Patent Description:
In the process of shipping one or more articles from one location to another, a packer typically places some type of dunnage material in a shipping container, such as a cardboard box, along with the article or articles to be shipped. The dunnage material typically is used to wrap the articles or to partially or completely fill the empty space or void volume around the articles in the container. By filling the void volume, the dunnage prevents or minimizes movement of the articles that might lead to damage during the shipment process. The dunnage also can perform a cushioning function. Some commonly used dunnage materials are plastic foam peanuts, plastic bubble pack, air bags, and converted paper dunnage material.

Expandable slit-sheet packing material, also referred to as slit-sheet material, slit-sheet stock material, die-cut sheet stock material, slit material, stock material, or sheet material, for example, is useful as a cushioning material for wrapping articles and as a void-fill material for packages. The term expanding, as used herein, refers to a three-dimensional expansion, or a volume expansion. The material expands in length and thickness while decreasing in width, to yield an increase in volume and comparable decrease in density. The slit-sheet material has multiple slits typically arranged in parallel, longitudinally-spaced rows that run across the sheet material. When the slit-sheet material is stretched in a longitudinal direction, which is transverse to the direction of the slits in the rows, the material deforms, increasing in length and thickness.

Exemplary slit-sheet packing materials, and the manufacturing thereof, are described in greater detail in <CIT> and <CIT>. <CIT> discloses a package of expandable wrapping material, and a method of using that package. The package comprises a folder and a supply of sheets of expandable paper material connected to the folder. To use a sheet, the folder is opened, and a user grips the bottom edge of one of the sheets and stretches that sheet. As it is stretched, the sheet expands into a three-dimensional shape. The desired amount of expanded material is formed, and then that expanded material may be cut or torn from the folder. The expanded material may be used to wrap an article, either while that expanded material is still attached to the folder, or after that material is torn from the folder. Also, the expanded material may be used to fill voids or cavities in a box or container. Preferably, the package is secured to a fixed location, such as a work surface or a holder, while a sheet is stretched and cut or torn from the folder, and the package may be provided with means to facilitate attaching the folder to this fixed location. <CIT> discloses a cushioning wrap material that includes an elongate layer of expanded sheet material comprising an array of openings, and an elongate layer of interleaf material secured to the layer of expanded sheet material in a face-to-face relationship. The expanded sheet material is expanded in length and thickness, and the layer of interleaf material may have a width equal to or less than a width of the layer of expanded sheet material. Typically, the layer of interleaf material is secured to the layer of expanded sheet material such that respective longitudinal centerlines of each layer are substantially aligned. The layer of expanded sheet material and layer of interleaf material secured thereto are then wound onto a roll.

Slit sheet stock material typically is supplied in the form of a roll or a fan-folded stack, along with a roll of a separator sheet material that keeps layers of expanded slit sheet stock material from nesting. The separator sheet material also may be referred to as an interleaf sheet material. Conventional forms of presenting the two-ply construction of slit-sheet stock material include manual and motorized expanding devices or a disposable, prefabricated box. Such devices and boxes must accommodate two types of sheet material and may contain tensioning devices, cutting surfaces, motors, and blades. As a result, many conventional devices and boxes are large, heavy, and inconvenient for use in many locations where space is limited, such as the cash register station at the point-of-sale in retail stores and other low-volume applications.

The present invention provides a compact and convenient form of presenting the two-ply construction of slit-sheet stock material interleaved with a separator sheet material in a flat pack that may be positioned on or hung from a flat surface (e.g., tabletop, drawer, easel, wall). As a result, a cushioning or void-fill dunnage product can be provided even where space is limited. Because the flat surface of the pack also can be used as a work surface, the useability of a countertop or other flat work surface may be substantially retained after the addition of the flat pack provided by the invention. Additionally, due to the arrangement of the flat pack, a user may easily grasp and expand the slit-sheet stock material, wrap an article in the separator sheet and expanded slit-sheet stock material, and then tear the slit-sheet stock material and separator sheet material to obtain a cushioned article. Additionally, the flat pack is easy to package for presentation in traditional shelf space at points of retail sale. It can be sold at an economically viable price in units with just a few sheets of packaging material as there is no need to recover the cost of an expanding device or box.

Accordingly, the present invention provides a bound pad comprising a generally rectangular stack of a plurality of sheets of stock material, including a plurality of sheets of slit stock material, the sheets of slit stock material each including a plurality of slits arranged in a plurality of transversely-extending, longitudinally-spaced rows of slits, where each slit is longitudinally expandable and the slits in adjacent rows are staggered such that the slits are configured to separate under tension applied in a direction across the length of the slits, characterized by
each sheet of slit stock material being separated from an adjacent sheet of slit stock material by an interleafed uncut separator sheet, and the plurality of sheets of the slit stock material and the interleafed uncut separator sheets are bound together along one edge.

