Patent Publication Number: US-2007117703-A1

Title: Machine and method for converting a web of material into dunnage

Description:
BACKGROUND OF THE INVENTION  
      The present invention relates generally to packaging materials and, more specifically, to a machine and method for making dunnage.  
      Dunnage is a type of packaging material that is used primarily to fill void spaces between an item and a container, e.g., a carton or box, in which the item is to be shipped. By filling such void spaces, the dunnage material prevents the item from moving around within the container during shipment, or at least reduces any such movement. Dunnage may also provide a degree of cushioning protection to the packaged item. Examples of dunnage materials include loose-fill ‘peanuts’ (i.e., expanded polystyrene particles), air-filled bags, and crumpled webs of material, particularly paper. The present invention is directed to a method and machine for making dunnage by crumpling a web of material.  
      Many types of machines exist for converting a web of material, such as paper, into dunnage. Such machines, however, tend to be rather expensive and complex.  
      Accordingly, there is a need in the art for a simpler and less expensive machine and method for producing dunnage from a web of material.  
     SUMMARY OF THE INVENTION  
      That need is met by the present invention, which, in one aspect, provides a machine for converting a web of material into dunnage, the machine comprising:  
      a) a mechanism for conveying the web through the machine;  
      b) a first web-shaping device for crumpling the web;  
      c) a second web-shaping device for further crumpling the web; and  
      d) a severing mechanism to sever the web into discrete lengths.  
      In one embodiment, the second web-shaping device comprises a three-dimensional, annular member having a passage therein through which the web may travel, the annular structure having a web-contact region bordering the passage, wherein the web-contact region comprises a curved surface and provides sliding contact with the web to effect the further crumpling thereof.  
      In another embodiment, the second web-shaping device comprises a generally toroidal-shaped structure having a passage therein through which the web may travel, the generally toriodal-shaped structure having a web-contact region bordering the passage, wherein the web-contact region provides sliding contact with the web to effect the further crumpling thereof.  
      Another aspect of the invention pertains to a method for converting a web of material into dunnage, the method comprising:  
      a) crumpling the web in a first web-shaping device;  
      b) further crumpling the web in a second web-shaping device, the second web-shaping device comprising one of the two embodiments as described immediately above;  
      c) conveying the web through the first and second web-shaping devices; and  
      d) severing the web into discrete lengths.  
      These and other aspects and features of the invention may be better understood with reference to the following description and accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       FIG. 1  is a schematic view of a machine and method for converting a web of material into dunnage in accordance with the present invention;  
       FIG. 2  is a plan view of the schematic illustration shown in  FIG. 1 ;  
       FIG. 3  is similar to  FIG. 1 , but shows the converted web being severed into a discrete length for placement into a shipping container;  
       FIG. 4  is a perspective view of one of the web-shaping devices shown in  FIGS. 1-3 ;  
       FIG. 5  is a perspective view of a working embodiment of a dunnage machine in accordance with the present invention, showing a web of material being fed into the machine;  
       FIG. 6  is a frontal elevational view of the machine shown in  FIG. 5 ;  
       FIG. 7  is a partial perspective view of the machine illustrated in  FIG. 5 , wherein a trailing end of the web is shown protruding from the second web-shaping device;  
       FIG. 8  is a plan view of the machine shown in  FIG. 5 , wherein the outer cover has been removed;  
       FIG. 9  is another perspective view of the machine shown in  FIG. 5 , but of the other side and exit end of the machine, i.e., as viewed from a position 180 degrees removed from the perspective shown in  FIG. 5 , and with the outer cover removed;  
       FIG. 10  is a sectional view of the web-shaping device shown in  FIG. 4 , taken along lines  10 - 10  and illustrating the circular cross-sectional shape of the device;  
       FIG. 11  is similar to  FIG. 10 , except that a semi-circular cross-sectional shape of an alternative web-shaping device is illustrated;  
       FIG. 12  is similar to  FIG. 10 , except that an elliptical cross-sectional shape of a further alternative web-shaping device is illustrated;  
       FIG. 13  is similar to  FIG. 10 , except that a semi-elliptical cross-sectional shape of another alternative web-shaping device is illustrated; and  
       FIG. 14  is a cross-sectional view of web-shaping  18 ′ and mounting plate  62 , taken along lines  14 - 14  in  FIG. 8 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       FIGS. 1-3  schematically illustrate a machine  10  in accordance with the present invention for converting a web  12  into dunnage. Web  12  may comprise any type of material capable of conversion into dunnage, including paper, e.g., kraft paper; thermoplastic film; recycled plastic; etc.  
