or a continuous fiber-based web, or a carrier of a fiber-based material to be molded. Upon entry into the mold, this fiber-based material is often subjected to pressure and / or heat and pressure, and / or heat, pressure, and steam, and / or another known molding process and step is utilized to generally compress and form the fibers or fiber-based materials into the dimensioned article of the tray 100. After forming in the mold, the tray 100 is then often subjected to cutting or trimming, within the mold or outside of the mold, to form the final dimensioned article including the edge 104. As this edge 104 is generally not in contact with a typical mold surface and thus compressed or formed, the edge 104 is generally considered raw, wherein a portion of the fibers forming this edge 104 are particularly susceptible to the ingress of moisture.

[0029] To prevent the edge 104 from moisture intrusion, the tray 100 is further processed with the application of a film 200 in alignment with the edge 104. Accordingly, a method of manufacture for the tray 100 is utilized to apply the film 200 and secure it in position only along this recently cut and / or trimmed edge 104. In a first step, (FIG. 1) the film portion 200 is positioned adjacent to the cut edge 104 with the film portion 200 being in an initial perpendicular alignment relative to the edge 104 and the thickness 103. Accordingly, the film portion 200 is provided in a dimensional configuration having a width 201 that is at least as large as the thickness 103, and preferably slightly larger than the thickness 103 so as to encompass at least the entire edge 104 and a portion of the first surface 101 and the second surface 102. Due to its relatively small dimensions the film portion 200 may be referred to as a band or a sleeve.

[0030] The film portion 200 is selected to shrink or have its dimensions reduced upon an application of heat, wherein the film portion 200, upon this application of heat, will reduce in size and conform to the edge 104 providing a protective barrier (FIG. 2). The film portion 200 is comprised of a polymer- based film specifically selected to shrink and have moisture barrier capabilities, wherein this film is preferably polyolefin based. The film portion200 may comprise polyethylene (PE), low-density polyethylene (LDPE), polypropylene (PP), ethylene vinyl acetate copolymer (EVA), or other combinations thereof. The polymers of the film portion 200 may be based off of or utilize recycled materials for all or part of the composition of the film portion 200. The film portion 200 may be comprised of a single layer and / or multiple layers or may be comprised of a laminate of multiple films. Alternate to polyolefin-based films, the film portion may be of a polyvinyl chloride (PVC) type.

[0031] Upon application of heat to the film portion 200, due to the chemical composition and process conditions used to form the film portion 200, the film portion 200 will preferably wrap around the edge 104 and be mechanically secured, through a compressive force of the film portion 200, upon both the first surface 101 and the second surface 102 of the tray 100 concealing the raw edge 104. The method of manufacture of the tray 100 may include the use of a heat tunnel or other similar heat source that may direct heated air at a desired temperature towards the positioned film portion 200 for activating the shrink properties. The desired temperature for the heated air source is one that is capable of inducing shrink in the film portion 200 but not capable of harming or damaging the integrity of the tray portion 100.

[0032] In certain trays 100 provided for certain uses, upon application of the film portion 200, the tray 100 manufacturing process may be considered complete. In uses requiring additional properties to the first surface 101 and / or the second surface 102, an additional film 300 is applied to the tray 100. As is shown in FIGS. 3-4 (Section “A”), this additional film 300 may be applied directly over the film portion 200. The additional film 300 may be any type ofbarrier film, such as, but not limited to a vacuum skin film. Alternate to the application of the additional film 300, the tray 100 at this step may be treated or coated to improve its material properties.

[0033] In alternate methods of manufacture for the tray 100, the cutting and trimming step and / or the application of the film portion 200 to the edge 104 may occur prior to molding the dimensioned article. Accordingly, in a first alternate method of manufacture, the tray 100 may be cut and / or trimmed to a final dimensioned shape revealing the raw edge portion 104, the film portion 200 placed in alignment with the edge portion 104 and secured to the tray 100, the optional additional film 300 is added with this assembly and then placed into a mold and formed to a final shape. In a second alternate method, the tray 100 may be cut and / or trimmed to a final dimensioned shape revealing the raw edge portion 104, the film portion 200 placed in alignment with the edge portion 104 and secured to the tray 100, the assembly of the dimensioned shape with the film portion 200 is placed into a mold and formed to a final shape, and then the optional and additional film 300 is added to molded article to form a final shaped and protected fiber-based article.