At least one of the plurality of sheets of slit stock material and the interleafed uncut separator sheets may be recyclable, biodegradable, and composed of a renewable resource.

At least one of the plurality of sheets of slit stock material and interleafed uncut separator sheets may include paper.

The bound edge may be bound with an adhesive.

The bound pad may be configured for attachment to a structure to provide tension when a user pulls a sheet of slit stock material to cause the slit stock material to expand to form an expanded packaging material.

The bound pad may further include a tear strip adjacent the bound edge to facilitate removal of sheets from the stack.

The sheets of slit stock material and the interleafed uncut separator sheets may be perforated or otherwise weakened adjacent the bound edge to facilitate removal from the stack.

The present invention also provides a method of using the bound pad described above. The method includes the steps of (a) pulling an edge of a sheet of the plurality of sheets of slit stock material away from the bound edge, thereby expanding the slit stock material to form a sheet of expanded packaging material; (b) placing an item to be protected on the stack; (c) simultaneously wrapping the item within a sheet of expanded packaging material and a uncut separator sheet; and (c) tearing the sheet of expanded packaging material and the uncut separator sheet adjacent to the bound edge to remove the wrapped item from the bound pad.

The placing step (b) may include placing the item on the uncut separator sheet.

The foregoing and other features of the invention are fully described below and particularly pointed out in the claims, the following description and annexed drawings setting forth in detail certain illustrative embodiments of the invention, these embodiments being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.

Referring now to the drawings in detail, and initially to <FIG>, the present invention provides a compact supply of sheet stock material ready for conversion into a packaging product in the form of a pack <NUM> of pre-cut slit sheet stock material <NUM> interleaved with non-cut separator sheets <NUM>, all of which are bound together adjacent one edge. The pack also may be referred to as a bound pad <NUM>. An exemplary bound pad <NUM> is shown supported by a table <NUM> or other generally-horizontal work surface at a packaging station <NUM>. The bound pad <NUM> is substantially flat, and has a top surface generally parallel to the work surface of the table <NUM> or other support. The bound pad <NUM> may be secured to the work surface with friction strips, adhesive tape, mechanical fasteners such as nails or screws, by placing the pad so that one or more holes drilled through the pad near the bound edge fit over a corresponding number of similarly-spaced posts protruding from the work surface, for example, or other means for securing the pad to the table <NUM> sufficiently to permit sheets to be pulled from the bound pad <NUM> in the longitudinal direction D, away from the bound edge <NUM> of the pad <NUM> without pulling the bound pad <NUM> off the table.

The bound pad <NUM> is generally rectangular, with length L and width W dimensions that typically are much greater than the thickness T or height of the bound pad <NUM>. The rectangular volume occupied by the bound pad <NUM> is very compact, and multiple bound pads can be efficiently stacked for transport, storage or in a display at the point of retail sale. Moreover, the flat top surface of the bound pad <NUM> may function as a work surface in addition to the bound pad <NUM> providing a supply of packaging material. The compactness and convenience of the bound pad <NUM> provided by the present invention allows it to be easily shipped and used in packaging stations <NUM> at many locations, such as the cash register station at the point-of-sale in retail stores. As mentioned above, the bound pad <NUM> is a generally rectangular stack of a plurality of sheets of stock material, including a plurality of sheets of die-cut slit sheet material <NUM> and non-die cut sheets <NUM> interleafed and separating adjacent sheets of slit sheet material <NUM>.

Turning now to <FIG>, an exemplary sheet of slit stock material is depicted at <NUM>. The slit-sheet stock material <NUM> may include paper, such as kraft paper, and typically includes single-ply kraft paper. A suitable kraft paper may have various basis weights, such as twenty-pound or forty-pound, for example. Paper is recyclable, biodegradable, and composed of a renewable resource. The paper itself may be made of zero to <NUM>% recycled material. In some embodiments, the slit-sheet stock material <NUM> may be laminated or may include any other suitable material such as another paper, plastic sheets, metal foil, or any other combination thereof. In some embodiments, the slit-sheet stock material <NUM> may not include paper.

The slit-sheet stock material <NUM> has a plurality of slits <NUM> arranged in a plurality of longitudinally-spaced, transversely-extending rows <NUM> of slits <NUM> arranged across the width W of the slit-sheet stock material <NUM>. The slit-sheet stock material <NUM> may have any of many alternative arrangements of slits <NUM> and/or differing sheet thickness. Different arrangements of slits may include any one or more of different arrangements of rows relative to one another, differently-sized slits, different spacing between slits, different slit shape or slit positioning, such as angular positioning, relative to adjacent slits, etc. The slits <NUM> may be formed by perforating, such as by cutting, or otherwise weakening the slit-sheet material <NUM> intermittently across the width of the slit-sheet stock material <NUM>.

