Lattice structure for furniture and apparel and springs

Abstract

A cellular structure comprising: a lattice formed of a plurality of generally parallel rows of cells; each cell is formed as an irregular hexagonal cell; the cells are oriented such that each cell wall creates an acute, obtuse or reflex angle relative to a horizontal or a vertical axis; each individual row is comprised of a plurality of generally identical cells, wherein the cells are inclined at generally the same degree of inclination; the cells in adjacent rows are inclined at generally opposite degrees of inclination; each wall of each cell forms a common wall between two adjacent cells either in a same row or in an adjacent row such that, with the exception of cells at an outer periphery of the structure or directly adjacent any structural or ventilation apertures, and each cell has a common wall with six adjacent cells with the exception of cells at an outer periphery of the structure or directly adjacent any structural or ventilation apertures; and the lattice is formed with substantially no gaps or spaces between adjacent cells either in each row of cells, or between adjacent rows of cells.

Description

[0001] Lattice Structure for Furniture and Apparel and Springs

[0002] This application claims priority from Australian provisional application2024903092 filed on 25

[0003] September 2024, the contents of which are incorporated herein by this reference.

[0004] Technical Field

[0005] The invention relates to a three-dimensional polygonal structure incorporated into furniture and / or apparel.

[0006] Background of Invention

[0007] The following discussion of background art is included to explain the context of the present invention. A reference herein to a matter which is given as prior art is not to be taken as an admission that the matter was known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.

[0008] Materials used in the manufacture of furniture and apparel have come a long way since ancient times. Up until recently, we relied on naturally harvested materials such as wood, animal hides, leaves, grass, straw, feathers, fur, cotton, and horsehair. However, since the industrial revolution, and particularly since the development of the coil spring cushion in the 19thcentury, we have seen the development and use of a combination of natural and synthetic materials.

[0009] The introduction and continuous improvement of synthetic materials have provided us with comfortable, light and durable products. To achieve optimum comfort and commercial viability, products and apparel such as sofas, mattresses and footwear are made of a combination of synthetic and naturally harvested materials.

[0010] While the use of a combination of synthetic materials provides users with a better end product, this comes with an environmental cost. Once a product such as a mattress or shoe is disposed of, there is no simple recycling process it can be subjected to. This is despite the fact that 90% of the materials found within a mattress or a shoe are recyclable. Most of these products end up in landfill. Furniture such as mattresses and apparel such as shoes have complex compositions. They may include foams, springs, fabrics, metals, gels, rubber, and a variety of polymers. To effectively recycle these products requires the separation of these materials into groups which can be repurposed, and this most often means that each separate material needs to be isolated and separated. To do so is manually intensive and hazardous given the equipment required for transportation and handling of these bulky and unhygienic items, as well as the resources required to physically separate the materials the products are made of.

[0011] Further challenges lie in the fact that not all products are made of the same materials, so certain methods of separation of one product such as a shoe or mattress may not apply to another shoe or mattress. Furthermore, for recycling to occur, further individual components such as the sole of a shoe may need to undergo several separation processes to extract individual polymers. This may include chemical separation such as solvent extraction, selective dissolution, chemical hydrolysis, depolymerisation, chemical digestion, and enzymatic degradation, all of which are complex and resource intensive processes.

[0012] The challenges involved in the separation of products such as mattresses and shoes to material groups which can be repurposed makes the recycling process lack commercial viability. Even where the products are put through the recycling process, only a portion of the materials are recycled, with the remaining unrecycled material becoming refuse waste and ending up in landfill mainly due to there being a lack of commercial viability in recycling the product.

[0013] In light of the above, there is a need to address the lack of commercial viability involved in the recycling of furniture and apparel to reduce the number of useful materials ending up in landfill. At the other end of the product life cycle, there is also a need to address the amount of waste generated during the manufacturing of such products.

[0014] The manufacturing processes of products such as cushions, mattresses and shoes generate a lot of waste for several reasons. This is attributed to a number of factors, some of which include the complex design of these products which include a combination of materials, inefficiencies in the manufacturing process generating excessive amounts of offcuts, and the need to cater to a wide range of consumer preferences which requires product adjustment and tailoring. Ultimately, addressing the wastefulness in manufacturing of these products may require a combination of changes in design, production processes, and consumer behaviour. In this vein, it is desirable to develop lighter, stronger, and overall better products that are cheaper and easier to manufacture and ultimately cheaper and easier to recycle.

[0015] Summary of Invention

[0016] There exist common design requirements between items of furniture and apparel, specifically, in the design and calibration of impact absorption and body supporting components. For example, shoe soles, couch cushions, pillows and mattresses. While cushions / mattresses and shoe soles are designed with different parts of the human body in mind, they fundamentally seek to cushion impact and support the human body using resilient materials with high thresholds to plastic deformation.

[0017] To reduce material usage and cost at the manufacturing stage, one option that has been investigated is the adoption of polygonal 'honeycomb' polymer structures. Theoretically, a honeycomb shaped structure provides a material with minimal density and relatively high out- of-plane compression and shear properties. Despite these theoretical advantages, the practical reality of adopting a honeycomb structure into products that are required to be elastic and resilient is riddled with obstacles, one being an inclination to saddle and / or plastically deform after being exposed to repetitive or a low threshold of three-dimensional stress.

[0018] A standard honeycomb structure is a network of extruded hexagons each having a hexagonal face or cross-section, and an extruded depth / thickness. The hexagonal face comprises a top side (comprising a pair of angled sections), a bottom side (also comprising a pair of angled sections) and intermediate sides in between. The extruded depth / thickness provides each hexagon with its third-dimensional element. Honeycomb structures provide comparable strength characteristics to solid, more dense, structures, however, they are limited in their resilience / elasticity. With this limitation in mind, honeycomb structures are not commonly used in mattresses, cushions, pillows or shoe soles for the dual purpose of structural support and elasticity / resilience. Rather, sheets of material with regular apertures are often used (and mistakenly referred to as honeycomb), and these sheets are often used to lighten the weight of a structure or to provide additional ventilation. Further, where these 'honeycomb' sheets are used, the hexagonal structures are configured to provide resilience through the depth direction (i.e. perpendicularto a hexagonal face hexagon) of the hexagonal structure and sheer resilience, as any compression or tension applied laterally across the hexagonal face (i.e. a force perpendicular to the extruded depth, across the width or height of the cells) results in the distortion of the intersecting angles and vertices of the hexagon. This results in collapse of the structure, and / or rapid plastic deformation. Please refer to Figure 1 for reference to the width 36, height 38 and depth 34 of the cells.

[0019] With the above in mind, the inventors of the present invention sought to rectify the deficiencies of the hexagonal honeycomb structure by developing a lattice that has improved resilience / elasticity, and which resembles actual honeycomb. This was pursued by modifying the traditional hexagonal structure of honeycomb after observing the deformation characteristics of the traditional hexagonal honeycomb structure when the top and bottom (not face) are compressed or stretched. In particular, no wall of any honeycomb cell was configured to be vertical (i.e., at 90° to a purely horizontal axis).

[0020] Accordingly, inspired by deformed honeycomb structures resulting from a top and bottom compression test, a new structure was developed in which the traditional hexagonal shape of each cell was significantly altered to form a new cellular structure.

[0021] Specifically, according to one form of the invention there is provided a cellular structure comprising: a. a lattice formed of a plurality of generally parallel rows of cells, b. each cell is formed as an irregular hexagonal cell, c. the cells are oriented and inclined such that each cell wall creates an acute, obtuse or reflex angle relative to a horizontal or a vertical axis, d. each individual row is comprised of a plurality of generally identical cells, wherein the cells are inclined at generally the same degree of inclination, e. the cells in adjacent rows are inclined at generally opposite degrees of inclination, f. each wall of each cell forms a common wall between two adjacent cells either in a same row or in an adjacent row such that, with the exception of cells at an outer periphery of the structure or directly adjacent any structural or ventilation apertures, and each cell has a common wall with six adjacent cells with the exception of cells at an outer periphery of the structure or directly adjacent any structural or ventilation apertures; and g. the lattice is formed with substantially no gaps or spaces between adjacent cells either in each row of cells, or between adjacent rows of cells.

