Sterilizable package

Abstract

A sterilizable package is disclosed. The sterilizable package includes a formed container and a lid. The formed container includes polypropylene and at least one cavity. The lid includes an exterior film, a barrier layer, and a sealant layer. The sealant layer includes one or more of a polypropylene homopolymer and a polypropylene random copolymer in a range of from 59% to 63%, by weight. The sealant layer further includes one or more of a low density polyethylene and a linear low density polyethylene in a range of from 21% to 32%, by weight. The sealant layer further includes an inorganic filler in a range of from 5% to 20%, by weight. The sterilizable package further includes a seal attaching the sealant layer of the lid to the formed container in a location surrounding the at least one cavity. The seal has been formed by a rim sealing process.

Description

[0001] Attorney Case No. 21396-WO

[0002] STERILIZABLE PACKAGE

[0003] TECHNICAL FIELD

[0004] The present application relates generally to a sterilizable package, and in particular to a sterilizable package that provides smooth and clean peeling of a lid from a container.

[0005] BACKGROUND

[0006] Sterilizable packages including a container and a lid sealed to the container are used in a variety of packaging applications which demand sterilization. For example, such packages may be used in food and medical sectors. Typically, the container of such packages includes a flange with a rim, and the lid is sealed to the rim by a rim sealing process. However, opening of conventional sterilizable packages, or more specifically, peeling of the lid from the container of the conventional sterilizable packages, may cause formation of fibers (also called “fiber lifting” or “skin formation”) as the lid is peeled off from the container. These fibers can potentially contaminate the packaged product and may be harmful to consumers.

[0007] SUMMARY

[0008] A sterilizable package has been developed. The sterilizable package includes a container and a lid. The lid includes a sealant layer including one or more of a polypropylene homopolymer and a polypropylene random copolymer in a range of from 59% to 63%, by weight. The sealant layer further includes one or more of a low density polyethylene and a linear low density polyethylene in a range of from 21% to 32%, by weight. The sealant layer further includes an inorganic filler in a range of from 5% to 20%, by weight. The sterilizable package further includes a seal attaching the sealant layer of the lid to the container.

[0009] The sterilizable package may provide a clean and smooth opening. That is, the lid may be cleanly peeled off from the container to open the sterilizable package. The inorganic filler in a range of from 5% to 20%, by weight of the sealant layer may improve the peelability of the lid from the container. The inorganic filler in sealant layer may reduce formation of fibers and skins during peeling of the lid from the container. Further, theAttorney Case No. 21396-WO

[0010] inorganic filler of the sealant layer may not detrimentally affect the peel performance of the lid. Further, the sterilizable package may be suitable for sterilization. The sterilizable package may be used for packaging a wide variety of products, including foodstuffs, beverages, cosmetics, lotions, pharmaceuticals, etc.

[0011] A first embodiment of the present disclosure is a sterilizable package. The sterilizable package includes a formed container. The formed container includes polypropylene and at least one cavity. The sterilizable package further includes a lid. The lid includes an exterior film. The lid further includes a barrier layer. The lid further includes a sealant layer. The sealant layer includes one or more of a polypropylene homopolymer and a polypropylene random copolymer in a range of from 59% to 63%, by weight. The sealant layer further includes one or more of a low density polyethylene and a linear low density polyethylene in a range of from 21% to 32%, by weight. The sealant layer further includes an inorganic filler in a range of from 5% to 20%, by weight. The sterilizable package further includes a seal attaching the sealant layer of the lid to the formed container in a location surrounding the at least one cavity. The seal has been formed by a rim sealing process.

[0012] The sterilizable package may provide a clean and smooth opening. That is, the lid may be cleanly peeled off from the formed container to open the sterilizable package and access products contained within the at least one cavity. Specifically, the inorganic filler in a range of from 5% to 20%, by weight of the sealant layer may improve the peelability of the lid from the formed container. The inorganic filler in the sealant layer may reduce formation of fibers and skins during peeling of the lid from the formed container. The inorganic filler of the sealant layer may enable the lid to be peeled off from the formed container without leaving undesired fibers in the location of the seal. Further, the inorganic filler of the sealant layer may not detrimentally affect the peel performance of the lid.

[0013] Moreover, the sterilizable package may be suitable for sterilization. The formed container and the lid having high polypropylene content may make the sterilizable package suitable for sterilization. The sterilizable package may be sterilized, for example, with moist heat in temperatures ranging from 110 °C to 120 °C and sterilization time ranging from 20 minutes to 40 minutes.Attorney Case No. 21396-WO

[0014] In some embodiments, the lid further includes a core layer between the barrier layer and the sealant layer. The core layer includes one or more of a polypropylene homopolymer, a heterophasic polypropylene copolymer, and a polypropylene random copolymer. The core layer may facilitate peel-by-fracture from the sealant layer of the lid.