The rows <NUM> of slits <NUM> generally are parallel to one another and are generally periodically, and typically equally, longitudinally-spaced from one another. The slits <NUM> are intermittently but periodically dispersed across the rows <NUM>, with the slits <NUM> of each row <NUM> generally being staggered in relation to slits <NUM> of directly adjacent rows <NUM>. Across each row <NUM> of slits <NUM>, there may be a greater length of combined slits <NUM> than a length of un-slit portions <NUM> disposed between laterally-opposed endpoints <NUM> of each slit <NUM>, providing for an optimum amount of expansion of the slit-sheet stock material <NUM> when stretched in a direction perpendicular to the slit <NUM>.

The slit-sheet stock material <NUM> is configured to expand in one or more dimensions. When the slit-sheet stock material <NUM> is stretched under tension applied in a direction transverse to the direction of the slits <NUM>, typically in a longitudinal feed direction D (<FIG>), perpendicular to a width dimension of the slit-sheet stock material <NUM>, the length and thickness of the stock material increase, while the lateral width dimension decreases. As a result of the reduced width of the expanded slit-sheet stock material <NUM> relative to the width of the original slit-sheet stock material <NUM>, the width of the separator sheet <NUM> typically is less than the width of the unexpanded slit-sheet stock material <NUM> (see <FIG>, for example).

The increased thickness as the slit-sheet stock material <NUM> is stretched longitudinally is caused as least in part by portions of the slit-sheet stock material <NUM> between the rows of slits <NUM> rotating relative to the plane of the unexpanded slit-sheet stock material <NUM>. The thickness dimension extends in a normal direction N (<FIG>) relative to a face of the slit-sheet material <NUM>. The normal direction N is defined as generally orthogonal to the paper's longitudinal length and also generally orthogonal to a lateral extent between laterally-opposed edges <NUM> of the slit-sheet stock material <NUM>, i.e., the width W. The thickness of the expanded packaging material <NUM> may be greater than the thickness of the unexpanded slit-sheet stock material <NUM> by an order of magnitude, or more, when stretched in this manner.

The expanded packaging material <NUM> has an increased length and thickness and a reduced width as compared to the unexpanded slit-sheet stock material <NUM>. This longitudinal stretching and increase in thickness results in the volumetrically-expanded dunnage product <NUM>. The expansion is effected by the rotation of the un-slit portions <NUM> between the slits <NUM> that increases the thickness and by the longitudinal separation of the sheet material on opposing upstream and downstream sides of each slit <NUM> from each other that increases the length. The increased volume allows the expanded dunnage product <NUM> to serve as a perforate protective void-fill or protective cushioning material for packaging articles in containers.

Referring back to <FIG>, the non-die cut separator sheet <NUM> may be any suitable sheet material such as paper (e.g., kraft paper, tissue paper, etc.), plastic sheets, metal foil, or any other combination thereof. The non-die cut sheet <NUM> keeps layers of expanded packaging material <NUM> from nesting, thereby retaining and enhancing the protective cushioning properties of the expanded packaging material <NUM>. Additionally, if the non-die cut sheet <NUM> were not included in the bound pad <NUM>, a user may have to insert an interleaf sheet, either by unrolling and cutting it, or by taking it from a separate pre-cut stack of interleaf sheets. These scenarios would require extra handling and shelf space at the point-of-use, reducing the utility of the bound pad <NUM> as a convenient and compact solution.

An exemplary bound pad <NUM> is shown in more detail in <FIG> and includes sheets of slit-sheet material <NUM> and non-die cut interleaf sheets <NUM> bound together adjacent a top edge <NUM>, also referred to as the bound edge <NUM>. The sheets <NUM>, <NUM> may be bound with tape or other adhesive, such as a hot-melt binding adhesive, or the edge <NUM> may be mechanically bound by staples, other mechanical clamping elements, or other means for holding the stack of sheets <NUM>, <NUM> together in the bound pad <NUM>.

As mentioned above, when the slit sheet material <NUM> is stretched lengthwise to create the expanded packaging material <NUM>, the expanded packaging material <NUM> has a narrower width than the starting slit sheet material <NUM> but a greater length and thickness. The illustrated sheets of slit-sheet material <NUM> and non-die cut separator sheets <NUM> have equal lengths but unequal widths. The non-die cut separator sheets <NUM> typically have a width that is approximately the expected width of the expanded packaging material <NUM>. In other embodiments, the sizes of the sheets of slit-sheet material <NUM> and non-die cut separator sheets <NUM> may be any combination of matched or mismatched lengths and widths depending upon the size of the article to be wrapped and/or the desired cushioning properties.