[0034] In further embodiments, the tray 100 may comprise a single layer or multiple layers, such as an inner layer, a middle layer, and an outer layer. Accordingly, the first surface 101 may be the inner layer, the second surface 102 may be the outer layer, with the bulk of the tray 100 between the first surface 101 and the second surface 102 being the middle layer. In this alternate tray 100 configuration, the middle layer may be molded and cut with the film portion 200 secured upon the middle layer and application of the inner layer and outer layer applied after the film portion 200.

[0035] In further embodiments, the tray 100 and method of manufacture may utilize an adhesive to aid in the compressive forces of the film portion 200 and / or secure multiple layers, such as the inner, middle, and outer layers of a multi-layer tray 100. In these embodiments of the tray 100, the tray 100 may have one or more adhesive layers that are made of a compostable adhesive applied by an adhesive lamination process. Commercially available compostable adhesives may be solvent-based, solvent-free or water-based. Commercially available adhesives may have base reactive chemistry of isocyanate.

[0036] As used herein, the term “compostable” refers to materials such as polymers, layers, films or packages that are able to disintegrate and biodegrade at industrial and home composting conditions (12 weeks at 58°C or 26 weeks at 21°C, respectively) and fulfill industrial compostable standards such as EN 13432-2000, ASTM D6400 “Standard Specification for Labeling of Plastics Designed to be Aerobically Composted in Municipal or Industrial Facilities” or ASTM D6868 “Standard Specification for Labeling of End Items that Incorporate Plastics and Polymers as Coatings or Additives with Paper and Other Substrates Designed to be Aerobically Composted in Municipal or Industrial Facilities”, and home compostable standards such as AS-5810- 2010 NF T51800, among others.

[0037] In some embodiments, each of the layers of the tray 100 and film portion 200 are strongly bonded to each other. In other embodiments, the tray 100 and film portion 200 are loosely boded to each other, wherein the film portion 200 and additional film 300, if utilized, may be easily separated from the tray 100 for disposal.

[0038] The term “film” or “film portion", as used herein, refers to a web built of layers and / or films, all of which are directly adjacent to and connected to each other. A film can be described as having a thickness that is insignificant as compared to the length and width of the film. Films are generally regarded as having two major surfaces, opposite each other, expanding in the length and width directions. As used herein, a “laminate” is a film that may be built from an unlimited number of films and / or layers, the films and / or layers being bonded together by any known process such as, but not limited to, coextrusion, coating or laminating, to form a composite article.

[0039] The term “package” is used herein to describe an article that may house an object (i.e. , a product), the article formed by shaping or molding a fiber-based agglomeration into a defined shape to form a package interior space. A “packaged product” refers to the one or more packaging components forming a hermetically sealed package and the product therein. As used herein, hermeticity refers to a seal or sealed package that is completely closed and essentially airtight. Hermetically sealed packages generally have a need for storage and package integrity over a period that is greater than a few days. Package integrity includes a consistent appearance, maintenance of barrier properties, maintenance of lamination bonds, and maintenance of seals.

[0040] The product may be any type of food, beverage, pharmaceutical or other medical aid, nutraceutical, consumer good or industrial good. The product may be fluid in nature. Examples of products include, but are not limited to, condiments such as ketchup, mustard, mayonnaise, or relish, pudding, yogurt, cheese sauce, nut butter, jam / jelly, dairy or non-dairycreamer, guacamole, applesauce, pureed baby food, baby formula, nutritional drinks / shakes, beverage or supplement concentrates, cough syrup, fish oil, lotion, salve / ointment, personal care items, soap / detergent, or solvent.

[0041] As mentioned, the product may be fluid in nature, or may have a fluid component. The product may be water-based (i.e., has water as a medium or main ingredient) or oil-based (i.e., has oil as a medium or main ingredient). The fiber-based article described herein may be particularly useful in containing an acidic product for a significant shelf-life (days, weeks or months) with minimal loss of barrier. The product may have a pH below 7, below 6, below 5, below 4 or even below 3.

