Expandable sheet having path-reversing hook slit patterns

Abstract

The present disclosure provides a sheet defining a vertical axis and a horizontal axis along a major surface. The sheet includes a substrate of sheet material defining the major surface. The sheet further includes a pattern of slits formed in the substrate in a repeating pattern based on the sheet being in a flat configuration. Each slit is configured to open in response to a minimum tension applied to the substrate along one or more axes. Each slit includes a plurality of reverse hooks. Each reverse hook includes a stem region, a cap region, and at least one reversing region.

Description

EXPANDABLE SHEET HAVING PATH-REVERSING HOOK SLIT PATTERNSTechnical Field

[0001] The present disclosure relates generally to sheets and, in particular, to expandable sheets with a plurality of slits configured to expand into a three-dimensional structure. Tension-activated, expandable sheets are sheets, for example of paper or plastic, that are cut with a slit pattern enabling them to be expanded when tension is applied along one or more axes of the sheet.Background

[0002] Conventionally, to ship goods / objects that are fragile or sensitive, shipping containers, particularly cardboard boxes, are primary modes of transport used by individuals and businesses. These containers are widely favored due to their numerous advantages, including their ability to stand upright, lightweight nature, and ease of storage when flattened. Additionally, they are environmentally friendly, as they are recyclable, and are relatively inexpensive compared to alternative shipping solutions. However, boxes come in standard sizes that often do not match the size of an item being shipped, so a user must fill the box with a large amount of filler or cushioning material to try to protect the item being shipped from jostling around in a box that is too large and becoming damaged.

[0003] Package cushioning materials protect items during shipment. The effects of vibration and impact shock during shipment and loading / unloading are mitigated by the cushioning materials to reduce the chance of product damage. Cushioning materials are often placed inside the shipping container where they absorb energy by, for example, buckling and deforming, and / or by dampening vibration or transmitting the shock and vibration to the cushioning material rather than to the item being shipped. In other instances, packaging materials are also used for functions other than cushioning, such as to immobilize the item to be shipped in the box and fix it in place. Alternatively, packaging materials are also used to fill a void such as, for example, when a box that is significantly larger than the item to be shipped is used. Some exemplary packaging materials include plastic Bubble Wrap™, bubble film, cushion wrap, air pillows, shredded paper, crinkle paper, shredded aspen, vermiculite, cradles, and corrugated bubble film. However, many of these packaging materials are not recyclable and are not always effective.Summary

[0004] In a first aspect, the present disclosure provides a sheet defining a vertical axis and a horizontal axis along a major surface. The sheet includes a substrate of sheet material defining the major surface. The sheet further includes a pattern of slits formed in the substrate in a repeating pattern based on the sheet being in a flat configuration. Each slit is configured to open in response to a minimum tension applied to the substrate along one or more axes. Each slit includes a plurality of reverse hooks. Eachreverse hook includes a stem region, a cap region, and at least one reversing region.

[0005] In a second aspect, the present disclosure provides a face mask including the sheet of the first aspect to secure the face mask to a person.

[0006] In a third aspect, the present disclosure provides an arm cuff including the sheet of the first aspect to secure the arm cuff to a person.

[0007] In a fourth aspect, the present disclosure provides a diaper including the sheet of the first aspect to secure the diaper to a person.

[0008] In a fifth aspect, the present disclosure provides a method. The method includes cutting a pattern into an expandable sheet of material having a tension axis. The pattern includes one or more tension- activated slits. Each slit includes a plurality of reverse hooks. Each reverse hook includes a stem region, a cap region, and at least one reversing region.

[0009] The details of one or more examples of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.Brief Description of the Drawings

[0010] Exemplary embodiments disclosed herein may be more completely understood in consideration of the following detailed description in connection with the following figures. The figures are not necessarily drawn to scale. Like numbers used in the figures refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.

[0011] FIG. 1 is a top view line drawing of a sheet depicting a slit pattern that includes non-reverse hooks in a multi-slit arrangement;

[0012] FIG. 2a is a top view line drawing of a sheet depicting an exemplary slit pattern in a pretensioned form, in accordance with an embodiment of the present disclosure;

[0013] FIG. 2b is a top view of the sheet of FIG. 2a in a deployed form when the sheet is exposed to a tension along a tension axis, in accordance with an embodiment of the present disclosure;

[0014] FIG. 3 is a perspective view of the sheet of FIG. 2a;

[0015] FIG. 4 is a top view line drawing of a sheet depicting another exemplary slit pattern in a pretensioned form, in accordance with another embodiment of the present disclosure;

[0016] FIG. 5 is a top view of the sheet of FIG. 4 in a deployed form when the sheet is exposed to a tension along a tension axis;

[0017] FIG. 6 is a perspective view of the sheet of FIG. 4 in the deployed form;

[0018] FIG. 7 is a schematic diagram depicting different design alternatives for reverse hooks, in accordance with an embodiment of the present disclosure;

[0019] FIGS. 8a to 8f illustrate an exemplary application of a sheet having reverse hook slit patterns to bundle a collection of books, in accordance with an embodiment of the present disclosure;

