Patent Description:
Flexible materials, such as polymers and flexible films, are often used to construct packages for products, such as bags and pouches. Such packages can be used to hold a variety of items such as snack food, trail mix, chips, nuts, fruit pieces, and other foods. In some cases, as in the snack food example, the type of product contained in the package is meant for consumption by the user one portion at a time. For example, the consumer may consume a portion of a snack mix and then wish to reclose the package in a manner which will preserve the freshness of the snack mix for later use.

Standard pouch reclosure features include press-to-close zippers. However, zippers have certain disadvantages. For example, pouches are typically made from extensible films such as polyethylene and polypropylene. A zipper applied to the pouch must be compatible with the pouch material. Due to the nature of these various polymers, the extensible polymers will stretch during application of the zipper to the pouch, creating differential forces. The pouch and/or the zipper may become deformed and/or inoperable due to the extension and differential forces.

Further, if a brittle or non-extensible closure feature is utilized, such as a brittle magnet, the magnetic material will often break during application to the pouch, due to the stretching, differential forces, and/or deformation of the extensible film. As the film web stretches, the magnets may break. The inventors have developed an inventive closure system utilizing a magnetic reclose which avoids these disadvantages and provides numerous advantages. <CIT> describes bag packing that has three sides of connected front wall and rear wall which limit the bag opening. <CIT> describes a paper beverage pack comprising: a body configured so as to contain the contents therein; drinking parts formed in an opening part arranged on both upper ends of the body, so as to pushed out to the outside by a triangular-shaped folding line; first adhesive surfaces attached onto the outside of the drinking parts while being folded such that the drinking parts face each other; and second adhesive surfaces, for attaching the entire opening part, formed on an upper inner side of the opening part located on the upper part of the drinking parts, wherein plate-shaped magnetic sealing parts are arranged at the lower part of the first adhesive surfaces of the paper beverage pack so as to be parallel with the first adhesive surfaces such that, when the opening part is folded again, the magnetic sealing parts are sealed while coming in close contact with each other by a magnetic force. <CIT> describes a zipper bag with magnet strips. <CIT> describes a water impermeable sealing apparatus that includes a first sealing strip having a base that has a first set of fastener elements carried on its surface in two spaced-apart areas.

Embodiments of the invention described herein provide improved packages and methods for constructing packages that provide a magnetic reclose feature.

In an aspect, the invention comprises a carrier film for a magnetic closure comprising: a first non-extensible inner layer; a second non-extensible inner layer, wherein an inner surface of the first inner layer forms a peelable heat seal with an inner surface of the second inner layer; a first outer layer having an inner surface adhesively bonded to an outer surface of the first inner layer, wherein the first outer layer comprises a plastomer and wherein the outer surface of the first outer layer is configured to form a permanent heat seal with a first wall of a packaging structure; a second outer layer having an inner surface adhesively bonded to an outer surface of the second inner layer, wherein the second outer layer comprises a plastomer and wherein the outer surface of the first outer layer is configured to form a permanent heat seal with a second wall of the packaging structure; a first magnetic member disposed adjacent the outer surface of the first outer layer and configured to be sealed between the first wall of the packaging structure and the first outer layer; and a second magnetic member disposed adjacent the outer surface of the first outer layer and configured to be sealed between the second wall of the packaging structure and the second outer layer.

In another aspect, the invention comprises a packaging structure comprising: a polymeric film folded into a pouch structure such that the pouch comprises a first end, a folded second end opposite the first end, and two sealed side edges, wherein the first end comprises an opening into the package and wherein the pouch comprises an interior surface; a carrier film disposed adjacent the first end of the pouch, on the interior surface of the pouch, on opposite sides of the opening, wherein the carrier film comprises: an inner layer, wherein at least a first portion of the inner layer is peelably heat sealed to a second portion of the inner layer on the opposite side of the opening so as to seal the packaging structure closed; and an outer layer adhesively bonded to the inner layer, wherein the outer layer comprises a plastomer and is permanently sealed to the interior surface of the pouch; and a magnetic member disposed between the pouch and the outer layer of the carrier film.

