Elongate tube volume filling article

Abstract

A volume filling article is formed from an expandable sheet and includes an elongate tube having a wall surrounding a longitudinal axis. The wall is formed of overlapping layers of the expandable sheet in a deployed configuration arranged in an overlapping helix. The expandable sheet has a plurality of protruding portions in the deployed configuration. At least some of the protruding portions that extend outwardly in each overlapping layer are interlocked with at least some protruding portions that extend outwardly from a respective adjacent layer. An apparatus includes two rollers and an elongate member arranged to make the elongate tube from the expandable sheet material.

Description

EEONGATE TUBE VOLUME FILLING ARTICLE

[0001] The present disclosure relates to a volume filling article and related systems and methods and, in particular, an elongate tube volume filling article made of sheet material.

[0002] Sheets suitable for the tubular volume filling article may include tension-activated, expandable sheets, for example of paper or plastic, that are cut with a slit pattern enabling them to be expanded when tension is applied along a tensioning axis of the sheet. An exemplary tension- activated, expandable sheet is SCOTCH™ CUSHION LOCK™ protective wrap available from 3M Company (St. Paul, Minnesota, USA), a paper-based, tension-activated, expandable sheet. Upon application of tension to expand such a sheet, portions of the sheet rotate to create an interlocking folded-wall structure that absorbs energy and can be used, for example, to cushion and protect objects during shipping.SUMMARY

[0003] In one aspect, the present disclosure relates to a volume filling article formed from an expandable sheet. The article includes an elongate tube having a wall surrounding a longitudinal axis. The wall is formed of overlapping layers of the expandable sheet in a deployed configuration arranged in an overlapping helix. The expandable sheet has a plurality of protruding portions in the deployed configuration. Each protruding portion extends outwardly from a tension plane of the expandable sheet in a first direction or in a second direction. The tension plane extends along an expansion axis and a cross axis. At least some of the protruding portions that extend outwardly in the first direction in each overlapping layer are interlocked with at least some protruding portions that extend outwardly in the second direction from a respective adjacent layer.

[0004] In one aspect, the present disclosure relates to a package including an object for shipping disposed interior to an outer surface of the elongate tube according to the present disclosure.

[0005] In another aspect, the present disclosure relates to an apparatus for making a volume filling article. The apparatus includes a first roller rotatable around a first axis parallel to an input feed plane for receiving the expandable sheet along the input feed plane. The apparatus also includes a second roller rotatable around a second axis offset from the first axis along a height axis intersecting the first axis and the second axis. A first angle between the first axis and the second axis projected onto the input feed plane is between 15 and 45 degrees. The apparatus further includes an elongate guide member positioned between the first roller and the second roller and extending along an output axis. A second angle between the first axis and the output axis projected onto the input feed plane is less than the first angle. The first roller and the second roller are configured to be rotated to form an elongate tube comprising a wall surrounding a longitudinal axis in response to an expandable sheet being fed between the first roller and thesecond roller along the input feed plane and at least partially around the elongate guide member. The elongate tube has a length extending along the output axis. The wall is formed of overlapping layers of the expandable sheet arranged in an overlapping helix.

[0006] In another aspect, the present disclosure relates to a method of forming an article for a package. The method includes feeding an expandable sheet to engage at least one roller. The expandable sheet defines an expansion axis and a cross axis. In a flat configuration, the expandable sheet defines a first major surface extending along the expansion axis and the cross axis and a second major surface opposite the second major surface. The expandable sheet defines a plurality of slits formed in the expandable sheet extending at least partially between the first major surface and the second major surface in a repeating pattern. The repeating pattern includes at least a first row of the slits and a second row of the slits adjacent to the first row. The rows extend along the cross axis. The slits are configured to open in response to a minimum tension applied to the sheet along the expansion axis to move into a deployed configuration. The method also includes winding the expandable sheet in a deployed configuration to form an elongate tube comprising a wall. The wall is formed of overlapping layers of the expandable sheet in the deployed configuration arranged in an overlapping helix.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0008] FIG. 1A is a plan view of one example of a volume filling article including an elongate tube according to the present disclosure.

[0009] FIG. IB is a cross-sectional view of the elongate tube of FIG. 1A along line 1B-1B.

[0010] FIG. 1C is an image of the elongate tube of FIG. 1A in the form of a spiral.

[0011] FIG. ID is an image of the spiral elongate tube of FIG. 1C being used as void fill in a box.

[0012] FIG. IE is a plan view of the expandable sheet of the elongate tube of FIG. 1A in a flat configuration.

[0013] FIG. IF is a perspective view of the expandable sheet of FIG. IE in a deployed configuration.

[0014] FIG. 2A is a plan view of another example of an expandable sheet usable in the elongate tube of FIG. 1A in a flat configuration according to the present disclosure.

[0015] FIG. 2B is a perspective image of the expandable sheet of FIG. 2A in a deployed configuration.

[0016] FIG. 2C is a cross-sectional view of an overlapping helix formed from the expandable sheet of FIG. 2B in the deployed configuration.

[0017] FIG. 3A is a plan view of one example of an apparatus for making a volume filling article according to the present disclosure.

[0018] FIG. 3B is an elevation view of the apparatus of FIG. 3A.

[0019] FIG. 3 C is an elevation view of the apparatus of FIG. 3 A in use making a volume filling article.

[0020] FIG. 4 is a flow diagram showing one example of a method of making a volume filling article according to the present disclosure.DETAILED DESCRIPTION

[0021] The present disclosure relates to a volume filling article and related systems and methods and, in particular, an elongate tube volume filling article made of sheet material. An elongate tube is formed using an expandable sheet arranged in an overlapping helix. The expandable sheet is in a deployed configuration that interlocks with other layers in the overlapping helix. Elongate tubes of varying lengths and widths can be made using this technique from an expandable sheet having a fixed width. Elongate tubes may be used, for example, as void fill in a package protection article. For example, the elongate tube can be wrapped into a spiral to cover the bottom of a box. Other uses for the elongate tube will become apparent to one skilled in the art having the benefit of the present disclosure.

[0022] FIG. 1A to FIG. IF show various views of a volume filling article 100, which is one example of a volume filling article according to the present disclosure. FIG. 1A is a perspective schematic view of the volume filling article 100 including an elongate tube 102 in a cylindrical configuration formed from an expandable sheet 110. The elongate tube 102 includes a wall 106. The wall 106 is formed of overlapping layers 108 of an expandable sheet 110 in a deployed configuration arranged in an overlapping helix.