[0015] In some embodiments, the inorganic filler includes calcium carbonate or talc. In some embodiments, the core layer and the sealant layer are comprised in a non¬ oriented film.

[0016] In some embodiments, the thickness of the sealant layer includes from about 10% to about 35% of the combined thickness of the core layer and the sealant layer.

[0017] In some embodiments, the exterior film includes one or more of a polyester, a polypropylene, and a polyamide.

[0018] In some embodiments, the barrier layer includes one or more of an aluminum foil, a vacuum deposited metal, or an inorganic oxide.

[0019] In some embodiments, upon peeling the lid from the formed container, a whitened and fiber free area is exposed in the location of the seal.

[0020] In some embodiments, the lid includes a peak peel strength of 10 N / 15 mm to 18 N / 15 mm and an average peel strength of 6 N / 15 mm to 12 N / 15 mm after sealing to a layer of polypropylene terpolymer (Ter-PP) comprised in an encapsulating flexible laminate of Ter-PP 40 microns / aluminum foil 20 microns / oriented polyethylene terephthalate 12 microns at a temperature of 200 °C, a pressure of 80 N / cm, and a dwell time of 0.5 seconds using a 0.5 cm wide top sealing bar according to ASTM F88 / F88M-23.

[0021] In some embodiments, the lid includes a dead-fold property.

[0022] In some embodiments, the lid including the dead-fold property includes one or more of an aluminum foil, a polymeric film, an adhesive, and a fiber-based material.

[0023] In some embodiments, the lid further includes a printed indicia located on the exposed surface of the exterior film or between the exterior film and the barrier layer.

[0024] In some embodiments, the formed container includes a raised profile sealing rim. In some embodiments, the sterilizable package further includes a liquid or a powder within the at least one cavity. For example, the sterilizable package may include liquid or powder containing products in the food, pharma, and medical sectors.Attorney Case No. 21396-WO

[0025] There are several aspects of the present subject matter which may be embodied separately or together. These aspects may be employed alone or in combination with other aspects of the subject matter described herein, and the description of these aspects together is not intended to preclude the use of these aspects separately or the claiming of such aspects separately or in different combinations.

[0026] BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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:

[0028] FIG. 1 illustrates perspective view of a sterilizable package with a lid partially peeled back in accordance with an embodiment of the present disclosure;

[0029] FIG. 2 illustrates a cross-sectional view of the lid of the sterilizable package in accordance with an embodiment of the present disclosure;

[0030] FIG. 3 illustrates a lid for the sterilizable package in accordance with another embodiment of the present disclosure;

[0031] FIG. 4 illustrates a graph depicting a variation of percentage of samples which exhibited fiber tear with respect to the percentage of CaCOs in sealant layer;

[0032] FIG. 5 illustrates a graph depicting a variation of an average peel force measured during peeling of the sealant film from the flexible laminate (Ter-PP) with respect to the percentage of CaCOs in the sealant layer; and

[0033] FIG. 6 illustrates a graph depicting a variation of a maximum peel force measured during peeling of the sealant film from the flexible laminate (Ter-PP) with respect to the percentage of CaCOs in the sealant layer.

[0034] The figures are not necessarily to scale. Like numbers used in the figures refer to like components. It will be understood, however, that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.Attorney Case No. 21396-WO

[0035] DETAILED DESCRIPTION

[0036] The present application describes a sterilizable package. The sterilizable package includes a formed container. The formed container includes polypropylene and at least one cavity. The sterilizable package further includes a lid. The lid includes an exterior film. The lid further includes a barrier layer. The lid further includes a sealant layer. The sealant layer includes one or more of a polypropylene homopolymer and a polypropylene random copolymer in a range of from 59% to 63%, by weight. The sealant layer further includes one or more of a low density polyethylene and a linear low density polyethylene in a range of from 21% to 32%, by weight. The sealant layer further includes an inorganic filler in a range of from 5% to 20%, by weight. The sterilizable package further includes a seal attaching the sealant layer of the lid to the formed container in a location surrounding the at least one cavity. The seal has been formed by a rim sealing process.

[0037] The sterilizable package may provide a clean and smooth opening. That is, the lid may be cleanly peeled off from the formed container to open the sterilizable package and access products contained within the at least one cavity. Specifically, the inorganic filler in a range of from 5% to 20%, by weight of the sealant layer may improve the peelability of the lid from the formed container. The inorganic filler in the sealant layer may reduce formation of fibers and skins during peeling of the lid from the formed container. The inorganic filler of the sealant layer may enable the lid to be peeled off from the formed container without leaving undesired fibers in the location of the seal. Further, the inorganic filler of the sealant layer may not detrimentally affect the peel performance of the lid.