[0020] FIGS. 9a to 9e illustrate an exemplary application of a sheet to secure closure of a bag containing a plurality of items, in accordance with an embodiment of the present disclosure;

[0021] FIGS. 10a to lOd illustrate a multi-layer overlapping phenomenon, in accordance with an embodiment of the present disclosure;

[0022] FIG. 11 illustrates an exemplary application of a sheet to secure a wearable object, in accordance with an embodiment of the present disclosure;

[0023] FIGS. 12a to 12c illustrate a user wearing a face mask secured by utilizing the sheet of FIG. 2a, in accordance with an embodiment of the present disclosure;

[0024] FIGS. 13a to 13c illustrate a user wearing a shirt having an arm cuff secured by utilizing the sheet of FIG. 2a, in accordance with an embodiment of the present disclosure;

[0025] FIGS. 14a to 14c illustrate a diaper secured by utilizing the sheet of FIG. 2a, in accordance with an embodiment of the present disclosure; and

[0026] FIG. 15 is a flowchart of a method for forming the sheet of FIG. 2a, in accordance with an embodiment of the present disclosure.Detailed Description

[0027] In the following description, reference is made to the accompanying figures that form a part thereof and in which various embodiments are shown by way of illustration. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense.

[0028] In the following disclosure, the following definitions are adopted.

[0029] As used herein, all numbers should be considered modified by the term “about”. As used herein, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably.

[0030] The term “about”, unless otherwise specifically defined, means to a high degree of approximation (e.g., within + / - 5% for quantifiable properties) but again without requiring absolute precision or a perfect match.

[0031] As used herein as a modifier to a property or attribute, the term “generally”, unless otherwise specifically defined, means that the property or attribute would be readily recognizable by a person of ordinary skill but without requiring absolute precision or a perfect match (e.g., within + / - 20 % for quantifiable properties).

[0032] As used herein, “at least one of A and B” should be understood to mean “only A, only B, or both A and B”.

[0033] As used herein, “substantially” means “for the most part” relevant to the term being modified as would be understood by one of ordinary skill in the art.

[0034] As used herein, “corresponding” indicates that two structural components are sized and shaped similar to each other and can be coupled with a minimum amount of friction. Thus, an opening“corresponding” to a member is sized slightly larger than the member so that the member can pass through the opening with a minimum amount of friction. This definition is changed when the two components are said to “snugly” fit together or “just correspond”. In that situation, the difference between the sizes of those components is even smaller, thereby increasing the amount of friction.

[0035] 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 nonlinear, 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 surface area 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 0.18 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.

[0036] As used herein, the term “compound slit” refers to a slit with more than two terminal ends, which is distinguished from a “simple slit,” which is defined herein as a slit with exactly two terminal ends. Compound slits have at least two slit segments with at least one segment intersection. As such, a “compound slit pattern” is a pattern including a plurality of individual slits at least some of which are compound slits. In some embodiments, the pattern includes a plurality of rows of slits that are phase offset from one another. In some embodiments, the slits are substantially perpendicular to the tension axis.

[0037] 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.

[0038] The present disclosure provides a sheet defining a vertical axis and a horizontal axis along a major surface. The sheet includes a substrate of sheet material defining the major surface. The sheet further includes a pattern of slits formed in the substrate in a repeating pattern based on the sheet being in a flat configuration. Each slit is configured to open in response to a minimum tension applied to the substrate along one or more axes. Each slit includes a plurality of reverse hooks. Each reverse hook includes a stem region, a cap region, and at least one reversing region.

[0039] The sheet of the present disclosure may be used as cushioning material or a filler material to protect fragile or sensitive objects during transit into shipping containers. Formation of the pattern ofslits in the substrate in a repeating pattern may allow interlocking of adjacent row of slits with each other. Further, the presence of the reverse hook having the stem region, the cap region, and the at least one reversing region may result in excellent interlocking. Moreover, the sheet may be able to sustain increased deployment force or tension without tearing.

[0040] Referring now to Figures, FIG. 1 is a top view line drawing of a sheet 50 depicting a slit pattern that includes non-reverse hooks in a multi-slit arrangement. The sheet 50 includes a pattern of slits 52 formed in a substrate in a repeating pattern based on the sheet 50 being in a flat configuration. Specifically, the slits 52 include regions of hooks that are non-reversing. In other words, the slits 52 include non-reverse hooks 54.

[0041] FIG. 2a is a top view line drawing of a sheet 100 depicting an exemplary slit pattern in a pretensioned form Fl, in accordance with an embodiment of the present disclosure. The sheet 100 is a nonadhesive, tension-activated expandable sheet. In some embodiments, the sheet 100 is a cushioning article. In some embodiments, the sheet 100 is made of paper. In some embodiments, the sheet 100 is made of extensible paper. In some embodiments, the sheet 100 is made of plastic. In some embodiments, the sheet 100 may be made of a woven or nonwoven fabric of natural fiber, for example, hemp / bamboo / coir etc. for sustainability. In other metals, thin metal films (foils) may also be used. In some embodiments, the sheet 100 has a thickness of about 0.001 inch (0.025 mm) to about 5 inches (127 mm). The sheet 100 may be stored in a roll or any other suitable manner.

