Patent Description:
Flexible "stand-up" pouches and bottles for holding liquids and other pourable products are very popular. Such products are advantageous as compared to traditional containers for pourable products because, among other reasons, flexible plastic pouches and bottles help reduce solid waste and are less costly to manufacture. An early stand-up pouch design dubbed the "Doyen pouch" is described in <CIT>, and it is still in use today. A well-known version of traditional Doyen pouch, at least in the United States, is the Capri Sun® juice drink pouch. Subsequent modifications of the Doyen design included installation of fitments between the two panels at the top portion of the pouch to allow the pouch to be reclosed after opening.

A major difficulty with the installation of fitments in Doyen pouches, however, (and in other pouch designs as well) is that, according to early prior art fitment sealing methods, the fitment must be of the "canoe" style to create a joint that can be reliably sealed. Canoe style fitments are illustrated in, e.g., <CIT>, <CIT>, and <CIT>. The canoe type of fitment was an attempt to minimize the change in direction of pouch material as it comes into contact with the fitment. Put another way, the canoe type of fitment is designed to minimize the angle of divergence of two portions of container material that separate and move apart to envelope (and subsequently be sealed to) the fitment. In so doing, canoe style fitments improved the integrity of the joint where the two sides of the pouch come together at the fitment. However, even the use of a canoe shaped fitment does not completely solve the difficulties in sealing a fitment into a pouch, and a more reliable sealing means is desirable.

This problem was addressed in <CIT> and <CIT>. As shown in the '<NUM> and '<NUM> patents, while canoe style fitments can be used in connection with the present invention, "cylindrical base" fitments are preferred. The sealing surface of a cylindrical base style fitment is preferably substantially parallel to the axis of the fitment, as in the canoe style, but it does not include external corners at sharply acute angles around its circumference, as do canoe style fitments. Rather, in accordance with a first style of cylindrical base fitment, the circumference is preferably comprised of smooth and preferably convex curves. Having the circumference comprised of smooth curves is intended to facilitate the sealing of web material to the base of the fitment with two overlapping sealing steps applied from different directions. These sealing steps include: (i) clamping bottle material to the fitment with a heated clamping means to create a seal between the bottle material and the fitment, and (ii) clamping the bottle material to the fitment with a heated clamp a second time, the second clamping being at a different radial angle. By this method, the fitment is installed (i.e., adhered to by heat and pressure) in a neck of the bottle by way of a leakproof seal formed by the clamps.

Suitable optionally refillable flexible containers for use in connection with the present invention may be formed, by way of non-limiting example, in accordance with the disclosures of the '<NUM> and '<NUM> patents, as well as <CIT>, <CIT>, and <CIT>.

Despite the technological advancements in the art provided by the '<NUM> and '<NUM> patents, there remains room for an improvement to the methods and devices described therein, particularly with respect to method of the sealing of the fitment to the bottle. For example, although the two-step multi-directional sealing process for attaching a substantially cylindrical fitment to the neck of a flexible bottle has proven to be substantially reliable, the strength and integrity of the seal at the respective surfaces of the fitment and the bottle neck are enhanced by way of the improvements described herein. This is particularly important with respect to containers constructed in accordance with the '<NUM> and '<NUM> patents, which may be used to contain larger volumes of flowable material than what is suitable for Doyen style pouches. For example, the containers of the '<NUM>, '<NUM>, '<NUM>, '<NUM>, and '<NUM> patents can stand up on their own at volumes of <NUM> liters, whereas Doyen style pouches will typically fall over and/or are very unwieldy at such large volumes, particularly where the pouches have no carrying handles. These larger volumes, which are highly desirable in the flexible container market, put higher physical stresses on the fitment and the film structure, particularly at the junction of the fitment and the film neck of the container.

For example, because fitments are often sealed to varying layers of flexible material at different locations along the circumference of a fitment, it is a challenge to apply the proper temperature, pressure, time, and location of such seals on the fitment as would otherwise help to optimize the strength and reliability of the overall seal. Thicker layers of material will typically require a greater amount of heat and pressure to cause such layers to be reliably sealed to a fitment. However, the same amount of heat and pressure may compromise the integrity of thinner layers of material to be adhered to the fitment, which may become brittle. Therefore, there remains an unmet need in the art for flexible containers fabricated from flexible film and comprising a fitment, wherein an improved seal at the junction of the flexible film and the fitment is provided.

It has been found that larger volume flexible containers of the prior art, such as those having <NUM> liters of water inside, can withstand the physical stresses of being dropped vertically on their base from several feet. However, when dropped on their cap (i.e., at a top portion where the fitment is typically located and connected to the cap) from <NUM> inches, the prior art containers may burst open at the junction of the film and the fitment at the neck of the container. This integrity imbalance in drop performance between the ability of the container to sustain drops on its base as compared to drops on its cap needs to be addressed.

<CIT> describes standup bags made of a flexible material and methods of producing these standup bags. <CIT> relates to a process for producing a flexible container with a dispensing fitment and a standup flexible container with a dispensing fitment in particular.

The present invention meets the aforementioned unmet need by providing the method for sealing a fitment to a flexible container according to claim <NUM> and the flexible container and fitment combination according to claim <NUM>.