[0023] FIG. IB is a cross-sectional view of the elongate tube 102 along line 1B-1B shown in FIG. 1A. In the deployed configuration, the expandable sheet 110 has a plurality of protruding portions 124. Each protruding portion 124 extends outwardly from a tension plane 118 of the expandable sheet 110 in a first direction 130 or in a second direction 132. As illustrated, when used to form the elongate tube 102, the tension plane 118 follows a substantially spiral path in the cross-sectional view. At least some of the protruding portions 124 that extend outwardly in the first direction 130 in each overlapping layer 108 are interlocked with at least some protruding portions 124 that extend outwardly in the second direction 132 from a respective adjacent layer.

[0024] One example of an application for the volume filling article 100 is as a package protection article. FIG. 1C is a perspective photo of the elongate tube 102 in a spiral configuration. FIG. ID is a perspective photo of the article 100 further including a box 104, inwhich the elongate tube 102 in the spiral configuration is disposed in the box for use as void fill to protect an object disposed in the box, for example, during shipping or other handling.

[0025] FIG. IE is an overhead view of the expandable sheet 110 in a flat configuration, which is one example of an expandable sheet according to the present disclosure. FIG. IF is a perspective view of the expandable sheet 110 in the deployed configuration before winding to form the overlapping helix. Generally, the expandable sheet 110 may be expanded from the flat configuration to the deployed configuration before winding.

[0026] In the flat configuration of the expandable sheet 110, the tension plane 118 may be defined as extending parallel to either major surface of the expandable sheet 110. The expandable sheet 110 may define an expansion axis 126 and a cross axis 128 orthogonal to the expansion axis, which is perhaps best seen in FIG. IE showing the expandable sheet 110 in the flat configuration. A sheet length may be defined parallel to the expansion axis 126. A sheet width may be defined parallel to the cross axis 128.

[0027] In general, the article 100 may be formed by winding the expandable sheet 110 in a helical motion to form the wall 106 of the elongate tube 102. Before winding, the expandable sheet 110 may be provided in the form of a roll and unwound from the roll along its length. In some embodiments, some or all of the wall 106 may be formed from a single, continuous expandable sheet 110. As a leading portion of the expandable sheet 110 is used to form the wall 106 of the elongate tube 102, a remaining portion 112 of the expandable sheet 110 is used to feed the overlapping helix. In some embodiments, some or all of the wall 106 is formed from one expandable sheet 110. As more of the expandable sheet 110 is used to feed the helix, one or both of the diameter and the length of the elongate tube 102 may grow. In some embodiments, after a tapered portion of the elongate tube 102 is formed, the diameter of the elongate tube 102 may be substantially constant while the length of the elongate tube 102 increases as more of the expandable sheet 110 is used to feed the overlapping helix. Once the desired size of elongate tube 102 is achieved, any remaining portion 112 of the expandable sheet 110 may be removed to leave the elongate tube 102 in a substantially cylindrical configuration.

[0028] The elongate tube 102 may define a cavity, such as cavity 120. In some embodiments, the wall 106 may surround the cavity 120, and the cavity 120 may be at least partially defined by a minimum diameter. The cavity 120 may be a result of the technique used to form the elongate tube 102. The cavity 120 may be described as an elongate cavity extending along the longitudinal axis 116. In other embodiments, the elongate tube 102 may have no cavity, for example, when no minimum diameter can be reasonably measured. In some embodiments, the elongate tube 102 may have a cavity 120 at the time of formation that is configured to collapse during use as void fill and leave no measurable cavity. In such case, the minimum diameter of the cavity 120 may be measured before use as void fill, preferably in the cylindrical, or linear, configuration.

[0029] As can be seen in FIG. 1A, each layer 108 of the wall 106 may be described as a tapered tube, or discrete cone, that partially overlap one another and form the wall 106. As the overlapping helix is created, each layer 108 may be described as having a leading end portion and trailing end portion. In the illustrated embodiment, the trailing end portion of each layer 108 is tapered. A first width of the trailing end portion is less than a second width of the leading end portion. The formation of tapered overlapping layers 108 is at least partially facilitated by the stretchability of the expandable sheet 110 along the expansion axis 126. In particular, the stretch of the expandable sheet 110 may vary across its width, which allows the same length of sheet substrate 140 to be used to form both the tapered trailing end portion having a smaller width, or diameter, and the leading end portion having a larger radius, or diameter. In some embodiments, the expandable sheet 110 once deployed in its deployed configuration is interlocking across its width, even across various degrees of stretch. Repeating patterns of slits 138 configured to form protruding portions of the present disclosure, such as folding walls or undulating beams, are particularly well-suited to provide interlocking across various degrees of stretch.

[0030] When used as void fill, one or more objects to be protected may be disposed adjacent to the article 100. Additionally, or alternatively, one or more objects to be protected may be disposed in the elongate tube 102 itself for protection. In general, one or more objects may be disposed interior to the outer surface 154, or outer layer, of the wall 106. In some embodiments, one or more objects may be disposed in the cavity 120 interior to all layers of the wall 106. In some embodiments, one or more objects may be disposed between adjacent layers of the wall 106.

[0031] The wall 106 may include a plurality of openings formed in the expandable sheet 110. The openings may be formed from one or more slits 138 formed in the expandable sheet 110 that have been opened. The openings may be at least partially covered by other layers of the expandable sheet 110.

[0032] The length of the elongate tube 102 may be described as extending along a longitudinal axis 116 and may be measured along the longitudinal axis 116. The wall 106 surrounds the longitudinal axis 116. In the cylindrical configuration, or linear configuration, the longitudinal axis 116 may be follow a substantially linear path (see FIG. 1A). In the spiral configuration, the longitudinal axis 116 may be follow a substantially spiral path (see FIG. 1C). In any configuration of the elongate tube 102, the length of the elongate tube 102 may be measured along the longitudinal axis 116.

