Patent Publication Number: US-2022234323-A1

Title: Ultrasonically joined hang tab

Description:
CLAIMS OF PRIORITY 
     This patent application claims priority from: 
     (1) U.S. provisional patent application No. 63/141,986, entitled ‘Ultrasonically joined hang tab’ filed on Jan. 27, 2021. 
     The application is incorporated by reference herein in its entirety. 
    
    
     FIELD OF TECHNOLOGY 
     This disclosure relates to ultrasonically joining paper material to manufacture a hang tab for displaying a product. 
     BACKGROUND 
     A hang tab may be a tag attached to a packaging of an article of merchandise for display in a retail environment, or for giving information about its material and proper care. In the packaging industry, numerous types of adhesive bonding connections for the manufacturing of hang tabs may be used with the aid of adhesive emulsions, such as, e.g., cold glue, and hot-melt adhesives, such as, e.g., hot glue. 
     Ultrasonic welding is an industrial manufacturing process whereby high frequency acoustic vibrations are applied to mating work pieces held together under pressure to create a solid-state bond. Ultrasonic welding may be preferable to other bonding methods in high volume manufacturing environments due to short weld times and ease of automation. An ultrasonic welding apparatus may include a welding tip—a sonotrode—that applies mechanical vibrations above an audible range to a surface of one of the parts to be bonded. These vibrations may be directed into two mating parts that are held together under pressure, and the resulting friction may cause any material along the mating surfaces of the pieces to fuse, creating a weld. This local material transformation is a result of the work pieces absorbing the frequency and amplitude of the vibration energy that is applied. The sonotrode can limit initial contact between the mating parts to a very small area, and thus focus the ultrasonic energy at the apex of its triangular or wedge-like shape, which includes a tapered end. Normally, an upper piece is pressed straight down into a lower piece during the welding operation to ensure that approximately equal amounts of ultrasonic energy are applied along the surface of the sonotrode. Depending on the work pieces that need to be joined, it is often desirable to connect flexible materials without actually stitching the materials together as this would create holes in the materials, such as, e.g., through which liquid could penetrate. For example, flexible thermoplastic materials would benefit from being joined together without stitching. 
     As compared with the adhesive bonding process, ultrasonic welding requires less time and energy, since no continuous heating of glue is necessary. The energy used for the ultrasonic joining process is needed only in the period of the joining time, which may be in the millisecond range. In addition, there is no risk of migration of glue, which may provide for a cleaner and more hygienic work product. The ultrasonic process may be suitable for mass production in high numbers. 
     SUMMARY 
     A system and method for ultrasonically welding a paper blank to form a hang tab coats the blank with a thermoplastic material, kiss-cuts the blank to form one or more fold lines, folds the blank inward along the one or more fold lines toward a middle line, bonds one or more folds corresponding to the fold lines to a middle portion of the blank using an ultrasonic welding apparatus, and die-cuts one or more shapes of a hang tab. The bonding the one or more folds comprises positioning a joining site of the one or more folds and the middle portion within a gap between a sonotrode and an anvil of the ultrasonic welding apparatus, applying a joining force to the joining site, and oscillating the sonotrode at an ultrasonic frequency. The oscillation of the sonotrode is parallel or perpendicular to the joining force. For example, a fold may be half the width of the middle portion of the paper blank, depending on a predetermined final shape and size of the hang tab. In some cases the blank is not coated with thermoplastic material, and in other cases it is moistened with demineralized water. 
     The hang tab may include a bottom portion that is substantially square shape configured to adhere to a packaging of a retail item, and a top portion may include a substantially square shape middle portion disposed between two substantially square shape tabs. The middle portion may be larger than the two substantially square shape tabs, and includes a substantially triangular opening. The substantially triangular opening may include two rounded acute corners and a sharp obtuse corner configured to mount to a display apparatus of a retail environment. The top portion and the bottom portion of the hang tab are divided by the middle line. The middle line may be a physical depression formed from the folds. The system and method is not so limited, and other configurations for the hang tab are possible. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Figures are illustrated by way of example and are not limited to the accompanying drawings, in which, like references indicate similar elements. 
         FIG. 1  is a schematic diagram of an ultrasonic welding assembly. 
         FIG. 2  is a schematic diagram of a portion of an ultrasonic welding assembly. 