[0038] Moreover, the sterilizable package may be suitable for sterilization. The formed container and the lid having high polypropylene content may make the sterilizable package suitable for sterilization. The sterilizable package may be sterilized, for example, with moist heat in temperatures ranging from 110 °C to 120 °C and sterilization time ranging from 20 minutes to 40 minutes.

[0039] As used herein, the term “film” refers to a material with a very high ratio of a length or a width to a thickness. A film has two major surfaces defined by a length and a width. Films typically have good flexibility and can be used for a wide variety of applications, including flexible packaging. Films may also have thickness and / or material compositionAttorney Case No. 21396-WO

[0040] such that they are flexible, semi-rigid, or rigid. Films may be described as monolayer or multilayer.

[0041] As used herein, the term “layer” refers to a thickness of material that may be homogeneous or heterogenous. Layers may be of any type of material including polymeric, cellulosic, and metallic, or a blend thereof. A layer may include a single polymer-type or a blend of polymers and may be accompanied by additives. A given layer may be combined or connected to other layers to form films. A layer may be either partially or fully continuous as compared to adjacent layers or the film. A given layer may be partially or fully coextensive with adjacent layers. A layer may contain sub-layers.

[0042] The term “about,” unless otherwise specifically defined, means to a high degree of approximation (e.g., within + / - 5% for quantifiable properties) but without requiring absolute precision or a perfect match.

[0043] As used herein, the terms “polyethylene” and “polyethylene polymer” refers to polymers that include an ethylene linkage. Polyethylenes may be homopolymers, copolymers, or interpolymers. Polyethylene copolymers or interpolymers may include other types of polymers (i.e., non-polyethylene polymers). Polyethylenes may have functional groups incorporated by grafting or other means. Polyethylenes include, but are not limited to, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), ultra-low density polyethylene (ULDPE), and high-density polyethylene (HDPE).

[0044] As used herein, the term “low-density polyethylene” or “LDPE” refers to branched homopolymers of ethylene having densities from about 0.915 g / cm3to about 0.935 g / cm3, as well as copolymers of ethylene containing polar groups resulting from copolymerization (such as with vinyl acetate or ethyl acrylate). LDPE also refers to copolymers produced by polymerizing ethylene in a high pressure autoclave or tubular reactor (typically at 100 Megapascals (MPa) to 300 MPa) and at high temperatures (typically between 100 °C and 300 °C), often without a catalyst.

[0045] As used herein, the term “linear low-density polyethylene” or “LLDPE” refers to specific polymers obtained by polymerizing ethylene, e.g., according to processes implemented for the preparation of LDPE, with the further presence of small amounts of a-olefins other than ethylene, e.g., butene, hexene, and / or octene, which induces aAttorney Case No. 21396-WO

[0046] substantially linear structure for the obtained polymer. LLDPE polymers generally have a density of between 0.90 and 0.94.

[0047] As used herein, the terms “polypropylene” and “polypropylene polymer” refer to polymers that are derived from monomers of propylene. Polypropylenes may be homopolymers, copolymers, or interpolymers. Polypropylene copolymers or interpolymers may include other types of polymers (i.e., non-polypropylene polymers). Propylene linkage can be represented by the general formula: [CH2 — CH(CH3)]n. Polypropylenes may have functional groups incorporated by grafting or other means. Polypropylenes include, but are not limited to, propylene-ethylene copolymers, ethylene¬ propylene copolymers, and maleic anhydride grafted polypropylenes (MAHgPP). As used herein, the term “polypropylene terpolymer” or “Ter-PP” refers to copolymers deriving from three different monomers. An example of Ter-PP is ethylene-butylene polypropylene copolymer.

[0048] As used herein, the term “polyester” refers to a homopolymer or copolymer having an ester linkage between monomer units which may be formed, for example, by condensation polymerization reactions between a dicarboxylic acid and a diol. The ester linkage can be represented by the general formula: [O — R — OC(O) — R — C(O)], where R and R' are the same or different alkyl (or aryl) group and may be generally formed from the polymerization of dicarboxylic acid and diol monomers containing both carboxylic acid and hydroxyl moieties.

[0049] As used herein, the term “polyamide” refers to a high molecular weight polymer having amide linkages ( — CONH — )nwhich occur along the molecular chain, and includes “nylon” resins which are well known polymers.

[0050] As used herein, the term “sealant layer” refers to a layer, or layers, involved in the sealing of a film: to itself; to another layer of the same film or another film; and / or to another article which is not a film. In general, the sealant layer is a surface layer, i.e., an exterior or an interior layer of any suitable thickness, that provides for the sealing of the film to itself or another layer.