[0042] The packaged products disclosed herein include a package formed from at least one fiber-based material in an amount of about 80% or greater than 80% by weight and optionally other components. In some embodiments of the packaged product, the entire tray 100 with the exception of the film portions 200, 300 is formed from a single fiber-based material. In some embodiments of the packaged product, a film is sealed to the tray 100. In some embodiments of the packaged product, a film is a lidding component which is sealed to a formed container such as a cup or tray. Packages that include components that are not according to the articles disclosed herein may also be compostable, such that the entire package is compostable. In some embodiments, the package includes components that are not compostable but can be separated from the portions that are compostable for proper disposal.

[0043] The packaged products disclosed herein advantageously include a compostable package which may allow the product to have a shelf-life of up toone week, up to two weeks, up to one month, up to two months, up to three months, up to 4 months, up to 5 months, up to 6 months, up to 7 months, up to 8 months, up to 9 months, up to 10 months, up to 11 months or up to 12 months. The shelf-life is dependent upon one or more variables including: the product packaged, the storage conditions of the packaged product and the barrier of the packaging components. As used herein, the shelf-life of a packaged product is the time period in which the product maintains quality (i.e., taste and appearance) acceptable for consumer use. The shelf-life may be determined due to degradation of product color, taste or suitability for consumption (i.e., microbial growth).

[0044] In some embodiments, the packaged product is refrigerated during storage and distribution (i.e., during the packaged product shelf-life). In other embodiments, the packaged product may be stored at non-refrigerated or room temperature conditions. It has been found that refrigerated storage of the packaged product may assist in prolonging the time frame in which the fiber-based article can maintain high barrier, thus lengthening the shelf-life of the packaged product. In yet other embodiments, the packaged product may be directly heated within the package, wherein the construction of the package is designed to withstand temperatures utilized for the heating of food products within standard appliances.

[0045] The fiber-based articles disclosed herein are particularly useful for packaged product formats and / or product types which result in significant product residue remaining in the package after consumer use. The packaged product may be of a style or configuration that inhibits / prohibits complete removal of the product. The packaged product may be of a style orconfiguration that inhibits / prohibits cleaning the package after use. The product packaged may be one that tends to cling or adhere to the package. In these cases, the package should not be recycled because the product residue contaminates the recycling process. In these cases, composting is an excellent solution as the product residue may promote the decomposition process. In other cases, the package may be constructed in a layered assembly that allows for removal of the food / product contact area prior to disposal.

Claims

What is claimed is:1 . A packaging article comprising: a compressed fiber-based article having a defined dimensioned shape with a raw edge formed by cutting or trimming; and a film portion secured over the raw edge, wherein the film portion is secured over the raw edge by shrinking upon an application of heat.

2. The packaging article according to claim 1 , wherein the article contains at least 80% fiber by weight.

3. The packaging article according to claim 1 , wherein the article contains at least 90% fiber by weight.

4. The packaging article according to claim 1 , wherein the film portion is a multi-layer film.

5. The packaging article according to claim 1 , wherein the dimensioned shape includes a first surface adjacent and perpendicular to the raw edge, a second surface adjacent and perpendicular to the raw edge, and wherein the film portion is secured over the raw edge and upon the first surface and the second surface.

6. The packaging article according to claim 1 , wherein the dimensioned shape includes a first surface adjacent and perpendicular to the raw edge, a second surface adjacent and perpendicular to the raw edge, wherein the film portion is secured over the raw edge and upon the first surface and the second surface, and wherein an additional film is secured upon at least the first surface and over the film portion.

7. The packaging article according to claim 1 , wherein the packaging article is specifically designed for use as a packaging article for food and wherein the packaging article includes surfaces that are considered safe and approved for use with foods.

8. A method for making a packaging article comprising the steps of: introducing a fiber-based agglomeration into a mold; using the mold to compress the fiber-based agglomeration into a defined and dimensioned shape in the form of a fiber-based article; trimming / cutting the fiber-based article to a final shape having a raw edge; applying a film portion to only the raw edge; applying heat to the film portion to shrink the film portion around the raw edge, wherein the film portion provides a moisture barrier to the raw edge.

9. The method of claim 8, wherein a final step comprises adding an additional film over the film portion to an entire surface of the fiber-based article.

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