         FIG. 3  is a block diagram of an electronic controller of an ultrasonic welding assembly. 
         FIGS. 4A-E  schematically outline a method for manufacturing a hang tab using an ultrasonic welding apparatus. 
         FIG. 5  is a flowchart of a method for joining a plurality of paper material using an ultrasonic welding apparatus. 
         FIG. 6  is a flowchart of a method for manufacturing a hang tab using an ultrasonic welding apparatus. 
         FIGS. 7A-D  illustrate a variety of hang tab shapes that may be manufactured using an ultrasonic welding apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     Although the present has been described with reference to specific examples, it will be evident that various modifications and changes may be made without departing from their spirit and scope. The modifications and variations include any relevant combination of the disclosed features. Equivalent elements, materials, processes or steps may be substituted for those representatively illustrated and described herein. Certain structures and features may be utilized independently of the use of other structures and features. In addition, the components shown in the figures, their connections, couplings, relationships, and their functions, are meant to be exemplary only, and are not meant to limit the examples described herein. 
     A plurality of paper material joined together with ultrasonic welding to form a hang tab for displaying products, such as, e.g., in a retail environment, without the use of an adhesive, such as, e.g., glue, and/or printing dye or ink. The paper hang tab may replace plastic hooks or tabs, which may be more environmentally beneficial. The paper material, such as, e.g., cardboard, paperboard, Couche paper, tissue paper, newsprint paper, repro paper, recycled paper, construction paper, or cardstock, may be thermoplastically coated, such as, e.g., with polyethylene or polypropylene. The paper material may be corrugated or non-corrugated. Two or more pieces of paper may be inserted into a gap between a sonotrode and an anvil of an ultrasonic joining device. A joining force from an actuator, such as, e.g., pneumatic, mechanical, piezoelectric or hydraulic, may be applied to secure the pieces of paper, and the sonotrode may oscillate a high-frequency vibration, either parallel or perpendicular, to the joining force. Adequate compaction of the pieces of paper is produced in addition to a high development of heat from friction generated in the micro-region of the thermoplastic coating. Melting of the coating then forms a physical connection between the pieces of paper, effectively fusing them together. A transducer of the device may be configured to impart the vibration to a welding tip of the sonotrode in response to an electrical signal received from an electronic controller. 
     In some cases, the paper material is not thermoplastically coated, and the heat energy that is generated from molecular friction permits direct joining of the pieces of paper. In other cases, ultrasonic welding of pieces of paper takes place with the inner joining points being moistened, e.g., with liquid water, water vapor, and/or a humectant. This facilitates a firm and stable joining of the paper material without adhesives, thermoplastic coatings, and printing ink or dyes. Demineralized water may be used, opposed to conventional water, which may have reduced surface tension of the moistening agent. This may lead to a more uniformly wetted area, and the ability to penetrate paper more quickly with a relatively high tensile strength. 
       FIG. 1  is a schematic diagram of an ultrasonic welding assembly. A plurality of substrates to be joined through high-frequency bonding, such as, e.g., a paper material, may comprise a lower part  102  and an upper part  104 . The paper material, such as, e.g., cardboard, paperboard, Couche paper, tissue paper, newsprint paper, repro paper, recycled paper, construction paper, or cardstock, may be thermoplastically coated, such as, e.g., with polyethylene or polypropylene. The paper material may be corrugated or non-corrugated. In some cases, lower part  102  and upper part  104  are made from the same paper material; while in other cases, they are made from different paper materials. Lower part  102  may be held in place by an anvil  106 . Upper part  104  may be disposed above lower part  102 . A joining force may be applied to gap  108 , formed between sonotrode  110  and the anvil  106 , wherein lower part  102  and upper part  104  are inserted. 