[0051] As used herein, the term “barrier” refers to a material that controls permeability of one or more elements through a film structure including moisture, chemicals, heat, odorAttorney Case No. 21396-WO

[0052] and oxygen or other gases. A barrier material can be provided by a single film layer or multiple film layers acting individually or in concert with each other, respectively.

[0053] As used herein, the term "peel force" means a force to separate two layers. For example, this is the force necessary to separate two layers of one inch width by pulling the two layers apart. Sometimes, the peel force is referred to as the peel strength. The peel force on a sealed lid is used to separate and to release from sealed engagement of the sealed lid with a container body while both the lid and the body substantially retain their integrity. Such separation and release may be achieved by manually applying a separating force to an outer edge portion of the lid.

[0054] As used herein, the term “oriented,” refers to a film, sheet, web, etc. that has been elongated in at least one of the machine direction or the transverse direction. The term “non-oriented” refers to a film, sheet, web, etc. that has not been elongated in the machine direction or the transverse direction.

[0055] As used herein, the term "Melt index (Ml)" means is a measure of how easily a thermoplastic material can flow under a specified pressure and temperature. It is an indicator of the viscosity and molecular weight of the polymer. The term “Melt index (Ml)” may also be referred to as the Melt flow Index (MFI). The terms “Melt index (Ml)” and “Melt flow index (MFI)” are interchangeably used herein.

[0056] As used herein, the term “fiber-based” refers to a substrate paper or nonwoven, including any coatings or additives that may be part of the substrate.

[0057] As used herein, the term "dead fold property" refers to the ability of a lid to retain its shape permanently once it is folded or wrapped about a food item or container and not spring back to an unfolded state.

[0058] Referring now to the Figures, FIG. 1 illustrates a perspective view of a sterilizable package 10 in accordance with an embodiment of the present disclosure.

[0059] Sterilizable package 10 includes a formed container 50. Formed container 50 includes polypropylene. In other words, formed container 50 is a polypropylene-based container. In some embodiments, formed container 50 may include polypropylene in an amount of at least 70 percent, by weight.

[0060] Formed container 50 further includes at least one cavity 60 (hereinafter referred to as “cavity 60”). Cavity 60 may contain a product (not shown) that is packaged inAttorney Case No. 21396-WO

[0061] sterilizable package 10. In some embodiments, sterilizable package 10 includes a liquid or a powder within cavity 60. Examples of products that can be packaged in sterilizable package 10 include, but are not limited to, liquid or powder containing products in the food, pharma, and medical sectors, such as yoghurt, fruit bowl, compote, soups, sauces, pot noodles, milk, honey, mayonnaise and other condiments, saucy ready meals, liquid-borne contact lens, and the like.

[0062] Formed container 50 may further include a sidewall 51 that at least partially defines cavity 60. Formed container 50 may further include a flange 70. Flange 70 may extend from an upper edge of sidewall 51 in a direction generally away from cavity 60. Flange 70 may be used to connect packaging components (e.g., a lid) or some other packaging components to formed container 50. Flange 70 may include a surface 71 that faces opposite to sidewall 51.

[0063] Formed container 50 may further include a raised profile sealing rim 80 (hereinafter referred to as “sealing rim 80”). Sealing rim 80 may extend from surface 71 of flange 70. Sealing rim 80 may be raised or elevated with respect to surface 71. For example, sealing rim 80 may have a height of greater than 0.2 millimeters (mm), greater than 0.3 mm, or greater than 0.4 mm relative to surface 71. Sealing rim 80 may be positioned proximal to and surround cavity 60. The raised profile of sealing rim 80 may reduce contamination of a sealing area by one or more products contained in cavity 60 of formed container 50.

[0064] Flange 70 may also have arc-shaped corners. As used herein, the term “arcshaped” encompasses circular, elliptical, and other desired types of curvilinear shapes. Arc-shaped corners may provide a smooth edge to flange 70 and prevent injury to a user, for example, while handling formed container 50.

[0065] Formed container 50 may be formed using any suitable manufacturing process, such as thermoforming, vacuum forming, injection molding, compression molding, and rotomolding. In some examples, formed container 50 may have a unitary structure which is formed by thermoforming a single piece of a polypropylene sheet. Flange 70 and / or sealing rim 80 may be formed during manufacturing of formed container 50.

[0066] Sterilizable package 10 further includes a lid 100. Sterilizable package 10 further includes a seal 90. Lid 100 may be attached to formed container 50 in a location surrounding cavity 60 via seal 90. Lid 100 may be hermetically sealed to flange 70, orAttorney Case No. 21396-WO

[0067] more specifically, to sealing rim 80 of formed container 50 to seal products within formed container 50. Lid 100 may be peelable. That is, lid 100 may be peeled off from formed container 50, when required, to open sterilizable package 10 and access packaged products. Lid 100 may be configured to have a peel tab. Lid 100 is shown as partially peeled off from formed container 50 in FIG. 1.