[0033] As can be seen in FIG. 1A, the pitch P of the helix is approximately the length of a layer 106 uncovered by an adjacent layer. The length of the elongate tube 102 may be calculated based on the pitch of the helix, the number of overlaps, and to some extent the width of the expandable sheet 110 in a deployed configured created while winding the helix. For example, LT= N x P + W, where LT is the length of the elongate tube 102, N is the number of overlapping layers, P is the pitch, and W is the width of the expandable sheet 110 in the deployed configuration. Thethickness of the wall 106 and thereby the diameter, or width, of the elongate tube 102 may also be approximated based on the pitch of the helix, the width of the expandable sheet 110, and the thickness of the expandable sheet 110 in the deployed configuration. For example, WT= C +2 x T , where WT is the width of the elongate tube 102, C is the width of the cavity 120, T is the thickness of the expandable material 102 in the deployed configuration, and P is the pitch. In some embodiments, the cavity width C may be reduced to zero or almost zero by laterally compressing the elongate tube 102. The elongate tube 102 continuously grows as layers are added. The length of a discrete elongate tube can be controlled by cutting or tearing the continuously growing elongate tube. The selection of length and the width of the elongate tube 102 may be beneficial in void fill applications, for example, by providing multiple lengths and diameter of tubular-shaped void fill from one roll of expandable sheet 110 having a fixed width.

[0034] As used herein, the “pitch” of the helix means the distance of one complete helix revolution as measured parallel to the longitudinal axis 116. The pitch may be selected based on the particular application of the elongate tube 102. For example, in applications related to void fill, the pitch may be less than or equal to 1 / 2, 1 / 3, 1 / 4, or even 1 / 5 of the width of the expandable sheet 110 and greater than or equal to 1 / 10, 1 / 5, 1 / 4, or even 1 / 3 of the width of the expandable sheet 110. The maximum number of overlapping layers of the wall 106 may also be determined by the pitch of the helix, for example, calculated as the multiplicative inverse of the pitch relative to the width of the expandable sheet 110. For example, a pitch of 1 / 5 of the width of the expandable sheet has 5 overlapping layers in the wall 106.

[0035] The width of the expandable sheet 110 may be measured along a cross axis 128 defined relative to the expandable sheet 110. As illustrated arrangement in FIG. 1A, the cross axis 128 is oriented parallel to the longitudinal axis 116, and the width of the expandable sheet 110 may also be measured along the longitudinal axis 116. In general, the length of the elongate tube 102 is greater than the width of the expandable sheet 110. The length of the elongate tube 102 may be selected based on the particular application of the elongate tube 102. For example, in applications related to void fill, the length of the elongate tube 102 may be at least 1.5, 2, 2.5, 5, 10, 15, or even 20 times a width of the expandable sheet 110.

[0036] The width, or thickness, of the elongate tube 102 may be described as extending orthogonal to the longitudinal axis 116. The width may depend on the size of any protruding portions, such as folding walls or undulating beams, of the expandable sheet 110, the pitch, and the size of any cavity 120.

[0037] Based on the selection of material, repeating pattern of slits, pitch, and width of the expandable material, the elongate tube 102 may be configured to have a compressibility and conformability suitable for various applications.

[0038] In some embodiments for void fill applications, the elongate tube 102 has a conformability measured in the cylindrical configuration. The conformability may be measuredaccording to the Bending Test, the Spiral Roll Test, or a combination thereof as described herein. As used herein, the conformability is defined as passing the Bending Test by having a smooth arc that is free of kinks. As used herein, the conformability is defined as passing the Spiral Roll Test by having more than 50% of samples that do not unravel, for example, with a sample size of at least 5, 10, or more.

[0039] The expandable sheet 110 is at least partially formed from a sheet substrate 140. In the flat configuration, the sheet substrate 140 defines a first major surface 136 extending along the expansion axis 126 and the cross axis 128 and a second major surface opposite the first major surface 136. The expandable sheet 110 defines a plurality of slits 138 formed in the sheet substrate 140 extending at least partially between the first major surface 136 and the second major surface in a repeating pattern.

[0040] The slits 138 are arranged in a slit pattern, which may be a repeating pattern and may be described as repeating slit pattern. The repeating pattern of slits 138 has a plurality of rows 142, including at least a first row of the slits 138 and a second row of the slits 138 adjacent to the first row. Each row 142 extends substantially parallel to the cross axis 128. Each slit 138 is configured to open in response to a minimum tension applied to the sheet substrate 140 parallel to the expansion axis 126 to move the expandable sheet 110 into the deployed configuration. In some embodiments, in the deployed configuration, the expandable sheet 110 has a plurality of protruding portions 124, which may include a plurality of folding walls (see FIG. IE and FIG. IF), a plurality of undulating beams (see FIG. 2A and FIG. 2B), or both. Elongate tubes of the present disclosure may be made using expandable sheets including a plurality of folding walls (see cross-section view of FIG. IB), a plurality of undulating beams (see FIG. 2C), or any combination of them.

[0041] As used herein, “opening” or “expanding” the slits means separating at least a portion of the sheet material on each side of the slit. In particular, when the expandable sheet is in a flat configuration and tension-activated (pulled along the expansion axis 126), portions of the sheet substrate 140 may move upward and downward from the substantially two-dimensional major surface and become a three-dimensional article.

[0042] As used herein, the term “slit” refers to a narrow cut through the article forming at least one line or segment, which may be straight or curved, or described as linear or non-linear, having at least two terminal ends. Slits described herein are discrete, meaning that individual slits do not intersect other slits. A slit is generally not a cut-out, where a “cut-out” is defined as a surface area of the sheet that is removed from the sheet when a slit intersects itself. However, in practice, many forming techniques result in the removal of some surface area of the sheet that is not considered a “cut-out” for the purposes of the present application. In particular, many cutting technologies produce a “kerf,” or a cut having some physical width. For example, a laser cutter will ablate some surface area of the sheet to create the slit, a router will cut away some surfacearea of the material to create the slit, and even crush cutting creates some deformation on the edges of the material that forms a physical gap across the surface area of the material.Furthermore, molding techniques require material between opposing faces of the slit, creating a gap or kerf at the slit. In various embodiments, the gap or kerf of the slit will be less than or equal to the thickness of the material. For example, a slit pattern cut into paper that is 0.007” (approximately 18 mm) thick might have slits with a gap that is approximately 0.007” or less. However, it is understood that the width of the slit could be increased to a factor that is many times larger than the thickness of the material and be consistent with the technology disclosed herein.

[0043] Slits can be characterized as “simple slits” or “compound slits,” where a “simple slit” is defined as having exactly two terminal ends and a “compound slit” has more than two terminal ends. As used herein, the term “single slit pattern” refers to a pattern of individual slits that form individual rows each extending across the sheet transversely (e.g., along a horizontal axis), where the rows form a slit pattern of individual rows arranged along the axial length of the sheet (e.g., along a vertical axis), and the pattern of slits in each row is different than the pattern of slits in the directly adjacent rows. For example, the slits in one row may be axially offset or out of phase with the slits in the directly adjacent rows. Various slits described herein include simple slits having four vertical distal end portions, including at least one non-terminal vertical distal end portion.

