The present disclosure relates to machines that convert a web and more specifically to machines that convert a web into pouches or bags with lap seals using ultrasonic sealers.
The following U.S. patents are incorporated herein by reference in entirety.
U.S. Pat. No. 7,191,575 discloses a vertical form fill-and-seal continuous pouch machine having a forming tube.
U.S. Pat. No. 8,029,428 discloses a machine and method for making bags from a web traveling from an input section to a rotary drum to an output section.
U.S. Pat. No. 10,946,591 discloses a method and apparatus for making bags or pouches. An ultrasonic sealer may be used to form the seals, and different sealing patterns may be utilized.
This Summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
In certain examples, a machine that forms a web into bags or pouches includes a sealing section through which the web is conveyed in a machine direction. The sealing section is configured to form a lap seal in the web and has an input end configured to receive the web which has a first web section and a second web section. An ultrasonic sealer with a horn and an anvil defines a nip therebetween through which the first web section passes. The ultrasonic sealer is configured to form the lap seal in the first web section. The anvil is positioned between the first web section and the second web section. An output end is configured to dispense the web with the lap seal formed therein.
Various other features, objects, and advantages will be made apparent from the following description taken together with the drawings.
The present disclosure is described with reference to the following Figures. The same numbers are used throughout the Figures to reference like features and like components.
Known web processing machines convert a web, which is usually supplied as a continuous sheet of material from a web supply roll, into pouches or bags. The machine may be a continuous motion machine or an intermittent motion machine, or a combination machine with features of both continuous motion machines and intermittent motion machines.
Continuous motion machines convey the web at a constant speed, and various operations are performed on or to the web as the machine conveys the web through the machine. The machine may further conduct various operations or maneuvers on the web to create the bag or pouch. For example, the machine may form one or more seals in the web with a sealer to at least partially form the pouches or bags. The machine may also heat the web with a heater, cool the web with a cooler, apply an insert (e.g., zipper) into the web, cut the web with a knife or cutter, and/or perforate the web with a perforator. The machine may include rotary drums and/or shuttles that move sealer components such that there is no relative motion between the web to the sealer components.
Alternatively, intermittent motion machines move and stop the web such that one or more operations are performed on the web when the web is stopped. For example, when the web is stopped, the sealer may form a seal in the web. The web is then advanced and again stopped so that a different operation may be performed on the web.
When forming pouches or bags, the machine (such as the continuous motion machines or intermittent motion machines noted above), forms one or more seals in the web. Each individual bag or pouch includes one or more seals, and each bag or pouch typically has an unsealed opening through which objects, such as food products, are placed into the bag or pouch. After objects are placed into the bag or pouch, the machine may subsequently form an additional seal in the web, or add a closure mechanism such as a zipper, to thereby close the opening and fully enclose the objects in the bag or the pouch.
A lap seal is a seal that is commonly formed in a web when forming bags or pouches. To form the lap seal, the machine conveys the web in a machine direction from the supply roll and through a folding station that folds opposing sides of the web toward each other in the cross directions. Note that the cross directions oppose each other and are transverse (e.g., perpendicular) to the machine direction (the machine direction and the cross direction are described further hereinbelow). Accordingly, the opposing sides of the web overlap each other such that the web is folded into the shape of a continuous tube. In this shape, a portion of the inside surface of the web overlaps a portion of the outside surface of the web.
The folded web is conveyed downstream to a sealing station where the lap seal is formed by sealing or adhering the overlapping sides of the web to each other. Known machines include sealing components, such as heated seal bars, that form the lap seal in the folded web. Through research and experimentation, the present inventors recognized that machines that use heated seal bars to form lap seals require that the seal bars be pre-heated to a desired sealing temperature and further require a large amount of energy to maintain the desired sealing temperature while the machine is operated and the seals are being formed. Furthermore, the present inventors recognized that other machines for forming seals often include multiple sealers and may further include cooling devices, sections for cooling the seals, and/or require compressed air systems that cool the formed seal and/or surrounding web. As such, the present inventors developed improved machines that form the lap seal in the web at lower energy costs, with good seal strengths, and the forming does not require cooling devices or cooling areas to cool the seals allowing the machine to have a smaller footprint and a shorter web path than conventional machines. Note the shorter web path can improve web handling and reduces web scrap. The present inventors also developed machines that require little maintenance, have minimal start-up time requirements, permit real-time seal adjustments, permit seal customizations, and/or have increased machine efficiency. Accordingly, the present inventors developed the machines and the sealing stations (and features and components thereof) of the present disclosure.