[0042] The sheet 100 defines a vertical axis Y-Y and a horizontal axis X-X along a major surface 102. The vertical axis Y-Y and the horizontal axis X-X are orthogonal to each other. The sheet 100 further defines a plane P in a pre-tensioned form Fl extending along the horizontal axis X-X and the vertical axis Y-Y. The sheet 100 is substantially planar in its pre-tensioned form Fl prior to application of tension along a tension axis TA. The sheet 100 is three-dimensional when the tension is applied along the tension axis TA. In the illustrated embodiment of FIG. 2a, the tension is applied along the vertical axis Y-Y. In other words, the vertical axis Y-Y is the tension axis TA. Therefore, “the vertical axis Y- Y” can be interchangeably referred to herein as “the tension axis TA”.

[0043] The sheet 100 includes a substrate 104 of sheet material defining the major surface 102. The sheet 100 further includes a pattern of slits 106 formed in the substrate 104 in a repeating pattern based on the sheet 100 being in a flat configuration (or pre-tensioned form Fl). In other words, the sheet 100 defines the major surface 102 into which a tension-activated kirigami pattern of slits 106 may be cut. The slits 106 are arranged in a plurality of rows 108 extending in an axial direction DI along the horizontal axis X-X. The plurality of rows 108 is arrayed in a transverse direction D2 along the vertical axis Y-Y. As shown, each slit 106 travels along a path, and each slit 106 reverses direction at least once before continuing along the path.

[0044] Further, the slits 106 may be compound slits with more than two terminal ends. In the illustrated embodiment of FIG. 2a, each slit 106 has two terminal ends 110. However, in other embodiments, each slit 106 may have more than two terminal ends. In the illustrated embodiment of FIG. 2a, each slit 106is oriented along a horizontal midline path MP. Further, each slit 106 defines a length L along the horizontal axis X-X. In other words, the length L of each slit 106 is perpendicular to the vertical axis Y-Y. In the illustrated embodiment of FIG. 2a, the length L of each slit 106 is constant (i.e., same). Alternatively, in some other embodiments, the length L of each slit 106 may be different from each other.

[0045] Further, each slit 106 includes a plurality of reverse hooks 120. In the illustrated embodiment of FIG. 2a, reverse hook slits 106 are arranged in single slit rows. However, in other embodiments, the reverse hook slits 106 are arranged in multiple slit rows. In some embodiments, adjacent reverse hooks 120 in each slit 106 protrude in different directions. In the illustrated embodiment of FIG. 2a, adjacent reverse hooks 120 in each slit 106 protrude in opposite directions. In some embodiments, the reverse hook slits 106 are part of a folding -wall pattern.

[0046] In the illustrated embodiment of FIG. 2a, each slit 106 includes 10 reverse hooks in total. However, in other embodiments, each slit 106 may include only 1 reverse hook. Therefore, it is not necessary to have multiple reverse hooks per slit in a multi-slit pattern. Further, in the sheet 100, each slit 106 includes at least one segment or region including reverse hooks 120. However, in other embodiments, one or more slits may include regions of straight or curved slit segments that do not contain reverse hooks.

[0047] Each reverse hook 120 includes a stem region 122, a cap region 124, and at least one reversing region 126. In the illustrated embodiment of FIG. 2a, each reverse hook 120 includes two reversing regions 126. As shown in FIG. 2a, the reversing region 126 moves away from the cap region 124, reverses direction, and joins the stem region 122. Accordingly, the cap region 124 is disposed between both reversing regions 126. Each of the cap region 124, the stem region 122, and the reversing region 126 may have different shapes / designs which will be described later in the disclosure.

[0048] FIG. 2b is a top view of the sheet 100 in a deployed form F2 when the sheet 100 is exposed to the tension along the tension axis TA, in accordance with an embodiment of the present disclosure. FIG. 3 is a perspective view of the sheet 100 in the deployed form F2. When the threshold amount of tension is applied along the tension axis TA of the sheet 100 in the axial direction DI, the sheet 100 switches from the pre-tensioned form Fl to the deployed form F2. In other words, in response to a minimum tension applied to the substrate 104 along one or more axes (i.e., the vertical axis Y-Y) each slit 106 is configured to open. In some embodiments, the tension is applied by hand or with a machine. Accordingly, the plane P becomes three-dimensional and a plurality of walls 116 is created.

[0049] In the illustrated embodiment of FIGS. 2a to 3, the slits 106 form anchor-shaped reverse hooks 120 upon applying the tension along the tension axis TA. The anchor-shaped reverse hooks 120 may be formed in upper portion 115 as well as in lower portion 117 of the slit 106. The presence of the reverse hook features in the upper portion 115 and the lower portion 117 of the slit 106 may result in excellent interlocking. However, these features may be included in only one of the upper portion 115 or lower portion 117 and still provide excellent interlocking.