[0068] It may be noted that lid 100 may have any suitable shape, such as rectangular, triangular, pentagonal, hexagonal, octagonal, polygonal, or square, according to shape of formed container 50, which may have different shape, dimensions, and volume capacities.

[0069] FIG. 2 illustrates a cross-sectional view of lid 100 in accordance with an embodiment of the present disclosure.

[0070] Referring to FIGS. 1 and 2, lid 100 includes an exterior film 110. Exterior film 110 may be exposed to external environment when lid 100 is attached to formed container 50. In some embodiments, exterior film 110 may include one or more of a polyester, a polypropylene, and a polyamide. In some embodiments, exterior film 110 may be single layered. In some other embodiments, exterior film 110 may be multilayered. Exterior film 110 may be oriented or non-oriented.

[0071] Lid 100 further includes a barrier layer 120. Barrier layer 120 may be configured to restrict passage of at least one of water vapor and gas therethrough. In some embodiments, barrier layer 120 includes one or more of an aluminum foil, a vacuum deposited metal, or an inorganic oxide. Aluminum foil may be preferred for some packaging applications, for example, contact lens packaging application.

[0072] Lid 100 further includes a sealant layer 150. Sealant layer 150 may be positioned opposite to exterior film 110. Sealant layer 150 may form an exposed surface of lid 100 that is used for sealing with formed container (shown in FIG. 1). Barrier layer 120 may be arranged between exterior film 110 and sealant layer 150.

[0073] Sealant layer 150 includes one or more of a polypropylene homopolymer and a polypropylene random copolymer in a range of from 59% to 63%, by weight. Sealant layer 150 further includes one or more of a low density polyethylene (LDPE) and a linear low density polyethylene (LLDPE) in a range of from 21% to 32%, by weight. In some embodiments, the LDPE in sealant layer 150 is a high-pressure LDPE.Attorney Case No. 21396-WO

[0074] Sealant layer 150 further includes an inorganic filler in a range of from 5% to 20%, by weight. The inorganic filler may be provided in a masterbatch including a premix of the inorganic filler, carrier polymers, and optionally, auxiliary compounds. The masterbatch may be designed to be compatible with sealant layer 150 (i.e., materials of sealant layer 150). The carrier polymers may preferably be polypropylene based. In some embodiments, the inorganic filler may include calcium carbonate (CaCOa) or talc.

[0075] Referring to FIGS. 1 and 2, as discussed above, sterilizable package 10 includes seal 90. Seal 90 attaches sealant layer 150 of lid 100 to formed container 50 in the location surrounding cavity 60. Seal 90 has been formed by a rim sealing process. For example, seal 90 may be formed by the rim sealing process at sealing rim 80.

[0076] Sterilizable package 10 may provide a clean and smooth opening. That is, lid 100 may be cleanly peeled off from formed container 50 to open sterilizable package 10 and access products contained within cavity 60. Specifically, the inorganic filler in a range of from 5% to 20%, by weight of sealant layer 150 may improve the peelability of lid 100 from formed container 50. The inorganic filler in sealant layer 150 may reduce formation of fibers and skins during peeling of lid 100 from formed container 50. In some embodiments, upon peeling lid 100 from formed container 50, a whitened and fiber free area may be exposed in the location of seal 90. The inorganic filler of sealant layer 150 may enable lid 100 to be peeled off from formed container 50 without leaving undesired fibers in the location of seal 90.

[0077] Further, the inorganic filler of sealant layer 150 may not detrimentally affect the peel performance of lid 100. In some embodiments, lid 100 may include a peak peel strength of from 10 N / 15 mm to 18 N / 15 mm and an average peel strength of from 6 N / 15 mm to 12 N / 15 mm after sealing to a layer of polypropylene terpolymer (Ter-PP) comprised in an encapsulating flexible laminate of Ter-PP 40 microns / aluminum foil 20 microns / oriented polyethylene terephthalate 12 microns at a temperature of 200 °C, a pressure of 80 N / cm, and a dwell time of 0.5 seconds using a 0.5 cm wide top sealing bar according to ASTM F88 / F88M-23.

[0078] Moreover, sterilizable package 10 may be suitable for sterilization. Formed container 50 and lid 100 having high polypropylene content may make sterilizable package 10 suitable for sterilization. In sterilization with moist heat, temperaturesAttorney Case No. 21396-WO

[0079] generally range from 110 °C to 120 °C with sterilization time ranging from 20 minutes to 40 minutes. A lower temperature or reduced time may be applied for packaged contents having acidic contents. As examples of sterilization conditions for contact lens packaging application, sterilizable package 10 may be heat treated at 124 °C for 18 minutes or at 121 °C for 30 minutes.