In yet another aspect, the invention comprises a packaging structure comprising: a first polymeric film sheet and a second polymeric film sheet sealed together to form a package having a first end, a closed second end opposite the first end, and at least two sealed side edges, wherein the first end comprises an opening into the package and wherein the first polymeric film sheet and the second polymeric film sheet comprise an interior surface; a first carrier film strip disposed adjacent the first end of the package, on the interior surface of the first polymeric film sheet, wherein the first carrier film strip comprises: an inner layer; and an outer layer which comprises a plastomer, wherein the outer layer is permanently sealed to the interior surface of the first polymeric film sheet; a second carrier film strip disposed adjacent the first end of the package, on the interior surface of the second polymeric film sheet, wherein the second carrier film strip comprises: an inner layer peelably heat sealed to the inner layer of the first carrier film strip so as to seal the packaging structure closed; and an outer layer which comprises a plastomer, wherein the outer layer is permanently sealed to the interior surface of the second polymeric film sheet; a first magnetic member disposed between the first polymeric film sheet and the outer layer of the first carrier film strip; and a second magnetic member disposed between the second polymeric film sheet and the outer layer of the second carrier film strip.

In still another aspect, the invention comprises a method for forming a packaging structure comprising: providing a polymeric film web; providing a carrier film, wherein the carrier film comprises: an inner layer comprising polyethylene terephthalate; and an outer layer which comprises a plastomer; and providing a magnetic member; layering the magnetic member and the carrier film on the polymeric film web as follows to form a closure member: a first layer of the film web, a first magnetic member, a first carrier film, a second carrier film, a second magnetic member, and a second film web, wherein the carrier film is disposed such that the outer plastomer layer is adjacent the magnetic member and wherein the carrier film extends beyond at least one of an upper edge and a lower edge of the magnetic member; and heat sealing the closure member at a temperature that is higher than the seal initiation temperature of the polyethylene terephthalate layer such that the seal at the interface of the first carrier film and the second carrier film is a peelable seal, the seal at the interface of the first film web and the first carrier film is a permanent seal, and the seal at the interface of the second film web and the second carrier film is a permanent seal.

The present invention now will be described more fully hereinafter with reference to the accompanying drawings in which some but not all embodiments of the inventions are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements.

The packages of the present invention may be made of flexible materials, such as various polymer-based materials. The packages may be used to hold food products, such as baking ingredients (e.g., sugar, flax seed, oatmeal, etc.), snack foods (e.g., trail mix, nuts, fruit pieces, chips, etc.), and/or other materials. Examples of such packages are illustrated in <FIG>. As depicted in the figures, such packages may, for example, have a front (or first) panel <NUM> defining an opening end <NUM>, a base end <NUM>, and two side edges and a back (or second) panel <NUM> defining an opening end <NUM>, a base end <NUM>, and two side edges. The front panel <NUM> and the back panel <NUM> may be joined to each other along respective side edges of the panels (e.g., via heat sealing) to create longitudinal seams <NUM>. In some cases, the packages may be gusseted, as shown in <FIG>, to form stand-up pouches. Thus, a base panel <NUM> may be connected to base ends <NUM>, <NUM> of the respective front and back panels <NUM>, <NUM> to form the base of the stand-up pouch. In other cases, the base ends <NUM>, <NUM> may be joined to each other without the use of an additional base panel to form a bag, as shown in <FIG>.

In an embodiment, the package may not be sealed at the base ends <NUM>, <NUM>, but instead, the packaging structure may comprise a strip of material which is folded at the base end <NUM> to form a bottom of the package (shown in <FIG> and <FIG>). In this embodiment, the film may be folded along a fold line <NUM> located centrally between the closure strip region <NUM> to form a C-fold or a V-fold configuration. The resulting two opposing portions of the film may be sealed together along their side edges <NUM> to form side seals. Optionally, the top end of the bag can also include a peelable heat seal or cold seal <NUM> located either outward or inward of the closure region <NUM>, as depicted in <FIG>. In other embodiments, however, the packaging structure does not include a separate heat seal or cold seal <NUM> which must be removed/opened. Embodiments of the invention are applicable in, and may be embodied by, various kinds of packages including stand-up pouches, bags, or any other reclosable package that includes front and back panels joined at longitudinal seams.