[0050] Many other patterns can be used to create tension activated expanding sheets that include hooks (reverse hooks or non-reverse hooks). For example, the folding-wall pattern described in {Corrigan, T. etal. Strong conformable structure via tension activated kirigami. Commun Mater 4, 31 (2023).} can also be used with portions of the compound slits including reverse hooks or non-reverse hooks.

[0051] Specifically, upon application of the minimum tension along the vertical axis Y-Y, portions of the sheet 100 rotate relative to the plane P and the plurality of walls 116 each extending in a zig-zag manner is created (as shown in FIGS. 2b and 3). Consequently, the sheet 100 is stretched in the deployed form F2. Therefore, the sheet 100 may be used as a cushioning material or a filler material to protect fragile or sensitive objects during transit into shipping containers. Formation of the pattern of slits 106 in the substrate 104 in a repeating pattern may allow interlocking of adjacent row 108 of the slits 106 with each other. Further, the presence of the reverse hook 120 having the stem region 122, the cap region 124, and the at least one reversing region 126 may result in excellent interlocking. Moreover, the sheet 100 may be able to sustain increased deployment force or tension without tearing.

[0052] FIG. 4 is a top view line drawing of a sheet 100’ depicting another exemplary slit pattern in a pre-tensioned form Fl, in accordance with an embodiment of the present disclosure. The sheet 100’ is substantially similar to the sheet 100 of FIG. 2a, with common components being referred to by the same reference numerals. FIG. 5 is a top view of the sheet 100 in the deployed form F2 when the sheet 100’ is exposed to the tension along the tension axis TA, in accordance with an embodiment of the present disclosure. FIG. 6 is a perspective view of the sheet 100’ in the deployed form F2.

[0053] The sheet 100’ may be substantially similar to that of the sheet 100 of FIG. 2a, with common components being referred to by the same numerals. However, in the sheet 100’, the reverse hook slits 106 are arranged in double slit rows. In other words, there are pairs of parallel rows having reverse hook slits 106. In some embodiments, the reverse hook slits 106 may be arranged in multiple slit rows, for example, triple slit rows, and quadruple slit rows. In other words, any number of parallel rows having reverse hook slits 106 may be used in various embodiments. It should be noted that the multi-slit patterns may be particularly advantageous because of the undulating ribbons of material that move out of the original plane of the sheet 100’, making them more likely to interact with other layers of material so the reverse hooks 120 may interlock with other reverse hooks or other materials.

[0054] FIG. 7 is a schematic diagram depicting different design alternatives for reverse hooks 120, in accordance with an embodiment of the present disclosure. Each of the cap region 124, the stem region 122, and the reversing region 126 may have different shapes which are shown in different rows of FIG. 7. First row R1 depicts various shapes for the cap regions 124. It is shown and contemplated that the cap region 124 may have different shapes, such as, round, orthogonal point, sharp point, and rectangular, by way of non-limiting example, although any other suitable type of cap region 124 may also be utilized.

[0055] Second row R2 depicts various shapes for the reversing region 126. As shown, the reversing region 126 may take any suitable shape / style that protrudes downward past the top of the stem region 122. In various embodiments, the reversing region 126 generally moves away from the cap region 124,and then reverses direction towards the cap region 124 before joining the stem region 122. For comparison, FIG. 1 shows the non-reverse hooks 54 that do not move back towards the cap region. Third row R3 depicts various shapes for the stem region 122. The stem region 122 may also take any suitable shape / design as shown in the third row R3. Fourth row R4 depicts different shapes for reverse hooks 120 as per different cap regions 124, reversing regions 126, and stem regions 122 in the above three rows (i.e., the first row Rl, the second row R2, and the third row R3). It should be noted that the design of each of the cap region 124, reversing region 126, and the stem region 122 may be interchangeable in various embodiments and any other suitable shape(s) / design(s) may be utilized.

[0056] FIGS. 8a to 8f illustrate an exemplary application of the sheet 100 having slit 106 of reverse hook patterns to bundle a collection of books 130, in accordance with an embodiment of the present disclosure. Although bundling of the books 130 is shown and contemplated, it should be noted that any suitable collection of objects may be bundled. As shown, the sheet 100, having two or more layers of slits 106 of reverse hook patterns which are configured to overlap each other, may be used for bundling books 130. In the illustrated embodiment of FIGS. 8a to 8f, the sheet 100 has four layers 132, 134, 136, 138 of slits 106 of reverse hook pattern. Each of the layers 132, 134, 136, and 138 is configured to overlap each other. However, any suitable number of overlapping layers may be utilized. Further, the reverse hooks 120 may be arranged into any number of patterns, such as single-slit, or double-slit on the layers which may be used to bundle the collection of books 130. However, it should be noted that the slits 106 in one layer of the sheet 100 may be arranged in a manner that the tension axis TA of slits 106 in one layer (for example, layer 132 and 134) is different than the tension axis TA of other slits 106 in another layer (for example, layers 136 and 138) of the sheet 100.