[0080] Lid 100 may further include a core layer 140 between barrier layer 120 and sealant layer 150. Core layer 140 may be directly connected to sealant layer 150. Core layer 140 may include one or more of a polypropylene homopolymer, a heterophasic polypropylene copolymer, and a polypropylene random copolymer. Core layer 140 may facilitate peel-by-fracture from sealant layer 150. In some examples, the peel-by-facture may occur cohesively (i.e., within core layer 140). In some embodiments, peeling lid 100 from formed container 50 may cause core layer 140 to separate from sealant layer 150.

[0081] In some embodiments, core layer 140 and sealant layer 150 may be included in a non-oriented film. The non-oriented film including core layer 140 and sealant layer 150 may be referred to herein as “sealant film.” The sealant film may be a cast film of ‘polypropylene / polypropylene / sealant layer.’

[0082] In some embodiments, the thickness of sealant layer 150 includes from about 10% to about 35% of the combined thickness of core layer 140 and sealant layer 150. In other words, the thickness of sealant layer 150 may be from about 10% to about 35% of the thickness of the non-oriented film (or the sealant film).

[0083] In the illustrated embodiment of FIG. 2, lid 100 further includes an adhesive layer 130 positioned between core layer 140 and barrier layer 120. Adhesive layer 130 may laminate core layer 140 to barrier layer 120 (i.e., adhesive lamination). In some embodiments, adhesive layer 130 may laminate the sealant film to barrier layer 120. However, other suitable lamination techniques may be alternatively employed.

[0084] In some embodiments, lid 100 includes a dead-fold property. In some embodiments, lid 100 including the dead-fold property includes one or more of an aluminum foil, a polymeric film, an adhesive, and a fiber-based material. The fiber-based material may be arranged in exterior film 110 or in an optional additional film (not shown) of lid 100.Attorney Case No. 21396-WO

[0085] FIG. 3 illustrates a lid 200 for the sterilizable package 10 in accordance with another embodiment of the present disclosure. Lid 200 is similar to lid 100 of FIG. 1 , with like elements designated by like reference characters. However, lid 200 includes additional layers as compared to lid 100.

[0086] In the illustrated embodiment of FIG. 3, lid 200 includes exterior film 110, barrier layer 120, adhesive layer 130, core layer 140, and sealant layer 150. Lid 200 further includes printed indicia 210. Printed indicia 210 may be located on the exposed surface of exterior film 110 or between exterior film 110 and barrier layer 120. In the illustrated embodiment of FIG. 3, printed indicia 210 is positioned between exterior film 110 and barrier layer 120. Alternatively, printed indicia 210 may be located on the exposed surface of exterior film 110. Printed indicia 210 may be of any suitable type or pattern or ink composition. Any suitable printing technique can be used to form printed indicia 210, such as rotary screen, gravure, or flexographic techniques.

[0087] Printed indicia 210 can be decorative or informational in nature and can be in the form of registration marks or a message. Printed indicia 210 may be used to display registration mark of a manufacturer or any informational message for a consumer of sterilizable package 10 (shown in FIG. 1).

[0088] In the illustrated embodiment of FIG. 3, lid 200 further includes an adhesive layer 220 positioned between exterior film 110 and barrier layer 120. Adhesive layer 220 may laminate exterior film 110 to barrier layer 120 (i.e., adhesive lamination). However, other suitable lamination techniques may be alternatively employed.

[0089] Other examples of lid structures include the following.

[0090] Extrusion coated exterior film / barrier layer (foil) / adhesive layer / sealant film.

[0091] Extrusion coated exterior film / barrier layer (foil) / extrusion coated sealant film. Exterior film with a deposited barrier layer / adhesive layer / sealant film.

[0092] Exterior film / adhesive layer / barrier layer (foil) / extrusion coated sealant film.

[0093] Examples

[0094] The following illustrative examples are merely meant to exemplify the present disclosure and are not intended to limit or otherwise define the scope of the present disclosure.Attorney Case No. 21396-WO

[0095] For the comparative example, a conventional polypropylene-based sealant film was selected. The reference example included a core layer (including core layer 1 and core layer 2) and a sealant layer. Core layer 1 had a thickness of 3 microns and included polypropylene (PP), and core layer 2 had a thickness of 15 microns and included PP. The sealant layer had a thickness of 7 microns and included PP and low density polyethylene (LDPE). The sealant layer was devoid of CaCOa.

[0096] Example 1 was produced with a core layer having a similar structure as the reference example. However, the sealant layer of Example 1 included 5% CaCOa, by weight. The sealant layer of Example 1 included 10% of a filler masterbatch (MB), by weight. The filler MB contained 50% CaCOa and 50% polypropylene PP. The sealant layer included 63% PP in total.

