Patent Publication Number: US-2023136872-A1

Title: Flexible Mouth Insert for Pouch

Description:
RELATED APPLICATION 
     This application claims priority to the Nov. 2, 2021 filing date of U.S. Provisional Patent Application Ser. No. 63/274,692, which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a flexible pouch, and more particularly to a flexible mouth insert for a flexible pouch. 
     BACKGROUND OF THE INVENTION 
     It is known to use a flexible pouch to contain a flowable substance, such as food, medicine, or hand sanitizer. The flexible pouch is typically provided with a rigid spout for filling and/or dispensing the flowable substance from the pouch. For example, United States Patent Application Publication No. US 2019/0358939 to Ophardt et al., published Nov. 28, 2019 and incorporated herein by reference, discloses a flexible pouch with an injection molded polyethylene spout. The spout has a sealing portion that is placed into an open end of the pouch and heat sealed in place. The spout also has an outlet portion that extends outwardly from the pouch, and provides an opening for receiving a fluid pump for dispensing fluid from the pouch. 
     Typically, the spout of a flexible pouch is made from a material and/or has a thickness that causes the spout to be rigid. This rigidity may be desired to provide a strong and relatively inflexible connection to another component, such as a fluid pump or a screw-top closure. 
     The inventors of the present invention have recognized a number of disadvantages of the prior art. For example, the rigid spouts often used in the prior art are relatively large and heavy, adding material costs and shipping costs. Furthermore, in order to provide the desired rigidity, the spouts are often made from a different material than the body of the pouch, with a different melting temperature. This can make it difficult to produce a strong heat sealed connection between the spout and the pouch body. Alternatively, if the spout is made from the same material as the pouch body, the spout may not have the desired degree of rigidity and/or other desired material properties. 
     SUMMARY OF THE INVENTION 
     To at least partially overcome some of the disadvantages of previously known methods and devices, in one aspect the present invention provides a flexible mouth insert for a flexible pouch. The mouth insert preferably includes a sealing portion for forming a sealed connection to the flexible pouch, and a lip portion configured to extend outwardly from the pouch. The lip portion preferably has a height that is less than ⅓ of the total height of the mouth insert. 
     The inventors of the present invention have appreciated that providing a flexible mouth insert for a flexible pouch advantageously allows the mouth of the pouch to be opened wide to allow for efficient filling of the pouch through the mouth insert, while also allowing the mouth to be flattened to enable compact and cost effective storage, shipping, and packaging. Making the mouth insert flexible and configured to extend only a short distance from the body of the pouch also allows the mouth insert to be manufactured using a relatively small amount of material, which preferably reduces material costs, shipping costs, and environmental costs. 
     Making the mouth insert flexible also allows the mouth insert to be made from the same material as the body of the flexible pouch. This preferably allows for more effective heat sealing between the mouth insert and the body of the pouch, and also preferably allows for easier recycling of the pouch. 
     Preferably, the mouth insert is configured to connect to an attachment, such as a closure, a spout, and/or a fluid pump. For example, the mouth insert may have a ridge or a groove that is configured to engage with the attachment in a snap fit. The attachment is optionally made from a different material than the mouth insert. This allows the attachment to, for example, be made from a rigid material with a different melting temperature than the flexible pouch, without impacting the strength of the heat seal between the mouth insert and the pouch. 
     Optionally, the pouch is manufactured and the mouth insert is heat sealed in place, and the pouch is then packaged, shipped, and/or sold in an empty state, without an attachment. The purchaser of the flexible pouch may then fill the pouch with a flowable substance, via the mouth insert, and then attach an attachment to the mouth insert such as a closure, a spout, and/or a fluid pump. 
     Advantageously, the same mouth insert design can be used to attach to a variety of different attachments. For example, one purchaser of the flexible pouch may fill the pouch with baby food and attach a twist-top closure to the mouth insert, and another purchaser may fill the pouch with hand sanitizer and attach a fluid pump to the mouth insert. 
     Preferably, the mouth insert is configured to connect to an attachment only at the outer end of the mouth insert, with the inner end of the mouth insert being unconnected to the attachment. This arrangement preferably helps to make the connection between the mouth insert and the attachment more resilient. In particular, when the flexible pouch is dropped or otherwise subjected to a compressive force, the inner end of the mouth insert is preferably able to flex outwardly, away from the attachment, to accommodate the fluid that is displaced by the compression. This preferably reduces the fluid pressure within the pouch, and thus reduces the force pulling the outer end of the mouth insert and away from the attachment. 
     Preferably, the sealing portion of the mouth insert has one or more slots that extend therethrough, so as to increase the flexibility of the mouth insert. This increased flexibility preferably helps to reduce the fluid pressure within the pouch during compression, in the manner as described above. Preferably, the slots have a wave-like shape. 
     The outer end of the mouth insert preferably forms a liquid tight seal with the attachment. Optionally, thes mouth insert may be laser welded and/or ultrasonic welded to the attachment, in addition to or in place of the snap fit connection. 
     Accordingly, in a first aspect, the present invention resides in a mouth insert for a flexible pouch, the mouth insert defining a passageway that extends along an axis from an axially outer end of the mouth insert to an axially inner end of the mouth insert; the mouth insert comprising: a sealing portion for forming a sealed connection to the flexible pouch; and a lip portion configured to extend axially outwardly from the flexible pouch; wherein the mouth insert is flexible; wherein the lip portion defines the axially outer end of the mouth insert; wherein the mouth insert has a mouth insert axial height, the sealing portion has a sealing portion axial height, and the lip portion has a lip portion axial height; and wherein the lip portion axial height is less than ⅓ of the mouth insert axial height. 
     In a second aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of the first aspect, wherein the sealing portion defines the axially inner end of the mouth insert; and wherein the mouth insert axial height is a sum of the sealing portion axial height and the lip portion axial height. 
     In a third aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first and second aspects, wherein the sealing portion has a first sealing wall and a second sealing wall; wherein the first sealing wall and the second sealing wall each have an outer surface and an inner surface; wherein the outer surface of the first sealing wall is for forming the sealed connection to a first portion of the flexible pouch; wherein the outer surface of the second sealing wall is for forming the sealed connection to a second portion of the flexible pouch; and wherein the passageway is defined, in part, between the inner surface of the first sealing wall and the inner surface of the second sealing wall. 
     In a fourth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to third aspects, wherein the lip portion has a first lip that extends axially outwardly from the first sealing wall of the sealing portion; wherein the lip portion has a second lip that extends axially outwardly from the second sealing wall of the sealing portion; wherein the first lip and the second lip each have an outside surface and an inside surface; and wherein the passageway is defined, in part, between the inside surface of the first lip and the inside surface of the second lip. 
     In a fifth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to fourth aspects, wherein the inside surface of the first lip extends radially inwardly, past the inner surface of the first sealing wall, and the inside surface of the second lip extends radially inwardly, past the inner surface of the second sealing wall. 
     In a sixth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to fifth aspects, wherein the inside surface of the first lip and the inside surface of the second lip are configured to connect to an attachment. 
     In a seventh aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to sixth aspects, wherein the attachment comprises at least one of: a spout, a closure, and a pump. 
