Abstract:
A system for applying a tin-tie, from a supply of tin-ties releaseably adhered along the length of a liner, with the tin-tie length generally aligned along a length of packaging moving in a first direction includes a tamp applicator for extending and retracting along a second direction substantially transverse to the first direction. The tamp applicator includes a magnet for carrying the tin-tie after it is released from the liner by a peeler, an air assist for aid in releasing and positioning the tin-tie, and a recess and edge for positioning the tin-tie. Part of the tamp applicator carrying the released tin-tie is also moveable in the same first direction, allowing travel in the same first direction as the moving packaging material when putting the tin-tie on the moving packaging material. A spring biases the part to return in a third direction opposite the first direction.

Description:
RELATED APPLICATION 
       [0001]    This application is based on, and claims benefit of, U.S. Provisional Application No. 61/516,229, filed Mar. 31, 2011. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates generally to the application of tin-ties to packaging, and an improved apparatus and method for the application of tin-ties. 
         [0004]    2. Background Art 
         [0005]    Ties such as twist-ties or tin-ties generally comprise one or more pieces of malleable, magnetic metal, such as a wire or ribbon, with the length of the metal covered by paper or plastic. Such ties are often used by consumers to close or reclose flexible bags. Sometimes the ties are provided separately to be later attached to the packaging by the consumer. At other times, the ties are attached to packaging, such as a bag of coffee, by the manufacturer or packager of the product. A method of manufacture of such ties is to make, such as by extrusion, a continuous length of tie material and then cut individual ties to the desired lengths. Such prior art ties have the ends of the metal exposed immediately adjacent the ends of the tie, which may cause a puncture in the bag or present a hazard to the user. 
         [0006]    Kinigakis, et al U.S. Pat. No. 5,941,641 issued Aug. 24, 1999 discloses a wrap around recloseable pouch with a tin-tie or deadfold strip attached to a flexible flap of a pouch. The deadfold strip is generally aligned along the length of the open pouch, and is used to reclose the pouch after a portion of its contents have been consumed. Larsen et al U.S. Pat. Nos. 5,215,797 issued Jun. 1, 1993 and 5,328,436 issued Jul. 12, 1994 disclose a deadfold strip for hand pressure attachment in a vertical or lengthwise orientation on a bag, generally perpendicular to the bag mouth, to facilitate reclosure of the partially consumed contents. 
         [0007]    Larsen et al U.S. Pat. Nos. 5,227,210 issued Jul. 13, 1993 and 5,302,222 issued Apr. 12, 1994 disclose a dispensing roll of deadfold stickers on a length carrier tape with each sticker having at least two deadfold wires in spaced parallel alignment transverse to the length of the tape. The stickers are peeled off the tape and adhered onto an unfilled, flatted condition bag, perpendicular to the bag mouth. The sticker and at least the area of the bag wall covered by the sticker are passed between pressure rollers. 
         [0008]    Nelson, et al U.S. Pat. Nos. 5,390,473 issued Feb. 21, 1995 and 5,402,619 issued Apr. 4, 1995 disclose a tin-tie applied across the width of a bag, generally parallel to the bag mouth, and bent to seal the bag. A magnetic head is used for positioning the bag after the tin-tie is attached to the bag. Larsen, et al U.S. Pat. No. 5,389,190 issued Feb. 14, 1995 discloses a twist-tie applicator in which a continuous length of twist tie material is extracted, cut to a desired length, removed with a magnetic attraction mechanism and then adhesively secured to a container. In Drietz, et al 5,916,108 issued Jun. 29, 1999 a magnetic attracting mechanism facilitates manipulation of a tie fastener that is fastened on an article. DiFabio, et al. U.S. Pat. Nos. 6,453,967 issued Sep. 24, 2002 and 6,824,629 issued Nov. 30, 2004 discloses applying twist-ties to formed bags held at a station by spraying glue onto a twist-tie as it is advanced onto a carrier which pivots to a position orienting glued face of the twist-tie facing the bag held at the station and then moves in a horizontal direction to carry the twist-tie into engagement with the bag held at the station to secure the twist-tie on the bag. The carrier includes an air jet to aid in the release of the twist-tie from the magnetic holding of the carrier. 