[0044] The sheet substrate 140 may be formed of various suitable materials. Some exemplary materials into which the slit patterns described herein can be formed include, for example, paper (including cardboard, corrugated paper, coated or uncoated paper, kraft paper, cotton bond, recycled paper, extensible paper); plastic; woven and non-woven materials and / or fabrics; elastic materials (including rubber such as natural rubber, synthetic rubber, nitrile rubber, silicone rubber, urethane rubbers, chloroprene rubber, Ethylene Vinyl Acetate or EVA rubber); inelastic materials (including polyethylene and polycarbonate); polyesters; acrylics; and polysulfones. The article can be, for example, a material, sheet, film, or any similar construction.

[0045] Examples of thermoplastic materials that can be used include one or more of polyolefins (e.g., polyethylene (high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE)), metallocene polyethylene, and the like, and combinations thereof), polypropylene (e.g., atactic and syndiotactic polypropylene)), polyamides (e.g. nylon), polyurethane, polyacetal (such as Delrin), polyacrylates, and polyesters (such as polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), and aliphatic polyesters such as polylactic acid), fluoroplastics (such as THV from 3M company, St. Paul, MN, US), and combinations thereof. Examples of thermoset materials can include one or more of polyurethanes, silicones, epoxies, melamine, phenolformaldehyde resin, and combinations thereof. Examples of biodegradable polymers can includeone or more of polylactic acid (PLA), polyglycolic acid (PGA), poly (caprolactone), copolymers of lactide and glycolide, polyethylene succinate), polyhydroxybutyrate, and combinations thereof.

[0046] “Paper” as used herein refers to woven or non-woven sheet-shaped products or fabrics (which may be folded, and may be of various thicknesses) made from cellulose (particularly fibers of cellulose, (whether naturally or artificially derived)) or otherwise derivable from the pulp of plant sources such as wood, com, grass, rice, and the like. Paper includes products made from both traditional and non-traditional paper making processes, as well as materials of the type described above that have other types of fibers embedded in the sheet, for example, reinforcement fibers. Paper may have coatings on the sheet or on the fibers themselves. Examples of non- traditional products that are “paper” within the context of this disclosure include the material available under the trade designation TRINGA from PAPTIC (Espoo, Finland), and sheet forms of the material available under the trade designation SULAPAC from SULAPAC (Helsinki, Finland).

[0047] The extensibility of paper can be defined as the ability of paper to increase its linear length under the action of external mechanical forces due to elastic, viscoelastic, and plastic deformations. One type of mechanical deformation in paper is tensile deformation, where extensibility is determined as the strain at break value of the stress-strain curve. Many papers, which may be described as non-extensible papers created by existing manufacturing techniques may have extensibility around 1% to 4% in a machine direction (MD) and 3% to 6% in a cross direction (CD), or even greater values in the MD and CD. Various techniques that can achieve greater extensibility include mechanical treatments, as well as chemical treatments.

[0048] The material in which the single slit pattern is formed can be of any desired thickness. In some embodiments, the material has a thickness between about 0.001 inch (0.025 mm) and about 5 inches (127 mm). In some embodiments, the material has a thickness between about 0.01 inch (0.25 mm) and about 2 inches (51 mm). In some embodiments, the material has a thickness between about 0.1 inch (2.5 mm) and about 1 inch (25.4 mm). In some embodiments, the thickness is greater than 0.001 inch (.025 mm), or 0.01 inch (.25 mm), or 0.05 inch (1.3 mm), or 0.1 inch (2.5 mm), or 0.5 inch (13 mm), or 1 inch (25 mm), or 1.5 inches (38 mm), or 2 inches (51 mm), or 2.5 inches (64 mm), or 3 inches (76 mm). In some embodiments, the thickness is less than 5 inches (127 mm) or 4 inches (101 mm), or 3 inches (76 mm), or 2 inches (51 mm), or 1 inch (25 mm), or 0.5 inch (13 mm), or 0.25 inch (6.3 mm), or 0.1 inch (2.5 mm).

[0049] In some embodiments, where the material is paper, the thickness is between about 0.003 inch (0.076 mm) and about 0.010 inch (0.25 mm). In some embodiments where the material is plastic, the thickness is between about 0.005 inch (0.13 mm) and about 0.125 inch (3.2 mm).

[0050] In some embodiments, the slit pattern extends substantially to one or more of the edges of the sheet, film, or material. In some embodiments, this allows the material to be of unlimited length and also to be deployed by tension, particularly when made with non-extensible materials.The amount of edge material is the area of material surrounding and not including the single slit pattern. In some embodiments, the amount of edge material, or down-web border, can be defined as the width of the rectangle whose long axis is parallel to the tension axis and is infinitely long and can be drawn on the substrate without overlapping or touching any slits. In some embodiments, the amount of edge material is less than .010 inch (0.25 mm) or less than .001 inch (0.025 mm). In some embodiments, the width of the down-web border is less than .010 inch (0.25 mm) or less than .001 inch (0.025 mm). In some embodiments, the amount of edge material is less than 5 times the thickness of the substrate. In some embodiments, the width of the down-web border is less than 5 times the thickness of the substrate.

[0051] In general, expandable sheet 110 may be made in any suitable manner. For example, slit patterns can be formed by extrusion, molding, laser cutting, water jetting, machining, stereolithography or other 3D printing techniques, laser ablation, photolithography, chemical etching, rotary die cutting, stamping, other suitable negative or positive processing techniques, or combinations thereof. For example, rotary die cutting uses a rotary die with cutting surfaces (e.g., blades) to form slits in sheet substrate 140 according to the slit pattern to provide the expandable sheet 110. After being formed, the expandable sheet 110 may be used to form a roll. A user may unroll and deploy the expandable sheet 110, for example, using a dispenser or manually.

[0052] The slit pattern may define a plurality of nonrotating beam regions. Each nonrotating beam region may be positioned between adjacent slits 138 in the same row. Each nonrotating beam region may be defined at least partially between two vertical distal end portions of a first slit and two vertical distal end portions of a second slit adjacent to the first slit in the same row. In some embodiments, the vertical ends of adjacent slits may be aligned. For example, one vertical distal end portion of the first slit may be aligned to intersect a horizontal line and one vertical distal end portion of the second slit aligned to intersect the same horizontal line. A vertical distal end portion may be terminal or non-terminal.