     Transducer  112  may be positioned near the top of the assembly and may convert electrical energy from a generator to mechanical vibrations used in the welding process. Transducer  112  may include, e.g., a number of piezo-electric ceramic discs sandwiched between two metal blocks. Between each of these ceramic disks, a thin metal plate may be positioned to form an electrode. A sinusoidal electrical signal may be fed to the transducer via the electrodes, causing the ceramic discs to expand and contract. This motion may produce an axial peak-to-peak amplitude of up to, e.g., approximately 100 μm, and a frequency of up to, e.g., approximately 100 kHz. Amplifier  114  may be disposed below transducer  108 . Amplifier  114  may magnify the mechanical vibrations produced at the tip of the transducer and transfers the vibrations to sonotrode  110 , which in turn transfers the energy to upper part  104 . In some cases, sonotrode  110  amplitude may be set between 10 and 50 μm, and frequency may be set between 10 and 80 kHz; however, actual settings depend on the paper material that is used. In addition, amplifier  114  may provide an attachment point for arm  116 . Sonotrode  110  may be positioned between amplifier  114  and upper part  104 , and is formed from any suitably robust material, such as, e.g., aluminum or titanium. Sonotrode  110  may comprise a wedge-like shape that has a tapered bottom portion for magnifying energy into a contact point with a work piece, such as the pieces of paper; however, other designs may be used. Actuator  118  may exert a downward pressure on upper part  104  and lower part  102  through arm  116 . Actuator  118  may be any technically feasible means of generating pressure, such as, e.g., pneumatic, mechanical, piezoelectric or hydraulic. For example, a piezoelectric actuator may be configured to apply a dynamically variable load to the welding assembly in response to an electrical signal provided by a pressure controller (not shown). Controller  120  may be electrically connected to the assembly and can be used to control the frequency and amplitude of vibrations produced by transducer  112 , and the amount of force exerted by actuator  118 . Power of the electrical signal provided to transducer  112  may be controlled by controller  120 , which may be directly proportional to the power injected into the assembly to maintain a constant generated frequency. 
       FIG. 2  is a schematic diagram of a portion of an ultrasonic welding assembly. The assembly comprises a sonotrode  202  and an anvil  204 . A plurality of substrates to be joined through high-frequency bonding, such as, e.g., a paper material, may comprise a lower part  206  and an upper part  208 . The paper material, such as, e.g., cardboard, paperboard, Couche paper, tissue paper, newsprint paper, repro paper, recycled paper, construction paper, or cardstock, may be thermoplastically coated, such as, e.g., with polyethylene or polypropylene. The paper material may be corrugated or non-corrugated. In some cases, lower part  206  and upper part  208  are made from the same paper material; while in other cases, they are made from different paper materials. Lower part  206  may be held in place by an anvil  204 . Upper part  208  may be disposed above lower part  206 . A joining force  210  may be applied to gap  212 , formed between sonotrode  202  and the anvil  204 , wherein lower part  206  and upper part  208  are inserted. 
     Sonotrode  202  may execute an ultrasonic oscillation in a particular direction, such as, e.g., parallel or perpendicular, to the joining force. Parallel may be defined as 180°, and perpendicular may be defined as 90°. Deviations of ±10° may still be viewed as perpendicular. This oscillation direction may correspond to the expansion direction of the amplitudes of the ultrasonic oscillation. Lower part  206  and upper part  208  may be joined to each other by friction through the application of the joining force  210  and ultrasonic oscillation. Anvil  204  may restrain the applied pressure load from bending, or otherwise deforming the lower part  206  and upper part  208 . Melting of the coating then forms a physical connection between the pieces of paper, effectively fusing them together. In some cases, the paper material is not thermoplastically coated, and the heat energy that is generated from molecular friction permits direct joining of the pieces of paper. In other cases, ultrasonic welding of pieces of paper takes place with the inner joining points being moistened, e.g., with liquid water, water vapor, and/or a humectant. A moistening device for moistening the paper material may be provided (not shown). This facilitates a firm and stable joining of the paper material without adhesives, thermoplastic coatings, and printing ink or dyes. Demineralized water may be used, opposed to conventional water, which may have reduced surface tension of the moistening agent. This may lead to a more uniformly wetted area, and the ability to penetrate paper more quickly with a relatively high tensile strength. The moistening of joining points may be carried out before and/or during the ultrasonic welding process. 
       FIG. 3  is a block diagram of an electronic controller of an ultrasonic welding assembly. The controller may include power source  302 , and processor  304  for controlling an overall operation of the assembly, and may comprise instruction data of manufacturing instructions in a file system  306  and a cache  308 . File system  306  may be a storage disk or a plurality of disks, and typically provides high capacity storage capability for the controller. Since access time to file system  306  may be relatively slow, the controller may also include cache  308 . Cache  308  is, for example, Random-Access Memory (RAM) provided by semiconductor memory, which may provide substantially shorter access time compared with file system  306 . The controller may also include RAM  310  and Read-Only Memory (ROM)  312 . ROM  312  may store programs, utilities or processes to be executed in a non-volatile manner. RAM  310  may provide volatile data storage, such as for cache  308 . 