[0057] Upon applying the tension, the sheet 100 is expanded with the deployed reverse hook patterns, the expanded sheet 100 grips onto itself with overlap grip strength sufficient to hold objects together. Moreover, the reversing region 126 (not shown in FIGS. 8a to 8f) of each reverse hook 120 of one layer (i.e., layer 132) add to the overlap grip strength by catching onto the reversing regions 126 (not shown in FIGS. 8a to 8f) of other reverse hooks 120 of another layer (i.e., layer 134). Similarly, the reversing regions 126 of each reverse hook 120 of the layer 136 add to the overlap grip strength by catching onto the reversing regions 126 of other reverse hooks 120 of the layer 138. Accordingly, the sheet 100 conforms to the books 130 without adding unnecessary bulk to the package, thereby making it suitable for securely bundling the different objects for shipping without making the overall package unnecessarily large . With the help of the sheet 100 cables, wires, draperies, may be organized or retained together by stretching the material and wrapping it around the objects with at least a portion of overlap.

[0058] In a related application, the sheet 300 having the pattern of slits 306 in the repeating manner may be used not just to bundle or hold objects together, but to cover one or more objects for aesthetic reasons. For example, sheets of material could be provided with any of the kirigami slit patterns disclosed here to function as a gift wrap or decorative covering of objects. Even single objects could be covered with the material which has an attractive appearance, a high level of conformability to coverany object, and strongly interlocks with itself to avoid the need for tape. The material can be sheets or rolls of any type of paper (such as kraft paper, extensible paper, recycled paper, etc) or any type of plastic (PET, recycled plastics, reclaimed plastics etc). The material could be colored or printed to include additional decorative elements.

[0059] Further, the sheet 100 having the pattern of slits 106 in the repeating manner may effectively and gently hold plant material in a configuration for transportation. Because trees and other plant materials are delicate but require some gentle control of branches and other plant material. Therefore, the plants and trees may be held or wrapped with the sheet 100 before being put in a box for example with or without additional cushioning material. In other words, before being loaded into a vehicle for transport from a nursery the plants and trees may be held or wrapped with the sheet 100. Furthermore, fragile gift items may be covered with the sheet 100 having the pattern of slits 106 to ensure safety during transportation.

[0060] FIGS. 8a to 8f illustrate a complete step-by-step process for bundling an object, (for example, books 130) by the sheet 100 having four overlapping layers 132, 134, 136, 138 each having the pattern of slits 106. Firstly, the sheet 100 is placed on a floor or any flat surface, as shown in FIG. 8a. Then, the objects, such as books 130, are placed onto the sheet 100, as shown in FIG. 8b. Upon placing the books 130 on the sheet 100, each layer 132, 134, 136, 138 of the sheet 100 is stretched by applying the minimum tension along the corresponding tension axis TA of each layer 132, 134, 136, 138. Upon applying the tension along the tension axis TA of each layer 132, 134, 136, 138, each slit 106 in the corresponding layer 132, 134, 136, 138 gets opened up and walls 116 (not shown in FIGS. 8a to 8f) having anchor-shaped hooks are formed. Then, each layer 132, 134, 136, 138 of the sheet 100 is wrapped around the books 130 one by one, as shown in FIGS. 8c to 8f.

[0061] As each layer 132, 134, 136, 138 is overlapped over one-another, for example, the layer 132 is overlapped with the layer 134 and the layer 136 is overlapped with the layer 138, the reverse hooks 120 of each layer 132, 134, 136, 138 are interlocked with the overlapped layer. For example, the reverse hooks 120 of the layer 132 are interlocked with the reverse hooks 120 of the layer 134, similarly, the reverse hooks 120 of the layer 136 are interlocked with the reverse hooks 120 of the layer 138. Specifically, the reversing regions 126 of each reverse hook 120 of each layer (e.g., the layers 132, 134, 136, 138) interlock with the reversing regions 126 of reverse hooks 120 of another overlapping layer. For example, the reversing regions 126 of reverse hooks 120 of layer 132 interlocks with the reversing regions 126 of reverse hooks 120 of overlapping layer 134, similarly, the reversing regions 126 of each reverse hooks 120 of the layer 136 interlocks with the reversing regions 126 of the reverse hooks 120 of overlapping layer 138. Additionally, because of the random motion and dynamic nature of the reverse hooks 120, adjacent layers that are not directly opposed to each other, such as layer 134 and layer 136, will still experience significant interlocking. Accordingly, the bundle of books 130 is packed.