[0053] The rows of the slit pattern may be staggered. Each slit may include a connector portion extending at least partially along the horizontal axis between two of the vertical distal end portions of the slit. The connector portion may also be described as extending between two horizontal distal end portions of the slit. In a slit pattern having staggered rows, the connector portion of a slit and a nonrotating beam region between slits in an adjacent row may be aligned to intersect a vertical line, which is generally parallel to the vertical axis.

[0054] As used herein, the terms “vertical line” and “horizontal line” refer to imaginary lines oriented relative to the expandable sheet 110 that extend substantially parallel to the expansion axis 126 or the cross axis 128, respectively.

[0055] As used herein, the term “staggered row” refers to the locations of substantially all the slits 138 in a given row being out of phase, or phase offset, by a set amount or a minimum distance along the horizontal axis when compared to corresponding slits in a directly adjacentrow. In some embodiments, the adjacent rows are out of phase by one half of the horizonal spacing between slits in the row, as measured by the geometric center-to-center distance between slits.

[0056] The repeating slit pattern may define a repeating region within the repeating pattern. The repeating region includes at least two staggered rows of the slits. The repeating region may repeat at least two times along at least one row of the slits in the repeating pattern, at least two times along the expansion axis 126 in the repeating pattern, or both.

[0057] The slits 138 may have one or more orientations in the repeating region. In some embodiments, the repeating region includes at least two slits oriented in the same direction or includes each slit being oriented in the same direction. In some embodiments, the repeating region includes at least one inverted slit in the same row to at least one noninverted slit or includes at least one inverted slit in an adjacent row to at least one noninverted slit. The at least one inverted slit may be an inversion across a horizontal line, which is parallel to the horizontal axis. Such a slit pattern may be described as having slit inversions.

[0058] The repeating slit pattern may also include shifted pattern features. For example, the slits 138 in a row may have one or more shifted pattern features compared to the slits 138 in an adjacent row. As used herein, the term “pattern features” refers to a slit or of a slit feature along the major surface. As used herein, the term “slit feature” refers to a segment, a segment intersection, or an end point of a slit. The term “shifted pattern feature” of an arrangement refers to a shifted location or orientation of a slit or a slit feature compared to a corresponding slit or slit feature in another arrangement. The term “shifted slit” refers to a shift in the location or orientation of an entire slit. The term “shifted slit feature” refers to a shift in the location or orientation of a slit feature in a slit. Different arrangements may be compared by overlaying one region on top of another region and identifying how one or more slits or slit features have shifted.

[0059] The expandable sheet 110 with protruding portions 124 may be described as having interlocking features and being an interlocking expandable sheet, which can hold its shape after being wound into a cylinder or helix in its deployed configuration, particularly without the assistance of an additional coupling mechanism, such as adhesive tape. As used herein, whether an expandable sheet is “interlocking” is determined by the following Interlocking Test.

[0060] Interlocking Test

[0061] An expandable sheet sample measuring 36-inches (0.91 m) long and 7.5-inches (19 cm) wide is obtained. The sample is fully deployed without tearing, and then placed directly adjacent to a smooth PVC pipe, for example, a one having an outer diameter (OD) of 3.15 inches (8 cm) and a length of 23 inches (58.4 cm), ensuring that the sample remains fully deployed during rolling. The sample is wrapped over the pipe ensuring that each successive layer is placed directly over the previous layer and that the sample is placed at the center (along the length) of the pipe. The sample will provide a minimum of two complete wraps around the pipe. When all the sampleis wrapped around the pipe, the sample is released and whether the sample unfolded or unwrapped is observed. If the sample does not unfold or unwrap after a 1 -minute wait, the sample is slid off the pipe onto a smooth surface, such as a tabletop. The sample is then lifted by the trailing edge to see if it unrolls or unwraps or otherwise holds its shape. A sample that holds its shape is an “interlocking” sample.

[0062] If the sample opened / unwrapped within a minute of being released, during sliding it off the pipe, or when lifted by the trailing edge, the sample is deemed “not interlocking”. If the sample holds its tubular shape during and after sliding it off the pipe and when lifted by the trailing edge, then it is deemed interlocking. The test is repeated at least 5, 10, or more times for each sample.

[0063] FIG. IE and FIG. IF show the expandable sheet 110 having a plurality of slits 138 configured to provide protruding portions in the deployed configuration and, in particular, the protruding portions may be described as folding walls. The expandable sheet 110 has a tension- activatable kirigami slit pattern in the flat configuration as shown in the schematic plan view of FIG. IE and a tension-activated, deployed configuration as shown in the perspective view of FIG. IF.

[0064] The expanded configuration of the expandable sheet 110 is a three-dimensional (3D) structure wherein portions of the expandable sheet 110 extend along all three axes in space. As illustrated, the slit pattern includes a plurality of slits 138 each having the general shape of a capital “H” with an undulating cross beam and arranged to define a plurality of nonrotating beam regions 156 and folding wall regions 158 such that, when the expandable sheet 110 is expanded, or deployed, the nonrotating beam regions 156 form nonrotating beams 164 between adjacent slits in the same row and folding wall regions 158 form folding walls 168 between slits in adjacent rows.

[0065] Although the slits 138 may have various shapes, each slit may be described as being formed of various slit features, such as segments, segment intersections, and terminal ends.

[0066] In general, each slit 138 includes at least one segment. In the illustrated embodiment, each slit 138 includes three segments, one generally horizontal segment 172 and two vertical segments 176 connected to each end of the horizontal segment. As illustrated, the horizontal segment 172 has an undulating shape and the vertical segments 176 have linear shapes. A segment of a slit may be described as continuous and linear (e.g., straight) or non-linear (e.g., curved). A segment may also be described relative to the tool used to form the segment. For example, each segment may be cut by a distinct cutting surface on a rotary die .

[0067] In general, each slit 138 includes at least two terminal ends 178. The slits 138 in the slit pattern as illustrated may be described as compound slits. The compound slits have at least two slit segments with at least one segment intersection 174. In the illustrated embodiment, eachsegment intersection 174 is the intersection of a horizontal segment 172 and a vertical segment 176, and each slit 138 has two segment intersections 174.

[0068] In some embodiments, the folding walls 168 are generally perpendicular, or generally 90 degrees, to the tension plane 118. “Generally” being at an angle, such as perpendicular, is defined herein as encompassing angles within a 5 -degree margin of error or within a 3 -degree margin of error.