         [0009]    There remains a need for a tie-tie applicator for self-adhering tin-ties that are precut to a selected length and supplied transversely on a carrier liner for removal from the liner just prior to applying the tin-ties lengthwise on a moving web of packaging material. More particularly, there remains a need for application of such tin-ties during a continuous packaging process, after the packaging containers are formed and are being filled with the product. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention is concerned with providing a system for applying a tin-tie to a length of packaging capable of moving in a first direction in a packaging process including a peeler for removing a tin-tie from a supply of adhesive backed tin-ties releaseably adhered along a length of liner. A tamp applicator capable of extending and retracting along a second direction substantially transverse to the first direction of movement of the length of the packaging material is capable of carrying the released tin-tie for application to the moving packaging material. The tamp applicator may include a magnet for carrying the released tin-tie. A tube, capable of carrying compressed air, may be positioned adjacent the peeler and the tamp applicator, the tube having a plurality of openings for directing compressed air to assist in releasing a tin-tie from the liner and positioning the tin-tie on the applicator. The tamp applicator may also include a recess and edge for aligning the released tin-tie. A portion of the tamp applicator carrying the released tin-tie is also moveable in the same first direction of movement of the length of the packaging material. The portion of the tamp applicator capable of carrying the released tin-tie that is also moveable in the same first direction of movement of the length of the packaging material may include a spring biasing the portion to return in a third direction opposite to the first direction. The portion of the tamp applicator capable of carrying the released tin-tie that is also moveable in the same first direction of movement of the length of the packaging material may be carried by a piece that is capable of extending and retracting in the second direction substantially transverse to the first direction of movement of the length of the packaging material. The portion of the tamp applicator capable of carrying the released tin-tie that is also moveable in the same first direction of movement of the length of the packaging material may be carried by the piece that is capable of extending and retracting in the second direction substantially transverse to the first direction of movement of the length of the packaging material by a rib and attached rod that are secured to one of the piece or portion and received in a slot in the other of the portion or piece. 
         [0011]    The present invention is also concerned with providing a system for applying an adhesive backed attachment to a moving packaging material during a packaging process. A length of liner has a supply of the adhesive backed attachments releaseably adhered along the length of the liner. There is a peeler for removing an adhesive backed attachment from the liner. A tamp applicator, including a portion capable of carrying the released adhesive backed attachment removed from the liner, is capable of extending and retracting along a second direction substantially transverse to the first direction of movement of the length of the packaging material, and the portion of the tamp applicator capable of carrying the adhesive backed attachment is also moveable in the same first direction of movement of the length of the packaging material. The portion of the tamp applicator capable of carrying the adhesive backed attachment removed from the liner that is also moveable in the same first direction of movement of the length of the packaging material may include a spring biasing the portion to return in a third direction opposite to the first direction. The portion of the tamp applicator capable of carrying the adhesive backed attachment removed from the liner that is also moveable in the same first direction of movement of the length of the packaging material may be carried for such movement in the same first direction by a piece that extends and retracts in the second direction substantially transverse to the first direction of movement of the length of the packaging material. The portion of the tamp applicator capable of carrying the adhesive backed attachment removed from the liner that is also moveable in the same first direction of movement of the length of the packaging material may be carried for such movement in the same first direction by the piece that extends and retracts in the second direction substantially transverse to the first direction of movement of the length of the packaging material by a rib and attached rod that are secured to one of the piece or portion and received in a slot in the other of the portion or piece. 