     In an eighth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to seventh aspects, wherein the inside surface of the first lip and the inside surface of the second lip are configured to form a snap fit connection with the attachment. 
     In a ninth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to eighth aspects, wherein the inside surface of the first lip and the inside surface of the second lip are configured to form a liquid tight seal with the attachment. 
     In a tenth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to ninth aspects, wherein the outside surface of the first lip extends radially outwardly, past the outer surface of the first sealing wall, and the outside surface of the second lip extends radially outwardly, past the outer surface of the second sealing wall. 
     In an eleventh aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to tenth aspects, wherein the first lip has a first axially inwardly facing shoulder that is configured to be positioned axially outwardly from an axially outer end of the first portion of the flexible pouch; and wherein the second lip has a second axially inwardly facing shoulder that is configured to be positioned axially outwardly from an axially outer end of the second portion of the flexible pouch. 
     In a twelfth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to eleventh aspects, wherein the first sealing wall has at least one slot that extends radially through the first sealing wall from the inner surface to the outer surface; and wherein the second sealing wall has at least one slot that extends radially through the second sealing wall from the inner surface to the outer surface. 
     In a thirteenth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to twelfth aspects, wherein the at least one slot in the first sealing wall and the at least one slot in the second sealing wall each extend in a transverse direction that is perpendicular to the axis. 
     In a fourteenth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to thirteenth aspects, wherein the at least one slot in the first sealing wall comprises a first slot and a second slot, the first slot being axially spaced from the second slot; and wherein the at least one slot in the second sealing wall comprises a third slot and a fourth slot, the third slot being axially spaced from the fourth slot. 
     In a fifteenth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to fourteenth aspects, wherein the at least one slot in the first sealing wall and the at least one slot in the second sealing wall each have a wave-like shape. 
     In a sixteenth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to fifteenth aspects, wherein, when the mouth insert is in an unbiased condition, the mouth insert has an eye-like shape when viewed from the axis, with two convex walls that are connected at two corners; and wherein the passageway is defined between the two convex walls. 
     In a seventeenth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to sixteenth aspects, wherein the two corners are rounded. 
     In an eighteenth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to seventeenth aspects, wherein the mouth insert is injection molded. 
     In a nineteenth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to eighteenth aspects, wherein the mouth insert is extrusion molded. 
     In a twentieth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to nineteenth aspects, wherein the mouth insert is formed from LDPE. 
     In a twenty first aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to twentieth aspects, wherein the mouth insert is formed from PET. 
     In a twenty second aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to twenty first aspects, wherein the mouth insert is formed from rPET. 
     In a twenty third aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to twenty second aspects, wherein the mouth insert is formed from a single material. 
     In a twenty fourth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to twenty third aspects, wherein the passageway is unobstructed. 
     In a twenty fifth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to twenty fourth aspects, wherein the passageway is obstructed by a membrane. 
     In a twenty sixth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to twenty fifth aspects, wherein the membrane is formed from at least one of: LDPE, PET, rPET, and rubber. 
     In a twenty seventh aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to twenty sixth aspects, wherein the membrane is elastic. 
     In a twenty eighth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to twenty seventh aspects, wherein the lip portion axial height is less than ¼ of the mouth insert axial height. 
     In a twenty ninth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to twenty eighth aspects, wherein the lip portion axial height is less than ⅕ of the mouth insert axial height. 
     In a thirtieth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to twenty ninth aspects, wherein the lip portion axial height is less than ⅙ of the mouth insert axial height. 
     In a thirty first aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to thirtieth aspects, wherein the lip portion axial height is less than 5 mm. 
     In a thirty second aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to thirty first aspects, wherein the lip portion axial height is less than 4 mm. 
     In a thirty third aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to thirty second aspects, wherein the lip portion axial height is less than 3 mm. 
     In a thirty fourth aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to thirty second aspects, wherein the lip portion axial height is less than 2 mm. 
     In a thirty fifth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to thirty fourth aspects, the flexible pouch comprising: a film that defines an internal compartment of the flexible pouch; and a mouth insert that is sealed between a first portion of the film and a second portion of the film to define a mouth of the flexible pouch; the mouth insert defining a passageway that extends along an axis from an axially outer end of the mouth insert to an axially inner end of the mouth insert; wherein the passageway extends from the internal compartment of the flexible pouch, at the axially inner end of the mouth insert, to an external environment, at the axially outer end of the mouth insert; wherein the mouth insert is flexible; and wherein the mouth insert extends from 0 mm to 5 mm axially outwardly from the film. 
     In a thirty sixth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to thirty fifth aspects, wherein the mouth insert has a first sealing wall and a second sealing wall; wherein the first sealing wall and the second sealing wall each have an outer surface and an inner surface; wherein the outer surface of the first sealing wall is sealed to the first portion of the film; wherein the outer surface of the second sealing wall is sealed to the second portion of the film; and wherein the passageway is defined, at least in part, between the inner surface of the first sealing wall and the inner surface of the second sealing wall. 
     In a thirty seventh aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to thirty sixth aspects, wherein the mouth insert has a snap fit connector that extends radially inwardly, past the inner surface of the first sealing wall and the inner surface of the second sealing wall. 
     In a thirty eighth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to thirty seventh aspects, wherein the snap fit connector is located at the axially outer end of the mouth insert. 
     In a thirty ninth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to thirty eighth aspects, wherein the snap fit connector is for forming a snap fit connection with an attachment. 
     In a fortieth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to thirty ninth aspects, wherein the attachment comprises at least one of: a spout, a closure, and a pump. 
     In a forty first aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to fortieth aspects, wherein the snap fit connector is configured to form a liquid tight seal with the attachment. 
     In a forty second aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to forty first aspects, further comprising an attachment that is attached to the mouth insert. 
     In a forty third aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to forty second aspects, wherein the attachment comprises at least one of: a spout, a closure, and a pump. 
     In a forty fourth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to forty third aspects, wherein the attachment extends into the passageway. 
     In a forty fifth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to forty fourth aspects, wherein the attachment is connected to the mouth insert by at least one of: a snap fit connection, a laser weld, and an ultrasonic weld. 
     In a forty sixth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to forty fifth aspects, wherein the attachment is attached to the axially outer end of the mouth insert. 
     In a forty seventh aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to forty sixth aspects, wherein the axially inner end of the mouth insert is unattached to the attachment. 
     In a forty eighth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to forty seventh aspects, wherein the mouth insert has a snap fit connector that extends radially inwardly, past the inner surface of the first sealing wall and the inner surface of the second sealing wall. 
     In a forty ninth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to forty eighth aspects, wherein the snap fit connector is located at the axially outer end of the mouth insert. 
     In a fiftieth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to forty ninth aspects, wherein the attachment has a groove; and wherein the groove receives the snap fit connector in a snap fit. 
     In a fifty first aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to fiftieth aspects, wherein the mouth insert forms a liquid tight seal with the attachment. 
     In a fifty second aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to fifty first aspects, wherein the attachment is formed from a different material than the mouth insert. 
     In a fifty third aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to fifty second aspects, wherein the attachment is rigid. 