[0097] Example 2 was produced with a core layer having a similar structure as the reference example. However, the sealant layer of Example 2 included 20% CaCOa, by weight. The sealant layer of Example 2 included 40% of the filler MB, by weight. The sealant layer included 59% PP in total.

[0098] Table 1 provided below summarizes the composition details of the aforementioned Examples.

[0099] Table 1 : Details of Examples

[0100]

[0101] Examples shown in Table 1 were produced on a coextrusion line equipped with a three-layer feedblock system, which included three extruders, namely, extruder A, extruder B, and extruder C. The dimensions of extruder A were 2*30 mm, of extruder BAttorney Case No. 21396-WO

[0102] were 1*25 mm, and of extruder C were 2*30 mm. The feedblock was connected with a 350 mm cast die. Both feedblock and die temperatures were set at 230 °C. Core layer 1 (having 3 microns thickness) was produced with extruder C in contact with a chill-roll. Core layer 2 (C-extruder) had a 15 microns gauge. The sealant layer (having 7 microns thickness) in the C-extruder was at the air-knife side.

[0103] Experimental Results

[0104] For testing, the above-described sealant films of Comparative Example and Examples 1 and 2 were used. That is, the test sealant films were neat sealant films without an exterior film and a barrier layer of a lid (as described with reference to FIGS.

[0105] 2 and 3). Each sealant film was covered on both surfaces by a laminate of OPET / aluminum / Ter-PP, orienting OPET towards the heated sealing bars. The Ter-PP used for conducting the tests was an ethylene-butylene polypropylene copolymer having a melting point of 130 °C. The sealant film was sandwiched during sealing between the top and bottom OPET / aluminum / Ter-PP laminate to avoid deformation of the 25 microns thin sealant film during opening. The sealing was performed with a Brugger HSG-CC sealer having 2 heated jaws at 200 °C, with a pressure of 80 N / cm and a dwell-time of 0.5 seconds. It may be noted that the sealing and peel opening were tested towards a flexible laminate (containing Ter-PP) instead of a formed PP-based container.

[0106] The appearance of fibers (fiber tear) was evaluated by manual opening of the seal perpendicular to the direction of the seal. 14 samples of each Example were evaluated. The fiber score (less is better) is expressed as a percentage of opened samples 14 samples that exhibited tear / stringing visible as polymeric fibers. Zero to one sample out of 14 were considered acceptable. The maximum (or initial) peel force (Fmax) and the average peel force (Favg) were also recorded during manual opening of the seal. The test results were collated and tabulated in table 2 provided below.

[0107] Table 2: Test results

[0108]

[0109] Attorney Case No. 21396-WO

[0110]

[0111] As depicted by Table 1 , Examples 1 and 2 provided a sealing performance similar to that of the Comparative Example. Further, Examples 1 and 2 showcased a reduction in fiber tears (and fiber score). Example 2 had a fiber score of 0, i.e., no sample out of the 14 tested samples of Example 2 exhibited tear / stringing visible as polymeric fibers.

[0112] Various additional sealant films with different percentages of CaCOs in the sealant layer were produced. The aforementioned tests were further conducted on the additional sealant films.

[0113] FIG. 4 illustrates a graph 300 depicting a variation of percentage of samples which exhibited fiber tear with respect to the percentage of CaCOs in the sealant layer.

[0114] Graph 300 demonstrates a reduction in the percentage of samples of the sealant films that exhibited fiber tear with the increase in the percentage of CaCOs in the sealant layer. It was concluded that the addition of CaCOs reduced the formation of such fibers upon peeling.

[0115] FIG. 5 illustrates a graph 400 depicting a variation of an average peel force measured during peeling of the sealant film from the flexible laminate (Ter-PP) with respect to the percentage of CaCOs in the sealant layer. FIG. 6 illustrates a graph 500 depicting a variation of a maximum peel force measured during peeling of the sealant film from the flexible laminate (Ter-PP) with respect to the percentage of CaCOs in the sealant layer. Graphs 400, 500 demonstrate that the increase in the percentage of CaCOs in the sealant layer did not detrimentally affect the seal performance of the sealant film.

[0116] Each and every document cited in this present application, including any cross referenced, is incorporated in this present application in its entirety by this reference, unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any embodiment disclosed in this present application or that it alone, or in any combination with any other reference or references, teaches, suggests, or discloses any such embodiment. Further, to the extent that any meaning or definition of a term in this present application conflicts with any meaning orAttorney Case No. 21396-WO

[0117] definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this present application governs.