         [0012]    The present invention also is concerned with providing a method for applying a tin-tie to a length of packaging material moving in a first direction during a packaging process including the steps of peeling a tin-tie having a length from a length of liner on which a supply of tin-ties with an adhesive on one side are releaseably adhered, with the length of each tin-tie transverse to the length of the liner, positioning the peeled tin-tie on an applicator head with the adhesive away from the applicator head, pushing the applicator head in a second direction transverse to the first direction toward the moving packaging material, and putting the peeled tin-tie on the moving packaging material with the length of the tin-tie aligned in the first direction. The method may include a step of picking up the peeled tin-tie with a magnetic applicator head. Positioning the tin-tie may also include the step of positioning the tin-tie in a recess or against an edge. The method may include a step of allowing the applicator head to travel in the same first direction as the moving packaging material when putting the peeled tin-tie on the moving packaging material. The method may further include a step of returning the applicator head in a third direction opposite the first direction. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    For a better understanding of the present invention, reference may be had to the accompanying drawings in which: 
           [0014]      FIG. 1  is a perspective view of a portion of a tin-tie applicator of the present invention, showing the tin-tie supply and empty take-up; 
           [0015]      FIG. 2  is perspective view of another portion of the tin-tie applicator of the present invention, showing the applicator unit; 
           [0016]      FIG. 3  is an enlarged perspective view showing the applicator unit; 
           [0017]      FIG. 4  is an enlarged perspective view showing the back of the applicator unit with a piece removed for ease of illustration; 
           [0018]      FIG. 5  is an enlarged exploded perspective view showing the applicator unit with the middle block removed for ease of illustration; 
           [0019]      FIG. 6  is an enlarged perspective view showing the applicator unit with the middle block partially in section; and 
           [0020]      FIG. 7  is an enlarged perspective view showing the middle block piece of the applicator. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    The present invention relates to the field of applying tin-ties to product packaging.  FIGS. 1 and 2  generally illustrate a system  10  for applying tin-ties  12  to product packaging  14 , as part of a continuous vertical form, fill and seal packaging machine. System  10  may be attached to a vertical or horizontal form, fill and seal packaging machine for the application of tin-ties  12  so that the length of the tin-tie is generally parallel to the length of the product packaging. Although illustrated in the drawings with respect to a vertical form, fill and seal line, it will be apparent that it may be reoriented with respect to a horizontal line. Such an application of a tin-tie facilitates re-closure of the packaging after it has been opened by the customer and partially consumed. 
         [0022]    Tin-ties  12  are not shown in detail, however they generally comprise at least one piece of malleable, magnetic metal, such as a wire or ribbon  16 , with the length of the metal sandwiched between, and covered by, top and bottom layers or pieces of paper or plastic that are held together by an adhesive. The tin-ties also have an adhesive  18  on the back side, more particularly on the exposed side of the bottom piece of paper or plastic. 
         [0023]    Each tin-tie  12  is releasably adhered on top of release liner  20  by an adhesive  18 , which has less adhesive, or peel, strength than adhesive(s) keeping the wire or ribbon  16  sandwiched between cover layers. Adhesive  18  may be a silicon, rubber, acrylic or ethylene-vinyl acetate (EVA) based pressure sensitive adhesive, which is preferred, or it may be a thermal bond film. As the force of adhesion between tin-tie  12  and liner  20  will be less than the force of adhesion between the parts or layers of tin-tie  12 , a tin-tie  12  may be removed from liner  20  without taking the tin-tie apart. The force of adhesion of adhesive  18  is strong enough to carry a tin-tie  12  on the release liner until it is removed from the release liner by an applied force for application to the packaging  14  immediately prior to the application to the packaging. Adhesive  18  then more permanently affixes the tin-ties to packaging  14 . The adhesive may be applied on the entire back side of the tin-tie, or a may be applied in strips or some other pattern, as long as there is sufficient adhesive to releaseably adhere the tin-tie to the transporting release liner for stable progression during the process until it is removed from the liner with a force to then allow for application and adhesion to the packaging. 