     In a fifty fourth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to fifty third aspects, wherein the attachment is formed from at least one of: HDPE and PP. 
     In a fifty fifth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to fifty fourth aspects, wherein the first sealing wall has at least one slot that extends radially through the first sealing wall from the inner surface to the outer surface; and wherein the second sealing wall has at least one slot that extends radially through the second sealing wall from the inner surface to the outer surface. 
     In a fifty sixth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to fifty fifth aspects, wherein the at least one slot in the first sealing wall and the at least one slot in the second sealing wall each extend in a transverse direction that is perpendicular to the axis. 
     In a fifty seventh aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to fifty sixth aspects, wherein the at least one slot in the first sealing wall comprises a first slot and a second slot, the first slot being axially spaced from the second slot; and wherein the at least one slot in the second sealing wall comprises a third slot and a fourth slot, the third slot being axially spaced from the fourth slot. 
     In a fifty eighth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to fifty seventh aspects, wherein the at least one slot in the first sealing wall and the at least one slot in the second sealing wall each have a wave-like shape. 
     In a fifty ninth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to fifty eighth aspects, wherein, when the mouth insert is in an unbiased condition, the mouth insert has an eye-like shape when viewed from the axis, with two convex walls that are connected at two corners; and wherein the passageway is defined between the two convex walls. 
     In a sixtieth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to fifty ninth aspects, wherein the two corners are rounded. 
     In a sixty first aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to sixtieth aspects, wherein the mouth insert is injection molded. 
     In a sixty second aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to sixty first aspects, wherein the mouth insert is extrusion molded. 
     In a sixty third aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to sixty second aspects, wherein the mouth insert is formed from LDPE. 
     In a sixty fourth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to sixty third aspects, wherein the mouth insert is formed from PET. 
     In a sixty fifth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to sixty fourth aspects, wherein the mouth insert is formed from rPET. 
     In a sixty sixth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to sixty fifth aspects, wherein the mouth insert is formed from a single material. 
     In a sixty seventh aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to sixty sixth aspects, wherein the film is formed by blown film extrusion. 
     In a sixty eighth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to sixty seventh aspects, wherein the film is formed from a single material. 
     In a sixty ninth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to sixty eighth aspects, wherein the mouth insert and the film are formed from the same material. 
     In a seventieth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to sixty ninth aspects, wherein the film has multiple layers. 
     In a seventy first aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to seventieth aspects, wherein the film has an inner layer that is sealed to the mouth insert; and wherein the mouth insert and the inner layer of the film are formed from the same material. 
     In a seventy second aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to seventy first aspects, wherein the inner layer of the film comprises at least one of: LDPE, PET, and rPET. 
     In a seventy third aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to seventy second aspects, wherein the film comprises at least one of: LDPE, PET, and rPET. 
     In a seventy fourth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to seventy third aspects, wherein the passageway is unobstructed. 
     In a seventy fifth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to seventy fourth aspects, wherein the passageway is obstructed by a membrane. 
     In a seventy sixth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to seventy fifth aspects, wherein the membrane is formed from at least one of: LDPE, PET, rPET, and rubber. 
     In a seventy seventh aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to seventy sixth aspects, wherein the membrane is elastic. 
     In a seventy eighth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to seventy seventh aspects, wherein the mouth insert extends less than 4 mm axially outwardly from the film. 
     In a seventy ninth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to seventy eighth aspects, wherein the mouth insert extends less than 3 mm axially outwardly from the film. 
     In an eightieth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to seventy ninth aspects, wherein the mouth insert extends less than 2 mm axially outwardly from the film. 
     In an eighty first aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to eightieth aspects, wherein the mouth insert is the mouth insert according to any one of the first to thirty fourth aspects. 
     In an eighty second aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to eighty first aspects, the method comprising: producing a flexible film that defines an internal compartment of the flexible pouch; producing a flexible mouth insert, the flexible mouth insert defining a passageway that extends along an axis from an axially outer end of the mouth insert to an axially inner end of the mouth insert; positioning the flexible mouth insert between a first portion of the flexible film and a second portion of the flexible film, so that the flexible mouth insert extends from 0 mm to 5 mm axially outwardly from the flexible film; and sealing the flexible mouth insert to the first portion of the flexible film and the second portion of the flexible film, so that the flexible mouth insert defines a mouth of the flexible pouch, with the passageway extending from the internal compartment, at the axially inner end of the flexible mouth insert, to an external environment, at the axially outer end of the flexible mouth insert. 
     In an eighty third aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to eighty second aspects, wherein sealing the flexible mouth insert to the first portion of the flexible film and the second portion of the flexible film comprises: inserting a core pin into the passageway; applying heat to the flexible film to heat seal the flexible mouth insert to the first portion of the flexible film and the second portion of the flexible film; and removing the core pin from the passageway. 
     In an eighty fourth aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to eighty third aspects, wherein producing the flexible film comprises producing the flexible film by blown film extrusion. 
     In an eighty fifth aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to eighty fourth aspects, wherein producing the flexible mouth insert comprises producing the flexible mouth insert by injection molding. 
     In an eighty sixth aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to eighty fifth aspects, wherein producing the flexible mouth insert comprises producing the flexible mouth insert by extrusion molding. 
     In an eighty seventh aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to eighty sixth aspects, further comprising: filling the internal compartment of the flexible pouch with a fluid. 
     In an eighty eighth aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to eighty seventh aspects, wherein the fluid is introduced into the internal compartment through the passageway defined by the flexible mouth insert. 
     In an eighty ninth aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to eighty eighth aspects, wherein the flexible mouth insert has a membrane that obstructs the passageway; and wherein filling the internal compartment comprises puncturing the membrane. 
     In a ninetieth aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to eighty ninth aspects, wherein the fluid is a hand cleaning fluid. 
     In a ninety first aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to ninetieth aspects, further comprising: attaching an attachment to the flexible mouth insert. 
     In a ninety second aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to ninety first aspects, wherein the attachment comprises at least one of: a spout, a closure, and a pump. 
     In a ninety third aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to ninety second aspects, wherein the attachment comprises a pump. 
     In a ninety fourth aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to ninety third aspects, wherein attaching the attachment to the flexible mouth insert comprises inserting the attachment into the passageway of the flexible mouth insert. 
     In a ninety fifth aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to ninety fourth aspects, wherein attaching the attachment to the flexible mouth insert comprises attaching the attachment to the flexible mouth insert with a snap fit. 
     In a ninety sixth aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to ninety fifth aspects, wherein attaching the attachment to the flexible mouth insert comprises laser welding the attachment to the flexible mouth insert. 
     In a ninety seventh aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to ninety sixth aspects, wherein attaching the attachment to the flexible mouth insert comprises ultrasonic welding the attachment to the flexible mouth insert. 
     In a ninety eighth aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to ninety seventh aspects, wherein attaching the attachment to the flexible mouth insert comprises attaching the attachment to the axially outer end of the flexible mouth insert, without attaching the attachment to the axially inner end of the flexible mouth insert. 
     In a ninety ninth aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to ninety eighth aspects, wherein the attachment is attached to the flexible mouth insert before the flexible mouth insert is sealed to the first portion of the flexible film and the second portion of the flexible film. 
     In a one hundredth aspect the present invention resides in a method of producing a flexible pouch, which optionally incorporates one or more features of one or more of the first to ninety ninth aspects, wherein the flexible pouch is the flexible pouch according to any one of the thirty fifth to eighty first aspects. 
     In a one hundred and first aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to one hundredth aspects, wherein the sealing portion is for forming a heat sealed connection to the flexible pouch. 
     In a one hundred and second aspect the present invention resides in a mouth insert, which optionally incorporates one or more features of one or more of the first to one hundred and first aspects, wherein the sealing portion is for forming a laser welded connection to the flexible pouch. 
     In a one hundred and third aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and second aspects, wherein the mouth insert is heat sealed to the first portion of the film and the second portion of the film. 
     In a one hundred and fourth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and third aspects, wherein the mouth insert is laser welded to the first portion of the film and the second portion of the film. 
     In a one hundred and fifth aspect the present invention resides in a method, which optionally incorporates one or more features of one or more of the first to one hundred and fourth aspects, wherein sealing the flexible mouth insert to the first portion of the flexible film and the second portion of the flexible film comprises: heat sealing the flexible mouth insert to the first portion of the flexible film and the second portion of the flexible film. 
     In a one hundred and sixth aspect the present invention resides in a method, which optionally incorporates one or more features of one or more of the first to one hundred and fifth aspects, wherein sealing the flexible mouth insert to the first portion of the flexible film and the second portion of the flexible film comprises: laser welding the flexible mouth insert to the first portion of the flexible film and the second portion of the flexible film. 
     In a one hundred and seventh aspect the present invention resides in a method, which optionally incorporates one or more features of one or more of the first to one hundred and sixth aspects, wherein the flexible mouth insert is laser welded to the first portion of the flexible film and the second portion of the flexible film after the flexible mouth insert is heat sealed to the first portion of the flexible film and the second portion of the flexible film. 
     In a one hundred and eighth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and seventh aspects, comprising; a film that defines an internal compartment of the flexible pouch; and a mouth insert that is sealed between a first portion of the film and a second portion of the film to define a mouth of the flexible pouch; the mouth insert defining a passageway that extends along an axis from an axially outer end of the mouth insert to an axially inner end of the mouth insert; wherein the passageway extends from the internal compartment of the flexible pouch, at the axially inner end of the mouth insert, to an external environment, at the axially outer end of the mouth insert; and wherein the mouth insert is flexible. 
     In a one hundred and ninth aspect the present invention resides in a method, which optionally incorporates one or more features of one or more of the first to one hundred and eighth aspects, comprising: producing a flexible film; producing a flexible mouth insert, the flexible mouth insert defining a passageway that extends along an axis from an axially outer end of the mouth insert to an axially inner end of the mouth insert; positioning the flexible mouth insert between a first portion of the flexible film and a second portion of the flexible film; and sealing the flexible mouth insert to the first portion of the flexible film and the second portion of the flexible film, so that the flexible mouth insert and the flexible film together form a flexible pouch, with the flexible film defining an internal compartment of the flexible pouch and the flexible mouth insert defining a mouth of the flexible pouch, with the passageway extending from the internal compartment, at the axially inner end of the flexible mouth insert, to an external environment, at the axially outer end of the flexible mouth insert. 
     In a one hundred and tenth aspect the present invention resides in a mouth insert for a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and ninth aspects, the mouth insert defining a passageway that extends along an axis from an axially outer end of the mouth insert to an axially inner end of the mouth insert; the mouth insert comprising: a sealing portion for forming a sealed connection to the flexible pouch; and a lip portion configured to extend axially outwardly from the flexible pouch; wherein the mouth insert is flexible; and wherein the lip portion defines the axially outer end of the mouth insert. 
     In a one hundred and eleventh aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and tenth aspects, comprising: a film that defines an internal compartment of the flexible pouch; and a mouth insert that is sealed between a first portion of the film and a second portion of the film to define a mouth of the flexible pouch; the mouth insert defining a passageway that extends along an axis from an axially outer end of the mouth insert to an axially inner end of the mouth insert; wherein the passageway extends from the internal compartment of the flexible pouch, at the axially inner end of the mouth insert, to an external environment, at the axially outer end of the mouth insert; wherein the mouth insert is flexible; and wherein the mouth insert extends from 0 mm to 5 mm axially outwardly from the film. 
     In a one hundred and twelfth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and eleventh aspects, wherein the mouth insert comprises: a sealing portion that is sealed between the first portion of the film and the second portion of the film; and a lip portion configured to extend axially outwardly from the film; wherein the lip portion defines the axially outer end of the mouth insert; wherein the mouth insert has a mouth insert axial height, the sealing portion has a sealing portion axial height, and the lip portion has a lip portion axial height; wherein the lip portion axial height is less than ⅓ of the mouth insert axial height; wherein the sealing portion defines the axially inner end of the mouth insert; and wherein the mouth insert axial height is a sum of the sealing portion axial height and the lip portion axial height. 
     In a one hundred and thirteenth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and twelfth aspects, wherein the sealing portion has a first sealing wall and a second sealing wall; wherein the first sealing wall and the second sealing wall each have an outer surface and an inner surface; wherein the outer surface of the first sealing wall is sealed to the first portion of the film; wherein the outer surface of the second sealing wall is sealed to the second portion of the film; and wherein the passageway is defined, in part, between the inner surface of the first sealing wall and the inner surface of the second sealing wall. 
     In a one hundred and fourteenth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and thirteenth aspects, wherein the lip portion has a first lip that extends axially outwardly from the first sealing wall of the sealing portion; wherein the lip portion has a second lip that extends axially outwardly from the second sealing wall of the sealing portion; wherein the first lip and the second lip each have an outside surface and an inside surface; wherein the passageway is defined, in part, between the inside surface of the first lip and the inside surface of the second lip; and wherein the inside surface of the first lip extends radially inwardly, past the inner surface of the first sealing wall, and the inside surface of the second lip extends radially inwardly, past the inner surface of the second sealing wall. 
     In a one hundred and fifteenth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and fourteenth aspects, further comprising an attachment that is attached to the mouth insert; wherein the attachment extends into the passageway; wherein the attachment is attached to the lip portion of the mouth insert; and wherein the attachment is unattached to the sealing portion of the mouth insert. 
     In a one hundred and sixteenth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and fifteenth aspects, wherein the attachment comprises at least one of: a spout, a closure, and a pump; and wherein the attachment is connected to the mouth insert by at least one of: a snap fit connection, a laser weld, and an ultrasonic weld. 
     In a one hundred and seventeenth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and sixteenth aspects, wherein the attachment has at least one groove that receives the inside surface of the first lip and the inside surface of the second lip in a snap fit. 
     In a one hundred and eighteenth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and seventeenth aspects, wherein the mouth insert forms a liquid tight seal with the attachment; wherein the attachment is formed from a different material than the mouth insert; wherein the attachment is rigid; and wherein the attachment is formed from at least one of: HDPE and PP. 
     In a one hundred and nineteenth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and eighteenth aspects, wherein the outside surface of the first lip extends radially outwardly, past the outer surface of the first sealing wall, and the outside surface of the second lip extends radially outwardly, past the outer surface of the second sealing wall; wherein the first lip has a first axially inwardly facing shoulder that is positioned axially outwardly from an axially outer end of the first portion of the film; and wherein the second lip has a second axially inwardly facing shoulder that is positioned axially outwardly from an axially outer end of the second portion of the film. 
     In a one hundred and twentieth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and nineteenth aspects, wherein the first sealing wall has at least one slot that extends radially through the first sealing wall from the inner surface to the outer surface; wherein the second sealing wall has at least one slot that extends radially through the second sealing wall from the inner surface to the outer surface; and wherein the at least one slot in the first sealing wall and the at least one slot in the second sealing wall each extend in a transverse direction that is perpendicular to the axis. 
     In a one hundred and twenty first aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and twentieth aspects, wherein the at least one slot in the first sealing wall and the at least one slot in the second sealing wall each have a wave-like shape. 
     In a one hundred and twenty second aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and twenty first aspects, wherein, when the mouth insert is in an unbiased condition, the mouth insert has an eye-like shape when viewed from the axis, with two convex walls that are connected at two corners; and wherein the passageway is defined between the two convex walls. 
     In a one hundred and twenty third aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and twenty second aspects, wherein the mouth insert is at least one of: injection molded; extrusion molded; formed from LDPE; formed from PET; and formed from rPET. 
     In a one hundred and twenty fourth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and twenty third aspects, wherein the mouth insert and the film are formed from the same material; or the film has an inner layer that is sealed to the mouth insert, and the mouth insert and the inner layer of the film are formed from the same material. 
     In a one hundred and twenty fifth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and twenty fourth aspects, wherein the passageway is obstructed by a membrane; wherein the membrane is elastic; and wherein the lip portion axial height is less than ⅙ of the mouth insert axial height. 
     In a one hundred and twenty sixth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and twenty fifth aspects, wherein the attachment has at least one groove that receives the inside surface of the first lip and the inside surface of the second lip in a snap fit; wherein the mouth insert forms a liquid tight seal with the attachment; wherein the attachment is formed from a different material than the mouth insert; wherein the attachment is rigid; and wherein the attachment is formed from at least one of: HDPE and PP. 
     In a one hundred and twenty seventh aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and twenty sixth aspects, wherein the outside surface of the first lip extends radially outwardly, past the outer surface of the first sealing wall, and the outside surface of the second lip extends radially outwardly, past the outer surface of the second sealing wall; wherein the first lip has a first axially inwardly facing shoulder that is positioned axially outwardly from an axially outer end of the first portion of the film; wherein the second lip has a second axially inwardly facing shoulder that is positioned axially outwardly from an axially outer end of the second portion of the film; wherein the first sealing wall has at least one slot that extends radially through the first sealing wall from the inner surface to the outer surface; wherein the second sealing wall has at least one slot that extends radially through the second sealing wall from the inner surface to the outer surface; wherein the at least one slot in the first sealing wall and the at least one slot in the second sealing wall each extend in a transverse direction that is perpendicular to the axis; and wherein the at least one slot in the first sealing wall and the at least one slot in the second sealing wall each have a wave-like shape. 
     In a one hundred and twenty eighth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and twenty seventh aspects, wherein, when the mouth insert is in an unbiased condition, the mouth insert has an eye-like shape when viewed from the axis, with two convex walls that are connected at two corners; wherein the passageway is defined between the two convex walls; and wherein the mouth insert is at least one of: injection molded; extrusion molded; formed from LDPE; formed from PET; and formed from rPET. 
     In a one hundred and twenty ninth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and twenty eighth aspects, wherein the mouth insert and the film are formed from the same material; or the film has an inner layer that is sealed to the mouth insert, and the mouth insert and the inner layer of the film are formed from the same material. 
     In a one hundred and thirtieth aspect the present invention resides in a flexible pouch, which optionally incorporates one or more features of one or more of the first to one hundred and twenty ninth aspects, wherein the passageway is obstructed by a membrane; wherein the membrane is elastic; and wherein the lip portion axial height is less than ⅙ of the mouth insert axial height. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further aspects and advantages of the invention will appear from the following description taken together with the accompanying drawings, in which: 
         FIG.  1    is a top perspective view of a mouth insert in accordance with a first embodiment of the present invention; 
         FIG.  2    is a bottom perspective view of the mouth insert shown in  FIG.  1   ; 
         FIG.  3    is a side view of the mouth insert shown in  FIG.  1   ; 
         FIG.  4    is a top perspective view of the mouth insert shown in  FIG.  1   , showing the mouth insert placed in the open end of a flexible pouch, prior to heat sealing; 
         FIG.  5    is a perspective side view of the flexible pouch shown in  FIG.  4   , showing the mouth insert heat sealed in place to form the mouth of the flexible pouch; 
         FIG.  6    is a perspective view of a spout, configured to attach to the mouth insert shown in  FIG.  1   ; 
         FIG.  7    is a perspective view of the flexible pouch shown in  FIG.  5   , with the spout shown in  FIG.  6    connected to the mouth insert; 
         FIG.  8    is a schematic cross-sectional view of the flexible pouch with the mouth insert forming the mouth of the flexible pouch as shown in  FIG.  5   ; 
         FIG.  9    is a schematic cross-sectional view of the flexible pouch shown in  FIG.  8   , further showing a core pin inserted into the mouth insert during heat sealing; 
         FIG.  10    is a schematic cross-sectional view of the flexible pouch with the spout connected to the mouth insert as shown in  FIG.  7   , showing the mouth insert in an unbiased condition; 
         FIG.  11    is a schematic cross-sectional view of the flexible pouch with the spout connected to the mouth insert as shown in  FIG.  10   , showing the mouth insert in a biased condition adopted when the flexible pouch is subjected to a compressive force; 
         FIG.  12    is a perspective view of a fluid pump, configured to attach to the mouth insert shown in  FIG.  1   ; 
         FIG.  13    is a perspective side view of a flexible pouch, with the mouth insert shown in  FIG.  1    forming the mouth of the flexible pouch, and with the fluid pump shown in  FIG.  12    connected to the mouth insert; 
         FIG.  14    is a perspective view of the mouth insert shown in  FIG.  1    connected to the spout shown in  FIG.  6   ; 
         FIG.  15    is a bottom perspective view of a mouth insert in accordance with a second embodiment of the present invention; and 
         FIG.  16    is a top perspective view of a mouth insert in accordance with a third embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
       FIGS.  1  to  3    show a flexible mouth insert  10  in accordance with a first embodiment of the present invention. The mouth insert  10  has a sealing portion  12  and a lip portion  14 , and defines a passageway  16  that extends along an axis  18  from an axially outer end  20  of the mouth insert  10  to an axially inner end  22  of the mouth insert  10 . 