[0069] When in the deployed configuration and wound in an overlapping helix, the protruding portions 124, in the form of folding walls 168 shown in FIG. IF, may interlock with one another as shown in FIG. IB.

[0070] FIG. 2A and FIG. 2B show one example of an expandable sheet 200 usable in the article 100, in a schematic plan view and a perspective view, respectively. The expandable sheet 200 has a plurality of slits 202 arranged in a slit pattern. In the illustrated embodiment, each slit 202 is a multi-slit, or more particularly, a double-slit. The pattern of FIG. 2A in the flat configuration shows that the slits 202 can vary in position or shape within a row. In other words, the slits 202 in a single row vary in shape, position, or both, but the pattern is repeated in adjacent rows. With specific reference to the implementation of this general concept into an example, the slit pattern of FIG. 2A includes a first set of rows that include slits of a first shape and position and a second (vertically inverted) shape and position. The slits 202 in a single row alternate in their shape, position, or both such that first shape or position slit is next to second shape or position slit, and this pattern repeats down the row. The slit shape is substantially the same except for the inversion.

[0071] This double-slit pattern is formed in a sheet material and includes a plurality of slits 202 that each include two terminal ends 204, including a first terminal end and a second terminal end, and a midpoint 206. A plurality of individual slits 202 are aligned to form rows that are generally perpendicular to an expansion axis T. In the illustrated embodiment of FIG. 2A, the slits 202 are not straight lines (see the slits 138 of FIG. IE) but instead are generally v-shaped or cuspshaped. Slits 202 comprise a curved first portion that is generally at a 45-degree angle to expansion axis T and that connects with curved second portion at a generally oblique angle. First and second portions connect at midpoint 206. The slits 202 may be described as being generally perpendicular to the expansion axis T, except for the oblique first and second portions.

[0072] An axial beam region 208 is formed is between the terminal ends 204 of pairs of adjacent slits in adjacent rows. The axial beam region 208 may also be described as being positioned between transverse beam regions 210. Slits 202 in adjacent rows form sides or edges of a portion of a transverse beam regions 210. The material between slits 202 in the same row form sides or edges of a portion of overlap beam regions 218.

[0073] In this illustrated embodiment, the slits 202 each have two terminal ends 204. A straight, imaginary line extends between and connects these terminal ends. The straight, imaginary line extending between and connecting the terminal ends of a first slit is substantially colinear with thestraight, imaginary line extending between and connecting the terminal ends of a directly adjacent slit. In this embodiment, all of the straight, imaginary lines extending between and connecting the slit terminal ends in a single row are approximately colinear.

[0074] In the deployed configuration shown in FIG. 2B, portions of the sheet substrate of the expandable sheet 200 experience tension, compression, or both that cause portions of material to move out of the tension plane. In general, terminal ends 204 of the same slit 202 experience compression and are drawn toward one another, causing portions of transverse beam regions 210 to undulate out of the tension plane to form “loops”, or transverse beams 224, that are nominally parallel to the expansion axis T. The transverse beams 224 may be described as nonrotating beams. In general, the overlap beam region 218 buckle and rotate out of the plane of the original material or sheet to form overlap beams 226, and open portions are formed between the transverse beams and overlap beams. The axial beam regions 208 form axial beams 222 that may stay close to the tension plane between the transverse beams 224 and overlap beams 226. The axial beams 222 may also be described as nonrotating beams.

[0075] Those of skill in the art will appreciate that many changes may be made to the pattern and material while still falling within the scope of the present disclosure. For example, the terminal ends of one row of slits instead of being colinear with the terminal ends of an adjacent row of slits could move past the terminal ends of the adjacent row of slits creating a nested or overlapping pattern of slits. In some embodiments, multi-slit pattern will be a triple slit, quadruple slit, or other multi-slit instead of a double slit pattern. Alternatively, the slit length, slit size, slit thickness, slit shape, row size or shape, transverse beam size or shape, and / or overlap beam size or shape can vary. The degree of curvature shown in FIG. 2A and slit length can vary. Further, the degrees of offset or phase offset can vary from what is shown. The slit, row, or beam pitch can vary. Further, the pattern can alternate in 2 rows, 3 rows, 4 rows, etc. The angle between the tension axis and slits can vary. Many of these changes could change the deployment pattern.

[0076] The undulating beams, which include the transverse beams 224, form protruding portions. As can be seen in the cross-section view of FIG. 2C, when the expandable sheet 200 in the deployed configuration is wound in an overlapping helix, the protruding portions 228, such as the transverse beams 224, or loops or undulations, interlock with one another or other portions of the sheet substrate, to create an interlocking structure. Interlocking can be measured as stated in the Interlocking Test.

[0077] FIG. 3 A shows an overhead view of one example of an apparatus 300 for making a volume filling article of the present disclosure, such as the article 100. FIG. 3B shows an elevation view of the apparatus 300. FIG. 3C shows an elevation view of a portion of the apparatus 300 being used to form an elongate tube 322. The apparatus 300 may include a first roller 302, a second roller 304, and an elongate guide member 306.

[0078] The first roller 302 is rotatable around a first axis 310 in operation. The first axis 310 may be generally parallel to an input feed plane 308. In some embodiments, the angle between the first axis 310 and the input feed plane 308 may be selected to adjust the pitch of the overlapping helix. An expandable sheet, such as the expandable sheet 110 or the expandable sheet 200, may be fed to the first roller 302 along the input feed plane 308. The expandable sheet being fed between the first roller 302 and the second roller 304 may be in a deployed configuration. In some embodiments, the expandable sheet is in a deployed configuration before engaging the first roller 302. When being fed along the input feed plane, the width of the expandable sheet is generally perpendicular to the input feed direction, which is perpendicular to the first axis 310.

[0079] The second roller 304 is rotatable around a second axis 312 in operation. The second axis 312 is offset from the first axis 310 along a height axis 314. In general, a space exists between the first roller 302 and the second roller 304 to form an overlapping helix from the expandable sheet. The height axis 314 may be defined as intersecting both the first axis 310 and the second axis 312. The height axis 314 is generally defined as intersecting the input feed plane 308 and may be orthogonal to the input feed plane 308.

[0080] A first angle defined between the first axis 310 and the second axis 312 may be measured as a projection onto the input feed plane 308. The first angle may be selected to produce a desired pitch of the overlapping helix. In some applications to provide a volume filling article, the first angle may be generally between 5 and 60 degrees, generally between 15 and 45 degrees, or generally equal to 30 degrees. In some embodiments, the first angle may be greater than or equal to 5, 15, or even 30 degrees. The first angle may be less than or equal to 60, 45, or even 30 degrees.