         [0024]    Liner  20  may conveniently be a long length of non-tearing polyester provided with a silicon coating on one, or both, surfaces. The coating may be applied to the entire surface or may be applied in strips or some other pattern that facilitates removal of the tin-tie from the liner. Other siliconized substrates may also be used for the release liner, such as, a super calendared kraft paper, a glassine material, a clay coated kraft paper, a machine finished kraft paper, a machine glazed paper, or a biaxially oriented polypropylene. Non-silicoized substrates with low surface tension, such as high density polyesters, low density polyesters and poly ester plastic resins may also be used as a release liner. Tin-ties  12  are supplied on liner  20  with the length of each tin-tie generally transverse to the length of liner  20 .  FIG. 1  shows a roll or reel  22  of liner  20  and a plurality of tin-ties  12 . Some of the tin-ties are omitted from release liner  20  for ease of illustration. 
         [0025]    In addition to liner  20  carrying tin-ties  12 , liner  20  is also shown empty in  FIGS. 1 and 2 , after tin-ties  12  have been removed and applied to packaging  14 , as empty liner  24 . Release liner  20  carrying tin-ties  12  and empty liner  24  are actually the same liner; however, particularly as some of tin-ties  12  have been omitted for ease of illustration, the empty liner is separately designated by reference numeral  24  for clarity. It will be appreciated that both release liner  20  with tin-ties  12  and empty liner  24  are one continuous strip of the same material. As is shown in  FIG. 1 , empty liner  24  is taken up on a rewinder, or empty spool,  26  after the tin-ties have been applied to the packaging. 
         [0026]    System  10  provides for unwinding release liner  20  with tin-ties  12  from reel  22 . More particularly, as is best shown in  FIG. 1 , liner  20  with tin-ties  12  passes over guide roller  32 , roller  34  of a biased dancer arm to maintain proper tension, and is advanced by servo driven roller  36  with nip roller  38 . The liner and tin-ties then pass around roller  42  of another biased dancer arm and over, generally changing direction of liner  20  from vertical to horizontal. Release liner  20  with tin-ties  12  then passes around guide roller  52  to again change its direction, and then around generally vertically aligned roller  54  to change the orientation of the liner and tin-ties. In  FIG. 1 , as liner  20  comes around roller  52  it is the underside of the liner (without tin-ties  12 ) that is visible; liner  20  then twists around 90 degrees as it approaches roller  54  where tin-ties  12  are visible. For ease of illustration, some of the tin-ties are not shown on the liner as it twists around in  FIG. 1 . 
         [0027]    Liner  20  then passes around guide roller  56  and past spaced apart sensors  58  and  60 , as is best shown in  FIG. 2 . Application of tin-ties with the present invention is operated by a programmable logic controller (“PLC”) (not shown), which co-operates with the controls for the packaging line. Sensors  58  and  60  detect the beginning and end of each tin-tie  12  and control the dispensing of the tin-ties in combination with the PLC and controls for the packaging line. The changes of direction and the change or twist of the orientation of release liner  20  with tin-ties  12  illustrated in  FIG. 1  accommodate a small format applicator. In the particular embodiment illustrated, larger diameter rollers, particularly roller  54 , aid in preventing premature separation or dispensing of the tin-ties from the release liner. In another packaging environment, the particular configuration of rollers may be different. However, it is necessary to properly support the liner  20  with tin-ties  12  to prevent premature separation or dispensing of the tin-ties. In any configuration, some combination of guide or support rollers, drive rollers and tensioning mechanism(s) is needed. All of the rollers should be of a low surface energy material such as high density polyethylene or be silicone coated to reduce inadvertent build-up of adhesive  18  on the rollers. 
         [0028]    Liner  20  passes around peeler bar  62 , tin-ties  12  are separated from liner  20 , and the resulting empty liner  24  is returned to the rewinder take-up spool  26 . More particularly, empty liner  24  passes, in a generally vertical orientation, around guide rollers  64  and  66 . When empty liner  24  next passes over guide rollers  68  and  70 , the direction of the empty liner is reversed. Finally, empty liner  24  passes over guide roller  74 , through servo driven roller  76  and nip roller  78 , and is taken up by rewinder  26 . 