     The sealing portion  12  defines the axially inner end  22  of the mouth insert  10 , and has a first sealing wall  24  and a second sealing wall  26 . The first sealing wall  24  is connected to the second sealing wall  26  at a first corner  28  and at a second corner  30 . The first sealing wall  24  and the second sealing wall  26  each have an outer surface  32 , which faces radially away from the axis  18 , and an inner surface  34 , which faces radially towards the axis  18 . The passageway  16  is defined, in part, between the inner surface  34  of the first sealing wall  24  and the inner surface  34  of the second sealing wall  26 . A first sealing tab  46  extends radially outwardly from the first corner  28 , and a second sealing tab  48  extends radially outwardly from the second corner  30 . The radially inner surfaces of the first corner  28  and the second corner  30  are preferably rounded. 
     As can be seen in  FIG.  1   , the first sealing wall  24  has a first slot  36  and a second slot  38 , and the second sealing wall  26  has a third slot  40  and a fourth slot  42 . Each of the first slot  36  and the second slot  38  extend radially through the first sealing wall  24 , from the inner surface  34  to the outer surface  32 , and each of the third slot  40  and the fourth slot  42  extend radially through the second sealing wall  26 , from the inner surface  34  to the outer surface  32 . 
     Each of the first slot  36 , the second slot  38 , the third slot  40 , and the fourth slot  42  extend in a transverse direction  44  that is perpendicular to the axis  18 . The first slot  36  is spaced axially outwardly from the second slot  38 , and the third slot  40  is spaced axially outwardly from the fourth slot  42 . In the embodiment shown, each of the first slot  36 , the second slot  38 , the third slot  40 , and the fourth slot  42  has a wave-like shape. 
     The lip portion  14  defines the axially outer end  20  of the mouth insert  10 , and has a first lip  50  that extends axially outwardly from the first sealing wall  24 , and a second lip  52  that extends axially outwardly from the second sealing wall  26 . The first lip  50  and the second lip  52  each have an outside surface  54  that faces radially away from the axis  18 , and an inside surface  56  that faces radially towards the axis  18 . The passageway  16  is defined, in part, between the inside surface  56  of the first lip  50  and the inside surface  56  of the second lip  52 . 
     As is best shown in  FIG.  8   , the first lip  50  and the second lip  52  each have a radially inwardly extended ridge  58 . The ridge  58  of the first lip  50  extends further radially inwardly than the inner surface  34  of the first sealing wall  24 , and the ridge  58  of the second lip  52  extends further radially inwardly than the inner surface  34  of the second sealing wall  26 . This causes the passageway  16  to have a smaller circumference at the axial height of the lip portion  14  than at the axial height of the sealing portion  12 . 
     The first lip  50  and the second lip  52  also each have a radially outwardly extended collar  60 . The collar  60  of the first lip  50  extends further radially outwardly than the outer surface  32  of the first sealing wall  24 , and the collar  60  of the second lip  52  extends further radially outwardly than the outer surface  32  of the second sealing wall  26 . As can be seen in  FIG.  8   , the collar  60  of the first lip  50  has a first axially inwardly facing shoulder  62 , and the collar  60  of the second lip  52  has a second axially inwardly facing shoulder  64 . 
     Referring to  FIG.  3   , the sealing portion  12  has a sealing portion axial height  66 , the lip portion  14  has a lip portion axial height  68 , and the mouth insert  10  has a mouth insert axial height  70 . The mouth insert axial height  70  is the sum of the sealing portion axial height  66  and the lip portion axial height  68 . The lip portion axial height  68  is preferably less than ⅓ of the mouth insert axial height  70 ; more preferably less than ¼ of the mouth insert axial height  70 ; and even more preferably less than ⅕ or less than ⅙ of the mouth insert axial height  70 . 
     As can be seen in  FIGS.  1  and  2   , when the mouth insert  10  is in an unbiased condition, the mouth insert  10  has an eye-like shape when viewed from the axis  18 , with the first sealing wall  24  and the first lip  50  defining a first convex wall  72 , and the second sealing wall  26  and the second lip  52  defining a second convex wall  74 . The passageway  16  is defined between the two convex walls  72 ,  74 . Because the mouth insert  10  is flexible, the two convex walls  72 ,  74  can be drawn away from each other so that the passageway  16  has a more cylindrical shape, or can be pushed towards each other so that the passageway  16  has a more flattened shape. 
     The mouth insert  10  is optionally formed by injection molding or extrusion molding. Preferably, the mouth insert  10  is formed from a single material that is flexible, and has good heat sealing properties. The material is also preferably easily recyclable. The mouth insert  10  may, for example, be formed from low density polyethylene (LDPE), polyethylene terephthalate (PET), or recycled polyethylene terephthalate (rPET). 
     The mouth insert  10  is designed to be heat sealed to a flexible pouch  76  to form the mouth  78  of the flexible pouch  76 , as shown in  FIG.  5   . The mouth insert  10  is preferably formed from a material that can form a strong heat sealed connection to the flexible pouch  76 . The flexible pouch  76  may, for example, have a body  82  that is made from a flexible film  80 . The flexible film  80  may be made from a single material, or may have different layers made from different materials. If the flexible film  80  is made from a single material, the flexible film  80  is preferably made from the same material as the mouth insert  10 . If the flexible film  80  has multiple layers, an inner layer of the film  80 , which is heat sealed to the mouth insert  10 , is preferably made from the same material as the mouth insert  10 . The flexible film  80  is preferably made from a material that is easily recyclable, and that can be recycled together with the mouth insert  10  without requiring the mouth insert  10  to be separated from the flexible film  80 . The flexible film  80 , or the inner layer of the flexible film  80 , preferably has the same melting temperature as the mouth insert  10 . The film  80  may, for example, be formed by blown film extrusion. The film  80  is optionally made from or includes LDPE, PET, and/or rPET. 
     Referring to  FIG.  4   , during manufacturing of the flexible pouch  76  the mouth insert  10  is placed in an open end  84  of the body  82  of the flexible pouch  76 , the body  82  of the flexible pouch  76  being formed from a flexible film  80 . The mouth insert  10  is arranged with the outer surface  32  of the first sealing wall  24  facing towards a first portion  86  of the film  80 , and with the outer surface  32  of the second sealing wall  26  facing towards a second portion  88  of the film  80 . As is best shown in  FIG.  8   , the sealing portion  12  of the mouth insert  10  is positioned between the first portion  86  of the film  80  and the second portion  88  of the film  80 , and the lip portion  14  extends axially outwardly past the axially outer ends of the first portion  86  of the film  80  and the second portion  88  of the film  80 . The mouth insert  10  can be guided to the correct position by placing the mouth insert  10  so that the first shoulder  62  of the first lip  50  abuts the axially outer end of the first portion  86  of the film  80 , and the second shoulder  64  of the second lip  52  abuts the axially outer end of the second portion  88  of the film  80 . 
     Once the mouth insert  10  is in the correct position in the open end  84  of the film  80 , the mouth insert  10  is heat sealed in place by applying heat to the open end  84  of the film  80 . Any suitable heat sealing device known in the art could be used. To prevent the convex walls  72 ,  74  of the mouth insert  10  from heat sealing to each other, a core pin  90  is preferably inserted into the passageway  16  before the heat is applied, as shown in  FIG.  9   . The core pin  90  is preferably made from a material that has a much higher melting temperature than the mouth insert  10 , such as copper or brass. Once the heat sealing is finished, the core pin  90  is removed from the passageway  16 . 