     A user input device  314  may allow a user to interact with the controller, and hence, the assembly. For example, user input device  314  may take a variety of forms, such as, e.g., a button, keypad, dial, touch screen, audio input interface, visual/image capture input interface, and/or input in the form of sensor data. Display  316  may be controlled by processor  304  to display information to the user. Bus  318  may facilitate data transfer between file system  306 , cache  308 , processor  304 , and CODEC  320 . CODEC  320  may be used to decode and play a plurality of media items from file system  303  that may correspond to certain activities taking place during a particular manufacturing process. Interface  322  may be communicatively coupled to data link  324 , such as, e.g., a wired or wireless connection, and may permit the assembly to communicatively couple with a host computer or accessory device. Sensor  326  may be any form of circuitry for detecting any number of stimuli, such as, e.g., a magnetic field sensor, an audio sensor, and/or a light sensor, for monitoring a manufacturing operation. 
       FIGS. 4A-E  schematically outline a method for manufacturing a hang tab using an ultrasonic welding apparatus. In  FIG. 4A , a paper blank may be coated on both sides with a thermoplastic material, such as, e.g., polyethylene or polypropylene. Kiss cuts using a cutting apparatus are made along line  402  and line  404  into the substantially rectangular shape paper blank to form two parallel fold lines along the paper blank&#39;s length, such as, e.g., at approximately equal distances from their respective edges, and may depend on a predetermined final shape and size of the hang tab. For example, each of the equal distances may be half of a middle portion  406  to which they are juxtaposed. The blank may comprise a paper weight in the range of 200 to 400 grams, and may be cut into a square or rectangular shape at a predetermined size, e.g., using a cutting apparatus or pair of scissors.  FIG. 4B  folds the paper blank along both line  402  and line  404 , for example, which may reduce the blank&#39;s width into half.  FIG. 4C  bonds the two folds to the middle portion  406  of  FIG. 4A  using an ultrasonic welding apparatus, forming line  407 . For example, the two distances from the edges of the paper blank&#39;s width to the line  407  may be equal, and may depend on a predetermined final shape and size of the hang tab. The apparatus may be set at 25 kW, with a preloading time of 2.0 seconds, and a welding position of 3.0 seconds, and a cooling time of 2.0 seconds, and bonding at 1.8 A.  FIG. 4D  die cuts one or more shapes of hang tabs from the paper blank. A hang tab may comprise a bottom portion  408  that may be generally square or rectangular shaped and may be configured to adhere to a packaging of an item for display, such as, e.g., with an adhesive, and a top portion  414  may comprise two generally square or rectangular shaped tabs  410  positioned on both sides of a larger generally square or rectangular shaped middle portion  412 . Middle portion  412  of the top portion  414  may include a generally triangular portion, such as, e.g., an obtuse triangle shape, that is used to hang the hang tab, for example, onto a hook of a retail environment. The triangular portion may comprise rounded corners at the two acute angles and a sharp corner at the obtuse angle. Top portion  414  and bottom portion  408  may be divided by middle line  407 . Middle line  407  may include a groove or depression formed from the folds of  FIG. 4B , and may be flexible or bendable.  FIG. 4E  is a schematic diagram of a finished product of the hang tab manufactured using an ultrasonic welding apparatus. The hang tab may comprise rounded or sharp peripheral corners at tabs  410  and/or middle portion  412  of top portion  414 , and bottom portion  408 . 
       FIG. 5  is a flowchart of a method for joining a plurality of paper material using an ultrasonic welding apparatus. Operation  510  positions a joining site of a plurality of paper material within a gap between a sonotrode and an anvil of the ultrasonic welding apparatus. Operation  520  applies a joining force to the joining site in a predetermined direction to secure the plurality of paper material. The joining force may be applied by an actuator, such as, e.g., pneumatic, mechanical, piezoelectric or hydraulic. Operation  530  oscillates the sonotrode at a high frequency. The oscillation may be either parallel or perpendicular to the joining force. A transducer of the apparatus may be configured to impart the oscillation to a welding tip of the sonotrode in response to an electrical signal received from an electronic controller. Operation  540  bonds the paper material at the joining site. Adequate compaction of the pieces of paper is produced in addition to a high development of heat from friction generated in a micro-region. Melting of thermoplastic coating then forms a physical connection between the pieces of paper, effectively fusing them together. 