      Machine  10  includes a mechanism  14  for conveying the web through the machine, a first web-shaping device  16  for crumpling the web, a second web-shaping device  18  for further crumpling the web, and a severing mechanism  20  to sever the web into discrete lengths. As shown, conveyance mechanism  14  may include a first pair  14   a  of counter-rotating drive members and, if desired, a second pair  14   b  of counter-rotating drive members positioned downstream of the first pair  14   a . Drive member pairs  14   a  and  14   b  may be driven at the same speed or at different speeds as desired, e.g., to create tension or compression in the section of web  12  between the drive member pairs. Further, the drive member pairs  14   a, b  may be driven simultaneously or at different intervals, which may overlap as desired. The drive members may comprise a pair of counter-rotating drive rollers as illustrated. One or both drive roller pairs may be in contact with one another as shown, or may have a gap therebetween, depending, e.g., on the desired thickness of the dunnage product, the material of web  12 , etc. When drive member pairs  14   a, b  are in the form of drive rollers, the rollers may comprise any material suitable for conveying web  12 , such as metal (e.g., aluminum, steel, etc.), rubber, elastomer (e.g., RTV silicone), urethane, etc., including combinations of the foregoing materials. For example, one pair of drive rollers could be constructed from metal while the other pair could be made from a polymeric material or a metal/polymer composite material, e.g., a metal core with a polymeric outer/web-contact peripheral surface. Alternatively, within a drive member pair, one drive member may be metallic while the other is polymeric or at least has a polymeric web-contact/peripheral surface.  
      As an alternative to drive rollers, the drive members may comprise a pair of counter-rotating drive belts, drive bands, or any suitable mechanism for conveying a web.  
      As illustrated, severing mechanism  20  may be positioned between first pair  14   a  and second pair  14   b  of drive members. Such a configuration isolates the severing mechanism, thereby reducing the likelihood that an operator of machine  10  will place a hand in contact with the severing mechanism while the machine is operating. This configuration may also facilitate severance of the web, as described below.  
      Web  12  may be supplied from a roll  22  as illustrated, or from any convenient means of storage and dispensation, e.g., from a fan-folded stack contained in a carton. When in the form of a roll  22 , the roll may be wound on, and unwound from, a spool  24  as shown in  FIG. 2 .  
      First web-shaping device  16  may be positioned upstream of second web-shaping device  18  as shown, and may comprise any device that changes the shape of web  12 , e.g., from a generally planar form to one that is more three-dimensional, i.e., crumpled. For example, the first web-shaping device  16  may simply cause web  12  to at least partially fold upon itself as shown. First web-shaping device  16  may comprise a frame, bar, or other non-moving device that causes the web to crumple, e.g., fold. Alternatively, first web-shaping device  16  may comprise a movable device, such as one or more rotatable cylinders, paddlewheels, gears, etc. As shown, first web-shaping device  16  is in the form of a rotatable wheel, which may passively rotate when the web makes contact therewith in such a manner that the web folds upon itself in a generally longitudinal fashion, i.e., along the general longitudinal direction of web travel.  
      As shown, web  12  may move through machine  10  along a defined path of travel. If desired, the first web-shaping device  16  may cause the web to change direction along its travel path. For example, the first web-shaping device  16  may cause the web to change from a generally vertical direction of movement to a generally horizontal direction of movement as shown.  
      As shown perhaps most clearly in  FIG. 4 , second web-shaping device  18  may comprise a three-dimensional, generally annular member  26 , with a passage  28  therein through which the web  12  may travel. A web-contact region  30  borders the passage  28 . Web-contact region  30  may comprise a curved surface, e.g., a continuously curved surface as shown, and provide sliding contact with the web to effect the further crumpling thereof. A curved surface for web-contact region  30  may reduce the likelihood that web  12  will be ripped, torn, shredded, or otherwise damaged as it slides against web-contact region  30  while traversing passage  28 .  