The machine 10 includes a folding station 15 that folds opposing sides 21, 22 of the web 20 toward each other in the cross directions CD such that the sides 21, 22 (
A roller system having one or more rollers 17 (
The sealing station 30 is configured to form a lap seal in the web 20 by sealing the overlapping sides 21, 22 of the web 20 to each other. Referring to the example web 20 depicted in
The sealing station 30 has an upstream input first end 31 that receives the web 20 from the folding station 15 and an opposite downstream output second end 32 that dispenses the web 20 having the lap seal formed therein. A first frame 33 extends in the cross directions CD and is vertically spaced apart from the web 20. The first frame 33 is for vertically supporting an arm assembly 60 relative to the web 20, and the arm assembly 60 holds an anvil 52 of the ultrasonic sealer 50. In certain examples, the arm assembly 60 is a cantilever that is coupled at one end to the first frame 33 and the other opposite end (e.g., the end that holds the anvil 52) is freely suspended. The first frame 33 includes one or more mounting holes 34 such that the arm assembly 60 may be mounted to the first frame 33 and is movable in the cross directions CD. Note that in other examples the first frame 33 may have a rail with a channel (not depicted) that facilitates cross-directional movement of the arm assembly 60 along the first frame 33. In other examples, the arm assembly 60 is coupled to the first frame 33 via dovetail wedges, linear rails, and/or shaft slides. Note that in certain examples the arm assembly 60 and/or the horn 51 can be manually moved by an operator or automatically moved by actuators (not depicted) of the machine 10.
A second frame 35 is positioned downstream in the machine direction MD from the first frame 33. The second frame 35 is for vertically supporting a horn 51 of the ultrasonic sealer 50 relative to the web 20 and the anvil 52 that is held by the arm assembly 60. The second frame 35 and/or the horn 51 are movable in the cross directions CD, and in one example, the second frame 35 and/or the horn 51 are moved in a first cross direction CD1 (
Referring now to
The first arm 61 is cantilevered from the first frame 33 toward the web 20 and can includes a portion that generally extend in the machine direction MD. As such, in certain examples the arm assembly 60 is a cantilever that is coupled to the first frame 33 via the first arm 61 The first arm 61 includes one or more fasteners 63 (see
The second arm 62 is coupled to and cantilevered from the first arm 61 and extends in the machine direction MD along the web 20. Specifically, the second arm 62 has an input first end 64 coupled to the first arm 61 and an opposite second end 65 downstream from the first end 64 in the machine direction MD. The second arm 62 includes a first side 71, an opposite second side 72, and a body 73. A channel 66 is defined near the first end 64 of the second arm 62 and an opening 69 is defined in the first side 71 of the second arm 62. Note that a guide surface 67 at least partially defines the channel 66 and is spaced apart from the first arm 61 (see
The first arm 61 is connected to the second side 72 of the second arm 62 (see
The second end 65 of the second arm 62 includes a cutout 74 (see
Note that in certain examples the anvil 52 may generate heat during operation (e.g. frictional forces between the anvil 52 and the web 20 may be generated with heat), and thus, there may be a need to cool the anvil 52 to thereby ensure that the lap seal is properly formed in the web 20. That said, the body 73 of the second arm 62 is in close proximity to the anvil 52 and/or coupled to the anvil 52 via the pin and acts as a heat sink for the anvil 52. As such, heat may flow from the anvil 52 to the second arm 62 and the second arm 62 may include one or more cooling components that are configured to remove or dissipate the heat the second arm 62 receives from the anvil 52. In one example, the cooling components are channels extending along the exterior surface of the second arm 62 through which air flows to cool the second arm 62. In other example, the cooling components are conduits in the second arm 62 through which air or a fluid is conveyed to thereby cool the second arm 62. In one instance, the air is compressed air supplied from an air pump (not depicted).
Now referring specifically to
As noted above, the web 20 is conveyed in the machine direction MD through the sealing station 30 where the lap seal is formed in the web 20. As the web 20 is conveyed along the arm assembly 60, the each side 21, 22 and the second web section 42 of the web 20 are simultaneously conveyed along separate paths that extend between the upstream roller 17 (see point P) and the horn 51 and the anvil 52 (see point Q). Specifically, the first side 21 is conveyed along a first path, the second side 22 is conveyed along a second path, and the second web section 42 is conveyed along a third path. In certain examples, the length of the first side 21 of the web 20 in the machine direction MD within the first path equals the length of the second side 22 of the web 20 in the machine direction MD within the second path and equals the length of the second web section 42 in the machine direction MD within the third path such that the lap seal is properly formed by the sealer 50 and these components (the first side 21, the second side 22, and the second web section 42 of the web 20) are not offset relative to each other when the lap seal is formed in the web 20. If the lengths of the first side 21 in the first path, the second side 22 in the second path, and/or the second web section 42 in the third path are not equal, the lap seal may not be properly formed in the web 20 and the web 20 could include wrinkles, folds, or other undesirable features that negatively impact the lap seal strength and/or aesthetic look of the bags. As such, the surfaces and curved edges of the arm assembly 60 are designed in such a way that the lengths of the first side 21 in the first path and the second side 22 in the second path are equal to each other.