[0062] In some embodiments, overlap grip strength may be regarded generally as different combinations of expanding slit sheet patterns and sheet materials producing different amounts ofgripping to adjacent layers of that same combination. In one non-limiting example, to evaluate the overlap grip strength of an expanding slit sheet sample, two sections of that sample are produced. The first section is expanded and mounted onto a curved surface (for example, taping the ends around the circumference of a 3” diameter tube). The second section is held by one end in the clamp of a tensile testing apparatus such that it is directly above the center of the curved surface (6” for example) and the axis of the curved surface is parallel to the pivot axis of the clamp in the tensile testing apparatus. The free end of the second section is then pulled to fully deploy the second section and then pulled around a portion of the first section that is mounted to the curved surface. The overlap between the two sections is about 45 degrees of contact along the curved surface then the first section is released. If the sections do not interlock and stick to each other, then they have an overlap grip strength of zero. If they do stick together, then the tensile testing apparatus will pull the fixed end of the second section vertically while recording the force and distance. The maximum force recorded as the second section is dragged across the first section is the overlap grip strength. Other methods may also be utilized in other embodiments. Testing of similar patterns with non-reverse and reverse hooks has shown significant improvement in overlap grip strength when reverse hooks are employed.

[0063] FIGS. 9a to 9e illustrate an exemplary application of the sheet 100 to secure closure of a bag 150 containing a plurality of items, in accordance with an embodiment of the present disclosure. It should be noted that the sheet 100 may be a region or a part of the bag 150 in this particular embodiment. The plurality of items is placed inside the bag 150 from an access opening 152 defined on top of the bag 150, as shown in FIG. 9a. The bag 150 further includes two regions 103 having patterns of slits 106. As shown in FIG. 9a, each region 103 is provided on either side of the access opening 152. Upon placing the plurality of items in the bag 150, the regions 103 having patterns of slits 106 may be deployed through the tension and then brought into contact while deployed, as shown in FIG. 9b. The deployed reverse hook slits 106 then grip onto each other in a manner that the bag 150 keeps closed, as shown in FIG. 9c. The regions 103 with reverse hooks may be part of the same material (e.g. paper) comprising the bag itself, or they may be from a different or similar material added to the bag 150.

[0064] In some embodiments, the reverse hook slits 106 may be used for creating a handle-like structure. The handle-like structure may be used for carrying the bag 150. This may work in addition to basic bundling. In other words, the sheet 100 may be used to bundle items together and extra sheet may be used to create handle. Therefore, the sheet 100 may be used to create carrier bag for assorted / random shaped objects which are made with an elastomeric material and stored compactly in flat or roll form when not in use. These bags may be carried by holding them above the hands or hanging below and may be used for carrying light groceries and temporary carrying of any objects. For example, FIG. 9e shows the case where the expanding reverse hook region 103 exists on the short side of the bag and an expanded interlocked region has left an opening that can be used as a handle.

[0065] In some embodiments, the sheet 100, or region 103 may hold a dusting or cleaning material onto any handle (e.g., existing broom or mop handle) by wrapping the material around the tool. Thecleaning material may be removed from the tool, shaken or rinsed and then stretched and wrapped around the tool again (or another tool) for additional use. Further, the reverse hook slits 106 may be wound to increase the overlapping region and thereby the strength of the material, as shown in FIG. lOd.

[0066] FIGS. 10a to lOd illustrate a multi-layer overlapping phenomenon, in accordance with an embodiment of the present disclosure. It should be noted that two or more layers of the sheet 100 lock to adjacent layers above or below it. It should also be noted that the interlocking strength of a short region of material is often greater than the tensile strength (tear strength) of the material. In other words, if tension force SI (interchangeably called as tear strength SI) is applied to a layer 154 of deployed material shown in FIG. 10a until it tears, that value SI will be the tear strength of that material. If two layers 154 of the same deployed material are overlapped as shown in FIG. 10b, the interlocking strength in the overlap region OR1 is often greater than the tear strength SI, such that the samples in FIG. 10b will tear with a value of tension force S2 (interchangeably called as tear strength S2) that is similar to the tension force S 1 instead of releasing from each other at a lower force. This case where the interlock strength is greater than the tear strength can be easily achieved with many materials and slit patterns that include reverse hooks.

[0067] As the number of locked layers increases, the total strength of bundling may also get increased. In the illustrated embodiment of FIG. 10c, a deployed or expanded layer 154 is wrapped in a loop such that a small portion overlaps itself. The small overlapping region OR1 is formed, which results in reduced strength of bundling because only a single layer 154 of material exists for most of the loop, so only the tear strength of a single layer 154 of material can resist forces to tear the loop apart. In other words, tension force S3 (interchangeably called as tear strength S3) will be similar to the tension force SI and the tension force S2.

[0068] However, in FIG. lOd, the deployed, or expanded layer 154 forms more than two complete loops that are strongly interlocked such that a much larger force is required to tear apart this double loop. In other words, tension force S4 (interchangeably called as tear strength S4) will be significantly larger than the tension forces SI, S2 or S3, often it will be approximately double those forces. Accordingly, the tear strength of the loop of material is increased. When at least 100% of the loop has a second layer, as shown in FIG. lOd, then its strength will be about double the first scenario (S4~2*S3). In other words, the tear strength S4 of the sheet 100 increases two times as compared to the tear strength S3 in first scenario. Accordingly, increasing the overlap increases the hold strength. The user can apply more overlap to increase the hold strength. Because the interlocking is continuous across the surface of adjacent deployed layers, localized strength can also be added. In other words, a region with more layers of material can withstand a higher maximum force before tearing than another region with fewer layers interlocked.

