Patent Application
20070117703
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.
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.
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 14a of counter-rotating drive members and, if desired, a second pair 14b of counter-rotating drive members positioned downstream of the first pair 14a. Drive member pairs 14a and 14b 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 14a, 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 14a, 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 14a and second pair 14b 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
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
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
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
A further alternative cross-sectional shape for the annular member of the second web-shaping device 18 is shown in
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
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
First and second pairs of drive members 14a, 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 14a, b of drive members, but pair 14b may be ‘slaved’ to pair 14a by applying more force to drive member pair 14a than to drive member pair 14b, e.g., by employing a more powerful motor for pair 14a and/or through the use of different gearing so that more torque is applied to drive member pair 14a than to drive member pair 14b.
By ‘slaving’ pair 14b to pair 14a in this manner, both pairs will rotate at the same speed while conveying web 12 as shown in
If additional dunnage segments 44 are required, power may again be supplied to drive member pair 14a, which pushes the leading edge 40 of the severed web 12 into the nip between the pair 14b 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 14a, 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 14a, 2) maintain the flow of power to drive member pair 14b for a pre-determined additional period of time beyond the termination of power flow to drive member pair 14a, 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
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
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
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
Web-shaping device 18′ may be secured in place on plate 62 via suitable fasteners, e.g., screws 66 (
As shown in
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
Machine 10′ may further include an exit assembly 92, which may be supported on stand 50 by mounting assembly 76 as shown in
Referring back to
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.