[0118] Unless otherwise indicated, all numbers expressing sizes, amounts, ranges, limits, and physical and other properties used in the present application are to be understood as being preceded in all instances of the term “about.” Accordingly, unless expressly indicated to the contrary, the numerical parameters set forth in the present application are approximations that can vary depending on the desired properties sought to be obtained by a person of ordinary skill in the art without undue experimentation using the teachings disclosed in the present application.

[0119] As used in the present application, the singular forms “a,” “an,” and “the” encompass embodiments having plural referents, unless the context clearly dictates otherwise. As used in the present application, the term “or” is generally employed in its sense including “and / or”, “unless” the context clearly dictates otherwise.

[0120] Spatially related terms, including, but not limited to, “lower,” “upper,” “beneath,” “below,” “above,” “bottom,” and “top,” if used in the present application, are used for ease of description to describe spatial relationships of an element(s) to another. Such spatially related terms encompass different orientations of the device in use or operation, in addition to the particular orientations depicted in the figures and described in the present application. For example, if an object depicted in the drawings is turned over or flipped over, elements previously described as below, or beneath other elements would then be above those other elements.

[0121] 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.

[0122] The description, examples, embodiments, and drawings disclosed are illustrative only and should not be interpreted as limiting. The present invention includes the description, examples, embodiments, and drawings disclosed; but it is not limited to such description, examples, embodiments, or drawings. As briefly described above, the reader should assume that features of one disclosed embodiment can also be applied to all other disclosed embodiments, unless expressly indicated to the contrary. Modifications and other embodiments will be apparent to a person of ordinary skill in the packaging arts,Attorney Case No. 21396-WO

[0123] and all such modifications and other embodiments are intended and deemed to be within the scope of the present invention.

Claims

Attorney Case No. 21396-WOCLAIMSWhat is claimed is:

1. A sterilizable package comprising:a formed container comprising polypropylene and at least one cavity;a lid comprising:an exterior film;a barrier layer; anda sealant layer comprising i) one or more of a polypropylene homopolymer and a polypropylene random copolymer in a range of from 59% to 63%, by weight, ii) one or more of a low density polyethylene and a linear low density polyethylene in a range of from 21% to 32%, by weight, and iii) an inorganic filler in a range of from 5% to 20%, by weight; anda seal attaching the sealant layer of the lid to the formed container in a location surrounding the at least one cavity;wherein the seal has been formed by a rim sealing process.

2. The sterilizable package of claim 1 , wherein the lid further comprises a core layer between the barrier layer and the sealant layer, wherein the core layer comprises one or more of a polypropylene homopolymer, a heterophasic polypropylene copolymer, and a polypropylene random copolymer.

3. The sterilizable package according to any previous claim, wherein the inorganic filler comprises calcium carbonate or talc.

4. The sterilizable package according to any previous claim, wherein the core layer and the sealant layer are comprised in a non-oriented film.

5. The sterilizable package according to any previous claim, wherein the thickness of the sealant layer comprises from about 10% to about 35% of the combined thickness of the core layer and the sealant layer.Attorney Case No. 21396-WO6. The sterilizable package according to any previous claim, wherein the exterior film comprises one or more of a polyester, a polypropylene, and a polyamide.

7. The sterilizable package according to any previous claim, wherein the barrier layer comprises one or more of an aluminum foil, a vacuum deposited metal, or an inorganic oxide.

8. The sterilizable package according to any previous claim, wherein, upon peeling the lid from the formed container, a whitened and fiber free area is exposed in the location of the seal.

9. The sterilizable package according to any previous claim, wherein the lid comprises a peak peel strength of from 10 N / 15 mm to 18 N / 15 mm and an average peel strength of 6 N / 15 mm to 12 N / 15 mm after sealing to a layer of polypropylene terpolymer (Ter-PP) comprised in an encapsulating flexible laminate of Ter-PP 40 microns / aluminum foil 20 microns / oriented polyethylene terephthalate 12 microns at a temperature of 200 °C, a pressure of 80 N / cm, and a dwell time of 0.5 seconds using a 0.5 cm wide top sealing bar according to ASTM F88 / F88M-23.

10. The sterilizable package according to any previous claim, wherein the lid comprises a dead-fold property.

11. The sterilizable package of claim 10, wherein the lid comprising the dead-fold property comprises one or more of an aluminum foil, a polymeric film, an adhesive, and a fiber-based material.

12. The sterilizable package according to any previous claim, wherein the lid further comprises printed indicia located on the exposed surface of the exterior film or between the exterior film and the barrier layer.Attorney Case No. 21396-WO13. The sterilizable package according to any previous claim, wherein the formed container comprises a raised profile sealing rim.

14. The sterilizable package of according to any previous claim, further comprising a liquid or a powder within the at least one cavity.

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