      In some embodiments, second web-shaping device  18  may have a shape which may be described as being substantially toroidal, i.e., generally ring-shaped. For example, second web-shaping device  18  may have a substantially round toroidal shape, e.g., a shape that resembles a doughnut, as shown by annular member  26  in  FIGS. 1-4 . Alternatively, second web-shaping device  18  may have a substantially elliptical or oval toroidal shape, e.g., as shown in the embodiments illustrated in  FIGS. 5-9 .  
      In addition to selecting the overall shape of second web-shaping device  18  as described above, the cross-sectional shape of the annular member from which the second web-shaping device is constructed may also be selected. For example, annular member  26 , as depicted in  FIGS. 1-4 , may have a circular cross-sectional shape as shown in  FIG. 10 . Alternatively, the annular member could have a semi-circular shape as shown in  FIG. 11 , wherein such annular member is designated  26 ′. In this embodiment, annular member  26 ′ may advantageously be deployed such that the curved side  32  faces upstream to form the web-contact region  30 . As such, the flat side  34  may form a downstream-facing, non-web-contact region. As will be discussed below, the second web-shaping device  18 ′ illustrated in  FIGS. 5-9  has an annular member with a generally semi-circular cross-sectional shape, similar to annular member  26 ′ as shown in  FIG. 11 .  
      A further alternative cross-sectional shape for the annular member of the second web-shaping device  18  is shown in  FIG. 12 , wherein annular member  26 ″ has an elliptical cross-sectional shape. In  FIG. 13 , another alternative is shown, wherein annular member  26 ′″ has a semi-elliptical cross-sectional shape. With this embodiment, the curved side  36  of annular member  26 ′″ may face upstream to form the web-contact region while flat side  38  may form a downstream-facing, non-web-contact region. As will be discussed below, the second web-shaping device illustrated in  FIGS. 5-9  has an annular member  26 ′″ with a semi-elliptical cross-sectional shape as shown in  FIG. 13 .  
      The second web-shaping device  18  generally effects the further crumpling of the web, i.e., further to the crumpling provided by the first web-shaping device  16 , by forcing the web to continue to collapse upon itself as it is conveyed through passage  28 , wherein such further collapse is brought about by the sliding contact between the web  12  and web contact region  30 . That is, the shape of and size of passage  28  is constrained relative to the shape and size of the web  12  entering the second web-shaping device  18  so that, in order to go through passage  28 , the web must conform its cross-sectional shape and size to approximate that of passage  28 . The size, i.e., area, of passage  28  may be selected relative to the initial width of web  12  such that a desired amount of crumpling is achieved, with a smaller area for passage  28  leading to a greater degree of crumpling.  
      Second web-shaping device  18  may be constructed from any material that permits sliding contact between the device  18  and web  12  without significantly tearing or otherwise damaging web  12  as it is conveyed through device  18 , e.g., a material that provides minimal frictional resistance to the movement of the web through device  18 , which may be indicated by a material having a low coefficient of friction (“COF”). Ideally, such a material would also be one that is resistant to wear as caused by the movement of web  12  there against. Many suitable materials exist; examples include polymeric materials such as ultra-high molecular weight polyethylene (UHMWPE), polyimide, fluorocarbon resins such as polytetrafluoroethylene (PTFE) and perfluoropropylene, acetal resins, i.e., resins based on polyoxymethylene, including homopolymers (e.g., Delrine® brand polyoxymethylene), copolymers, and filled/impregnated grades, such as PTFE-filled acetal resins; various metals such as aluminum, steel, etc.; metals with low-COF coatings, e.g., anodized aluminum or nickel impregnated with low-COF polymers such as PTFE or other fluorocarbon resins; and mixtures or combinations of the foregoing.  
      Machine  10  may include an exit chute  42  which may, as illustrated, cause web  12  to change direction along its travel path, e.g., from a generally horizontal direction of movement to a generally vertical direction of movement as shown. In addition to providing a safety function, this feature may also be employed to direct severed web segments to a desired location, e.g., into a packaging container.  