In an embodiment, the opening end <NUM> of the front panel and the opening end <NUM> of the back panel define an opening <NUM> of the package that is configured to provide access to contents of the package when the package is opened by a user. A consumer may open the package by separating the front and back panels <NUM>, <NUM>, such as by peeling a heat seal, cold seal, or other seal above the reclose feature (in which case the reclose feature <NUM> may be disposed in an initially open position) or opening a closure feature in the reclose region <NUM>. As noted, the reclose feature may be any known in the art such as a press-and-close zipper, interlocking male/female strips, a slide zipper, a tongue-and-groove mechanism, or a magnetic mechanism, or any other closure known in the art that is useful for allowing the joining and separation of the opening ends <NUM>, <NUM> of the front and back panels together. In an embodiment, the reclose feature may be a linear reclose device.

As shown in the exploded cross-sectional side view of <FIG> and <FIG>, there is provided a pouch <NUM>, a magnetic material <NUM>, and a carrier film <NUM> in an embodiment. The carrier film <NUM> comprises a plurality of layers, in this embodiment at least two layers. The carrier film <NUM> of <FIG> and <FIG> comprises an inner layer <NUM> and an outer layer <NUM>, with respect to the interior of the packaging structure. Each of the inner layer <NUM> and the outer layer <NUM> of <FIG> and <FIG> comprises a film. The inner layer <NUM> (also referred to as the backbone) of <FIG> and <FIG> provides stiffness and tensile strength to the carrier film <NUM>. The inner layer <NUM> of <FIG> and <FIG> comprises a layer of heat-sealable polyethylene terephthalate (PET). In a particular embodiment, the inner layer may comprise heat sealable PET (HSPET).

The inner layer <NUM> of the carrier film <NUM> is, in the embodiment of <FIG> and <FIG>, adhered to an outer layer <NUM>. The outer layer <NUM> in this embodiment comprises a plastomer. In some embodiments, the outer layer <NUM> comprises a coextruded plastomer. In some embodiments, the plastomer may comprise a polyolefin plastomer. In certain embodiments, the plastomer may comprise coextruded polyethylene. In an embodiment, the outer layer <NUM> may comprise low density polyethylene (LDPE), linear low density polyethylene (LLDPE), polypropylene (PP), or oriented polypropylene (OPP). In an embodiment, the outer layer <NUM> is referred to as a skin layer and, the inner layer <NUM> and the outer layer <NUM> may be laminated to each other. Any resin or adhesive known in the art may be utilized to adhere the inner layer <NUM> and the outer layer <NUM>.

In the embodiment of <FIG> and <FIG>, the carrier film <NUM> is non-extensible or substantially non-extensible. In this embodiment, the inner layer <NUM> of the carrier film <NUM> is non-extensible or substantially non-extensible. In this embodiment, the carrier film <NUM> can be heat-sealed to the interior <NUM> of a packaging structure. The heat-seal to the interior <NUM> of the pouch <NUM> may comprise a permanent seal. In an embodiment, the carrier film <NUM> can be heat-sealed to another carrier film <NUM> on the opposite side of the pouch to create a peelable bond at the opening of the pouch. More particularly, the peelable bond may be disposed between the two inner layers <NUM> of the carrier film <NUM>, at an interface <NUM>. In an embodiment, the peelable bond comprises a PET/PET interface and the peelable bond located at the interface <NUM> between the inner layers <NUM> of the carrier film <NUM> comprises a hermetic seal until such time as the package is opened. After the package is opened, the peelable seal located at the interface <NUM> between the inner layers <NUM> of the carrier film <NUM> becomes a resealable seal due to the magnetic reclosure features provided herein. Thus, in some embodiments, there is not a need for a peelable heat seal or cold seal <NUM> located either outward or inward of the closure region <NUM> (shown in <FIG>) because the PET/PET interface <NUM> provides a peelable heat seal that is hermetic until the package is opened and then becomes a resealable seal.

In an embodiment, the bond between the outer layer <NUM> and the interior of the packaging structure <NUM>, is a permanent bond. In such an embodiment the outer layer <NUM> of the carrier film <NUM> cannot be separated from the interior of the packaging structure <NUM> without destruction of the packaging structure <NUM>, the carrier film <NUM>, or both. The packaging structure (i.e. front panel <NUM>, back panel <NUM>, etc.), may comprise polyethylene or polypropylene.