[0022] By having the cells oriented and inclined such that each cell wall creates an acute, obtuse, or reflex angle relative to a horizontal or a vertical axis, the irregular hexagonal cells do not have walls at right angles relative to a horizontal or a vertical axis. This has been found to provide the hexagonal cells with an increased resilience. Traditional hexagons comprise walls at right angles to a horizontal or a vertical axis, and it has been found that while such walls provide increased strength, they are not conducive to elastic deformation.

[0023] The resilience of the lattice is consistent across its width as the cells within each row are generally identical, and generally identically inclined. The cells in adjacent rows are inclined at generally opposite degrees of inclination. This is achieved by having the degree of inclination of cells between two rows being generally symmetrical i.e. approximately a mirror image.

[0024] To save on material and to reduce stiffness of the structure, each wall of each cell is configured to form a common wall between two adjacent cells, either in a same row, or in an adjacent row. With the exception of cells at an outer periphery of the structure, or directly adjacent any structural or ventilation apertures, each cell has a common wall with six adjacent cells.

[0025] The cells are inclined and configured in such a way that the lattice may be described as tessellated. That is, the lattice is formed with substantially no gaps or spaces between adjacent cells within a row, or adjacent cells of different rows.

[0026] To further reduce structural mass, the cells may be at least partially open, or entirely open. The terminology 'entirely open' in this context is intended to mean a cell with generally no matter between cell walls, and partially open is intended to mean some matter between cell walls whereby the cell is not fully closed or filled with matter.

[0027] In an alternative embodiment, some or all the cells may be open, or closed or partially open.

[0028] The reference to an "irregular" hexagonal cell is a reference to a hexagonal shape in which the angles between adjacent walls of the hexagon are not equal. This differs from a regular hexagon in which the angles between adjacent walls are equal. An irregular hexagon thus has a long dimension and a short dimension and in the present invention, it is about the axis of the long dimension that the cells in each row are inclined.

[0029] The term horizontal is a reference to a line / axis / plane at 0° (i.e. parallel to a traditional x-axis of the conventional x-y-z axis).

[0030] The term vertical is a reference to a line / axis / plane at 90° to horizontal (i.e. parallel to a traditional y-axis of a x-y-z axis).

[0031] The terminology 'generally opposite' in the context of the invention is intended to mean (but not necessarily always to mean) generally symmetrical.

[0032] The cell walls may be non-linear. However, irregular hexagonal cells with non-linear walls are costly and complex to manufacture. In an alternative embodiment, the cell walls are generally linear.

[0033] The lattice of the cellular structure is comprised of at least two rows, and preferably a plurality of more than two rows. As such, the lattice comprises odd numbered rows (first, third, fifth, seventh, etc rows) and even numbered (second, fourth, sixth, eight, tenth, etc).

[0034] In an embodiment, the cells in every odd numbered row are identical to each other and the cells of every even numbered row are identical to each other. For example, the cells in the first row are all identical to each other. The cells in the second row are identical to each other.

[0035] In an alternative embodiment the cells of the first row may not be identical to the cells of the second row. Further, the cells of the third row are identical to each other but may differ to the cells of the first row and so on. In essence, all cells within a single row are identical cells. To facilitate a tessellated arrangement, the cells of every even numbered row are inclined at a generally symmetrical angle to the cells of every odd numbered row, and vice versa. This provides a resilient balance to the cellular structure with respect to force distribution. In a further embodiment, the cells of every even numbered row are symmetrical to the cells of every odd numbered row, in that the cells between two rows are mirror images of each other. The cell rows may be offset such that they are configured in a tessellated pattern. In this respect, the cell walls may be of equal length, thickness, and depth.

[0036] In an embodiment, each cell of every odd or even numbered row is comprised of a first, second, third, fourth, fifth and sixth cell wall of generally equal length and thickness and wherein for each cell, the first cell wall and the second cell wall intersect at an angle between 110° and 150°, the second cell wall and the third cell wall intersect at an angle between 135° and 175°, the third cell wall and the fourth cell wall intersect at an angle between 55° and 95°, the fourth cell wall and the fifth cell wall intersect at an angle between 110° and 150°, the fifth cell wall and the sixth cell wall intersect at an angle between 135° and 175°, and the sixth cell wall and the first cell wall intersect at an angle between 55° and 95°.

[0037] In a more specific embodiment: the first cell wall and the second cell wall intersect at an angle of approximately 130°, the second cell wall and the third cell wall intersect at an angle of approximately 155.7°, the third cell wall and the fourth cell wall intersect at an angle of approximately 74.3°, the fourth cell wall and the fifth cell wall intersect at an angle of approximately 130°, the fifth cell wall and the sixth cell wall intersect at an angle of approximately 155.7°, and the sixth cell wall and the first cell wall intersect at an angle of approximately 74.3°.

[0038] In a further embodiment, the cell of every odd or even numbered row is inclined such that the third wall of each cell is configured to also be the sixth wall of an adjacent cell in the row and vice versa. Further, adjacent rows are offset such that each cell of every odd or even numbered row is arranged and inclined such that the first wall and second wall of each cell are configured to be common walls of cells in an adjacent row. Further, the fourth wall and fifth wall of each cell are configured to be common walls of cells in another adjacent row. For example, considering a cell in the second row, the first wall and second wall of the cell are configured to be common walls of cells in a first row. The fourth and fifth walls of the cells are configured to be walls of cells in a third row. If in the example the cells of the first and third rows are symmetrical to the cells of the second row, then the following is achieved through the offset: the first cell wall of a cell in the second row is configured to be a common wall with the mirror image of the second cell wall of a cell in the first row. The second cell wall is configured to be a common wall of the mirror image of another cell in the first row. The fourth cell wall is configured to be a common wall of a mirror image of the cell in a third row. The fifth cell wall is configured to be a common wall of a mirror image of another cell in the third row.

[0039] To provide a desired resilience, in an embodiment, the cells of the cellular structure of every odd or even row are inclined such that the first and sixth wall intersection of each cell is at a lower point along a vertical axis than the third and fourth wall intersection. The opposite applies to a symmetrical cell. That is, the intersection of the mirror image of the first and sixth wall is at a higher point along a vertical axis than the intersection of the mirror image of the third and fourth wall intersection.

[0040] It will be appreciated that the cell shape and configuration is a fundamental aspect to the lattice which imparts a property of resilience. However, there are other properties to which resilience and strength depend, and they include dimensions of the cells and importantly material makeup.

[0041] In an embodiment, the cell wall length is between approximately 3mm and approximately 10mm. In an embodiment where not all cell wall lengths are equal, the wall lengths may still be between approximately 3mm and 10mm. In a preferred embodiment, the cell walls are equal and are approximately 5mm in length.

[0042] It will be appreciated that the thickness of the cell walls varies the stiffness and resilience of the cellular structure for a particular material of cell. In an embodiment, the cell wall thickness is between approximately 0.2mm to 0.8mm and is preferably approximately 0.4mm. The depth of the cellular structure can be altered depending on the application of the structure. In an embodiment, the cellular structure has a depth of between approximately 40mm and 100mm, and preferably approximately 75mm. Further, the overall width of the cellular structure may be approximately 185mm, and the overall height may be approximately 200mm. These dimensions are appropriate for applications such as bedding, or couch / seat cushioning, or pillows.

[0043] In an embodiment, the cellular structure may include apertures spanning across at least two rows. These apertures can allow, for example, for enhanced ventilation throughout the structure, during manufacture and during use. In addition to providing a ventilation benefit during manufacture and use, the apertures may be used to adjust the stiffness of the structure where desirable.

[0044] With respect to material makeup, the cellular structure can be comprised of any reasonably resilient material. In the context of furniture, the material makeup may be that of natural or synthetic materials, and in an embodiment the cell walls of the structure are comprised of polyolefins and / or thermoplastic elastomers. In a specific embodiment, the cell walls are made of polypropylene. The polypropylene may be comprised of virgin pellets, or a combination of virgin and recycled pellets, or entirely of recycled pellets or recycled material, or any combination thereof.

[0045] The present invention in an embodiment provides a cellular structure that comprises a lattice formed of a plurality of generally parallel rows of open cells. Within each row of cells, each cell is formed as an irregular hexagonal cell of generally identical shape, and each wall of each cell is of generally the same length, while the cells in each row are inclined at generally the same degree of inclination and the cells in adjacent rows are inclined at equal and opposite degrees of inclination. Each wall of each cell is straight or linear and forms a common wall with two immediately adjacent cells either in a same row or in an adjacent row such that, with the exception of cells at an outer periphery of the structure or directly adjacent any structural or ventilation apertures, each cell has a common cell wall with six immediately adjacent cells. The lattice is formed with substantially no gaps or spaces between adjacent cells either in each row of cells, or in adjacent rows of cells. In an embodiment, the cells in a first row are inclined at an angle of 20° to 30° from a horizontal axis, and cells in the adjacent rows are inclined symmetrically.

[0046] This embodiment of the invention may be applied to domestic furniture and fittings. Therefore, in one form of the invention there is provided a mattress comprising a plurality of cellular structures according to the form and embodiments of the invention, wherein the cellular structures are placed adjacent to each other around the perimeter of the mattress forming an edge frame. The interior of the mattress may be comprised of additional cellular structures, or springs, or a combination thereof. In this respect, in an embodiment, the mattress comprises a filler, being comprised of a plurality of cellular structures positioned adjacent to one another, wherein the cellular structures are according to any one of the above-mentioned forms or embodiments of the cellular structure.

[0047] Where springs are used in the interior / filler section of a mattress, in an embodiment, the springs may be made of a suitable polymer, for example, they may be polyolefin based (polypropylene, or Polypropylene Bale Twine for example). The spring cross-section may comprise an integral rounded portion and a square or rectangular portion. This cross-section allows for ease of manufacture through injection moulding by facilitating the easier removal from a mould compared to other more complex cross-sections, or even a rounded crosssection. This unique cross-section avoids the need for complex moulds and facilitates relatively cost-effective manufacturing through injection moulding. In an embodiment, the cross- sectional radius of the rounded portion may be approximately 3.00mm and the width of the square or rectangular portion may be approximately 3.0mm.

[0048] In a further embodiment, the mattress may comprise a comfort layer, in the form of a 3- dimensional (3D) lattice structure. The lattice structure may be a polymer structure comprising a cross-hatch pattern. By utilising the cross-hatch pattern, the weight of the comfort layer can be reduced in comparison to that of a solid comfort layer, while providing similar performance and durability characteristics.

[0049] It is to be appreciated that the cellular structure, the spring, and the lattice of the present invention can be adapted to other items of furniture and apparel, such as couches and shoes. In this respect, each of the cellular structure, the spring, or lattice, can be incorporated into apparel or furniture individually, or in combination.

[0050] The present invention provides an alternative to conventional foams which are used in furniture components, in particular, in mattresses. The invention provides a cellular structure which is less dense than traditional solid foams, and one that can be manufactured at a relatively lower cost through additive manufacturing or through extrusion moulding. The ability of the present invention to be made from a wide variety of materials allows it to be customised and tailored to a plethora of applications, while providing superior resilient properties to that of a conventional honeycomb structure or a conventional spring. The invention is also able to be made from a wide variety of polymers, including homopolymers such as polypropylene and their copolymers and block copolymers, thus allowing it to be easily and cost effectively recycled, and to incorporate recycled material.

[0051] Brief Description of Drawings

[0052] In order that the invention may be more fully understood, some embodiments will now be described with reference to the figures in which:

[0053] Figure 1 is a perspective view of a cellular structure according to the present invention.

[0054] Figure 2 is a cross-section of the cellular structure of Figure 1 according to the present invention.

[0055] Figure 3 is a cross-section of a cell appearing in the odd numbered rows of Figure 2.

[0056] Figure 4 is a cross section of a cell appearing the even numbered rows of Figure 2, the cell being generally symmetrical to that of Figure 3.

[0057] Figure 5 is a front and perspective view of a cellular structure having ventilation / structural apertures.

[0058] Figure 6 is a perspective view of a spring according to the present invention.

[0059] Figure 7 is a cross section of the spring according of Figure 6. Figure 8 shows an injection moulding assembly for the manufacture of a spring according to the present invention.

[0060] Figure 9 shows a filament winding assembly in a perspective view and a side view.

[0061] Figure 10 shows prototype springs having different cross-sectional diameters.

[0062] Figure 11 shows a mattress assembly having a frame comprised of a cellular structure according to the present invention, and plurality of springs according to the present invention.

[0063] Figure 12 shows a perspective view, a side view and a top view of a lattice structure for a mattress comfort layer to be used in conjunction with the mattress assembly of Figure 11.

[0064] Figure 13 shows a couch having a plurality of springs and cellular structures according to the present invention.

[0065] Figure 14 shows a shoe in which a cellular structure according to the present invention is incorporated.

[0066] Figure 15 shows a cellular structure according to the present invention manipulated into a curved geometry.

[0067] Figure 16 shows a criss-cross continuous deposition strategy.

[0068] Figure 17 shows extruded cellular structure segments that are connectable to other segments.

[0069] Figure 18 shows an injection moulding assembly for a 3x4 comfort layer structure.

[0070] Figure 19 shows an aspect of an extrusion and punching method of manufacturing the comfort layer structure.

[0071] Figure 20 shows modules connected to form a comfort layer structure Detailed Description

[0072] Figure 1 is a perspective view of a cellular structure 10. The structure 10 is comprised of a lattice having a plurality of generally parallel rows of cells. The manner in which the individual cells 14 are arranged is illustrated in Figure 2 which is a cross-section view of the structure 10 of Figure 1. Each cell 14 is an irregular hexagon having six generally linear walls labelled as 1, 2, 3, 4, 5 and 6. Traditional hexagons comprise six walls, whereby each intersecting wall forms a 120° angle. It is found that traditional hexagonal walls arranged at 120° angles provide increased strength but are not conducive to elastic deformation. The modified hexagonal shape of the cells 14 of the present invention provide for a structure 10 with a relatively higher elasticity.

[0073] The reference to an "irregular" hexagonal cell is a reference to a hexagonal shape in which the angles between adjacent walls of the hexagon are not equal. As shown in Figure 2, the irregular hexagonal cells 14 of the present invention have a long dimension 16 and a short dimension 18. It is about the axis of the long dimension 16 that the cells 14 in each row are angled / inclined.

[0074] The cells 14 are oriented and inclined such that each cell wall 1, 2, 3, 4, 5, 6 creates an acute, obtuse or reflex angle relative to a horizontal 20 or a vertical axis 22. For the purposes of this description, the term horizontal is a reference to a line / axis / plane at 0° (i.e. parallel to a traditional horizontal x-axis of the conventional x-y-z axis) 20. The term vertical is a reference to a line / axis / plane at 90° to horizontal (i.e. parallel to a traditional vertical y-axis of an x-y-z axis) 22.

[0075] The orientation of cells 14 within and between rows 12 is such that there are no gaps between cells 14. That is the cells 14 are tessellated. Each wall 1, 2, 3, 4, 5, 6 of each cell 14 forms a common wall between two adjacent cells 14 either in a same row or in an adjacent row such that, with the exception of cells 14 at an outer periphery of the structure 10 or cells immediately adjacent an aperture 39 as shown in figure 5, each cell 14 has a common wall with six adjacent cells 14. In this respect, the lattice of the structure 10 is generally formed with substantially no gaps or spaces between adjacent cells either in each row of cells 14, and no gaps between adjacent rows of cells 14. As depicted in figure 5, in which apertures 39 spanning across multiple rows 12 may be incorporated into the structure 10 for ventilation purposes during manufacture and use and / or structural purposes.

[0076] Each individual row 12 is comprised of a plurality of generally identical cells 14. The cells 14 within a row 12 are generally identically oriented, in that they are inclined at generally the same angle (i.e. they are oriented at the same degree of inclination 24). The degree of inclination is approximately 20° to 30° to a horizontal axis 25.

[0077] The cells 14 in adjacent rows 12 are orientated at generally opposite degrees of inclination 24. The terminology 'generally opposite' in the context of the invention is intended to mean generally symmetrical. This arrangement provides the structure 10 with a multidirectional resilience and rigidity. For example, if cells 12 within and across every row 12 are oriented at the same degree of inclination, a relatively smaller force in a particular direction may result in the collapse of the structure 10 in a particular direction, while a relatively larger force in a different direction may be required to compress or collapse the structure 10, thus resulting in an imbalanced structure. Having cells 14 in adjacent rows 12 oriented at generally opposite degrees of inclination 24 is found to provide a similar or equal degree of resilience and resistance across all force directions, and thus an improved shape recovery after compression and a consistent plastic deformation in comparison to a traditional hexagonal structure.

[0078] The lattice of the cell structure 10 shown in the drawings is comprised of a plurality of rows 12. With reference to Figure 2, the utmost top row is a first row 26, and the immediately adjacent row below the first row is a second row 27. In this respect, the proceeding lower rows are third 28, fourth 29, fifth 30, sixth 31 and seventh 32 rows. While figure 2 only shows seven rows, it is to be appreciated that the structure 10 may be comprised of as few as one row 12, or as many rows as required so as to serve a particular purpose.

[0079] In Figures 1 and 2, the cells 14 within every odd numbered row 26, 28, 30, 32 are identical to each other and the cells 14 within every even numbered row 27, 29, 31 are identical to each other. The cells 14 in the odd numbered rows 26, 28, 30, 32 are symmetrical (not identical) to the cells 14 of the even numbered rows 27, 29, 31 and vice-versa. The cell rows 12 are offset such that the cells 14 are configured in a tessellated pattern (i.e. there are no gaps between cells 14). Further, the cell walls 1, 2, 3, 4, 5, 6 are of equal length, thickness, and depth, thus allowing cells 14 between rows to have common walls 1, 2, 3, 4, 5, 6. Further, the cells 14 of every even numbered 27, 29, 31 row are inclined at a generally symmetrical angle 24 to the cells 14 of every odd numbered row 26, 28, 30, 32, and vice versa (in addition to the cells 14 being symmetrical, they are also symmetrically inclined 24). This provides a balanced resilience to the cellular structure 10 when subjected to multidirectional forces.

[0080] The cell geometry along with cell orientation (visible at the cell structure face 11) within the lattice, give the cellular structure 10 desirable resilience and recovery properties. Figures 3 and 4 show individual cells 14, the cell 14 of figure 4 being symmetrical (i.e. a mirror image) to the cell 14 of figure 3. The cell 14 of Figure 3 is generally identical to the cells 14 in the even numbered rows 27, 29, 31 of Figure 2. The cell 14 is comprised of a first 1, second 2, third 3, fourth 4, fifth 5 and sixth 6 cell wall of generally equal length and thickness.

[0081] The first cell wall 1 and the second cell wall 2 intersect at an angle between 110° and 150°, and more specifically at an angle of approximately 130°.

[0082] The second cell wall 2 and the third cell wall 3 intersect at an angle between 135° and 175°, and more specifically at an angle of approximately 155.7°.

[0083] The third cell wall 3 and the fourth cell 4 wall intersect at an angle between 55° and 95°, and more specifically at an angle of approximately 74.3°.

[0084] The fourth cell wall 4 and the fifth cell wall 5 intersect at an angle between 110° and 150°, and specifically at an angle of approximately 130°.

[0085] The fifth cell wall 5 and the sixth cell 6 wall intersect at an angle between 135° and 175°, and specifically at an angle of approximately 155.7°.

[0086] The sixth cell wall 6 and the first cell wall 1 intersect at an angle between 55° and 95°, and specifically at an angle of approximately 74.3°. As can be seen in Figure 2, the cell 14 of every odd 26, 28, 30, 32 or even 27, 29, 31 numbered row is inclined such that the third wall 3 of each cell 14 is configured to also be the sixth wall 6 of an adjacent cell 14 in the row 12 and vice versa.

[0087] Further, adjacent rows 12 are offset such that each cell 14 of every odd 26, 28, 30, 32 or even numbered row 27, 29. 31 is arranged and inclined such that the first wall 1 and second wall 2 of each cell 14 are configured to be common walls of cells 14 in an adjacent row 12. Further, the fourth wall 4 and fifth wall 5 of each cell 14 are configured to be common walls of cells 14 in another adjacent row 12. In this respect, each cell 14 shares a common wall 1, 2, 4, 5 with cells 14 in adjacent rows 12 above and cells 14 in adjacent rows 12 below.

[0088] Referring to Figure 2, considering a cell 14 in the second row 27, the first wall 1 and second wall 2 of the cell 14 are configured to be common walls of cells 14 in a first row 26. The fourth

[0089] 4 and fifth 5 walls of the cells 14 are configured to be walls of cells 14 in a third row 28.

[0090] As the cells 14 of the first 26 and third 28 rows are symmetrical to the cells 14 of the second row 27, and are offset so as to provide for the following arrangement: the first cell wall 1 of a cell 14 in the second row 27 is configured to be a common wall with the mirror image of the second cell wall 2 of a cell 14 in the first row 26. The second cell wall 2 is configured to be a common wall of the mirror image of the first cell wall 1 of another cell 14 in the first row 26. The fourth cell wall 4 is configured to be a common wall of a mirror image of the fifth cell wall

[0091] 5 of another cell 14 in a third row 28. The fifth cell wall 5 is configured to be a common wall of a mirror image of the fourth cell wall 4 in another cell 14 in the third row.

[0092] As shown in Figures 3 and 4, the cells 14 of the cellular structure 10 of every odd 26, 28, 30, 32 or even row 27, 29, 31 are inclined such that the first 1 and sixth wall 6 intersection of each cell is at a lower point along a vertical axis 22 than the third 3 and fourth wall 4 intersection. The opposite applies to a symmetrical cell 14. That is, the intersection of the mirror image of the first 1 and sixth 6 wall is at a higher point along a vertical axis 22 than the intersection of the mirror image of the third 3 and fourth 4 wall intersection.

[0093] Cell dimensions can be tailored to provide the cell structure 10 with properties, and thus the structure 10 can be tailored for specific uses such as in a mattress 40 body, a mattress 40 framing (see Figure 11), or foot apparel 76 (see Figure 14), or chair / couch 78 support / cushioning (see Figure 13). In relation to bedding and mattress makeup, the cell wall 1, 2, 3, 4, 5, 6 length is between approximately 3mm and approximately 10mm. In a sample embodiment tested by the inventors, the cell walls 1, 2 ,3 ,4, 5, 6 are of equal length at approximately 5mm.

[0094] It is appreciated that the thickness of the cell walls 1, 2, 3 ,4 ,5, 6 influences the stiffness and resilience of the cellular structure. With respect to a mattress, the cell wall thickness can be varied to alter the firmness of the mattress. In embodiments tested by the inventors, cell wall 1,2 ,3 4, 5, 6 thickness was designed to be between approximately 0.2mm and 0.8mm. In a specific embodiment the thickness is approximately 0.4mm.

[0095] The depth 34 and width 36 of the entire cellular structure 10 can be altered depending on the application of the structure. In the embodiment shown in Figure 1, the cellular structure 10 has a depth 34 of approximately 75mm. The dimensions of the cellular structure 10 can be varied indefinitely, and in an example where multiple structures 10 are used to form a mattress frame, each block may have a depth 34 of between approximately 40mm and 100mm. Further, the overall width 36 of the cellular structure 10 may be approximately 185mm, and the overall height 38 may be approximately 200mm. The dimensions listed in this description have been found appropriate for applications such as bedding(mattress), for couch / seat cushioning, and for general cushions. The dimensions listed in this paragraph are not exhaustive and can be varied depending on the application of the cell structure 10.

[0096] In addition to cell configuration, material make significantly contributes to the physical properties of the cellular structure 10. The present invention seeks to minimise the number of different materials used in the makeup if products such as a mattress to enhance recyclability. With this in mind, the cellular structure can be made from a single polymer, for example, polypropylene (PP) or Thermoplastic Polyurethane (TPU), Polyethylene (PE), co-polymers containing PP or TPU or PE with additives, or thermoplastic co-polyester elastomers.

[0097] It is to be appreciated that the cellular structure can be made from a suite of thermoplastics, elastomers and thermoplastic elastomers as other possible formulation of the aforementioned polymeric materials, in pure, neat or recycled form and in composites forms with or without other additives. Some possible examples of polymeric matrices included, but not limited to are: Polyethylene (PE), Polypropylene(PP), their co-polymers with additives and thermoplastic Co-polyester Elastomers. To determine the performance of a cellular structures 10 made solely of PP or solely of TPU, a series of compression tests were conducted. Polyurethane and Polyethylene based commercial mattress edge materials were also tested and compared to the PP and TPU cellular structures 10. Each material was initially compressed 75% to reach % of its initial height and remained under compression for six minutes. After unloading, the tested material was compressed by 35% and load-deformation graphs were obtained. The results of the test are displayed in the following graph.

[0098] Deformation (mm) In the above graph, XPE is a commercial foam. PP_SwinDesign is the PP cellular structure 10. PU_Edge is a commercial polyurethane mattress edge. Pocket_spring refers to a standard metallic mattress spring, and TPU_SwinDesign is the TPU cellular structure 10.

[0099] The test results of TPU and the PP cellular structures demonstrated recovery rates suitable for mattress components where a maximum reduction in recovery (permanent depression) of 20% is acceptable. The test results demonstrated 5.5% and negligible reduction respectively for PP and TPU samples. The TPU based cellular structure 10 had superior recovery properties, however, an obstacle to the mass adoption of TPU is cost, which is approximately 10 times higher than PP. Nevertheless, the recovery performance of both TPU and PP cellular structures 10 demonstrate that they can be used in place of a traditional combination foams. The cellular structures 10 are advantageous over existing foams in that they can be made of a single polymer, are less dense (use less material), and are lighter.

[0100] While only PP and TPU cellular structures 10 were tested, the cellular structure 10 may be comprised of any reasonably resilient material. In the context of furniture, the material makeup may be that of natural or synthetic materials such as latex, and in embodiments falling within the scope of the invention, the cell walls of the structure may be comprised of polyolefins and / or thermos plastic elastomers.

[0101] The performance of the cellular structures 10 comprising angles of inclination 24 of 20°, 25° and 30° were also tested. The results of a first compression and a second compression after recovery are presented below. Each angle of inclination 24 demonstrated similar 2ndcompression recovery results with the 20° inclination performing best. The results indicate suitability for a mattress application for each of the angles of inclination 24.

[0102]

[0103] In summary, the present invention according to the drawings of Figures 1 to 4 is a cellular structure 10 comprised of a lattice having a plurality of generally parallel rows 12 of open cells 14. Within each row 12, each cell 14 is an irregular hexagonal cell of generally identical shape, and each wall 1 ,2, 3, 4, 5, 6 of each cell 14 is of generally the same length. The cells 14 within a row 12 are each are inclined at generally the same degree of inclination 24 and the cells 14 in adjacent rows 12 are inclined at equal and opposite degrees of inclination (i.e. cells in adjacent rows are symmetrical). Each wall 1, 2, 3, 4, 5, 6 of each cell 14 is generally straight or generally linear and forms a common wall 1, 2, 3, 4, 5, 6 with two immediately adjacent cells either in a same row 12 or in an adjacent row 12 such that, with the exception of cells 14 at an outer periphery of the structure 10, each cell 14 has a common cell wall 1, 2, 3, 4, 5, 6 with six immediately adjacent cells 14. The lattice 10 is formed with substantially no gaps or spaces between adjacent cells 14 in the same row and adjacent cells 14 in adjacent rows 14.

[0104] It is appreciated that the structure's 10 mechanical performance can be modified and tailored by changing the wall 1, 2, 3, 4, 5, 6 thickness, individual cell 14 geometry and or by tailoring the viscoelasticity of the base polymeric material. For example, on alternative embodiments not shown in the drawings, the cells 14 in adjacent rows 12 may be symmetrically configured, but may comprise of different cell wall 1, 2, 3, 4, 5, 6 lengths or thicknesses. Further, cell walls 1, 2, 3, 4, 5, 6 may not be linear, and may be bowed, or curved or S shaped. Further, in an additional embodiment not shown in the drawings, some or all of cells 14 may be partially open, and / or filled / closed.

[0105] The cellular structure 10 can also include apertures 39 spanning across multiple rows 12 as shown in the embodiment of Figure 5. These apertures 39 are included to improve ventilation through the structure 10 and facilitate cooling during the manufacturing process resulting in desired end-use properties. This is advantageous particularly when the structure 10 is used as a component in furniture 40, 78 or apparel 76 as shown in Figures 10 to 13. The enhanced ventilation allows for enhanced cooling and breathability. In addition to enhanced ventilation, the apertures 39 also reduce the net mass and stiffness of the structure 10. The apertures are included in instances where such structural and / or ventilation effects are desirable.

[0106] The cellular structure 10 can be manufactured through a wide variety of methods such as 3D printing, injection moulding and extrusion dies, although it is to be appreciated that there are engineering challenges to be overcome to produce the cellular structure reliably at scale. To address some of the engineering challenges with respect to manufacturing, an integrated large area additive manufacturing (LAAM) process has been developed. The process also seeks to provide a closed-loop, on-demand mattress production process.

[0107] The LAAM system developed comprises a robotic arm (such as an ABB IRB 2600 robotic arm), a Massive Dimension direct pellet extruder, capable of processing flexible recycled thermoplastics, and an integrated software workflow combining Cura™ (control software) for slicing and ABB 'Robotstudio™' (control software) for motion planning. The hopper geometry was redesigned to minimise bridging which is problematic for relatively softer polymer pellets such as TPU pellets. Further, protocols for material purging are recommended to facilitate stable and reproducible print environments. Production trials of the cellular structure 10 were conducted with TPU. The trials included drying 13 kg of TPU at 90 °C for two hours. A nozzle temperature of 230 °C was set, and a bed temperature of 50 °C was set. The print speed was set at 40 mm / s, and the motion control was set to a "Fine" path setting in the control software 'Robotstudio'.

[0108] Initial prototype productions using the LAAM system suffered from extrusion delay at cell intersections due to command lag between robot and extruder, over-deposition at nodal points from path slowdowns, and clogging at the hopper neck, caused by heat creep from the nozzle. These issues were mitigated by switching the robot arm to Z01 movement accuracy to reduce abrupt deceleration; sending extrusion signals with an advanced offset to synchronise deposition with robot motion; introducing a start-up purge protocol to clear residual TPU before each print; and redefining the hopper using low-conductivity materials to prevent premature melting and bridging.

[0109] The intricate nature of the cellular structure 10 poses challenges with respect to robotic additive manufacturing. Geometric complexity of a structure to be printed leads to frequent interruptions in the toolpath of traditional additive manufacturing processes and compromises both the quality and mechanical integrity of the printed structure. Specifically, traditional slicing strategies rely on default software settings (in this case Cura™), which result in excessive stop / start movements during deposition. This results in filament dribble, open-cell artifacts, and visible discontinuities in the final structure.

[0110] With respect to the cellular structure 10, the shortfalls of traditional additive manufacturing methods are addressed through the novel design of the structure 10 and by employing custom additive manufacturing techniques such as that disclosed in Figure 16 which employs staggered print paths in alternative directions for each layer of the structure 10.

[0111] Figure 16 discloses a slicing technique which comprises a criss-cross continuous deposition strategy, in which staggered print paths are used in alternating directions between layers. This strategy comprises printing a vertical layer 82, and a horizontal layer 84 and then overlaying the two layers to form the full cell structure 86. This criss-cross method results in a fully closedcell structure 10 with excellent dimensional stability and no inter-filament strands, due to uninterrupted extrusion. A double layer version of this approach reinforced the printed structure effectively, but the resulting part was considerably heavier relative to a singler layer version and required up to 40 hours of printing for a 90 x 190 x 2000 mm structure 10. Conversely, a single-layer version was lighter and faster to produce (approximately 20 hours), however, it was found to have reduced structural integrity compared to the double-layer structure.

[0112] An alternative and stable additive manufacturing technique involves a layer-by-layer full pattern restoration. The entire structure 10 geometry is printed in each layer (rather than splitting it across two layers as is the case in the criss-cross slicing technique disclosed in Figure 16. By optimising printing parameters, this printing method was found to provide sound inter- structural support. A line width of 1.6 mm (determined by the nozzle diameter), a line height of 1.0 mm, and a print speed of 40 mm / s were found to provide reliable results. The extrusion rate in the 'Robotstudio™' program was set to 12%, balancing material flow with print precision. This slicing / printing method provides a balance between print time, material use, and wall stability. Attempts to further reduce weight by increasing line height or print speed led to undesirable outcomes such as wall sagging and interlayer delamination. Similarly, reducing the extrusion rate below 10% caused under-extrusion and print failure. Further, it is to be appreciated that a drawback of using this method is that it results in minor filament strings between internal walls caused by non-printing travel movements.

[0113] An alternative to additive manufacturing and injection moulding is extrusion. Due to the geometry of structure 10, component extrusion is considered an appropriate manufacturing technique. The extrusion process can be customised to produce a cellular structure 10 to a desired dimension, and this includes amending the extrusion die. An entire cellular structure 10 according to the dimension ranges noted in the preceding paragraphs can be made using a single die. Alternatively segmented parts 102 of the structure 10, as seen in Figure 17 can be made through a single die, with the segmented parts 102 connected to form a complete module of the cellular structure 10.

[0114] In the embodiment shown in Figure 17, segments 102 of the cellular structure 10 comprise interlocking sections 104, which allow the segmented parts 102 to securely connect with other corresponding parts 102 to form a cellular structure 106. This allows for ease of assembly whilst also allowing coolant to reach further toward the centre of the segments 102 during extrusion.

[0115] The cellular structure 10 depicted in the drawings and alternative embodiments described herein are applicable to domestic furniture and fittings. For example, a mattress 40 as shown in Figure 11 comprises a plurality of cellular structures 10. The cellular structures 10 are situated adjacent to each other around the perimeter of the mattress 40 forming an edge frame. The interior of the mattress 40 is comprised of springs 42. In an alternative embodiment not shown in the drawings, the interior of the mattress 40 may be comprised of additional cellular structures 10 of the same or differing mechanical properties to provide the mattress with a relatively firmer or softer central portion.

[0116] In a further alternative embodiment not shown in the drawings, the interior of the mattress 40 may be comprised of a combination of springs 42 and cellular structures 10. The springs 42 may be traditional metallic spring, or alternatively, they are the springs shown in either of Figures 6 and 7 or Figure 10.

[0117] In Figures 6 there is a polymer spring 44, specifically made of recycled Polyolefin-based material, in this case obtained from Polypropylene Bale Twine (PPBT). In alternative embodiments not shown in the drawings the spring can be made of any feasible polymer, and the make up of the spring can be of any suitable polymer providing similar characteristics to that of PPBT such as polypropylene. In this respect, the spring design 44 is not bound to PPBT.

[0118] Figure 7 shows a cross section 46 of the spring 44 of Figure 6. An advantage of using polyolefin- based material as a spring 44 material is that recyclate can be used to manufacture the spring 44, and the spring 44 can be recycled at the end of its useful life. In Figure 7, the spring crosssection 46 comprises a rounded portion 48 and a rectangular portion 50. This unique crosssection 46 allows for improved manufacture efficacy through injection moulding. The unique cross-section 46 facilitates the removal of the fabricated spring 44 from a mould assembly 90. This unique cross-section 46 avoids the need for complex mould modifications and facilitates relatively cost-effective manufacturing through injection moulding. Through finite element modelling and analysis (FEM and FEA) an optimal cross- sectional radius 54 of the rounded portion 3.00mm was determined along with a 3.0mm width 56 of the rectangular portion 50. Simulation testing through FEA resulted in a displacement of 262 mm after applying 10 N force, thus providing a flexibility and resilience within a desired range for furniture, bedding and apparel. It is appreciated that a larger cross-sectional radius 54 may be used such as 4mm, which gives comparable results to a standard metallic spring, or 5mm, or higher. Ultimately, the cross-sectional radius 54 and width 56 will be dictated by the properties required of the spring.

[0119] Mechanical compression tests were performed on two prototype springs 58, 60 shown in Figure 10, each having a different cross-sectional diameter 62, 64. Spring 60 has a cross- sectional diameter 64 of 8mm and the spring 58 has a cross-sectional diameter 62 of 5mm. Both springs 58, 60 are made of recycled polyolefin-based material using a circular extruder die (not shown in the drawings). The springs 58, 60 have diameters 66 of 70mm, with a pitch 68 of approximately 83mm. The results of the compression tests can be seen in the graphs below. As a point of reference, a metal spring with similar length, pitch and a general wire diameter of 2mm, was tested.

[0120]

[0121] 0 20 40 60 80 100 120 140 160 180

[0122] Deformation (mm)

[0123] Spring 60 having an 8mm cross-sectional diameter 62 recorded a 115 to 135 N / m spring constant. It is appreciated that the spring constant can be adjusted by amending spring diameter 66, pitch 68 and cross-section diameter 62, 64. Further compression testing was conducted on an assembly of springs 58 having a 5mm cross-sectional diameter 62. The assembly (not shown in the drawings) resembled that of a mattress or a cushion body. The test was compared to that of a mattress body comprising a standard metal spring. The results of the test are shown below.

[0124]

[0125] The load displacement results of the tests demonstrate comparable results between spring 58 and the traditional metallic spring, whereby the weight of both is similar at 28 grams. The test results of individual springs 58, 60, demonstrate that load displacement results of the spring 60 are higher. However, spring 60 weighs 48 grams, and therefore, it is appreciated that higher load displacement spring properties may result in heavier springs if the pitch 68 and diameter 66 are preserved, and that the optimum cross-sectional spring diameter 62, 64, diameter 66, pitch 68 and weight will ultimately depend on the end use and the desirable features sought. It is therefore appreciated that a combination of cellular structures 10 and springs 42 according to those shown in the drawings and their alternative embodiments can be used to make a mattress assembly 40 that is both recyclable, and one that utilises recycled material. The springs 42, 44, 58, 60 and cellular structures 10 used can be of varying dimensions and properties so as to provide different levels or resistance and resilience across the mattress 40 structure to cater to individual needs. Further, where the springs 42, 44, 58, 60 are incorporated into a mattress 40, in an embodiment they are pocketed in polypropylene textile, and the entire structure 40 is reinforced, for example in polypropylene sheets. The pocket and reinforcing material can be of any suitable material, for example any polymer and need not be the specific materials set out in this description.

[0126] The springs 42, 44, 58, and 60, as described above, can be manufactured through several processes, including injection moulding and extrusion-based filament winding.

[0127] Injection moulding is considered a viable method for commercial-scale production of springs 42, 44, 58, and 60 due to its high repeatability, excellent process control, and compatibility with existing workflows in the bedding industry.

[0128] Traditional high-precision injection moulding tools may produce inconsistent springs when recycled polyolefins are used as the predominant feedstock. To address the limitations of conventional tools and the challenges associated with recycled polyolefins, a complete assembly 90, as shown in Figure 8, has been designed. Assembly 90 is a two-cavity tool that includes four mechanically (pneumatically) actuated side sliders and over 40 individual components. A modular insert system is integrated to allow future design updates, ensuring long-term tool reusability. To eliminate undercuts and facilitate smooth ejection, the geometry of the assembly has been specifically designed for clean demoulding. Assembly 90 features a cold sprue system with pull-off features and is engineered for cycle times between 30-45 seconds per part. It also includes built-in provisions to increase sprue diameter without altering the core geometry.

[0129] It should be noted that the fabrication of assembly 90 requires precise CNC machining, grinding, and three-stage wire cutting for each of the side sliders. The assembly comprises more than 20 parts, the majority of which are manufactured using tight-tolerance engineering drawings to ensure seamless compilation.

[0130] As noted above, extrusion-based filament winding is also a viable technique for producing springs 42, 44, 58, and 60 at scale. This method is suitable for rapid prototyping, modular manufacturing, and potential integration into decentralised or adaptive production systems. A filament winding assembly 130, as shown in figure 9 includes a microcontroller used to control the winding mechanism. The microcontroller can be an ESP32™, Arduino Mega™, or any suitable alternative. The associated code is developed to synchronise a linear actuator and a rotational stepper motor to produce coil springs. The system automates the coiling process by managing two key motions:

[0131] • Linear Motion: Drives a carriage forward at a controlled speed in front of the plastic extruder die exit to define the spring's pitch; and

[0132] • Rotational Motion: Rotates the shaft to wind the polymer around it and form the spring coils.

[0133] The microcontroller code uses stepper motor drivers (such as the DM556™) to precisely manage speed, direction, and step counts. Key functionalities of the microcontroller include:

[0134] • Coordinated movement of the linear and rotational motors;

[0135] • Adjustable speed and step settings for customizing coil pitch and diameter;

[0136] • Direction control for both motors to accommodate various spring designs; and

[0137] • Integration with user inputs or sensors for semi-automatic control.

[0138] This setup enables efficient and repeatable production of springs 42, 44, 58, 60 with consistent geometry, suitable for prototyping or small-batch manufacturing.

[0139] An extruder, such as a Labtech™ twin-screw extruder, is used to produce a continuous molten thermoplastic strand. This strand is fed onto a winding mechanism comprising linear movement rails for horizontal translation of the extruded material, a rotating mandrel (core) for spring geometry formation, and speed control of both axes to regulate spring pitch and coil spacing. The extrudate can be cooled post-deposition using either air or water.

[0140] Multiple die configurations can be used in the filament winding assembly 130, including central, downward-facing, and upward-facing sprues. Each sprue configuration facilitates the manufacture of springs 42, 44, 58, and 60 as per the cross-section shown in Figure 7. It is noted that a central sprue provides a desirable balance between control and flow uniformity.

[0141] The mattress 40 of Figure 11 comprising a plurality of cellular structures 10 around the perimeter / frame and springs 42 can also be combined with a 3-dimensional (3D) lattice structure 70 as shown in Figure 12. This lattice structure is a polymer structure comprising a cross-hatch pattern. The pattern is visible in the side view 72 and top view 74 of the lattice 70. It has been found that this 3D cross-hatch lattice structure 70 made from a suitable polymer can be used as a mattress comfort layer 70, which sits above the mattress springs 42 or an alternative mattress filler. By utilising the cross-hatch pattern, the weight of the structure 70 is significantly less than that of a solid comfort layer, while providing similar performance and durability characteristics. It is to be appreciated that the cross-hatch structure 70 can be made of alternative materials such as metals, composites or a combination of metals, or composites or polymers.

[0142] As noted throughout this description, the cellular structure 10 can be adapted and used in additional items such as apparel (shoes) 76 and furniture (couches and chairs) 78. In figure 13 there is shown an example of cellular structure 10 and the spring 42 of the present invention being used in combination to form a support and cushion of a couch 78. Although not shown in the drawings, a lattice 70 shown in Figure 12 can also be incorporated into the couch 78 design, for example as a top cushion layer.

[0143] The design of the comfort layer structure 70 has been optimised for advanced manufacturing processes, including extrusion, filament winding, injection moulding, plastic welding and large- area additive manufacturing (LAAM).

[0144] In Figure 18 there is shown an injection moulding assembly 120 for a comfort layer structure. In the context of injection moulding, it is envisaged that moulds are designed and manufactured to accommodate specific mattress sizes, given that mattress dimensions (i.e., Single, King Single, Double, Queen, King, and Super King) are generally standardised within regions. Alternatively, the mould 120 is able to be configured to produce modules 98 that can be connected together according to Figure 20 to form a final comfort layer 70. By connecting modules 98 together, various final comfort layer 70 sizes can be achieved.

[0145] In prototype mould 120 designs, there is included a multi-gate system with a runner. Such a design has been found through simulations to have uniform flow and fill through channels with the mould having a part-leg dimension of 1.5mm. "Legs" in this context refer to branches of the runner system (the channels through which molten material flows into the mould cavities).

[0146] An alternative method to that shown in Figure 18 is extrusion and punching. This method involves extruding a plastic form to create a profile geometry 92, an example of which is shown in Figure 19. This geometry 92 is then be cut to length and fed onto a supporting tool 94. The extruded profile 92 is then be stamped or cut in a vertical direction to achieve the desired geometry 96.

[0147] The extrusion and punching manufacturing method is scalable to different sizes to cater to different mattress sizes. Alternatively, the method can be scaled down to modules 98 as shown in Figure 20, whereby the moules 98 are connected and / or cut to a desired size. The connection occurs by interlocking receiving portions 100 of the different modules 98.

[0148] Although not shown in the drawings, in an embodiment interlocking sections are incorporated in the comfort layer 70 to allow it to be securely connected to corresponding interlocking components of springs 42, 44, 58, 60 and / or cellular structures 10. In alternative embodiments not shown in the drawings, other connection means such as connection tabs, or magnets, or mechanical fasteners may be used.

[0149] Figure 14 further shows how the cellular structure 10 can be adapted to form part of a shoe 76. In the embodiment of Figure 14, the cellular structure 10 forms an integral part of the sole 80 of the shoe 76, mainly due to the strength and resilience the structure 10 provides to the shoe. Although not shown in the drawings, the cellular structure 10 can be incorporated into other components of a shoe 76 such as the collar, or the collar filler, the tongue, vamp or toe cap. In this respect, the cellular structure 10 can be used in different orientations to that described in earlier paragraphs.

[0150] Figure 15 shows the cellular structure 10 being bent about a plane parallel to the cell face 11. It has been found that the cellular structure 10 provides a high compression resistance against forces acting perpendicular to the face 11. The cellular structure 11 is able to conform to various surface geometries and curvatures, thus making the structure 10 versatile in that it can be incorporated in curved items such as shoe soles 80 or other apparel and furniture. Under high levels of strain, the cell geometry of the cell structure 10 switches from a modified hexagonal structure to parallelogram and is reversible when the structure is comprised of elastic or hyper-elastic materials, thus making the structure suitable for use in applications where regular multi-dimensional forces are applied to the structure 10. In essence, the cellular structure 10 is versatile in that it can resiliently withstand forces acting perpendicular to or parallel to its face 11, while providing desirable performance characteristics.

[0151] The present invention provides an alternative to conventional foams which are used in furniture components, in particular, in mattresses 40. These conventional foams are often multilayered foams and are comprised of different plastics or polymers which are fused together or mechanically attached. The separation of these foams is often costly, time consuming and not financially viable. As a result, conventional mattresses, furniture components and apparel such as shoes are not recycled. The invention provides a cellular structure which is less dense than traditional solid foams, and one that is able to be manufactured at a relatively lower cost through additive manufacturing or through extrusion moulding. The ability of the present invention to be made from a wide variety of materials allows it to be customised and tailored to a plethora of applications, all the while providing equal or superior mechanical resilience to that of a conventional honeycomb structure and to traditional springs. The invention is also able to be made from a wide variety of polymers and even monopolymers such as polypropylene, thus allowing it to be easily and cost effectively recycled, and to incorporate recycled material.

[0152] Unless the context requires otherwise, where the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components, or group thereof. List of Reference Numerals

[0153] First wall - 1

[0154] Second wall - 2

[0155] Third wall - 3

[0156] Fourth wall - 4

[0157] Fifth wall -5

[0158] Sixth wall - 6

[0159] Cell Structure - 10

[0160] Cell Structure Face - 11

[0161] Cell rows - 12

[0162] Individual Cells - 14

[0163] Long Dimension - 16

[0164] Short Dimension - 18

[0165] Horizontal axis - 20

[0166] Vertical axis - 22

[0167] Cell angle of inclination - 24

[0168] Horizontal axis - 25

[0169] First row - 26

[0170] Second row - 27

[0171] Third row - 28

[0172] Fourth row - 29

[0173] Fifth row - 30

[0174] Sixth row - 31

[0175] Seventh row - 32

[0176] Cellular structure depth - 34

[0177] Cellular structure width - 36

[0178] Cell structure height - 38

[0179] Cell Structure apertures - 39 Mattress - 40

[0180] Mattress springs - 42

[0181] Spring prototype 1 - 44

[0182] Spring cross section - 46

[0183] Rounded Portion - 48

[0184] Rectangular Portion - 50

[0185] Mould - 52

[0186] Cross-sectional radius - 54

[0187] Width of rectangular portion - 56

[0188] Spring prototype 2 - 58

[0189] Spring prototype 3 - 60

[0190] Spring prototype 2 cross sectional diameter - 62

[0191] Spring prototype 3 cross sectional diameter - 64

[0192] Spring diameter - 66

[0193] Spring pitch - 68

[0194] Lattice Structure -70

[0195] Lattice structure side view - 72

[0196] Lattice structure top view - 74

[0197] Shoe - 76

[0198] Couch - 78

[0199] Shoe Sole - 80

[0200] Vertical Layer - 82

[0201] Horizontal layer -84

[0202] Overlay of Vertical and Horizontal Layer - 86

[0203] Lattice Structure Injection Moulding Assembly - 88

[0204] Injection Moulding Assembly of Spring - 90

[0205] Profile Geometry - 92

[0206] Supporting tool - 94 Desired final Geometry of Comfort Layer - 96

[0207] Comfort Layer Modules - 98

[0208] Interlocking Receiving Portions of Modules - 100

[0209] Cellular Structure Segments - 102 Segment Interlocking Sections - 104

[0210] Cellular Structure with Segments Interlocked - 106

[0211] Comfort layer Injection Moulding Assembly - 120

[0212] Spring winding assembly - 130

Claims

1. Claims1. A cellular structure comprising: a. a lattice formed of a plurality of generally parallel rows of cells, b. each cell is formed as an irregular hexagonal cell, c. the cells are oriented such that each cell wall creates an acute, obtuse or reflex angle relative to a horizontal or a vertical axis, d. each individual row is comprised of a plurality of generally identical cells, wherein the cells are inclined at generally the same degree of inclination, e. the cells in adjacent rows are inclined at generally opposite degrees of inclination, f. each wall of each cell forms a common wall between two adjacent cells either in a same row or in an adjacent row such that, with the exception of cells at an outer periphery of the structure or directly adjacent any structural or ventilation apertures, and each cell has a common wall with six adjacent cells with the exception of cells at an outer periphery of the structure or directly adjacent any structural or ventilation apertures; and g. the lattice is formed with substantially no gaps or spaces between adjacent cells either in each row of cells, or between adjacent rows of cells.

2. The cellular structure of claim 1, wherein the cells are at least partially open cells.

3. The cellular structure of claim 1 or 2, wherein the cell walls are generally linear.

4. The cellular structure of any one of claims 1 to 3, wherein the cells in every odd numbered row are identical to each other and the cells in every even row are identical to each other.

5. The cellular structure of claim 4, wherein the cells of every even numbered row are inclined at a generally symmetrical angle to the cells of every odd numbered row.

6. The cellular structure of claim 5, wherein the cells of every even numbered row are symmetrical to the cells of every odd numbered row.

7. The cellular structure according to any one of claims 1 to 5, wherein each cell of every odd or even numbered row is comprised of a first, second, third, fourth, fifth and sixth cell wall of generally equal length and thickness and wherein for each cell,- the first cell wall and the second cell wall intersect at an angle between 110° and 150°,- the second cell wall and the third cell wall intersect at an angle between 135° and 175°,- the third cell wall and the fourth cell wall intersect at an angle between 55° and 95°,- the fourth cell wall and the fifth cell wall intersect at an angle between 110° and 150°,- the fifth cell wall and the sixth cell wall intersect at an angle between 135° and 175°, and- the sixth cell wall and the first cell wall intersect at an angle between 55° and 95°.

8. The cellular structure according to claim 7, wherein each cell of every odd or even numbered row is inclined such that the third wall of each cell is configured to also be the sixth wall of an adjacent cell in the row and vice versa.

9. The cellular structure according to claim 8, wherein adjacent rows are offset such that each cell of every odd or even numbered row are arranged and inclined such that the first wall and second wall of each cell are configured to be common walls of cells in an adjacent row, and the fourth wall and fifth wall of each cell are configured to be common walls of cells in another adjacent row.

10. The cellular structure according to claim 9, wherein the cells of every odd or even row are inclined such that the first and sixth wall intersection of each cell is at a lower point along a vertical axis than the third and fourth wall intersection.

11. The cellular structure according to any one of claims 7 to 10, wherein: the first cell wall and the second cell wall intersect at an angle of approximately 130°, the second cell wall and the third cell wall intersect at an angle of approximately 155.7°, the third cell wall and the fourth cell wall intersect at an angle of approximately 74.3°, the fourth cell wall and the fifth cell wall intersect at an angle of approximately 130°, the fifth cell wall and the sixth cell wall intersect at an angle of approximately 155.7°, and the sixth cell wall and the first cell wall intersect at an angle of approximately 74.3°.

12. The cellular structure of any one of claims 7 to 11, wherein the cell wall length is between approximately 3mm and approximately 10mm.

13. The cellular structure of claim 12, wherein the cell wall length is approximately 5mm.

14. The cellular structure of any one of claims 7 to 13, wherein the cell wall thickness is between approximately 0.2mm to 0.8mm.

15. The cellular structure of claim 14, wherein the cell wall thickness is approximately 0.4mm.

16. The cellular structure of any one of claims 1 to 15, wherein the cellular structure has a depth of between approximately 40mm and 100mm.

17. The cellular structure of claim 16, wherein the cellular structure has a depth of approximately 75mm.

18. The cellular structure of claim 17, comprising an overall width of approximately 185mm, and an overall height of approximately 200mm.

19. The cellular structure of any one of claims 1 to 18, comprising ventilation or structural apertures spanning across at least two rows.

20. The cellular structure of any one of claims 1 to 19, wherein the cell walls are made of polyolefins and / or thermos plastic elastomers.

21. The cellular structure of claim 20, wherein the cell walls are made of polypropylene.

22. The cellular structure of claim any one of claims 1 to 21, wherein cells in are inclined at 20° to 30° relative to a horizontal axis.

23. A mattress comprising a plurality of cellular structures according to any one of claims 1 to 22, wherein the cellular structures are placed adjacent to each other around the perimeter of the mattress forming an edge frame.

24. The mattress according to claim 23, comprising a filler, wherein the filler is a plurality of cellular structures according to any one of claims 1 to 22 positioned adjacent to one another.

Images