      For example, as illustrated in  FIG. 3 , severed lengths of web  12 , which have been converted into dunnage segments  44  and cut to a desired length by severing mechanism  20 , are directed into shipping container  46  by exit chute  42 , wherein the dunnage segments  44  will be used to protect item  48  during shipment in container  46 .  
      Severing mechanism  20  may comprise any conventional web-severing device suitable to sever web  12 . For example, when web  12  comprises a thermoplastic material, severing mechanism  20  may include a heated severing element to sever the web by melting through it. Suitable heated severing elements may include heatable wires, blades, bands, etc. As another example, particularly when web  12  comprises paper, paperboard, or other fibrous material, severing mechanism  20  may include a cutting blade, such as a rotary blade; a swinging blade; a reciprocating blade, e.g., ‘guillotine-type’ device; a pair of blades, wherein at least one moves relative to the other; etc.  
      With continuing reference to  FIGS. 1-3 , a method for converting web  12  into dunnage  34  will be described. In accordance with some methods, web  12  is crumpled by first web-shaping device  16 , and then further crumpled by second web-shaping device  18  as described above. Conveyance mechanism  14 , which may include first and second pairs of drive members  14   a, b  as shown, pulls the web over the first web-shaping device  16  and through the second web-shaping device  18  as shown in  FIG. 1 . When a desired amount of crumpled web has been conveyed past the second pair of drive members  14   b , severing device  20  may be activated to severe the web into a discrete length of dunnage  44 , as shown in  FIG. 3 .  
      First and second pairs of drive members  14   a, b  may be operated by separate power sources, e.g., motors, or by the same motors with appropriate linkage, and may be operated at the same speed or a different speed. In some embodiments, separate motors may be used to operate each pair  14   a, b  of drive members, but pair  14   b  may be ‘slaved’ to pair  14   a  by applying more force to drive member pair  14   a  than to drive member pair  14   b , e.g., by employing a more powerful motor for pair  14   a  and/or through the use of different gearing so that more torque is applied to drive member pair  14   a  than to drive member pair  14   b.    
      By ‘slaving’ pair  14   b  to pair  14   a  in this manner, both pairs will rotate at the same speed while conveying web  12  as shown in  FIG. 1 . When it is desired to sever the web as in  FIG. 3 , power to drive member pair  14   a  may be halted while power to drive member pair  14   b  continues to be supplied. The power differential between drive member pairs  14   a  and  14   b  may be such that drive member pair  14   b  is unable to advance the web due to the resistance produced by the idled power source for drive member pair  14   a , which remain in contact with the web. As a result, drive member pair  14   b  exerts tension on the section of the web disposed between the drive member pairs  14   a, b , which facilitates severance by severing mechanism  20 . In addition, by continuing to supply power to drive member pair  14   b  after power to pair  14   a  has been halted, upon the severance of the web, drive member pair  14   b  will immediately propel the severed dunnage segment  44  out of machine  10  as shown in  FIG. 3 .  
      If additional dunnage segments  44  are required, power may again be supplied to drive member pair  14   a , which pushes the leading edge  40  of the severed web  12  into the nip between the pair  14   b  of drive members, so that both pairs once again provide conveyance of web  12  through machine  10 .  
      The operation of machine  10  may be controlled automatically, manually, or via a combination of both automatic and manual control. For instance, an electronic controller (not shown), may be employed to manipulate all functions of the machine. This controller can be a printed circuit assembly, e.g., with an EEPROM-type memory chip containing pre-programmed operating code for the machine, a programmable logic controller (PLC), or other such control device as commonly used in machines of the type to which the present invention pertains. Machine  10  may thus be fully and automatically controlled via the controller.  
      Alternatively, machine  10  may be controlled by a controller, but with operator intervention, e.g., manually via a foot pedal, hand switch, or other manually-actuatable device (not shown). An operator may thus be able to select the length and number of dunnage segments desired by appropriate input to the controller, e.g., via a control panel (not shown), or may choose to operate a foot pedal or other means to manually control the length and number of dunnage segments produced.  