In an embodiment, the polymers selected as the backbone (inner layer <NUM>) and coextruded plastomer (outer layer <NUM>) are selected based upon their relative seal initiation temperatures. In this embodiment, the inner layer <NUM> may have a higher seal initiation temperature than that of the outer layer <NUM>. In an embodiment, the temperature differential for the seal initiation between the inner layer <NUM> and the outer layer <NUM> may be between about <NUM> and <NUM> degrees Fahrenheit (between about <NUM>° C and <NUM>° C). In an embodiment, the seal initiation temperature (and/or the seal activation temperature) of the inner layer <NUM> may be between about <NUM>° F (<NUM>° C) and <NUM>° F (<NUM>° C). In an embodiment, the inner layer <NUM> may be considered to have a high seal initiation temperature. In an embodiment, the seal initiation temperature (and/or the seal activation temperature) of the outer layer <NUM> may be between about <NUM>° and <NUM>° F (between about <NUM>° C and <NUM>° C). In an embodiment, the outer layer <NUM> may be considered to have a low seal initiation temperature.

In an embodiment, the carrier film <NUM> is provided in a strip form. That is, the carrier film <NUM> may extend along a width of the package, from side seal to side seam, without extending the length of the pouch (from top to bottom). In an embodiment, the carrier film <NUM> is not coextensive with the shape and size of the pouch or package, in at least one dimension. In an embodiment, the carrier film does extend into the side seams of the packaging structure.

In an embodiment, the magnetic members <NUM> may comprise extrudable magnetic particles, a printable hot melt magnet, or any other magnetic materials known in the art. For example, a printable hot melt magnet may be directly printed onto a substrate in a molten state without the use of any adhesive, or may alternatively be applied in a cooled state with the use of adhesive, or through a heat bonding method. Magnetizable compositions can be printed in a relatively thin coating at high speeds, and can be magnetically aligned, to maximize the magnetic holding force.

In an embodiment, the magnetic members <NUM> comprise magnetic particles or materials combined with a polymer material. For example, in an embodiment, the magnetic members <NUM> comprise about <NUM> wt-% to about <NUM> wt-% of the magnetizable particles and about <NUM> wt-% to about <NUM> wt-% of at least one polymer material. In some embodiments, the magnetic members <NUM> comprise about <NUM> wt-% to about <NUM> wt-% of the magnetizable particles and about <NUM> wt-% to about <NUM> wt-% of at least one polymer material. However, any percentage of magnetizable particles and polymer are contemplated herein.

The polymeric material, optionally referred to as a thermoplastic binder, may include any polymeric material that is readily processable with the magnetic particles. Such thermoplastic materials include both thermoplastic elastomers and non-elastomers or any mixture thereof. The polymer material and the magnetizable particles can be added to and melted in an extruder, in an embodiment. In another embodiment, the polymer and magnetizable particles may be provided in a premade form, such as a pellet. In an embodiment, the magnetic members <NUM> (polymer and magnetizable particles) are then extruded.

In an embodiment, the magnetic member <NUM> is coextruded with a resin, such as ethylene vinyl acetate (EVA). In an embodiment, the resin may comprise EVA copolymerized with other resins such as LDPE and LLDPE. In an embodiment, the resin may comprise a polyolefin-based hot melt adhesive such as an amorphous polyolefin or metallocene, or any other hot melt adhesive known in the art. In this embodiment, the resin may aid in bonding the magnetic member <NUM> to the pouch interior <NUM> and/or the carrier film <NUM>.

The magnetic members <NUM> may each have at least one north pole and at least one south pole. In some instances, the magnetic members <NUM> may comprise multipole magnets, each magnetic member <NUM> having a plurality of poles per magnet. In other embodiments, the magnetic members <NUM> may each have a single north pole or a single south pole, respectively. The scope of the disclosure is not limited by the arrangement of the magnetic members <NUM> provided that magnetic members <NUM> are magnetically attracted to one another.