         [0029]    As is shown in  FIG. 3 , tin-ties  12  are separated from liner  20  as they pass over edge  80  of peeler bar  62  (liner  20  and empty liner  24  are omitted for ease of illustration). Edge  80  is preferably made of a low surface energy material, such as Delrin plastic, and is attached to peeler bar  62  by recessed set screws  82  as is best shown in  FIG. 3 . Assisting in moving the tin-ties from the liner and into position for application to packaging  14 , is an air assist unit  84 . The air assist unit comprises a generally vertically positioned tube  86 , which is connected to a source of compressed air (not shown). As is best shown in  FIG. 3 , tube  86  is positioned behind peeler bar  62 , adjacent peeler edge  80 . A series of openings or ports  88  in tube  86  direct compressed air to assist in the release of the tin-tie from the liner and positioning of the tin-tie on a tamp applicator unit  90 . Actuation of the compressed air may be timed to immediately precede actuation of the tamp head through the PLC (not shown). More particularly, the tin-tie is picked up on the face  92  of front head  94  with adhesive  18  positioned away from face  92 . There is a lower recessed portion  96  on the right of face  92  as seen in  FIG. 3 , closer to peeler bar  62 , and an upper raised portion  98  on the left of face  92  as seen in  FIG. 3 , further from peeler bar  62 , with a vertical edge  100  formed where recessed portion  96  raised portion  98  meet. Tin-tie  12  is positioned, as illustrated in  FIG. 3 , in recessed portion  96  of face  92  of head  94  with a lateral edge of tin-tie  12  abutting vertical edge  100  providing a hard stop to aid in proper alignment and placement of the tin-tie. Although the front of tin-tie  12 , which does not intentionally have a coating of adhesive is in contact with tamp applicator  90 , head  94  is preferably made of a low surface energy material, such as high density polyethylene, or at least face  92  is silicon coated to reduce the unintentional build-up of adhesive from the tin ties. 
         [0030]    A vacuum, conveniently applied by vacuum lines through front head  94  to face  92  could be used to carry and releaseably retain the tin-tie. A system could then rely on the adherence of the tin-tie to the packaging to overcome the vacuum and release the tin-tie from face  92 ; alternatively, operation of the vacuum may be synchronized to be shut off, by a conventional solenoid control, at the time that the tin-tie is being applied to the packaging in order to facilitate its release. In the preferred embodiment illustrated in the drawings, tin-tie  12  is releaseably retained on face  92  by magnets  102 . The magnets are preferably rare earth permanent magnets. As illustrated, magnets  102  are generally rectangular solids positioned in spaced apart, generally vertical alignment in recesses in the back side of head  94  behind face  92 . Instead of the two magnets  102 , a single longer magnet could be used, or a plurality of magnets could be differently arranged, and need not be aligned. The magnets could be of a different shape, such as cylindrical or any other convenient shape. While selectively controlled electro-magnets synchronized to be shut off, by a conventional solenoid control, at the time that the tin-tie is being applied to the packaging in order to facilitate its release, might be used, they are generally too large for most for the size of tin-tie usually being applied. In the event that a synchronized assisting force is needed to facilitate release of the tin-tie at the time that the tin-tie is being applied to the packaging, a compressed air jet blower could be positioned behind the magnets. However, such an assisting force has not been found necessary in the present preferred embodiment. 
         [0031]    In addition to front head  94 , tamp applicator unit  90  includes, a middle block  104  and a back block  106 , which ride on base  108 . A plate  112 , spaced above base  108 , is connected to back block  106 . The plate is advanced and retracted laterally by a shaft  114 , which is carried by stationary assembly  116  for pneumatically operated axial movement between a retracted position and an extended position. More particularly compressed air is routed through fittings  118  as directed by the PLC. Liquid rather than air could be used to pneumatically operate the tamp applicator, or it could be servo or solenoid operated. In the extended position of shaft  114 , plate  112 , back block  106 , middle block  104 , head  94  and face  92  with tin-tie  12  is brought into contact with packaging  14 . 
         [0032]    If a thermoplastic, rather than pressure sensitive, adhesive is used, the tamp applicator unit could be provided with a heated tamp head for warming/softening of the adhesive to improve tack. A heated tamp head could also be used to melt the packaging material onto the tin-tie and eliminate adherence by an adhesive. 