[0069] FIG. 11 illustrates an exemplary application of the sheet 100 to secure a wearable object 160, in accordance with an embodiment of the present disclosure. To secure the wearable object 160 to adesired or predefined location, the sheet 100 includes at least one securement portion 162. The at least one securement portion 162 is made of cloth, fabric or other sheet material is shown. In some cases, the wearable object 160 may be a face mask, hats, scarfs, tight fitting clothing (for example, shirt cuff), or a sensor. The wearable object 160 may be secured to the predefined location by using the at least one securement portion 162. In the illustrated embodiment of FIG. 11, two securement portions 162 each connected on either side of the wearable object 160 are shown. The securement portions 162 may be made from the same material as the wearable object 160, cut from a continuous input material, or they may be made from other materials that are bonded together.

[0070] As shown in FIG. 11, each securement portion 162 includes a locking region 164 having a pattern of slits 106 in a repeating pattern. Each slit 106 is configured to open (i.e., deployed) in response to a minimum tension applied along the tension axis TA. Each securement portion 162 further includes atab region 166 that can be easily grabbed and pulled to facilitate deployment (i.e., opening) of the slits 106. Each securement portion 162 further includes a stretch control region 168 to control the tension forces experienced by the wearer once the locking regions 164 are engaged and a loop has been formed around part of a user’s body, such as a head, arm or leg.

[0071] In some embodiments, the locking region 164 of each securement portion 162 includes the pattern of slits 106 configured to open (be deployed) in response to a minimum tension applied via the tab region 166 along the tension axis TA. In such cases, the locking region 164 of one securement portion 162 overlaps and strongly grips with the locking region 164 of another securement portion 162 which enables the interlocking of the securement portions 162 to each other, thereby facilitating securement of the wearable object 160.

[0072] In some embodiments, the locking region 164 of one of the securement portions 162 includes a pattern of slits 106 that is configured to open in response to the minimum tension applied along the tension axis TA and the locking region 164 of the another securement portion 162 includes a structure or device (not shown) configured to be locked with the pattern of slits 106 of the associated securement portion 162. Accordingly, the securement portions 162 may interlock with each other, and securement of the wearable object 160 is achieved.

[0073] In some embodiments, the tab portion 166 of the at least one securement portion 162 may be omitted, and the user directly grabs the locking region 164 and applies tension to it to facilitate securement of the wearable object 160 to the predefined location. In some embodiments, the stretch control region 168 may be omitted and the locking region 164 may be configured to achieve the desired stretch to hold it comfortably. In such cases, the length and scale of pattern may be adjusted to tune stiffness of the securement portion 162. In some embodiments, the securement portion 162 may further include additional regions (not shown) that have rounded patterns to remove sharp edges and increase the comfort.

[0074] FIGS. 12a to 12c illustrate a user wearing a face mask 200 secured by utilizing the sheet 100, in accordance with an embodiment of the present disclosure. The face mask 200 includes the sheet 100to secure the face mask 200 to a person. It should be noted that the face mask 200 is substantially similar to the wearable object 160 of FIG. 11 and is secured in the same manner with the help of the sheet 100 (i.e., the securement portion 162). Although, in this figure, the wearable object 160 is shown and contemplated as the face mask 200. However, it should be noted that the wearable object 160 may be a hat, a scarf, a watch, a sensor, or a footwear. Further, similar to FIG. 11, two securement portions 162 of the sheet 100 are connected to either side of the face mask 200. The sheet 100 (i.e., the securement portion 162) is configured to hold and secure the face mask 200 in place on the user’s face. In some embodiments, the sheet 100 may be made from the same material as the rest of the facemask, for example, the filtration media.

[0075] In some embodiments, the wearable objects may be a footwear with the sheet 100 having two securement portions 162. In such cases, the sheet 100 or securement portions 162 may secure the footwear to a body with controlled tightness. In some embodiments, the wearable object may be a body covering with two interacting securement portions. The body covering may be a surgical gown or dressing gown and the securement portions are used to close the gown (i.e., surgical or dressing) quickly with large size adjustment and controlled tightness. Accordingly, the fit of the body covering is adjusted by pulling and locking the securement portions. In some embodiments, the wearable object is shirt, pants or other body covering and a single securement portion is used to control the tightness of fit and close gaps between the body covering and the body.

[0076] FIGS. 13a to 13c illustrate a user wearing a shirt having an arm cuff 300 secured by utilizing the sheet 100, in accordance with an embodiment of the present disclosure. The arm cuff 300 includes the sheet 100 to secure the arm cuff 300 to a person. It should be noted that the function and assembly of the sheet 100 with the arm cuff 300 is same as the face mask 200. The arm cuff 300 is also secured to a desired or predefined location by the sheet 100 similar to the face mask 200 of FIGS. 12a to 12c. As shown, the sheet 100 is configured to reduce a gap between the arm cuff 300 and the body (i.e., hand) of the user. As shown in FIGS. 13b and 13c, the securement portion 162 of the sheet 100 can be pulled and wrapped around itself to hold the arm cuff 300 against the body with a desired tightness.