The magnetic particles used in the magnetic members <NUM> of the invention may comprise any magnetic particles known in the art. In an embodiment, ferrites, strontium, strontium ferrite, neodymium, and/or samarium cobalt may be used. In one embodiment, the magnetic particles comprise ferrites having the general formula (M<NUM>+O6Fe<NUM>O<NUM>) MFe<NUM>O<NUM> where M represents Ba or Sr. Other examples of magnetic materials suitable for use herein include a rare earth-cobalt magnet of RCOs where R is one or more of the rare earth elements such as Sm or Pr, yttrium (Y), lanthanum (La), or cerium (Ce). Other specific examples of magnetic materials include, for instance, manganese-bismuth, and manganese-aluminum.

In an embodiment, the magnetic members <NUM> are provided in strip form. That is, the magnetic members <NUM> may extend from one side seam to the other side seam of the package (width), but may not extend the length of the packaging structure, from top to bottom. The magnetic members <NUM> may, in an embodiment, extend into the side seals <NUM> of the packaging structure. In other embodiments, the magnetic members <NUM> may be disposed interior of the side seals <NUM> of the packaging structure.

In an embodiment, the carrier film <NUM> has a greater longitudinal dimension (between the top and bottom of the packaging structure) than that of the magnetic members <NUM>. That is, the carrier film <NUM>, in an embodiment, extends above and/or below the magnetic members <NUM>, in the longitudinal direction of the packaging structure. This allows the outer layer of the carrier film <NUM> to be adhered directly to the packaging inner surface, adjacent to and/or around the edges of the magnetic member. In an embodiment, the carrier film <NUM> and the magnetic members <NUM> are each in strip form, and the carrier film strip <NUM> is wider than the magnetic member strip. In an embodiment, the magnetic members <NUM> have an upper edge and a lower edge and the carrier film <NUM> extends beyond one or both of the upper edge and/or lower edge of the magnetic members <NUM>. In an embodiment, the carrier film <NUM> surrounds or partially envelops the magnetic member <NUM>. In an embodiment, the carrier film <NUM> is sealed to the pouch inner surface above an upper edge of the magnetic member <NUM>, below a lower edge of the magnetic member <NUM>, or both.

In an embodiment, the inventive pouch or bag may be formed from polyolefins and copolymers or terpolymers thereof, for example, polypropylene (PP), polyethylene (PE), high density polyethylene (HDPE), medium density polyethylene (MDPE), LDPE and LLDPE, polyesters and copolymers thereof, for example, polyethylene terephthalate (PET), and so forth. In some embodiments, the pouch may comprise a barrier material. In other embodiments, the pouch or bag itself may comprise a metalized or foil laminated polypropylene, for example, aluminum laminated polypropylene. Additionally, in other embodiments, the pouch or bag of the invention may be formed from or comprise a layer of paper, paper products or pasteboard, for example, paperboard or cardboard, and laminated versions thereof.

Embodiments of a method of manufacturing a package as described above are also provided herein. In a first step, the outer layer <NUM> of the carrier film <NUM> may be formed. In an embodiment, the outer layer <NUM> is coextruded with a resin that is compatible with and allows it to bond to the inner layer <NUM> of the carrier film <NUM>. In an alternative embodiment, the outer layer <NUM> is coextruded with a resin that is compatible with and allows it to bond to the inner surface <NUM> of the pouch <NUM>.

In either embodiment, the outer layer <NUM> is coextruded or otherwise provided and aligned with a web of the inner layer <NUM>. An adhesive may optionally be applied to one or both of the inner layer <NUM> and/or the outer layer <NUM>. The outer layer <NUM> and the inner layer <NUM> may then be laminated together, using nip rollers or any other method known in the art, with the adhesive or resin being disposed between them. After lamination, the carrier film may be cut into strips, if desired.

In an embodiment, the magnetic members <NUM> are formed through extrusion techniques. In this embodiment, a polymeric resin may be heated to a molten or flowable temperature and mixed with magnetic particles in an extruder. The extrudate may be extruded in a sheet or strip form. A magnetizer, such as a rare earth magnet, can be used to magnetize the magnetic particles optionally as the extrudate cools. For example, a chill roll that is wrapped in magnets, such as neodymium magnets, could be employed. In an embodiment, the magnetic members <NUM> are then cut into strips of a size that is slightly smaller than the carrier film <NUM> strips.

The pouch material may also be provided in web form. In one embodiment, the magnetic members <NUM> may be applied by extrusion to the pouch material. Alternatively, however, the magnetic members <NUM> are provided in strip form and are applied to the pouch material as such. On the opposite side of the magnetic members <NUM>, the carrier film <NUM> may be applied such that the outer layer <NUM> of the carrier film <NUM> is disposed adjacent the magnetic member <NUM>.

<FIG> illustrates an embodiment of the web of pouch material which will form pouches <NUM> and <NUM>'. The carrier film <NUM> is disposed atop the magnetic members <NUM>. The web may be cut along lines <NUM> to define the edges of the pouch. That is, cut line <NUM> may define the top edge of the pouch on either side of a folded region <NUM> of the pouch <NUM>. As noted above, the magnetic member <NUM> may not extend to the top edge <NUM> of the carrier film <NUM>. In another embodiment, the magnetic member <NUM> may not extend to the bottom edge <NUM> of the carrier film <NUM>. In an embodiment, the magnetic member <NUM> may not extend to the top edge <NUM> or the bottom edge <NUM> of the carrier film <NUM>. In this embodiment, the carrier film <NUM> may be adhered directly to the pouch film interior <NUM> on either side of the magnetic member <NUM>.

Once the film web has been formed, the package may be side sealed and filled. Alternatively, the closure feature <NUM> may be first heat sealed, followed by filling of the package through one of the side seals. Regardless of how the package is filled, in an embodiment, the closure feature <NUM> is heat-sealed. In an embodiment, the closure feature <NUM> is heat sealed at approximately <NUM>° F (<NUM>° C). In this embodiment, the selective heat seal initiation temperatures of the various materials may provide a permanent seal between the carrier film <NUM> and the pouch interior <NUM> and a peelable seal between the inner layers <NUM> of the carrier film <NUM>. Thus, one heat seal process may provide both the permanent and peelable heat seal necessary for the invention.

Thought the method is discussed as related to a folded pouch, the method for forming the package having a sealed base portion or a sealed bottom edge will be understood to those of skill in the art. For example, the method may additionally comprise heat-sealing two sheets of film together to form a bottom seal and side seals or heat-sealing two sheets of film to a bottom panel and to each other to form side seals.

In use, a consumer may open the package by peeling the peelable seal of the closure feature <NUM>. The bag may then be reclosed via the magnetic closure feature <NUM>.

In each example, a <NUM> gauge sheet of PET with a heatseal initiation temperature of approximately <NUM>° F (<NUM>° C) was utilized. The PET sheet was adhered and laminated to one of the following for consideration as an outer layer of the carrier film:.

The heatseal side of the PET sheet was disposed opposite the respective PE/PP sheet. The laminated potential carrier film was then heat sealed to a magnetic member and a pouch at approximately <NUM>° F (<NUM>° C). For each trial, the packaging was considered as to stretching, breakage, curling edges, and direct coating ability. Trials <NUM>, <NUM>, and <NUM> each failed due to issues with one or more of stretching, breakage, curling edges, and/or direct coating ability. Surprisingly, in trial <NUM>, the PE coextruded film was found to be satisfactory in terms of each qualitative characteristic: stretching, breakage, curling edges, and direct coating ability.

Claim 1:
A packaging structure comprising:
a polymeric film folded into a pouch structure (<NUM>) such that the pouch (<NUM>) comprises a first end (<NUM>), a folded second end (<NUM>) opposite the first end (<NUM>), and two sealed side edges, wherein the first end (<NUM>) comprises an opening into the package and wherein the pouch (<NUM>) comprises an interior surface;
a carrier film (<NUM>) disposed adjacent the first end (<NUM>) of the pouch (<NUM>), on the interior surface of the pouch (<NUM>), on opposite sides of the opening, wherein the carrier film (<NUM>) comprises:
an inner layer (<NUM>), wherein at least a first portion of the inner layer (<NUM>) is peelably heat sealed to a second portion of the inner layer (<NUM>) on the opposite side of the opening so as to seal the packaging structure closed; and
an outer layer (<NUM>) adhesively bonded to the inner layer (<NUM>), wherein the outer layer (<NUM>) comprises a plastomer and is permanently sealed to the interior surface of the pouch (<NUM>); and
a magnetic member (<NUM>) disposed between the pouch (<NUM>) and the outer layer (<NUM>) of the carrier film (<NUM>).