     After the heat sealing, the mouth insert  10  is embedded in a heat sealed portion  92  of the film  80  so as to form a mouth  78  of the flexible pouch  76 . As can be seen in  FIG.  5   , only the lip portion  14  of the mouth insert  10  extends axially outwardly from the body  82  of the pouch  76 . As shown by dotted lines in  FIG.  5   , the sealing portion  12  is embedded in the heat sealed portion  92  of the film  80 . The passageway  16  of the mouth insert  10  extends from an internal compartment  94  of the flexible pouch  76 , at the axially inner end  22  of the mouth insert  10 , to an external environment  96 , at the axially outer end  20  of the mouth insert  10 . 
     Optionally, the film  80  can be folded or trimmed to any desired shape, such as by trimming the corners of the film  80  as shown in  FIG.  5   . The remainder of the pouch  76  may be formed in any suitable manner, such as by heat sealing the outer periphery of the film  80  so as to define the internal compartment  94 . Preferably, the internal compartment  94  of the pouch  76  can only be accessed via the passageway  16  of the mouth insert  10 . 
     The flexible pouch  76  with the mouth insert  10  embedded therein can optionally be packaged, shipped, and/or sold in an empty state. Advantageously, the flexibility of the mouth insert  10 , as well as the relatively small weight and size of the mouth insert  10 , preferably allows the flexible pouch  76  to be packaged and shipped in an efficient and cost effective manner. 
     The internal compartment  94  of the pouch  76  can then be filled with a flowable substance, such as a food product, a medicine, or a cleaning product. The flowable substance can be introduced to the internal compartment  94  via the passageway  16  of the mouth insert  10 . Advantageously, the flexibility of the mouth insert  10  allows the passageway  16  to be held open to allow for efficient filling of the internal compartment  94 . 
     Once the compartment  94  is full, an attachment  98  can be connected to the mouth insert  10 . Any desired attachment  98  may be selected to provide the desired functionality or functionalities, such as preventing the flowable substance from spilling out of the internal compartment  94  and/or allowing the pouch  76  to interface with another device, such as a dispenser, for dispensing the flowable substance from the pouch  76 . The attachment  98  may, for example, be a spout  100  as shown in  FIG.  6   , a fluid pump  102  as shown in  FIG.  12   , or a closure such as a twist-top closure, not shown. 
     Referring to  FIG.  6   , the attachment  98 , which in this case is a spout  100 , has a spout body  104  that defines an internal channel  106 . The spout body  104  has an insertion portion  108  that is configured to be received in the passageway  16  of the mouth insert  10 , and an extension portion  110  that is configured to extend axially outwardly from the mouth insert  10 . The axially outer end of the insertion portion  108  has a groove  112  that is configured to receive the ridge  58  of the mouth insert  10  in a snap fit connection. The axially inner end of the extension portion  110  has a stop ring  114  that has a greater radial extent than the insertion portion  108 . The stop ring  114  prevents the extension portion  110  from being inserted into the passageway  16  of the mouth insert  10 . 
     When the spout  100  is connected to the mouth insert  10 , as shown in  FIG.  7   , the insertion portion  108  sits inside the passageway  16 , with the stop ring  114  positioned axially outwardly from the lip portion  14 , and with the extension portion  110  extending axially outwardly from the mouth insert  10 . As can be seen in  FIG.  10   , the ridge  58  is received in the groove  112  in a snap fit connection. The snap fit connection preferably provides a strong, fluid tight seal between the mouth insert  10  and the spout  100 . Optionally, the connection between the mouth insert  10  and the spout  100  can be further strengthened by laser welding and/or ultrasonic welding. 
     The extension portion  110  may be configured to attach to other components or devices, such as a removable closure, not shown, that prevents the flowable substance from exiting the pouch  76  through the internal channel  106 . The flexible pouch  76  can then, for example, be packaged, shipped, and sold to customers, who can remove the removable closure in order to dispense the flowable substance from the pouch  76 . 
     Advantageously, because the spout  100  is a different component from the mouth insert  10 , the spout  100  may be made from a different material than the mouth insert  10  without affecting the strength of the heat sealed connection between the mouth insert  10  and the film  80 . The spout  100  may, for example, be made from a rigid material. Optionally, the spout  100  may be made from or include high density polyethylene (HDPE) or polypropylene (PP). 
     The fact that the mouth insert  10  is flexible and is only connected to the spout  100  at the axially outer end  20  of the mouth insert  10  preferably helps to improve the resiliency of the connection between the mouth insert  10  and the spout  100 , and decrease the likelihood of the mouth insert  10  becoming disconnected from the spout  100 . When the mouth insert  10  is in an unbiased condition, as shown in  FIG.  10   , the sealing walls  24 ,  26  of the mouth insert  10  extend parallel to the axis  18 , adjacent to the insertion portion  108  of the spout  100 . If the flexible pouch  76  is subjected to a compressive force, such as by dropping the flexible pouch  76  while the flexible pouch  76  is filled with a flowable substance, the compression of the pouch  76  will cause the fluid pressure within the internal compartment  94  to increase. Advantageously, the flexibility of the mouth insert  10  allows the axially inner end  22  of the mouth insert  10  to deflect radially outwardly, as shown in  FIG.  11   , when the fluid pressure within the internal compartment  94  increases. The slots  36 ,  38 ,  40 ,  42  help to increase the flexibility of the sealing walls  24 ,  26 , so as to allow or enhance the ability of the axially inner end  22  of the mouth insert  10  to deflect radially outwardly. 
     The radially outward deflection of the axially inner end  22  of the mouth insert  10  provides space to accommodate the flowable substance displaced by the compressive force, and thereby acts to reduce the fluid pressure within the internal compartment  94 . The relatively lower fluid pressure within the internal compartment  94  results in a relatively smaller force pulling the axially outer end  20  of the mouth insert  10  away from the spout  100 , and thus preferably helps to decrease the likelihood of the mouth insert  10  becoming disconnected from the spout  100 . 
     Other attachments  98 , such as the fluid pump  102  shown in  FIG.  13   , could also be connected to the mouth insert  10 . The fluid pump  102  shown in  FIG.  13    may, for example, be used to connect the pouch  76  to a dispenser housing, not shown, and to dispense the flowable substance from the pouch  76  upon activation of the dispenser housing. Advantageously, the fluid pump  102  can preferably be connected directly to the mouth insert  10 , rather than having to interface with a more bulky rigid spout such as that disclosed in United States Patent Application Publication No. US 2019/0358939 to Ophardt et al., published Nov. 28, 2019. This preferably helps to reduce material costs and environmental costs. The fluid pump  102  may, for example, be configured to connect to the mouth insert  10  with a snap fit connection in the same manner as the spout  100  described above. 
     Optionally, the spout  100  or other attachment  98  could be connected to the mouth insert  10  before the mouth insert  10  is connected to the pouch  76 , as shown in  FIG.  14   . The spout  100  could be connected to the mouth insert  10  by way of the snap fit connection as described above. Optionally, laser welding and/or ultrasonic welding could be used in place of, or together with, the snap fit connection. Forming the mouth insert  10  and the spout  100  as separate components that are attached together allows the mouth insert  10  to be made from a flexible material that forms a strong heat sealed connection to the film  80  of the flexible pouch  76 , while permitting the spout  100  to be made from a different material that may, for example, be rigid. 