     In some cases, the paper material is not thermoplastically coated, and the heat energy that is generated from molecular friction permits direct joining of the pieces of paper. In other cases, ultrasonic welding of pieces of paper takes place with the inner joining points being moistened, e.g., with liquid water, water vapor, and/or a humectant. This facilitates a firm and stable joining of the paper material without adhesives, thermoplastic coatings, and printing ink or dyes. Demineralized water may be used, opposed to conventional water, which may have reduced surface tension of the moistening agent. This may lead to a more uniformly wetted area, and the ability to penetrate paper more quickly with a relatively high tensile strength. 
       FIG. 6  is a flowchart of a method for manufacturing a hang tab using an ultrasonic welding apparatus. Operation  610  coats both sides of a paper blank with a thermoplastic material, such as, e.g., polyethylene or polypropylene. The blank may comprise a paper weight in the range of 200 to 400 grams, and may be cut into a square or rectangular shape at a predetermined size, e.g., using the cutting apparatus or pair of scissors. Operation  620  kiss cuts the paper blank to form two parallel fold lines, for example, at approximately equal distances from their respective edges, depending on a predetermined final shape and size of the hang tab. For example, each of the equal distances may be half of a middle portion to which they are juxtaposed. Operation  630  folds the paper blank along both fold lines, which may reduce the blank&#39;s width into half. Folding of the paper blank may be performed directly by human hands, or an electronically powered tool (not shown). Operation  640  bonds the two folds to the middle portion using an ultrasonic welding apparatus, forming a middle line. For example, the two distances from the edges of the paper blank&#39;s width to the middle line may be equal, and may depend on a predetermined final shape and size of the hang tab. The apparatus may be set at 25 kW, with a preloading time of 2.0 seconds, and a welding position of 3.0 seconds, and a cooling time of 2.0 seconds, and bonding at 1.8 A. Operation  650  die cuts one or more shapes of hang tabs from the paper blank. A bottom portion may be generally square or rectangular shaped, and a top portion may comprise two generally square or rectangular shaped tabs positioned on both sides of a larger generally square or rectangular shaped middle portion. The middle portion of the top portion may include a generally triangular portion, such as, e.g., an obtuse triangle shape, that is used to hang the hang tab, for example, onto a hook of a retail environment. The top portion and the bottom portion may be divided by a middle line. The middle line may include a groove or depression formed from the folds. 
       FIGS. 7A-D  illustrate a variety of hang tab shapes that may be manufactured using an ultrasonic welding apparatus. In each of the shapes, a bottom portion, which is approximately half the length of the hang tab (for example), is generally square or rectangular, similar to the hang tab presented in  FIG. 7E , and may be configured to adhere to a packaging of an item for display, such as, e.g., with an adhesive. Each of the hang tabs may comprise rounded or sharp outer corners at a top portion and the bottom portion. In  FIG. 7A , the top portion may be generally square or rectangular comprising a generally triangular opening, such as, e.g., an obtuse triangle shape, that is used to hang the hang tab, for example, onto a hook of a retail environment. The triangular portion may comprise rounded corners at the two acute angles and a sharp corner at the obtuse angle.  FIG. 7B  shows the top portion comprising an oblong shape that includes two rounded ends, and a middle portion with a half circle positioned above and another half circle positioned below. The oblong-shaped portion may be used to hang the hang tab, for example, onto a hook of a retail environment.  FIG. 7C  shows the top portion comprising a generally square or rectangular shape with a circular opening positioned within its center that is used to hang the hang tab, for example, onto a hook of a retail environment.  FIG. 7D  shows the top portion comprising a generally hook-shape that is used to hang the hang tab, for example, onto a hook of a retail environment. 
     A number of examples have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the claimed invention. In addition, the logic flows depicted in the figures do not require the particular order shown, or sequential order, to achieve desirable results. Other steps may be provided, or steps may be eliminated, from the described flows, and other components may be added or removed. Accordingly, other examples are within the scope of the following claims.