Referring back to
The operator then similarly pulls the first side 21 of the web 20 around the first side 71 of the second arm 62 (see arrow Q on
When the operator restarts the machine 10, the sides 21, 22 of the web 20 are conveyed along the second arm 62 while the second arm 62 and the anvil 52 remains within the void 29 (e.g., the web 20 passes around the second arm 62 and the anvil 52).
Referring now to
In another example, the spacing between the horn 51 and the anvil 52 may be automatically and/or dynamically changed while the web 20 is being conveyed through the nip to thereby maintain a desired pressure on the web 20 to properly form the lap seal. Automatically and dynamically changing the spacing accounts for material variations in the web 20 (e.g., thickness variations) such that the lap seal is properly formed in the web. In this example, a sensor (not depicted) is configured to sense the pressure exerted by the horn 51 and the anvil 52 on the web 20. An actuator (not depicted; e.g., a pneumatic piston, servo motor) coupled to the anvil 52 is controlled by a controller (described further herein) based on signals received from the sensor and the actuator moves the horn 51 relative to the anvil 52 to thereby maintain the desired pressure on the web 20.
The horn 51 and the anvil 52 define a nip 79 therebetween through which the sides 21, 22 and the first web section 42 are conveyed. As the sides 21, 22 of the web 20 are conveyed through the nip, the horn 51 and the anvil 52 compress the sides 21, 22 therebetween (note that
The horn 51 receives ultrasonic energy from an ultrasonic energy generator or source (not depicted) such that the horn 51 vibrates. The vibration of the horn 51 relative to the anvil 52 imparts energy into the sides 21, 22 of the web 20 as it is conveyed between the horn 51 and the anvil 52. The anvil 52 can include a pattern that imparts a pattern into the lap seal (e.g., the size and shape of the lap seal) formed in the web 20. However, in other examples, the anvil 52 does not have a pattern and instead the outer perimetral surface of the anvil 52 is smooth. Note that in certain examples, the application of the ultrasonic energy via the horn 51 to the web 20 melts portions of the web 20 which fuse or seal together to form the lap seal in the web 20. In one example, the application of ultrasonic energy via the horn 51 to the web 20 causes the inside surface 23 and the outside surface 24 to melt such that the melted material fuse to each other and the lap seal is formed in the web 20. In certain examples, the application of the ultrasonic energy is configured such that the surfaces 38 (
Also note that by cantilevering the second arm 62 and the anvil 52 into the void 29 defined by the web 20 via the first arm 61 and the first frame 33, the second web section 42 (see
Optionally, after the lap seal is formed in the web 20, finishing rollers 36 (see
Referring now to
The outer diameter μl of the anvil 52 varies, and the outer diameter μl may be based on the application of the machine 10, the specific material characteristics of the web 20, the desired characteristics of the lap seal, and/or the location of the lap seal in the web 20. In one example, the outer diameter of the anvil 52 is 0.9843 inches. In another example, the outer diameter of the anvil 52 is 1.9685 inches. The outer diameter may range from 0.10 inches to 4.0 inches and is preferably between 0.8 inches and 2.5 inches. In certain examples, an anvil 52 with a small outer diameter may be used with the lap seal is formed near the outer edge of the web 20. In other examples, an anvil with a large outer diameter may be used to form the lap seal near the center of the web 20 (see
Referring specifically to
In certain examples, the finishing rollers 36 are configured to compress the lap seal having a pattern (as noted above with respect to
Note that in certain examples, the sealer 50 may cause certain portions of the web 20 to also melt into the portions of the grooves 87 that are defined in the transition surfaces 84 and/or further flow or “ooze” in a cross direction CD. In this example, the material that melts into the transitions surfaces 84 helps to form a transition zone in the lap seal next to the adjacent unsealed web 20. This transition zone reduces or minimizes stress points between the lap seal and the adjacent unsealed web 20 to thereby reduce or minimize inadvertent tearing of the lap seal from the adjacent unsealed web 20. The finishing rollers 36 can compress the material in the transition zone to thereby create a flatter or smoother profile of the transition zone.