      For example, in one mode of operation, a foot switch (not shown) may be provided for the operator of machine  10 . When the foot switch is depressed, power is supplied both pairs of drive members  14   a, b,  causing the conveyance of web  12  through the machine. Once a suitable length of converted web has been produced, the operator may depress another switch, e.g., another foot switch, or the same foot switch again or, if spring loaded, simply reduce foot pressure on the switch. Through suitable programming of an associated controller, this may cause the following to occur: 1) stop the flow of power to drive member pair  14   a , 2) maintain the flow of power to drive member pair  14   b  for a pre-determined additional period of time beyond the termination of power flow to drive member pair  14   a , e.g., for five additional seconds, and 3) actuate the severing mechanism  20  through one cutting cycle. When the foot pedal or other switch is again depressed, the foregoing cycle is repeated.  
      Various alternative configurations may be practiced in accordance with the present invention. For example, instead of a single supply roll  22  and spool  24  associated with machine  10  as shown, two or more supply rolls/spools may be employed, e.g., with webs of different thickness, weight, density, etc. This would allow the operator of machine  10  to select a desired type of web when it is desired to produce dunnage segments having different levels of cushioning performance, e.g., when multiple items having different cushioning requirements are being packaged. Machine  10  may thus include two or more brackets to support the two or more supply rolls, or a supply cart having two or more brackets bearing two or more supply rolls could be moved into operational association with machine  10 . As a further alternative, when employing two or more webs, e.g., from two or more supply rolls, two or more first web-shaping devices and two or more second web-shaping devices may be used. For example, if using two supply rolls containing two different webs, a first web-shaping device  16  and a second web-shaping device  18  could be associated with one supply roll while a separate set of first and second web-shaping devices  16 , 18  could be associated with the other supply roll, wherein both webs feed into the same conveyance mechanism  14 , e.g., with one web entering the conveyance mechanism (after traveling through the first and second web-shaping devices) from above the conveyance mechanism and one entering from below (after traveling through a separate set of first and second web-shaping devices).  
      Referring now to  FIGS. 5-9 , a working embodiment of a machine in accordance with the present invention, designated  10 ′, will be described. Like components as previously described are designated with like reference numerals. Machine  10 ′ may include a support stand  50  (with a suitable base (not shown)), to which the working components of the machine may be mounted. A bracket  52  may be attached to stand  50 , or may be independently supported; spool  24  and supply roll  22  of web  12  may be rotatably mounted on bracket  52 . As shown in  FIGS. 5-6 , web  12  may thus be withdrawn from roll  22 , crumpled by first web-shaping device  16 , and further crumpled by second web-shaping device  18 ′.  
      First web-shaping device  16  may, as shown, be a rotatable wheel, or a disk, roller, ball, etc., which rotates in the general direction of web travel when contacted by the web as it moves past the device. Alternatively, device  16  may be rotated by a power source, e.g., a motor, or may be a stationary device, such as a frame, bar, anvil, shoe, etc. The first web-shaping device  16  may be mounted, e.g., rotatably mounted, to stand  50 , via brackets  54  as shown (see  FIGS. 7-8 ).  
      The second web-shaping device may, as describe above, have a variety of shapes, e.g., a round toroid, an elliptical torroid, etc. In the present embodiment, second web-shaping device  18 ′ is generally in the shape of an elliptical torroid, as perhaps most clearly shown in  FIGS. 5-7 . The cross-sectional shape of device  18 ′ may be generally semi-circular, e.g., as shown in  FIG. 11  (see also  FIG. 8 ). Thus, second web-shaping device  18 ′ may be described as having a semi-toroidal shape with a curved, upstream-facing web-contact region  56  and a substantially non-curved, e.g., flat or angular, downstream-facing non-web-contact region  58 .  
      Machine  10 ′ may further include frame members  60  attached to support stand  50 , to which some of the working components of machine  10 ′ may be mounted. For example, second web-shaping device  18 ′ may be attached to frame members  60  via mounting/cover plate  62 . Attachment of the second web-shaping device  18 ′ to mounting plate  62  may be facilitated by including in device  18 ′ an annular exit section  64 , which may extend from the otherwise flat, downstream-facing region  58 . As indicated in  FIG. 8 , and shown perhaps most clearly in  FIG. 14 , the exit section  64  may be inserted through an orifice  65  in mounting plate  62 , thereby fixing the placement of device  18 ′ on plate  62 . Exit section  64  may also be useful to prevent web  12  from contacting orifice  65  in mounting plate  62 , which could result in the tearing of the web. Exit section  64  may thus include a curved, web-facing region  67 , which may (1) merge with and/or constitute part of web-contact region  56 , and (2) border web-passage  69  in second web-shaping device  18 ′ ( FIG. 14 ).  