[0077] FIGS. 14a to 14c illustrate a diaper 400 secured by utilizing the sheet 100, in accordance with an embodiment of the present disclosure. The diaper 400 is also secured to a desired or predefined location by the sheet 100 similar to the face mask 200 of FIGS. 12a to 12c and arm cuff 300 of FIGS. 13a to 13c. As shown, the at least one securement portion 162 may be integrated into the diaper 400 (e.g. made from the same material). As shown, in the illustrated embodiment of FIG. 14a, two securement portions 162 of the sheet 100 are integrated into the diaper 400 and are positioned on opposite sides to each other. As shown, each of the securement portions 162 of the sheet 100 may further include the tab portion 166 configured to be stretched and overlapped to secure the diaper 400 to the predefined location. The same securement method can also be used to hold the diaper tightly closed for disposal once it is soiled.

[0078] Further, the tightness of the securement portion 162 may also have medical advantages, suchas pressure stockings to prevent blood clots, control swelling, manage circulation, reduce pain, etc. The securement portion 162 may be attached to other clothing (e.g. pants) so it is readily available.

[0079] FIG. 15 is a flow chart of a method 500 for forming the sheet 100, in accordance with an embodiment of the present disclosure. At step 502, the method 500 includes cutting a pattern into the expandable sheet 100 of material having the tension axis TA. The pattern includes one or more tension- activated slits 106. Each slit 106 includes the plurality of reverse hooks 120. Each reverse hook 120 includes the stem region 122, the cap region 124, and the at least one reversing region 126.

[0080] In some embodiments, the method 500 further includes applying tension to the sheet 100 of material along the tension axis TA. In some embodiments, the method 500 further includes rotating portions of the sheet 100 of material according to the pattern in response to the applied tension. Rotating portions of the sheet 100 further includes moving undulating ribbons of the sheet 100 of material out of the original plane (i .e . , plane P) of the sheet 100, causing at least one of the undulating ribbons to interact with another portion of the sheet 100 of material. In some embodiments, the method 500 further includes interlocking one of the reverse hooks 120 with another reverse hook 120. In some embodiments, the method 500 further includes wrapping the expanded sheet 100 around the objects to bundle them together.

[0081] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified by the term “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.

[0082] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and / or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.

Claims

CLAIMS1. A sheet defining a vertical axis and a horizontal axis along a major surface, the sheet comprising: a substrate of sheet material defining the major surface; and a pattern of slits formed in the substrate in a repeating pattern based on the sheet being in a flat configuration, wherein each slit is configured to open in response to a minimum tension applied to the substrate along one or more axes; each slit comprises a plurality of reverse hooks, and each reverse hook comprises: a stem region; a cap region; and at least one reversing region.

2. The sheet of claim 1, further defining a plane in a pre-tensioned form and is three-dimensional when tension is applied along the tension axis.

3. The sheet of claim 1, wherein each slit travels along a path and each slit reverses direction at least once before continuing along the path.

4. The sheet of claim 1 , wherein adj acent reverse hooks in each slit protrude in different directions .

5. The sheet of claim 4, wherein adjacent reverse hooks in each slit protrude in opposite directions.

6. The sheet of claim 1, wherein the reverse hook slits are arranged in single slit rows.

7. The sheet of claim 1, wherein the reverse hook slits are arranged in double slit rows.

8. The sheet of claim 1, wherein the reverse hook slits are arranged in multiple slit rows.

9. The sheet of claim 1, wherein the reverse hook slits are part of a folding-wall pattern.

10. The sheet of claim 1, wherein the reversing region moves away from the cap region, reverses direction, and joins the stem region.

11. A face mask comprising the sheet of claim 1 to secure the face mask to a person.

12. An arm cuff comprising the sheet of claim 1 to secure the arm cuff to a person.

13. A diaper comprising the sheet of claim 1 to secure the diaper to a person.

14. A gift wrap comprising the sheet of claim 1 configured to cover objects.

15. A method comprising: cutting a pattern into an expandable sheet of material having a tension axis, wherein the pattern comprises one or more tension-activated slits, and wherein each slit comprises a plurality of reverse hooks, wherein each reverse hook comprises: a stem region; a cap region; and at least one reversing region.

16. The method of claim 14, further comprising: applying tension to the sheet of material along the tension axis; and rotating portions of the sheet of material according to the pattern in response to the applied tension.

17. The method of claim 15, wherein rotating portions of the sheet further comprises moving undulating ribbons of the sheet of material out of the original plane of the sheet, causing at least one of the undulating ribbons to interact with another portion of the sheet of material.

18. The method of claim 14 further comprises interlocking one of the reverse hooks with another reverse hook.

19. The method of claim 14, further comprises wrapping the expanded sheet around the objects to bundle them together.

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