[0081] The elongate guide member 306 may be positioned between the first roller 302 and the second roller 304, for example, at least along the height axis 314. The elongate guide member 306 extends along the output axis 316. A second angle defined between the first axis 310 and the output axis 316 may be measured as a projection onto the input feed plane 308. In general, the second angle is less than the first angle. In some embodiments, the second angle is one-half the first angle.

[0082] When an expandable sheet in a deployed configuration is fed between the first roller 302 and the second roller 304 along the input feed plane 308 and at least partially around the elongate guide member 306, rotation of the first roller 302 and the second roller 304 is configured to form an elongate tube having a wall surrounding a longitudinal axis. The wall may be formed of overlapping layers of the expandable sheet arranged in the overlapping helix. The elongate tube has a length extending along the output axis 316. As more of the expandable sheet is provided through the rollers, the longer the elongate tube becomes.

[0083] The first roller 302, the second roller 304, and the elongate guide member 306 may be physically coupled together in any suitable manner and may be supported above a working surface by a support structure, which may be made of any suitable material.

[0084] In some embodiments, one or more of the rollers may be motor-powered to pull the expandable sheet past the rollers. In other embodiments, one or more of the rollers may be manually powered.

[0085] One or both rollers may include a material engagement surface made of any suitable material or structure. In some embodiments, one or more rollers are formed by a plurality of spaced apart wheels (or subrollers) connected by an axle, a cylindrical foam surface (e.g., a foam roller), or a plurality of bristles configured to extend through slits in the sheet substrate (e.g., a cylindrical bristle brush). In one example, each wheel of the spaced apart wheels may include a plurality of protrusions spaced around a circumference of the wheel to increase engagement with the sheet substrate. Any suitable material may be used for the wheel and the protrusions. In some embodiments, the protrusions may be made of a soft and somewhat tacky material (e.g., rubber). In other embodiments, the protrusions may be made of hard material (e.g., metal ridges).

[0086] The elongate guide member 306 may be made of any suitable material. The material may be selected to have a low coefficient of friction with expandable sheet in a deployed configuration, such as a stainless steel rod.

[0087] In some embodiments, the expandable sheet may be provided in the form of a roll 318. An expandable sheet dispenser 320 may be used to unroll the expandable sheet. In some embodiments, the expandable sheet dispenser 320 is configured to receive the expandable sheet in a flat configuration on the roll 318 then unroll and expand the expandable sheet into a deployed configuration. The expandable sheet dispenser 320 may be positioned to feed the expandable sheet between the first roller 302 and the second roller 304 along the input feed plane 308.

[0088] FIG. 4 shows a schematic diagram of a method 400 of forming an article for a package. The method 400 may include block 402 of feeding an expandable sheet to engage at least one roller of an apparatus for making an elongate tube volume filling article. The method 400 may include block 404 of winding the expandable sheet in a deployed configuration to form an elongate tube. The method 400 may include block 406 of disposing the elongate tube in a box, disposing an object in a cavity of the elongate tube, or both.EXAMPLES

[0089] Various tests were performed sequentially on the materials as they were prepared according to the methods below and the results were recorded in Table 1.Methods

[0090] The following 5 methods were conducted sequentially on the materials and the results were recorded in Table 1.

[0091] (1) Helix Tube Winding Test: Expand and wind enough material by hand from the dispenser to make a helix tube, or elongate tube, about 36” (914 mm) long. The inside diameter of the tube should be zero. Use a pitch of about 2” (51 mm). Only the tensile force used to expand the material (applied along the tension axis) can be used to interlock the expanded material with other material in the helix tube as it is being wound. No additional twisting or crushing of the material can be applied at the end of the helix tube to facilitate interlocking. Record observations on creating the helix tube. Record the number of samples created. Record the width of the deployed material during winding. Estimate the number of layers in the helix tube. Estimate and record the average diameter of the helix tube.

[0092] (2) Bending Test: Gently bend the helix tube of material to form a loop and then hold two regions of the helix tube together and parallel, such that the far end of the free loop that was bent is 12” (305 mm) from the touching region. Observe the shape of the free loop, for example, to determine whether it is smoothly arcing or contains kinks. Estimate the widest outside distance of the bent helix tube and average the measurements.

[0093] (3) Spiral Roll Test: Roll the helix tube into a spiral shape on a flat surface, such that the helix tube does not overlap itself in the direction orthogonal to the flat surface, and the outer surface of the helix tube makes contact with other regions of its outer surface along a continuous spiral path (no gaps). Apply enough force to wind the roll into that shape. Then release the spiral and observe whether it unrolls. If it unravels, then roll the helix tube again and apply more force to try and hold the spiral together. Release the spiral and observe whether it unravels.

[0094] (4) Shake Test: Hold the helix tube by the first end created during the initial winding procedure. Keeping the helix tube from touching the floor, wave the held end back and forth about24” (610 mm) at a frequency of about 1 Hz for 20 cycles. Observe whether the free end starts to unravel and estimate what percentage of the helix tube unravels.

[0095] (5) Tearing Test: Take a region of the helix tube that has not unraveled and with hands only, try to tear it into two pieces. Observe the difficulty and the effect on the helix tube when tearing.Table 1

[0096] Thus, various embodiments of ELONGATE TUBE VOLUME FILLING ARTICLE are disclosed. Other features and combinations of features within the scope of this disclosure may be readily apparent to one skilled in the art having the benefit of the figures, descriptions, and claims.

[0097] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims may be understood as being modified either by the term “exactly” or “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein or, for example, within typical ranges of experimental error.

[0098] The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range. Herein, the terms “up to” or “no greater than” a number (e.g., up to 50) includes the number (e.g., 50), and the term “no less than” a number (e.g., no less than 5) includes the number (e.g., 5).

[0099] Unless otherwise noted, all parts, percentages, ratios, etc. are by weight. These abbreviations are used herein: wt. = weight, °C = degrees Celsius or centigrade, and ppm = parts per million.

[0100] Terms related to orientation, such as “proximal,” “distal,” “top,” “bottom,” “side,” and “end,” are used to describe relative positions of components and are not meant to limit the absolute orientation of the embodiments contemplated.

[0101] The terms “coupled” or “connected” refer to elements being attached to each other either directly (in direct contact with each other) or indirectly (having one or more elements between and attaching the two elements). Either term may be replaced to “couplable” or “connectable” to describe that the elements are configured to be coupled or connected. In addition, either term may be modified by “operatively” and “operably,” which may be used interchangeably, to describe that the coupling or connection is configured to allow the components to interact to carry out functionality.