         [0033]    As tin-tie  12 , or more particularly, the back of the tin-tie with adhesive  18  is brought into contact with packaging  14 , adhesive  18  and the pressure resulting from the lateral contact exerted by tamp applicator  90  will adhere tin-tie  12  to packaging  14 . This application of the tin-tie occurs in a form and fill packaging process as moving packaging material  14  comes off a form and fill tube  120  and before sealing (not shown) of the formed and filled container. More particularly, tin-tie  12  is applied to packaging  14  as it comes down off of fill tube  120  and over anvil member  122  depending down from the fill tube. Tin-tie  12  is conveniently applied on the product packaging generally opposite the fin seal on the back, although it may be applied in almost any other position with respect to the fin seal. As the tin-tie and packaging materials are both generally low surface energy materials, a portion or strip of the packaging material could be pre-treated with a corona or plasma treatment to increase adhesion by increasing surface tension or wet out. A small corona treatment unit  124 , which might be obtained from Corotec Corporation, could be positioned as illustrated in  FIG. 2 . 
         [0034]    In the application of a tin-tie, there is a risk of damage to the product packaging, primarily tearing, from a generally transverse impact of an adhesive backed tin-tie and an applicator head to the moving packaging. To minimize such possible tearing or other damage to the moving packaging  14  from substantially transverse contact of tin-tie  12  and face  92  of the tamp applicator, front head  94  and middle block  104  are carried for vertical relief movement relative to back block  106 . Middle block  104  includes an integral lower portion  128  and an attached lower portion  132 . Machine screws  134  extend from the back side  136  of front head  94 , with the heads of machine screws  134  retained by front head  94 , through bores, and are threadedly received and secured in threaded holes, such as  138  in integral lower portion  128  of middle block  104 . Attached lower portion  132  is secured to bottom  144  of middle block  104  by machine screws  146  received and secured in threaded holes  148 . 
         [0035]    Attached to the front side  152  of back block  106  are a rib  154  and a rod  156 . The bottoms of rib  154  and rod  156  abut the top  162 , more particularly a shallow channel  164 , of attached lower portion  132 . As illustrated in  FIGS. 5 and 6 , rod  156  is generally cylindrical and is a little higher than middle block  104  and back block  106 . Rib  154  is generally rectangular in cross-section and does not extend as high as rod  156 . Positioned atop rod  156  is a compression spring  170 . 
         [0036]    In its back side  164 , middle block  104  has a keyhole shaped slot  174  that extends up from bottom  144  and ends inside of middle block  104 . Slot  174  slips down over spring  170 , rod  156  and rib  154 , with the top of spring  170  abutting the top  176  of slot  174 . In its uncompressed state, spring  170  atop rod  156  supports middle block  104  and front head  94  at substantially the same vertical height as back block  106 . When tamp applicator  90 , more particularly front face  92  and the tin-tie it carries is extended laterally to contact downward moving packaging  14 , the pressure of that contact will allow compression of spring  170  and permit middle block  104  and front head  94  to move downwardly with the packaging to instantaneously redirect the substantially transverse force of the impact and thus minimize damage to the packaging by the laterally exerted pressure. As soon as the lateral pressure is released by the retraction of shaft  114 , and in turn middle block  104  and front head  94 , spring  170  will bias middle block  104  and front head  94  back up to their staring position at substantially the same vertical height as back block  106 , and the cycle repeats. 
         [0037]    The vertical relief movement of the tamp face  92  and front head  94  could alternatively be pneumatically or servo or solenoid operated and controlled by the PLC. However, the spring biasing of the front face  92  and head  94  relative to the back block  106  eliminates the need for further program control in the system. 
         [0038]    While a particular embodiment of the invention has been shown and described, alternatives, variations and modifications will occur to those skilled in the art. It is intended in the appended claims to cover all such alternatives, variations and modifications that come within the true spirit and scope of the present invention.