The present invention , provides for a substantial improvement in drop performance when the container is dropped vertically on its cap (i.e., on the fitment portion). Testing has shown that a <NUM> liter container provided in accordance with a preferred embodiment of the present invention and filled with water can be dropped from one meter on its cap and not rupture, whereas containers of the prior art may rupture under the same testing parameters except that the drop distance is merely <NUM> centimeters. This is especially important when shipping hazardous liquids in containers formed in accordance with the present invention. For example, United Nations ("UN") testing of containers for hazardous liquids requires the container to be tested by being dropped on all sides including with the top and cap pointing downwardly and making first impact with a surface. <NUM> liter volume containers formed in accordance with the present invention passed UN #<NUM> Class <NUM> tests.

An advantage of the present invention is that it provides devices and methods that form a reliable and robust multiseal of flexible material at specific locations about the circumferential surface of a base of a fitment, thereby allowing greater heat and pressure to be applied as desired to multiple material layers adhered to the base of the fitment to form a leakproof seal at the multiseal, while concurrently preserving the enhanced integrity of other thinner sealed portions that require less heat and pressure to be effectively sealed to the fitment.

With reference to the figures and elements referenced herein, improved methods and devices for sealing a fitment to a flexible container are provided. It should be appreciated that the embodiments described and shown herein are exemplary in nature only and that various additional embodiments are contemplated and within the scope of the present invention.

As discussed in detail below, preferred embodiments of the present invention comprise flexible containers, such as optionally refillable bottles formed of a flexible material, such as webs of plastic film. In forming such bottles comprising a fitment sealed into a neck or other portion of the bottle, there often exists a need to seal one or more layers of the flexible material to a surface of the fitment. The process of doing so, as well as the corresponding bottle structure, provide for a robust, reliable, and preferably leak-proof seal at the juncture of the fitment and the layers of bottle material. Such seals are often critical to the endurance and utility of the containers that comprise them. This is because a rupture, such as in seals of the prior art, may result in catastrophic failure of the corresponding prior art bottle, such that bottle contents may leak or flow out of the bottle body at the ruptured seal between the fitment and bottle material, as opposed to through the installed fitment as intended. The present disclosure teaches novel and inventive improvements to such seals as applicable to a variety of flexible bottles that are suitable for use with preferred embodiments of the present invention.

<FIG> is a perspective view illustration of a finished flexible container <NUM> comprising a fitment <NUM> sealed therein and provided in accordance with a preferred embodiment of the present invention. As shown, the container <NUM> preferably comprises a multi-panel construction. In a preferred embodiment, container <NUM> comprises a front panel <NUM>, back panel <NUM> (not shown), first side panel <NUM>, second side panel <NUM> (not shown), as well as top segment <NUM>, handle <NUM>, container edges <NUM>, optional cap <NUM> (not shown), neck <NUM>, fitment <NUM>, and multiseal <NUM>. It will be appreciated by those of ordinary skill in the art that container <NUM> may comprise a different number of panels and/or additional features, such as a bottom handle. The container <NUM> may also omit handles altogether. In some preferred embodiments, panels <NUM>, <NUM> are gusseted. Non-limiting examples of methods of fabricating the container <NUM> are disclosed in <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>, except that all methods disclosed therein should be deemed to exclude disclosure of steps comprising the improved sealing of fitment <NUM> to the neck <NUM>, as provided in accordance with preferred embodiments of the present invention and as will be described below in further detail.

Container <NUM> is preferably formed by coextrusion of flexible film. For example, the film comprising container <NUM> is preferably a film formed of a coextrusion of high-density polyethylene ("HDPE") outer portion and a low-density polyethylene ("LDPE"), or linear low density polyethylene ("LLDPE") inner sealant portion. In this example, the outer HDPE portion of the film is preferably approximately <NUM>,<NUM> (<NUM> mils) thick, and the LDPE or LLDPE inner sealant portion of the film is preferably approximately <NUM>,<NUM> (<NUM> mils) thick. Therefore, in preferred embodiments of the present invention, the film comprising container <NUM> is preferably approximately <NUM>,<NUM> (<NUM> mils) thick. The film comprising container <NUM> may be formed of a single coextruded film comprising HDPE and LDPE or LLDPE portions, or one or more layers of coextruded film coupled with one or more layers of film that may or may not be coextruded. For example, in an alternative embodiment, the container <NUM> comprises two separate layers of film, wherein an outer layer is a coextrusion of HDPE and LDPE film that is preferably approximately <NUM>,<NUM> (<NUM> mils) thick (consistent with the above description of such a layer) and an inner layer of LDPE that is preferably approximately <NUM>,<NUM> (<NUM> mils) thick.

In an embodiment, container <NUM> is formed from a coextruded multilayer film wherein each layer is composed of polyethylene. A coextruded multilayer film wherein each layer is composed of a polyethylene is interchangeably referred to as an "all-polyethylene" film.

In an embodiment, container <NUM> is formed from an all-polyethylene film that is a five layer film. The five layer film has the following layer structure: HDPE(skin)/LLDPE/LLDPE/LLDPE/polyolefin plastomer (seal).