The shape, width, and/or the depth of the grooves 87 can vary and have any width or depth. Note that
In certain examples, the machine forms a web into bags or pouches. The machine includes a sealing section through which the web is conveyed in a machine direction. The sealing section is configured to form a lap seal in the web, and the web has a first web section and a second web section. An input end is configured to receive the web. An ultrasonic sealer has a horn and an anvil defining a nip therebetween through which the first web section passes. The ultrasonic sealer is configured to form the lap seal in the first web section, and the anvil is positioned between the first web section and the second web section. An output end is configured to dispense the web with the lap seal formed therein.
In certain examples, the first web section includes opposing sides of the web that overlap each other. In certain examples, the web is continuously conveyed through the sealing section and the ultrasonic sealer continuously forms the lap seal in the web. In certain examples, the web received via the input end has a tubular shape with an oblong cross section and a void defined between the first web section and the second web section. The anvil is in the void and each of the first web section and the second web section each pass along opposite sides of the anvil.
In certain examples, the web is conveyed in a machine direction through the machine and the machine includes a folding station upstream from the sealing station. The folding station is configured to fold each side of the web in opposite cross directions such that the sides the web overlap each other, and the first web section includes the overlapping sides of the web. In certain examples, the folding station is configured to fold the web into a tubular shape. In certain examples, the folding station is configured to fold the web such that a void is defined by the web, and the anvil is positioned in the void.
In certain examples, the web defines a void between the first web section and the second web section, and as the web is conveyed through the sealing section, the anvil is in the void and the first web section and the second web section pass along opposite sides of the anvil. In certain examples, the sealing section includes a frame that extends in a cross direction that is transverse to the machine direction, and the frame cantilevers the anvil into the void. For example, the arm assembly is a cantilever mounted on the first frame and the arm assembly cantilevers the anvil into the void.
In certain examples, the machine includes a roller system configured to convey the web in the machine direction. In certain examples, the web is conveyed in a machine direction through the machine and the sealing section further includes an arm assembly configured to extend in the machine direction such that the arm assembly extends between the first web section and the second web section to thereby hold the anvil. In certain examples, the sealing section can include a frame extending in a cross machine direction and being spaced apart from the web such that the frame supports the arm assembly relative to the web.
In certain examples, the machine forms a web into bags or pouches. The web is folded with a first side and an opposite second side of the web overlapping each other such that the web has a first web section comprising the first side and the second side, an opposite second web section, and a void defined between first web section and the second web section. The machine includes an ultrasonic sealer having a horn and an anvil that are collectively configured to form a lap seal in the first web section as the web is conveyed through the machine in a machine direction. A frame extends in a cross direction transverse to the machine direction and is spaced apart from the web. An arm assembly is coupled to the frame and is cantilevered into the void to thereby support the anvil in the void between the first web section and the second web section.
In certain examples, the web has an oblong cross section. In certain examples, the arm assembly is movable in the cross direction along the frame such that the anvil is repositionable relative to the horn. In certain examples, the arm assembly defines a first arm that is coupled to the frame, a second arm that extends in the machine direction and holds the anvil, and a channel between the first arm and the second arm. The web is conveyed in the machine direction along the arm assembly such that the first side of the web passes through channel. In certain examples, the first side of the web is conveyed along a first path along the arm assembly and the second side of the web is conveyed along a second path along the arm assembly before the lap seal is formed in the web. In certain examples, the arm assembly has a first arm that is coupled to the frame and a second arm that extends in the machine direction and holds the anvil. The second arm includes a cooling component configured to cool the arm and thereby cool the anvil.
Citations to a number of references are made herein. The cited references are incorporated by reference herein in their entireties. In the event that there is an inconsistency between a definition of a term in the specification as compared to a definition of the term in a cited reference, the term should be interpreted based on the definition in the specification.
In the present description, certain terms have been used for brevity, clarity, and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. The different apparatuses, systems, and method steps described herein may be used alone or in combination with other apparatuses, systems, and methods. It is to be expected that various equivalents, alternatives, and modifications are possible within the scope of the appended claims.
The functional block diagrams, operational sequences, and flow diagrams provided in the Figures are representative of exemplary architectures, environments, and methodologies for performing novel aspects of the disclosure. While, for purposes of simplicity of explanation, the methodologies included herein may be in the form of a functional diagram, operational sequence, or flow diagram, and may be described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance therewith, occur in a different order and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology can alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all acts illustrated in a methodology may be required for a novel implementation.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
The present disclosure is based on and claims priority to U.S. Provisional Patent Application No. 63/181,475 filed Apr. 29, 2021, the disclosure of which is incorporated herein in its entirety.
Number | Date | Country | |
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63181475 | Apr 2021 | US |