[0102] As used herein, the term “configured to” may be used interchangeably with the terms “adapted to” or “structured to” unless the content of this disclosure clearly dictates otherwise.

[0103] Th singular forms “a,” “an,” and “the” encompass embodiments having plural referents unless its context clearly dictates otherwise.

[0104] The term “or” is generally employed in its inclusive sense, for example, to mean “and / or” unless the context clearly dictates otherwise. The term “and / or” means one or all of the listed elements or a combination of at least two of the listed elements.

[0105] The phrases “at least one of,” “comprises at least one of,” and “one or more of’ followed by a list refers to any one of the items in the list and any combination of two or more items in the list.

[0106] As used herein, “have,” “having,” “include,” “including,” “comprise,” “comprising” or the like are used in their open-ended sense, and generally mean “including, but not limited to.” It will be understood that “consisting essentially of,” “consisting of,” and the like are subsumed in “comprising,” and the like.

[0107] In general, the terms “aspect” and “embodiment” may be used interchangeably to describe one or more examples of the present disclosure. Reference to “one embodiment,” “an embodiment,” “certain embodiments,” or “some embodiments,” etc., means that a particular feature, configuration, composition, or characteristic described in connection with the embodiment (or aspect) is included in at least one embodiment of the disclosure. Thus, the appearances of such phrases in various places throughout are not necessarily referring to the same embodiment of the disclosure. Furthermore, the particular features, configurations, compositions, or characteristics may be combined in any suitable manner in one or more embodiments.

[0108] The words “preferred” and “preferably” refer to embodiments of the disclosure that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the disclosure.

Claims

CLAIMSWhat is claimed is:

1. A volume filling article formed from an expandable sheet, the article comprising: an elongate tube comprising a wall surrounding a longitudinal axis, wherein the wall is formed of overlapping layers of the expandable sheet in a deployed configuration arranged in an overlapping helix, the expandable sheet having a plurality of protruding portions in the deployed configuration, each protruding portion extending outwardly from a tension plane of the expandable sheet in a first direction or in a second direction, the tension plane extending along an expansion axis and a cross axis, wherein at least some of the protruding portions that extend outwardly in the first direction in each overlapping layer are interlocked with at least some protruding portions that extend outwardly in the second direction from a respective adjacent layer.

2. The volume filling article of claim 1, wherein a length of the elongate tube along the longitudinal axis is at least 1.5 times a width of the expandable sheet along the cross axis.

3. The volume filling article of claim 1 or 2, wherein the plurality of protruding portions comprises a plurality of folding walls, a plurality of undulating beams, or both.

4. The volume filling article of any one of the preceding claims, wherein in a flat configuration, the expandable sheet comprises a sheet substrate defining a first major surface extending along the expansion axis and the cross axis and a second major surface opposite the first major surface, wherein the expandable sheet defines a plurality of slits formed in the sheet substrate extending at least partially between the first major surface and the second major surface in a repeating pattern, the repeating pattern comprising at least a first row of the slits and a second row of the slits adjacent to the first row, wherein each row extends parallel to the cross axis, wherein each slit is configured to open in response to a minimum tension applied to the sheet substrate parallel to the expansion axis to move the expandable sheet into the deployed configuration.

5. The volume filling article of any one of the preceding claims, wherein wall of the elongate tube has a cylindrical configuration.

6. The volume filling article of any one of claims 1 to 4, wherein the elongate tube has a spiral configuration.

7. The volume filling article of any one of the preceding claims, wherein the elongate tube has a conformability that passes the Bending Test, the Spiral Roll Test, or both.

8. The volume filling article of any one of the preceding claims, wherein the elongate tube is interlocking according to the Interlocking Test, the Shake Test, or both.

9. The volume filling article of any preceding claim, further comprising a box, wherein the elongate tube is disposed inside the box as void fill.

10. A package comprising an object for shipping disposed interior to an outer surface of the elongate tube according to any one of the preceding claims.

11. An apparatus for making a volume filling article, the apparatus comprising: a first roller rotatable around a first axis parallel to an input feed plane for receiving the expandable sheet along the input feed plane; a second roller rotatable around a second axis offset from the first axis along a height axis intersecting the first axis and the second axis, wherein a first angle between the first axis and the second axis projected onto the input feed plane is between 15 and 45 degrees; an elongate guide member positioned between the first roller and the second roller and extending along an output axis, wherein a second angle between the first axis and the output axis projected onto the input feed plane is less than the first angle, wherein the first roller and the second roller are configured to be rotated to form an elongate tube comprising a wall surrounding a longitudinal axis in response to an expandable sheet being fed between the first roller and the second roller along the input feed plane and at least partially around the elongate guide member, the elongate tube having a length extending along the output axis, wherein the wall is formed of overlapping layers of the expandable sheet arranged in an overlapping helix.

12. The apparatus of claim 11, wherein the first roller and the second roller are configured to be rotated to form the elongate tube when the expandable sheet being fed between the first roller and the second roller is in a deployed configuration.

13. The apparatus of claim 11 or 12, further comprising an expandable sheet dispenser positioned to feed the expandable sheet between the first roller and the second roller along the input feed plane.

14. The apparatus of any one of claims 11 to 13, wherein the expandable sheet dispenser is configured to receive the expandable sheet in a flat configuration and provide the expandable sheet in a deployed configuration.

15. A method of forming an article for a package, the method comprising: feeding an expandable sheet to engage at least one roller, wherein the expandable sheet defines an expansion axis and a cross axis, wherein in a flat configuration, the expandable sheet defines a first major surface extending along the expansion axis and the cross axis and a second major surface opposite the second major surface, wherein the expandable sheet defines a plurality of slits formed in the expandable sheet extending at least partially between the first major surfaceand the second major surface in a repeating pattern, the repeating pattern comprising at least a first row of the slits and a second row of the slits adjacent to the first row, wherein the rows extend along the cross axis, wherein the slits are configured to open in response to a minimum tension applied to the sheet along the expansion axis to move into a deployed configuration; and winding the expandable sheet in a deployed configuration to form an elongate tube comprising a wall, wherein the wall is formed of overlapping layers of the expandable sheet in the deployed configuration arranged in an overlapping helix.

16. The method of claim 15, further comprising disposing the elongate tube in a box, disposing an object in a cavity of the elongate tube, or both.

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