<FIG> is a perspective view illustration of a fitment <NUM> provided in accordance with a preferred embodiment of the present invention. As shown, fitment <NUM> comprises a base <NUM>, a base surface <NUM>, a top base edge <NUM> (at the lower edge of registration portion <NUM>), a bottom base edge <NUM>, a registration portion <NUM>, and a threaded portion <NUM>. In preferred embodiments of the present invention, the fitment <NUM> is preferably cylindrical, although fitments of other shapes may be used. Moreover, as a consequence of the preferably cylindrical shape of the fitment <NUM>, the base <NUM> is also preferably cylindrical and round in cross-section, having a circumference and a diameter. The base surface <NUM> is preferably smooth, although it is contemplated that the surface <NUM> may be ribbed or undulated. The fitment <NUM> is preferably comprised of HDPE, but other material combinations of film and fitment <NUM> may also be used, such as polypropylene film and fitment.

<FIG> is a perspective view illustration of the fitment <NUM> prepared for sealing to a neck <NUM> of the flexible container <NUM> (i.e., prior to sealing) as provided in accordance with a preferred embodiment of the present invention. As shown, the panels <NUM>, <NUM>, <NUM>, <NUM> preferably extend toward the neck <NUM> to form the top segment <NUM>. The panels <NUM>, <NUM>, <NUM>, <NUM> are sealed together at container edges <NUM>, such that the multiseal <NUM> is formed at the neck <NUM>.

As further shown in <FIG>, and as will be described further below, the multiseal <NUM> preferably comprises flaps <NUM>, and sealing portions <NUM>. In a preferred embodiment of the present invention, the flaps <NUM> are formed by the confluence and sealing together of two of the panels <NUM>, <NUM>, <NUM>, <NUM>, whereas the sealing portions <NUM> are formed by the material of a single panel <NUM>, <NUM>, <NUM>, <NUM>. For example, one of the flaps <NUM> is formed by the sealing together of the front panel <NUM> and first side panel <NUM> at a container edge <NUM>, whereas an adjacent flap <NUM> is formed by the sealing together of the front panel <NUM> and the second side panel <NUM> at adjacent container edge <NUM>. Therefore, the flaps <NUM> are preferably comprised of two layers of film. Meanwhile, the sealing portions <NUM> spanning between the flaps <NUM>, as shown in <FIG>, preferably comprising a single layer of film. For example, in the above described example, the sealing portion <NUM> spanning between the flaps <NUM> is comprised of the single layer of film forming the front panel <NUM>. Such will be discussed in further detail below.

Other devices and methods for forming the flexible container <NUM> prepared for the installation of the fitment <NUM> as provided in accordance with the present invention may be suitable for use with the present invention, as will be appreciated by those of ordinary skill in the art. In most, if not all such devices and methods, there will preferably exist a step whereby material comprising the flexible container <NUM> will be made adjacent to the body of the fitment <NUM>, such as at the neck <NUM> of the container <NUM> where the fitment <NUM> is be installed, and one or more layers of the material will be sealed, often by heat and pressure, to the fitment base <NUM> to form a robust and reliable seal intended to unite the fitment <NUM> and the container <NUM>.

For example, <FIG> is a perspective view illustration of the fitment <NUM> as installed in a sealing machine <NUM> (a corresponding flexible container body being omitted for clarity) as provided in accordance with a preferred embodiment of the present invention. As shown, the sealing machine <NUM> comprises a plurality of sealing jaws, including first sealing jaws <NUM>, second sealing jaws <NUM>, and third sealing jaws <NUM>. The sealing jaws <NUM>, <NUM>, <NUM> are used to seal the multiseal <NUM> to the fitment <NUM>, thereby installing the fitment <NUM> in the container <NUM>. As will be appreciated by those of ordinary skill in the art, the sealing jaws <NUM>, <NUM>, <NUM> are adjustable relative to each other and the fitment <NUM>, such that the sealing jaws <NUM>, <NUM>, <NUM> may be made to engage the base <NUM> at different portions (i.e., heights and widths along the circumference) of the base surface <NUM>. The sealing jaws <NUM>, <NUM>, <NUM> preferably comprise first sealing faces <NUM>, second sealing faces <NUM>, and third sealing faces <NUM>, respectively, that are preferably complementary to the shape of the base <NUM>, such that an indirect engagement of the sealing faces <NUM>, <NUM>, and <NUM> against the base surface <NUM> may be achieved, thereby forming a robust seal of the multiseal <NUM> to the base surface <NUM>. The sealing machine <NUM> further comprises a heating means and a pressure means, such that the sealing jaws <NUM>, <NUM>, <NUM> seal the multiseal <NUM> to the base surface <NUM> by engaging the fitment <NUM> and applying heat and pressure.

<FIG> is a perspective view illustration of the fitment <NUM> prepared for sealing to the neck <NUM> via the multiseal <NUM> of the flexible container <NUM> (i.e., flaps <NUM> "up," prior to sealing), the illustration being shown in cross-section at axis A-A of <FIG> (the remainder of the corresponding flexible container being omitted for clarity), as provided in accordance with a preferred embodiment of the present invention. As will be described herein is a method for an incremental (i.e., stepwise) sealing of the multiseal <NUM> to the base surface <NUM> of the fitment <NUM>. The method is referred to as the Multiseal Process. To be sure, the multiseal <NUM>, as described above, is integrally formed from the confluence and sealing together of the panels <NUM>, <NUM>, <NUM>, <NUM> at the neck <NUM> to form the flaps <NUM> and sealing portions <NUM>. Additionally, as shown in <FIG> and for the sake of clarity in defining the Multiseal Process, multiseal <NUM> preferably comprises flaps 110a,b,c,d and sealing portions 120a,b,c,d. In this example of a preferred embodiment of the present invention, sealing portions 120a,c comprise the single film layer portions of the front and back panels <NUM>, <NUM> respectively, whereas sealing portions 120b,d comprise the single film layer portions of the first and second side panels <NUM>, <NUM>, respectively. Therefore, the sealing portions 120a,b,c,d are preferably approximately <NUM> mils thick. Flap 110a comprises the film of front panel <NUM> and second side panel <NUM> sealed together at container edges <NUM> in the neck <NUM>, as described above. Flap 110b comprises the film of second side panel <NUM> and back panel <NUM> sealed together at container edges <NUM>. Flap 110c comprises the film of back panel <NUM> and first side panel <NUM> sealed together at container edges <NUM>. Flap 110d comprises the film of first side panel <NUM> and front panel <NUM> sealed together at container edges <NUM>.

In Multiseal Process Step <NUM>, sealing jaws <NUM> enclose the fitment <NUM> to form primary seals <NUM>, <NUM>.

<FIG> is a perspective view illustration of the fitment <NUM> and multiseal <NUM> of <FIG> engaged with first sealing jaws <NUM> pursuant to Multiseal Process Step <NUM> to form first and second primary seals <NUM>, <NUM> (see <FIG>) of the multiseal <NUM> as provided in accordance with a preferred embodiment of the present invention. In this example, as shown in the Figures, particularly in <FIG>, the base surface <NUM> has a height of preferably approximately <NUM> from a top base edge <NUM> to bottom base edge <NUM>. As shown, the two first sealing jaws <NUM> of the sealing machine <NUM> engage the unfinished multiseal <NUM> at opposite sides of the fitment base surface <NUM>. In this Step <NUM>, sealing faces <NUM> are preferably complementary in shape to the fitment base surface <NUM>, and the sealing jaws <NUM> apply heat and pressure at the sealing faces <NUM> to the multiseal <NUM> to seal it to the fitment base surface <NUM>. The heat applied by the sealing jaws <NUM> is preferably approximately <NUM> (<NUM>°F), at a pressure of preferably approximately <NUM>,<NUM> kPa (<NUM> psi), and a dwell of preferably approximately <NUM> seconds. The sealing jaws <NUM> engage the fitment <NUM> preferably simultaneously from opposing sides so the pressure applied to the fitment <NUM> is evenly distributed.

As will be appreciated by those of ordinary skill in the art, such sealing parameters listed herein correspond to the constituent materials and methods described herein with respect to the preferred embodiment of container <NUM>. Accordingly, such parameters in the various steps of the Multiseal Process may be amended to accommodate the sealing of alternative embodiments of the present invention, such as embodiments comprising different thicknesses and material compositions of the film, as well as different container sizes and corresponding fitments.

As further shown in <FIG>, when the first sealing jaws <NUM> engage the sealing portions 120a,c, the flaps 110a,b are pushed down toward, overlap with, and are made adjacent to the sealing portion 120b by the first sealing jaws <NUM>, and the flaps 110c,d are pushed down toward, overlap with, and are made adjacent to the sealing portion 120d by the first sealing jaws <NUM>, such that first and second primary seals <NUM>, <NUM> are formed in the multiseal <NUM>, as further shown in <FIG>.

Consequently, as best shown in <FIG>, first primary seal portions <NUM> of the first and second primary seals <NUM>, <NUM> adhere the single layer of film (i.e., <NUM>,<NUM> (<NUM> mils) thick) of the sealing portions 120b,d, respectively, to the base surface <NUM>. Second primary seal portions <NUM> of the first and second primary seals <NUM>, <NUM> adhere an overlapping portion comprising the two layers of film of the flaps <NUM> (i.e., <NUM>,<NUM> (<NUM> mils) thick) and the single layer of film of the sealing portions 120b,d, respectively, to the base surface <NUM>, thereby forming second primary seal portions <NUM> of the multiseal <NUM> that comprise film layers approximately <NUM> mils thick that have been partially sealed to the fitment <NUM>. Third primary seal portions <NUM> of the first and second primary seals <NUM>, <NUM> adhere the single layer of film (i.e., <NUM>,<NUM> (<NUM> mils) thick) of the sealing portions 120a,c, respectively, to the base surface <NUM>. As shown, the primary seals <NUM>, <NUM> primarily affect the sealing portions 120b, d and the sealing portions comprising the flaps <NUM>.

As shown in <FIG>, the primary seals <NUM>, <NUM> as formed adhere by welding the sealing portions 120a,c to the base surface <NUM>. Moreover, the primary seals <NUM>, <NUM> partially adhere by welding flaps <NUM> to sealing portions 120b,d, which are correspondingly partially adhered by welding to the base surface <NUM>. By "partially adhered," it is meant that although the primary seals <NUM>, <NUM> are formed, such seals <NUM>, <NUM> will be made more robust and reliable by way of additional steps of the Multiseal Process provided in accordance with the present invention.

As shown in <FIG>, there is preferably a gap between bottom edges <NUM> of the primary seals <NUM>, <NUM> and the bottom base edge <NUM> that is preferably approximately <NUM>,<NUM> (<NUM>,<NUM> inches) wide, and preferably approximately <NUM>,<NUM> (<NUM>,<NUM> inches) from top base edge <NUM> to fitment. The primary seals <NUM>, <NUM> in this example of a preferred embodiment are preferably approximately <NUM>,<NUM> (<NUM>,<NUM> inches) wide. As best shown in <FIG>, the arc length between outer edges <NUM> of flaps 110a,d is preferably approximately <NUM> degrees, as is the arc length between outer edges <NUM> of flaps 110b,c. The arc length between the respective outer edges <NUM> of the first primary seal <NUM> is preferably approximately <NUM> degrees, as is the arc length between the respective outer edges <NUM> of the second primary seal <NUM>. These lengths are complementary to the lengths of the sealing faces <NUM>. Moreover, the arc length between the respective outer edges <NUM> first and second primary seals <NUM>, <NUM> (i.e., where there exists no seal as of yet) is preferably approximately <NUM> degrees at each side. Although <FIG> depicts seal <NUM> only, it should be understood that seal <NUM> occurs in a complementary position on the opposite side of the fitment base surface <NUM>.

In Multiseal Process Step <NUM>, sealing jaws <NUM> enclose the fitment <NUM> to form secondary seals <NUM>, <NUM>, <NUM>, <NUM>, which overlap with the primary seals <NUM>, <NUM>.

<FIG> is a perspective view illustration of the fitment <NUM> and multiseal <NUM> of <FIG> engaged with second sealing jaws <NUM> pursuant to multiseal process step <NUM> to form first, second, third, and fourth secondary seals <NUM>, <NUM>, <NUM>, <NUM> (see <FIG>) of the multiseal <NUM> as provided in accordance with a preferred embodiment of the present invention. As shown, the four second sealing jaws <NUM> of the sealing machine <NUM> engage the partially finished multiseal <NUM> at opposite sides of the fitment base surface <NUM>. In this Step <NUM>, sealing faces <NUM> are preferably complementary in shape to the fitment base surface <NUM>, and the sealing jaws <NUM> apply heat and pressure at the sealing faces <NUM> to the multiseal <NUM> to further seal it to the fitment base surface <NUM>. The heat applied by the sealing jaws <NUM> is preferably approximately <NUM> (<NUM>°F), at a pressure of preferably approximately <NUM> psi, and a dwell of preferably approximately <NUM> seconds. The second sealing jaws <NUM> engage the fitment <NUM> preferably simultaneously from opposition sides so the pressure applied to the fitment <NUM> is evenly distributed.

As shown in <FIG>, the second sealing jaws <NUM> substantially overlap the primary seals <NUM>, <NUM>, including in particular at the flaps <NUM>. However, by comparison to the primary seals <NUM>, <NUM>, the secondary seals <NUM>, <NUM>, <NUM>, <NUM> formed by the second sealing jaws <NUM> are substantially thinner, having a width that is preferably approximately <NUM> inches wide. Moreover, the secondary seals <NUM>, <NUM>, <NUM>, <NUM> are preferably located in close proximity to top base edge <NUM>, the gap between the seals <NUM>, <NUM>, <NUM>, <NUM> and edge <NUM> being preferably approximately <NUM>,<NUM> (<NUM>,<NUM> inches).

Consequently, as best shown in <FIG>, first secondary seal portions <NUM> of the secondary seals <NUM>, <NUM>, <NUM>, <NUM> overlap with the first primary seal portions <NUM> and further adhere the single layer of film (i.e., <NUM>,<NUM> (<NUM> mils) thick) of the sealing portions 120b,d, respectively, to the base surface <NUM>. Second secondary seal portions <NUM> of the secondary seals <NUM>, <NUM>, <NUM>, <NUM> further adhere the overlapping portion comprising the two layers of film of the flaps <NUM> (i.e., <NUM>,<NUM> (<NUM> mils) thick) and the single layer of film of the sealing portions 120b,d, respectively, to the base surface <NUM>, thereby forming second secondary seal portions <NUM> of the multiseal <NUM> that reinforce the second primary seal portions <NUM>, which is particularly important in view of the thickness of the film in those portions of the multiseal <NUM> at the flaps <NUM>. Additionally, third secondary seal portions <NUM> of the secondary seals <NUM>, <NUM>, <NUM>, <NUM> overlap with the third primary seal portions <NUM> and further adhere the single layer of film (i.e., <NUM>,<NUM> (<NUM> mils) thick) of the sealing portions 120a,c, respectively, to the base surface <NUM>. As shown, the secondary seals <NUM>, <NUM>, <NUM>, <NUM> primarily affect the sealing portions <NUM> comprising the flaps <NUM>.

As shown in <FIG>, the secondary seals <NUM>, <NUM>, <NUM>, <NUM> as formed further adhere by welding the sealing portions 120a,c to the base surface <NUM>. Moreover, the secondary seals <NUM>, <NUM>, <NUM>, <NUM> further adhere by welding flaps <NUM> to sealing portions 120b,d, which are correspondingly partially adhered by welding to the base surface <NUM>. In this manner the multiseal <NUM> is made more robust and reliable by way of additional steps of the Multiseal Process provided in accordance with the present invention.

As best shown in <FIG>, there is preferably a gap between bottom edges <NUM> of the secondary seals <NUM>, <NUM>, <NUM>, <NUM> and the bottom base edge <NUM> that is preferably approximately <NUM> inches, and preferably approximately <NUM>,<NUM> (<NUM>,<NUM> inches) from top base edge <NUM> to top edges <NUM>. The secondary seals <NUM>, <NUM>, <NUM>, <NUM> in this example of a preferred embodiment are preferably approximately <NUM>,<NUM> (<NUM>,<NUM> inches) wide. As best shown in <FIG>, the arc length between the edges of a single flap <NUM> is preferably approximately <NUM> degrees. The arc length between the respective outer edges <NUM> of the first secondary seal <NUM> is preferably approximately <NUM> degrees, as is the arc length between the respective outer edges <NUM> of the other secondary seals <NUM>, <NUM>, <NUM>. These lengths are complementary to the lengths of the sealing faces <NUM>. Although <FIG> depicts seal <NUM> only, it should be understood that seals <NUM>, <NUM>, and <NUM> occur in complementary positions (i.e., at the flaps <NUM>) of the fitment base surface <NUM>. As shown in <FIG>, in order for the seal jaws <NUM> to have complementary angles of attack and thus be evenly space around the fitment <NUM>, it has been found that the flaps <NUM> are not centered on the sealing faces <NUM>, but instead are offset from the center of the sealing faces <NUM> by approximately <NUM>% of the arc length of the sealing faces <NUM>.

As previously discussed, a particular benefit of the reduced size and particular location of the secondary seals <NUM>, <NUM>, <NUM>, <NUM> is that additional heat may be applied to reinforce the sealing of the flaps <NUM> to the fitment <NUM> where the thickness of the film is greater. It is also advantageous to apply the secondary seals <NUM>, <NUM>, <NUM>, <NUM> nearer to the top base edge <NUM> so as to mitigate the possibility that single layer portions of the multiseal <NUM> may be made brittle or unreliable in view of the enhanced heat toward the bottom base edge <NUM>, where the pressure among the junction of the neck <NUM> and the fitment <NUM> is often the greatest and where most ruptures tend to occur in prior art containers.

In Multiseal Process Step <NUM>, sealing jaws <NUM> enclose the fitment <NUM> to form tertiary seals <NUM>, <NUM>, which overlap with the primary seals <NUM>, <NUM> and secondary seals <NUM>, <NUM>, <NUM>, <NUM>.

<FIG> is a perspective view illustration of the fitment <NUM> and multiseal <NUM> of <FIG> engaged with second sealing jaws <NUM> pursuant to multiseal process step <NUM> to form first and second tertiary seals <NUM>, <NUM> (see <FIG>) of the multiseal <NUM> as provided in accordance with a preferred embodiment of the present invention. As shown, the two tertiary sealing jaws <NUM> of the sealing machine <NUM> engage the partially finished multiseal <NUM> at opposite sides of the fitment base surface <NUM>. In this Step <NUM>, sealing faces <NUM> are preferably complementary in shape to the fitment base surface <NUM>, and the sealing jaws <NUM> apply heat and pressure at the sealing faces <NUM> to the multiseal <NUM> to further seal it to the fitment base surface <NUM>. The heat applied by the sealing jaws <NUM> is preferably approximately <NUM> degrees Celsius (<NUM> degrees Fahrenheit), at a pressure of preferably approximately <NUM> kPa (<NUM> psi) and a dwell of preferably approximately <NUM> seconds. The tertiary sealing jaws <NUM> engage the fitment <NUM> preferably simultaneously from opposition sides so the pressure applied to the fitment <NUM> is evenly distributed.

As shown in <FIG>, the tertiary sealing jaws <NUM> substantially overlap the primary seals <NUM>, <NUM>, and secondary seals <NUM>, <NUM>, <NUM>, <NUM>. Consequently, as best shown in <FIG>, first tertiary seal portions <NUM> of the tertiary seals <NUM>, <NUM> overlap with the first primary seal portions <NUM> and the first secondary seal portions <NUM> to further adhere the single layer of film (i.e., <NUM> mils thick) of the sealing portions 120b,d, respectively, to the base surface <NUM>. As shown, tertiary seals <NUM>, <NUM> also serve to seal the portions of sealing portions 120b,d that were previously unsealed to the base surface <NUM>. Second tertiary seal portions <NUM> of the tertiary seals <NUM>, <NUM> further adhere the overlapping portion comprising the two layers of film of the flaps <NUM> (i.e., <NUM> mils thick) and the single layer of film of the sealing portions 120b,d, respectively, to the base surface <NUM>, thereby forming second tertiary seal portions <NUM> of the multiseal <NUM> that reinforce the second primary seal portions <NUM> and the second secondary seal portions <NUM>, which is particularly important in view of the thickness of the film in those portions of the multiseal <NUM> at the flaps <NUM>. Additionally, third tertiary seal portions <NUM> of the tertiary seals <NUM>, <NUM> overlap with the third primary seal portions <NUM> and the third secondary seal portions <NUM> to further adhere the single layer of film (i.e., <NUM> mils thick) of the sealing portions 120a,c respectively, to the base surface <NUM>.

As shown in <FIG>, the tertiary seals <NUM>, <NUM> as formed further adhere by welding the sealing portions 120b,d to the base surface <NUM>. Moreover, the tertiary seals <NUM>, <NUM> further adhere by welding flaps <NUM> to sealing portions 120b,d, which are correspondingly partially adhered by welding to the base surface <NUM>. In this manner the multiseal <NUM> is made more robust and reliable by way of additional steps of the Multiseal Process provided in accordance with the present invention.

As best shown in <FIG>, there is preferably a gap between bottom edges <NUM> of the tertiary seals <NUM>, <NUM> and the bottom base edge <NUM> that is preferably approximately <NUM> inches, and preferably approximately <NUM> inches from top base edge <NUM> to top edges <NUM>. The tertiary seals <NUM>, <NUM> in this example of a preferred embodiment are preferably approximately <NUM> inches wide. As best shown in <FIG>, the arc length between the respective outer edges <NUM> of the first tertiary seal <NUM> is preferably approximately <NUM> degrees, as is the arc length between the respective outer edges <NUM> of the second tertiary seal <NUM>. Although <FIG> depicts seal <NUM> only, it should be understood that seal <NUM> occurs in a complementary position on the opposite side of the fitment base surface <NUM>.

<FIG> illustrates for clarity a flattened depiction of a fitment base surface <NUM> and a corresponding multiseal <NUM>. As shown, in one example of a preferred embodiment of the present invention, the fitment base surface <NUM> has a circumference of preferably approximately <NUM> inches and height of preferably approximately <NUM> inches. As shown, the preferably two seals <NUM>, four seals <NUM>, and two seals <NUM> are spaced apart and overlap as shown and also described above. Notably, the portions of the multiseal <NUM> where one each of seals <NUM>, <NUM>, and <NUM> overlap is at the flaps <NUM>. The flaps <NUM> in this example have a width of preferably approximately <NUM> inches and the width of the overlap portion of one each of seals <NUM>, <NUM>, and <NUM> is preferably approximately <NUM> inches and directly overlapping flap <NUM>. In this way, by providing the multiseal <NUM> having Multiseal Process Steps <NUM>-<NUM> (and sometimes <NUM>-<NUM> as described below), the integrity and drop performance of the container <NUM> at the juncture of the fitment <NUM> and the film of the neck <NUM> is dramatically improved because the flaps <NUM> have been made leak-proof at the fitment base surface <NUM> by, in particular the thinner, higher pressure, and higher temperature seal <NUM> near the top edge <NUM>. Moreover, other portions of the multiseal <NUM>, such as at third primary seal portions <NUM> and first tertiary seal portions <NUM> that seal single layer sealing portions <NUM> to the fitment base surface <NUM> are likewise leak-proof but have not been made weak or brittle by excessive sealing.

It is contemplated that a greater or lesser number of jaws may be used. For example, jaws <NUM> may be a pair of complementary jaws <NUM> instead of four jaws <NUM>, wherein a gap is machined between pairs of sealing faces <NUM> such that although jaws <NUM> are two instead of four, preferably four secondary seals <NUM>, <NUM>, <NUM>, <NUM> are still imparted on the multiseal <NUM>.

It is contemplated that extra steps of the Multiseal Process may be employed. For example, a Multiseal Process Step <NUM> comprising a repeat of Multiseal Process <NUM> for a one second dwell smooths out surface indents that may be imparted on the multiseal <NUM> by jaws <NUM> during the higher pressure and temperature Multiseal Process Step <NUM>.

It is contemplated that the previously described multiseal process step <NUM>, utilizing sealing jaws <NUM> (and hereafter "sealing step <NUM>"), multiseal process step <NUM>, utilizing sealing jaws <NUM> (and hereafter "sealing step <NUM>"), and multiseal process step <NUM>, utilizing sealing jaws <NUM> (and hereafter "sealing step <NUM>") may be employed in different sequential orders. For example, the multiseal sealing sequence can be sealing step <NUM> followed by sealing step <NUM>, followed by sealing step <NUM>. Alternatively, the multiseal sealing sequence can be sealing step <NUM> followed by sealing step <NUM>, followed by sealing step <NUM>.

In an embodiment, container <NUM> is formed from a five layer all-polyethylene film and container <NUM> has one, some, or all of the following properties:.

By way of example, and not limitation, examples of the present disclosure are provided.

Four panel flexible containers having a neck (with no fitment) and a body as shown in <FIG> and in <FIG> are formed using the five-layer film provided in Table <NUM> below. The five-layer film is an "all-polyethylene" multilayer film. Each of the four panels is made with the five-layer film shown in Table <NUM>. The four-panel flexible containers have a volume of one gallon (<NUM>).

Density is measured in accordance with ASTM D <NUM>.

Melt index (Ml) is measured in accordance with ASTM D <NUM>, Condition <NUM>/<NUM> (g/<NUM> minutes).

Four panels made from the flexible multilayer film in Table <NUM> are heat sealed together under the heat seal conditions provided in Table <NUM> (below) to produce flexible container blanks (i.e., a "blank" being a flexible container without a fitment). The four-sided flexible containers have the geometry and design of the flexible containers as shown in <FIG> and in <FIG>, without a fitment. The flexible containers have a volume of one gallon (<NUM>).

A fitment with a base diameter of <NUM> is inserted into the neck for each respective flexible container. Each fitment is made from the same high density polyethylene (HDPE). A <NUM> diameter mandrel inserted into the base of the fitment. The mandrel includes an expandable collar. The expandable collar is made of Shore A <NUM> +/- <NUM> durometer FDA approved silicone rubber.

With the mandrel inserted in the base, and the collar expanded, the base of the fitment is heat sealed to the neck of the flexible container using sealing jaws <NUM>, <NUM>, <NUM> as shown in <FIG> and the mandrel collar expanded to support the base of the fitment as set forth in <CIT>. The heat sealing parameters for sealing the fitment to the neck of the flexible container are set forth in Table <NUM> below.

The flexible container with fitment sealed thereto is evaluated for burst test, top drop test, and seal appearance. The procedure for the burst test and the procedure for the top drop test are provided below.

Each flexible container is filled with <NUM> grams of water was held by bottom handle with the cap directly aligned to the drop surface. The distance is measured from the cap to the drop surface. The drop surface is smooth concrete. Data was only collected from samples where the cap struck the drop surface first. Failure is defined as any leakage of the package after dropping.

The results for the burst test, the top drop test, and seal appearance are provided in Table <NUM> below.

Applicant discovered that the present three step multiseal process utilizing sealing jaws <NUM>, <NUM>, and <NUM> unexpectedly enables a reduction in heat seal temperature during heat sealing, thereby enabling an all-polyethylene film to be used for the flexible container. The present multiseal process with sealing jasws <NUM>, <NUM>, <NUM> eliminates the need for a polyamide skin layer or a polyester skin layer, typically required to provide heat resistance during the heat sealing procedure. A flexible package made from an all-polyethylene multilayer film is advantageous for processability (multilayer film with all-polyethylene layers is co-extrudable and does not require a lamination step). Another benefit of an all-polyethylene film is its recyclability.

Claim 1:
A method for sealing a fitment to a flexible container comprising the steps of:
providing a flexible container (<NUM>) formed of flexible film and having a plurality of panels (<NUM>, <NUM>, <NUM>, <NUM>), and a neck (<NUM>) configured to be connected to a fitment (<NUM>), via a multiseal (<NUM>), the multiseal formed from the plurality of panels being sealed at the neck and comprising a top edge (<NUM>), a bottom edge (<NUM>), a plurality of sealing surfaces, and a plurality of flaps (<NUM>);
providing the fitment (<NUM>), the fitment comprising a base surface (<NUM>);
placing the fitment (<NUM>) in the neck (<NUM>), wherein the multiseal (<NUM>) is provided around the base surface (<NUM>) such that the multiseal (<NUM>) and the base surface (<NUM>) are complementarily aligned;
providing a plurality of primary seals (<NUM>, <NUM>) of the multiseal (<NUM>) via engagement of the multiseal (<NUM>) by a plurality of primary sealing jaws (<NUM>), wherein the primary sealing jaws (<NUM>) form the primary seals (<NUM>, <NUM>) at the sealing surfaces and flaps of the multiseal, wherein the sealing surfaces are sealed to the base surface (<NUM>) and the flaps (<NUM>) are folded toward and sealed to the sealing surfaces;
providing a plurality of secondary seals (<NUM>, <NUM>, <NUM>, <NUM>) of the multiseal (<NUM>) via engagement of the multiseal (<NUM>) by a plurality of secondary sealing jaws (<NUM>), wherein the secondary sealing jaws (<NUM>) form the secondary seals at the sealing surfaces and flaps of the multiseal, wherein the secondary seals (<NUM>, <NUM>, <NUM>, <NUM>) overlap with the primary seals (<NUM>, <NUM>), and wherein the secondary seals (<NUM>, <NUM>, <NUM>, <NUM>) are located substantially closer to the top edge (<NUM>) of the multiseal than to the bottom edge (<NUM>) of the multiseal; and
providing a plurality of tertiary seals (<NUM>, <NUM>) of the multiseal (<NUM>) via engagement of the multiseal by a plurality of tertiary sealing jaws (<NUM>), wherein the tertiary sealing jaws form the tertiary seals (<NUM>, <NUM>) at the sealing surfaces and flaps of the multiseal, wherein the tertiary seals (<NUM>, <NUM>) overlap with the primary seals (<NUM>, <NUM>) and the secondary seals (<NUM>, <NUM>).