The bound pad <NUM> may be rigidly attached to the tabletop <NUM> or other structure using screws <NUM> or other fasteners to hold the bound pad <NUM> in place such that as the user pulls the slit sheet material <NUM> away from the bound edge <NUM>, tension in the slit sheet material <NUM> causes the slits to separate or open, stretching the slit sheet material <NUM> such that the slit sheet material <NUM> expands in length and thickness to form the expanded packaging material <NUM>. In another embodiment, the bound pad <NUM> may include two or more holes adjacent the bound edge <NUM> to enable the bound pad <NUM> to be set down over mounting screws, hooks, or other elements configured to resist a pulling force away from those elements. In another embodiment, a bottom layer of the bound pad <NUM> may be rigid, formed of carboard or a similar material, for example, such that tension may be provided by positioning a leading edge of the bottom layer against a raised edge that prevents the rigid bottom layer of the bound pad <NUM> from being pulled over that raised edge, or by sliding the bound pad into a folio, clipboard, or other device designed to hold a pad of writing paper of similar dimensions. The raised edge may be formed by a front of a drawer or a raised restraining strip, for example.

All of the sheets <NUM> and <NUM> in the bound pad <NUM> may be perforated or otherwise weakened along a line adjacent to the bound edge <NUM> to facilitate removal. The bound pad <NUM> may include a stiff wooden or cardboard tear strip <NUM> at the bound edge <NUM> to further facilitate removing sheets <NUM> or <NUM> as desired.

Referring now to <FIG>, an exemplary method of using the bound pad <NUM> will be described. In the first step of wrapping an article, a user creates tension by pulling a free edge <NUM> of the sheet of slit-sheet material <NUM> opposite the bound edge <NUM>, thereby expanding the slit-sheet material <NUM> to obtain a sheet of expanded slit-sheet packaging material <NUM> as shown in <FIG>.

Next, the user places an article <NUM> on the interleafed non-die cut separator sheet <NUM> and proceeds to wrap the article <NUM> within the expanded packaging material <NUM> and non-die cut separator sheet <NUM> pair, as shown in <FIG>. Although the separator sheet <NUM> is on top in the illustrated embodiment, alternatively the separator sheet <NUM> may be underneath the sheet of expanded packaging material <NUM>.

As the user nears the bound edge <NUM> of the bound pad <NUM>, the user tears the sheet of expanded slit-sheet material <NUM> and non-die cut separator sheet <NUM> adjacent to the bound edge <NUM> to remove the wrapped article <NUM> from the bound pad <NUM>. The wrapped article <NUM> is now ready to be placed in a container, or wrapped in additional layers of combined pairs of expanded slit-sheet material <NUM> and non-die cut separator sheet <NUM>.

In summary, the present invention provides a bound pad <NUM> that presents a compact and convenient form of providing a two-ply construction that includes a slit-sheet stock material that may be positioned on or hung from a flat surface at the end-user's site. The bound pad <NUM> includes sheets of slit-sheet stock material <NUM> that are interleafed with non-die cut separator sheets <NUM>. The sheets <NUM> and <NUM> are bound together adjacent one edge <NUM>, and may be weakened adjacent the bound edge <NUM> to facilitate their removal from the bound pad during use. A user creates tension by pulling a free edge <NUM> of the sheet of slit sheet material <NUM> away from the bound edge <NUM>, thereby expanding the slit material sheet <NUM> to form an expanded packaging material <NUM>. The user places an article <NUM> on the bound pad <NUM>, wraps the article <NUM> in the sheets <NUM>, <NUM>, and tears the sheets <NUM>, <NUM> to remove the wrapped article <NUM> from the bound pad <NUM>.

Claim 1:
A bound pad (<NUM>) comprising
a generally rectangular stack of a plurality of sheets of stock material, including a plurality of sheets of unexpanded slit-sheet stock material (<NUM>), the sheets of slit-sheet stock material (<NUM>) each including a plurality of slits (<NUM>) configured to separate under tension applied in a direction across the length of the slits (<NUM>), characterized by
each sheet of slit-sheet stock material (<NUM>) being separated from an adjacent sheet of slit-sheet stock material (<NUM>) by an interleafed uncut separator sheet (<NUM>), and the plurality of sheets of the slit-sheet stock material (<NUM>) and the interleafed non-die cut separator sheets (<NUM>) are bound together along one edge (<NUM>).