     Reference is now made to  FIG.  15   , which shows a mouth insert  10  in accordance with a second embodiment of the invention. Like numerals are used to denote like components. The mouth insert  10  shown in  FIG.  15    is identical to the mouth insert  10  shown in  FIGS.  1  to  3   , with the only difference being that in the mouth insert  10  shown in  FIG.  15    the passageway  16  is obstructed by a membrane  116  at the axially inner end  22  of the mouth insert  10 . 
     The mouth insert  10  shown in  FIG.  15    may be used to form the mouth  78  of a flexible pouch  76  and may be used in exactly the same ways as the mouth insert  10  shown in  FIGS.  1  to  3   , with the only difference being the manner in which the flexible pouch  76  is filled, and the manner in which the flowable substance may be dispensed from the pouch  76 . In order to fill the flexible pouch  76 , the membrane  116  needs to be pierced, for example by a needle. Preferably, the membrane  116  is formed from an elastic material that expands to substantially close the puncture hole after the needle is removed. The membrane  116  may, for example, be formed from LDPE, PET, rPET, and/or rubber. 
     The self-closing or self-healing membrane  116  is preferably able to prevent the flowable substance from leaking out of the flexible pouch  76 , at least if no substantial compressive force is applied to the pouch  76 . In some embodiments, the membrane  116  may be particularly effective at preventing relatively thick or viscous substances from leaking from the pouch  76 . Optionally, the flowable substance may be dispensed from the pouch  76  merely by squeezing the pouch  76 , forcing the flowable substance out through the puncture hole in the membrane  116 . In this way, the pouch  76  may be used to store and dispense a flowable substance without requiring a separate attachment to be connected to the mouth insert  10 . 
     Optionally, a pouch  76  having the mouth insert  10  shown in  FIG.  15    may be attached directly to a pump of a dispenser housing. This may be advantageous, for example, for dispensers that have a permanent pump that is not replaced each time a new pouch  76  is installed in the dispenser. The mouth insert  10  may, for example, connect to the permanent pump using a snap fit connection as described above. When a pouch  76  having the mouth insert  10  shown in  FIG.  15    is attached to a permanent pump, the pump preferably punctures or breaks the membrane  116 , so as to allow the flowable substance to be dispensed from the pouch  76 . 
     Reference is now made to  FIG.  16   , which shows a mouth insert  10  in accordance with a third embodiment of the present invention. Like numerals are used to denote like components. The mouth insert  10  shown in  FIG.  16    is identical to the mouth insert  10  shown in  FIGS.  1  to  3   , with the only difference being that the sealing walls  24 ,  26  do not have slots  36 ,  38 ,  40 ,  42 . 
     The mouth insert  10  shown in  FIG.  16    may be used in exactly the same ways as the mouth insert  10  shown in  FIGS.  1  to  3   . The slots  36 ,  38 ,  40 ,  42  may be omitted, for example, if the mouth insert  10  is made from a material that is sufficiently flexible such that the slots  36 ,  38 ,  40 ,  42  are not needed. 
     It will be understood that, although various features of the invention have been described with respect to one or another of the embodiments of the invention, the various features and embodiments of the invention may be combined or used in conjunction with other features and embodiments of the invention as described and illustrated herein. 
     The mouth insert  10  is not limited to the shape and size as shown in the drawings. Rather, any suitable shape and size could be used. For example, in some embodiments of the invention the lip portion  14  could be omitted, and the mouth insert  10  could be configured so as not to extend axially outwardly from the film  80 . The sealing walls  24 ,  26  could, for example, have a ridge  58  that extends radially inwardly for forming a snap fit connection to an attachment  98 , and the axially outer end  20  of the mouth insert  10  could be aligned with the axially outer end of the film  80 . Preferably, the mouth insert  10  extends from 0 mm to 5 mm axially outwardly from the film  80 . More preferably, the mouth insert  10  extends less than 4 mm, less than 3 mm, or less than 2 mm axially outwardly from the film  80 . 
     In some embodiments of the invention, the ridge  58  could be omitted, and the mouth insert  10  could be connected to an attachment  98  by laser welding and/or by ultrasonic welding and/or by any other suitable method or technique. 
     The slots  36 ,  38 ,  40 ,  42  are not limited to the configuration shown in the preferred embodiments. Rather, any suitable size, shape, and number of slots  36 ,  38 ,  40 ,  42  could be used, or the slots  36 ,  38 ,  40 ,  42  could be omitted entirely, so as to provide the desired degree of flexibility and other desired properties of the mouth insert  10 , such as heat sealing strength. The slots  36 ,  38 ,  40 ,  42  could, for example, be formed as straight lines, or could have different lengths, axial spacing, or number of waves. 
     The slots  36 ,  38 ,  40 ,  42  preferably have the wave-like shape as shown in  FIGS.  1  to  3   . The applicant has appreciated that the wave-like shape of the slots  36 ,  38 ,  40 ,  42  preferably helps to increase the resiliency of the connection between the mouth insert  10  and the film  80 , and decrease the likelihood of the mouth insert  10  becoming separated from the film  80  when subjected to a pressure pulling the film  80  away from the mouth insert  10 . In particular, the wave-like shape of the slots  36 ,  38 ,  40 ,  42  is believed to help distribute pressure along the length of the seal line between the film  80  and the mouth insert  10 , so that the pressure is not concentrated at a single point along the seal line. Distributing the pressure along the length of the seal line preferably helps reduce the likelihood of the mouth insert  10  becoming separated from the film  80 . 
     Optionally, in some embodiments of the invention the mouth insert  10  may be connected to the film  80  using both heat sealing and laser welding. For example, in a first step the mouth insert  10  may be heat sealed to the film  80  in the manner as described above. In a second step, laser welding may be used to further strengthen and enhance the seal between the mouth insert  10  and the film  80 . The initial heat sealing step preferably holds the mouth insert  10  in place relative to the film  80 , which preferably makes it easier to perform laser welding by preventing the mouth insert  10  from moving relative to the film  80  during the laser welding. Preferably, the laser welder is configured to weld along a set path. For example, the laser welder is preferably programmed to follow the wave-like contour around the outer periphery of the slots  36 ,  38 ,  40 ,  42 , to produce a strong laser welded seal line around the slots  36 ,  38 ,  40 ,  42 . 
     It is to be appreciated that the drawings are not necessarily drawn to scale, and the various components may have a different relative size compared to what is shown in the drawings. For example, in the cross-sectional views shown in  FIGS.  8  to  11   , the various components have been shown as having relatively similar thicknesses, in order to more clearly show the invention. However, in practice the various components may have significantly different thicknesses. For example, the film  80  may be significantly thinner than the mouth insert  10  and the attachment  98 . 
     Although this disclosure has described and illustrated certain preferred embodiments of the invention, it is to be understood that the invention is not restricted to these particular embodiments. Rather, the invention includes all embodiments which are functional, chemical or mechanical equivalents of the specific embodiments and features that have been described and illustrated herein.