      Web-shaping device  18 ′ may be secured in place on plate  62  via suitable fasteners, e.g., screws  66  ( FIG. 6 ).  
      As shown in  FIGS. 8-9 , frame members  60  may also be used to rotatably support the first drive-member pair  14   a . A motor  68  may be used to power the rotation of the drive member pair  14   a , which may be mounted to one of the frame members  60  as shown. Motor  68  may be directly coupled to one of the drive members, e.g., to upper drive member  70  as shown. Rotation of the other (e.g., lower) drive member  72  may be accomplished by linking the rotation of the two drive members, e.g., via gears  74   a  and  74   b.    
      Severing mechanism  20  may also be mounted to support stand  50 , e.g., via mounting assembly  76 , which may include mounting rails  78 , angle bracket  80 , and platform  82  (see  FIG. 9 ). In the illustrated embodiment, severing mechanism  20  is a vertically-oriented, ‘guillotine-type’ cutting device, including a translatable blade  84 , a pair of guide cylinders  86   a, b,  and upper and lower frame members  88   a, b . When it is desired to sever web  12 , blade  84  may be caused to translate in an upward direction from the ‘resting’ position shown in  FIG. 9 , i.e., near lower frame member  88   b , whereupon the blade cuts through the web as it moves towards upper frame member  88   a . Movement of blade  84  may be effected by any suitable conveyance means, e.g., a pair of pneumatically or hydraulically actuated pistons (not shown), each of which may travel inside of one of the guide cylinders  86   a, b  and may be attached to one of the ends  90   a, b  of blade  84 . Alternative means of conveyance may also be employed, such as a mechanical, electrical, and/or magnetic system, including combinations of any or all of the foregoing with pneumatic or hydraulic systems.  
      Machine  10 ′ may further include an exit assembly  92 , which may be supported on stand  50  by mounting assembly  76  as shown in  FIG. 9 . In the embodiment illustrated, exit assembly  92  contains the second drive-member pair  14   b , which may include upper and lower drive members  94  and  96 , respectively. The drive member pair  14   b  may be rotatively supported by a frame  98 , which rests on mounting assembly  76  as shown. The counter-rotation of upper and lower drive members  94 ,  96  may be powered by motor  100 , which may be supported by frame  98 . In the embodiment illustrated, the rotational output of motor  100  is linked to lower drive member  96  via pulleys  102 , 104  and drive belt  106 . The rotation of lower drive member  96  may, in turn, be linked to that of upper drive member  94  via intermeshing gears  108   a, b . If desired, upper drive member  94  may have a fully or, as shown, partially knurled surface  110 , which may facilitate guiding the leading edge  40  of severed web  12  (see  FIG. 3 ) between the upper and lower drive rollers  94 ,  96  following the severance of the web.  
      Referring back to  FIGS. 5-7 , one or more outer covers may be included on machine  10 ′, including top cover  112 , severing mechanism cover  114 , and exit assembly cover  116 . Such covers may be useful to provide both a safety function, i.e., to prevent accidental contact with the working components of machine  10 ′, and an aesthetically pleasing appearance.  
       FIG. 7  shows the trailing edge  118  of web  12  in a crumpled state in second web-shaping member  18 ′, i.e., after depletion of supply roll  22 , and thus illustrates one crumple pattern that may achieved with machine  10 ′. Additional dunnage material may once again be produced by simply supplanting the depleted supply roll with a new supply roll on bracket  52 , folding the web around the first web-shaping device  16 , stuffing the leading edge of the web into the second web-shaping device  18 ′, and then urging the leading edge of the web against the first pair  14   a  of drive members as the drive members rotate.  
      The foregoing description of preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention.