FIELD OF THE INVENTION

[0001] Various embodiments of fluted sheeting are described herein. SUMMARY

[0002] In one aspect, there is provided fluted sheeting, which includes:

an upper plastic wall and a lower plastic wall;

a fluted plastic member interposed between the upper and lower walls, the fluted plastic member including:

a plurality of ribs in which consecutive pairs of ribs converge towards each other between the upper wall and the lower wall to alternately oriented apices at each convergence; and

a bridge of between 0.5mm and 0.8mm formed by contact of each apex with the wall, each bridge being generally parallel to the wall.

[0003] Each pair of consecutive apices may be about 7mm apart, the upper wall and lower wall may be about 4mm apart, and the take-up factor of the sheeting may be less than 1.7.

[0004] Alternatively, each pair of consecutive apices may be from about 6mm to about 6.5mm apart, the upper wall and lower wall may be about 3mm apart, and the take-up factor of the sheeting may be less than 1.65.

[0005] In another embodiment, each pair of consecutive apices may be from about 5mm to about 5.5mm apart, the upper wall and lower wall may be about 2mm apart, and the take-up factor of the sheeting may be less than 1.4.

[0006] In yet a further embodiment of the invention, each pair of consecutive apices may be from about 4.2mm to about 4.8mm apart, the upper wall and lower wall may be about 1 mm apart, and the take-up factor of the sheeting may be less than 1.2.

[0007] The plurality of ribs may be arranged in at least one layer, or at least two layers. The, or each layer may be provided by an intermediate sheet having a corrugated profile.

[0008] The plastic of the walls and fluted member may be any plastic or combination of plastics and/or plastics with additives, including: polyethylene and calcium carbonate; polypropylene; polypropylene and calcium carbonate;

polypropylene and magnesium silicate; polypropylene and Talcum Powder.

[0009] In another aspect, there is provided a method of manufacture of fluted sheeting, the method comprising:

extruding a molten plastic material to an upper wall, a lower wall and a fluted plastic member, the fluted plastic member comprising a plurality of ribs in which consecutive pairs of ribs converge towards each other to alternately oriented apices at each convergence;

fixing the fluted plastic member between the upper wall and the lower wall such that the plurality of ribs converge towards each other between the upper wall and the lower wall and a bridge of between 0.5mm and 0.8mm, generally parallel to the wall, is formed by fixing each apex to the wall.

[0010] The fluted member may be extruded to each pair of consecutive apices being about 7mm apart, the upper wall and lower wall may be fixed at about 4mm apart, and the take-up factor of the sheeting may be less than 1.7.

[001 1] Alternatively, the fluted member may be extruded to each pair of consecutive apices being from about 6mm to about 6.5mm apart, the upper wall and lower wall may be fixed at about 3mm apart, and the take-up factor of the sheeting may be less than 1.65.

[0012] In another embodiment, the fluted member may be extruded to each pair of consecutive apices being from about 5mm to about 5.5mm apart, the upper wall and lower wall may be fixed at about 2mm apart, and the take-up factor of the sheeting may be less than 1.4.

[0013] In yet a further embodiment of the invention, the fluted member may be extruded to each pair of consecutive apices being from about 4.2mm to about 4.8mm apart, the upper wall and lower wall may be fixed at about 1 mm apart, and the take- up factor of the sheeting may be less than 1.2.

[0014] The method of the invention may further include at least a second fluted member fixed between the fluted member and the upper or lower wall. The, or each fluted member may also be fixed to an intermediate wall between the fluted sheets.

[0015] The plastic of the walls and fluted member may be any plastic or combination of plastics and/or plastics with additives, including: polyethylene and calcium carbonate; polypropylene; polypropylene and calcium carbonate;

polypropylene and magnesium silicate; polypropylene and Talcum Powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 shows an end profile of one embodiment of fluted sheeting.

[0017] Figure 2 shows an end profile of another embodiment of fluted sheeting

[0018] Figure 3 shows an end profile of another embodiment of fluted sheeting

[0019] Figure 4 shows an end profile of another embodiment of fluted sheeting

[0020] Figure 5 shows an end profile of another embodiment of fluted sheeting

[0021] Figure 6 shows an end profile of another embodiment of fluted sheeting

[0022] Figure 7 shows an end profile of conventional fluted sheeting.

DETAILED DESCRIPTION

[0023] In figure 1 , reference numeral 10 generally indicates fluted sheeting viewed from one end to show an end profile of the fluted sheeting 10.

[0024] The fluted sheeting 10 has two outside walls in the form of an upper wall

12.1 and a lower wall 12.2. A plurality of ribs 14, forming the fluted member 20 of the sheeting, are interposed between the outside walls 12, with consecutive pairs of ribs 14 converging towards each other between the upper wall 12.1 and the lower wall

12.2 to alternately oriented apices at each convergence. The outside walls 12 and the ribs 14 are of a plastics material.

[0025] The ribs 14 of the fluted sheeting 10 are arranged in at least one layer, for example, two layers 16.1 , 16.2. An intermediate wall 18 is interposed between the walls 12.1 , 12.2. The, or each, layer defines a series of alternately oriented apices.

[0026] The ribs 14 of the layer 16.1 are defined by a fluted plastic member 20 that is interposed between the upper wall 12.1 and the intermediate wall 18. The fluted member 20 defines a series of alternately oriented apices 22 with the ribs 14 interposed between respective consecutive apices 22. These are in the form of apices 22.1 in contact with the upper wall 12.1 and apices 22.2 in contact with the intermediate wall 18.

[0027] The ribs 14 of the layer 16.2 are defined by a fluted plastic member 24. The fluted member 24 defines a series of alternately oriented apices 26 with the ribs 14 interposed between respective consecutive apices 26. These are in the form of apices 26.1 in contact with the intermediate wall 18 and apices 26.2 in contact with the lower wall 12.2. The apices 26 form bridges 28 where the apices contact the lower wall 12.2, upper wall 12.1 or intermediate wall 18. The bridges 28 are generally parallel to the walls 12, 18, and can be from about 0.5mm to 0.8mm in length, for example from about 0.7mm to 0.8mm, and, in a particular example, 0.72mm.

[0028] In this example, the sheeting 10 can have a thickness of about 7 mm. However, other thicknesses are also possible. Furthermore, the layer 16.1 can have a thickness of about 4 mm and the layer 16.2 can have a thickness of about 3 mm. It will be appreciated that these thicknesses can vary, if necessary.

[0029] With the illustrative thicknesses described above, a distance between consecutive, aligned apices 22.1 and consecutive, aligned apices 22.2 is about 7 mm, for example 6.97 mm or 7.01 mm. A distance between consecutive, aligned apices 26.1 and consecutive, aligned apices 26.2 is about 6.5 mm, for example 6.31 mm.

[0030] In figure 2, reference numeral 30 generally indicates fluted sheeting viewed from one end to show an end profile of the fluted sheeting 30.

[0031] The ribs 14 of the fluted sheeting 30 are arranged in two layers 32.1 and 32.2.

[0032] The ribs 14 of the layer 32.1 are defined by a fluted member 34. The fluted member 34 defines a series of alternately oriented apices 38 with the ribs 14 interposed between respective consecutive apices 38.

[0033] The ribs 14 of the layer 32.2 are defined by a fluted member 36. The fluted member 36 is substantially identical to the fluted member 34. The fluted member 36 defines a series of alternately oriented apices 40 with the ribs 14 interposed between respective consecutive apices 40.

[0034] The apices 38 include apices 38.1 in contact with the upper wall 12.1. The apices 40 include apices 40.1 in contact with the lower wall 12.2. The apices 38 also include apices 38.2 and the apices 40 also include apices 40.2. The apices 38.2 are in contact with respective apices 40.2. The apices 38 form bridges 39 where the apices contact the lower 12.2 or upper 12.1 wall, or opposing apices. The bridges 39 are oriented parallel to the walls 12, and may be from about 0.5mm to 0.8mm in length, for example: 0.72mm. [0035] In this example, each of the layers 32 has a thickness of about 3 mm, giving the sheeting 30 an overall thickness of about 6 mm. With these illustrative thicknesses, a distance between consecutive, aligned apices 38.1 and consecutive, aligned apices 38.2 is about 6.5 mm, for example 6.31 mm.

[0036] In figure 3, reference numeral 50 generally indicates fluted sheeting viewed from one end to show an end profile of the fluted sheeting 50.

[0037] The ribs 14 of the fluted sheeting 50 are arranged in a single layer 52 between the outside walls 12. The ribs 14 of the layer 52 are defined by a fluted member 54. The fluted member 54 defines a series of alternately oriented apices 56.

[0038] The apices 56 include apices 56.1 in contact with the upper wall 12.1 and apices 56.2 in contact with the lower wall 12.2. The apices 56 form bridges 58 where the apices contact the lower 12.2 or upper 12.1 wall. The bridges 58 are oriented parallel to the walls 12, and may be from about 0.5mm to 0.8mm in length, for example: 0.72mm.

[0039] A distance between consecutive, aligned apices 56.1 and consecutive, aligned apices 56.2 is about 7 mm, for example 7.01 mm.

[0040] A thickness of the layer 52 is about 4 mm, giving the sheeting 50 an overall thickness of about 4 mm.

[0041] The fluted sheeting of the invention provides sheeting with strength 15- 30% greater than available with conventional plastic fluted sheeting. This may be indicated by the take-up factors of the sheeting of the invention. For example, the take-up factor of the fluted sheeting represented in figure 3 is about 1.67.

[0042] Take-up factor, or take-up ratio, is a measure of the amount of plastic material required for sheeting to provide a specified strength. Take-up factor is calculated by dividing the length of a fluted sheet by the length of plastic sheet required for the fluted member, for a given strength of sheeting. Alternatively stated, the fluted sheeting of the invention requires substantially less plastic material for the fluted member than standard fluted sheeting, to provide comparable strength fluted sheeting. It follows that the greater the take-up factor, the more material has been used to manufacture the sheeting. Generally speaking, this would be expected to proportionately increase the strength of the sheeting. The fluted sheeting of the invention, however, shows increased strength at lower take-up factors than conventional fluted sheeting. [0043] In figure 4, reference numeral 60 generally indicates fluted sheeting viewed from one end to show an end profile of the fluted sheeting 60.

[0044] The ribs 14 of the fluted sheeting 60 are arranged in a single layer 62 between the outside walls 12. The ribs 14 of the layer 62 are defined by an intermediate fluted member 64. The fluted member 64 defines a series of alternately oriented apices 66.

[0045] The apices 66 include apices 66.1 in contact with the upper wall 12.1 and apices 66.2 in contact with the lower wall 12.2. The apices 66 form bridges 68 where the apices contact the lower 12.2 or upper 12.1 wall. The bridges 68 are oriented parallel to the walls 12, and may be from about 0.5mm to 0.8mm in length, for example: 0.72mm.

[0046] A distance between consecutive, aligned apices 26.1 and consecutive, aligned apices 26.2 is about 6.5 mm, for example 6.31 mm.

[0047] A thickness of the layer 62 is about 3 mm, giving the sheeting 60 an overall thickness of about 3 mm.

[0048] The take-up factor of the fluted sheeting represented in figure 4 is about 1.63.

[0049] In figure 5, reference numeral 70 generally indicates fluted sheeting viewed from one end to show an end profile of the fluted sheeting 70.

[0050] The ribs 14 of the fluted sheeting 70 are arranged in a single layer 72 between the outside walls 12. The ribs 14 of the layer 72 are defined by an intermediate fluted member 74. The fluted member 74 defines a series of alternately oriented apices 76.

[0051] The apices 76 include apices 76.1 in contact with the upper wall 12.1 and apices 76.2 in contact with the lower wall 12.2. The apices 76 form bridges 78 where the apices contact the lower 12.2 or upper 12.1 wall. The bridges 78 are oriented parallel to the walls 12, and may be from about 0.5mm to 0.8mm in length, for example: 0.72mm.

[0052] A distance between consecutive, aligned apices 76.1 and consecutive, aligned apices 76.2 is about 5.5 mm, for example 5.32 mm. [0053] A thickness of the layer 72 is about 1.5 mm, giving the sheeting 70 an overall thickness of about 1.5 mm.

[0054] In figure 6, reference numeral 80 generally indicates fluted sheeting viewed from one end to show an end profile of the fluted sheeting 80.

[0055] The ribs 14 of the fluted sheeting 80 are arranged in a single layer 82 between the outside walls 12. The ribs 14 of the layer 82 are defined by an intermediate fluted member 84. The fluted member 84 defines a series of alternately oriented apices 86.

[0056] The apices 86 include apices 86.1 in contact with the upper wall 12.1 and apices 86.2 in contact with the lower wall 12.2. The apices 86 form bridges 88 where the apices contact the lower 12.2 or upper 12.1 wall. The bridges 88 are oriented parallel to the walls 12, and may be from about 0.5mm to 0.8mm in length, for example: 0.72mm.

[0057] A distance between consecutive, aligned apices 86.1 and consecutive aligned apices 86.2 is about 5 mm, for example 4.91 mm.

[0058] A thickness of the layer is about 1 mm, giving the sheeting 80 an overall thickness of about 1 mm.

[0059] The take-up factor of the fluted sheeting represented in figure 6 is about 1.16.

[0060] In figure 7, reference numeral 100 generally indicates conventional fluted sheeting, for comparative purposes, viewed from one end to show an end profile of the fluted sheeting 100.

[0061] The ribs 15 of the fluted sheeting 100 are arranged in a single layer 102 between the outside walls 13. The ribs 15 of the layer 102 are defined by an intermediate fluted member 104. The fluted member 104 defines a series of alternately oriented apices 96, which have a cylindrical profile, indicated at R. This results in contact points 96 between the fluted member 104 and the outside walls 13, without formation of a bridge.

[0062] In the examples of sheeting of the invention described herein, an internal radius of curvature in which each rib 14 transitions to a respective bridge, is approximately 1 mm. [0063] In the examples of sheeting of the invention described herein, an included or acute angle between each rib 14 and the outer walls 12 may be between about 60° and 70°, for example 65°.

[0064] It is to be understood that the ribs 14 need not be defined by corrugated sheeting. For example, the ribs 14 can be provided by discrete strips interposed between the outside walls 12. The strips can be angled with respect to the outside walls 12 to provide consecutive pairs of the ribs 14 converging towards each other from one outside wall 12 to the other outside wall 12.

[0065] In the examples described in figures 1 to 7, the walls 12 and the fluted members are extruded separately and subsequently fastened together in a fixing process, which may be lamination. Depending on the size requirements, any number of fluted members of a predetermined width can be extruded separately from any number of the walls of a predetermined width.

[0066] An actual thickness of the material used for the walls 12 is between about 100 μηη and 500 pm, depending on the application. An actual thickness of the material used for the fluted members is between about 100 pm and 500 pm, depending on the application.

[0067] Instead of being discreet, the fluted sheets and the outside walls 12 can be in the form of a unitary, one-piece structure. Such a structure can be the result of an extrusion process, for example, or some other process capable of producing such a structure.

[0068] Furthermore, the sheeting may have three or more layers of the ribs 14, depending on requirements.

[0069] The walls 12 and the ribs 14 are of a plastics material. The plastics material can be, or can include, polyethylene or polypropylene. The plastics material can be, or can include, recycled polyethylene or polypropylene.

[0070] The plastics material can be a composite material. The composite material can be polyethylene combined with calcium carbonate. Recycled

polyethylene can also be included. The percentages of polyethylene, calcium carbonate, and recycled polyethylene can depend on the application of the sheeting, and may additionally be implemented by at least the mixing process and bonding process of the material combinations. [0071] The composite material can also be polypropylene combined with magnesium silicate, also known as talc, which is an ingredient of talcum powder. This combination can also include recycled polypropylene.

[0072] The angular orientation of the ribs 14 and the bridge 28, 39, 58, 68, 78, 88, 98, impart a resistance to crushing to the sheeting. It will be appreciated that the angular orientation of the ribs 14 results in a lateral dispersion of compressive force through the ribs 14. This lateral dispersion is substantially equalised through the ribs 14 to inhibit buckling of the ribs 14 to an extent that is greater than a configuration in which the ribs 14 extend perpendicularly with respect to the outside walls 12. Thus, such a configuration uses less material than a configuration in which the ribs 14 extend perpendicularly for the same level of performance. For example, the angular orientation of the ribs 14 with reference to the outside walls 12 emulates angles used in structural engineering for the building of bridges and other structures. The strength of the fluted sheeting of the invention may be as a result of the generally triangular configuration of the ribs and bridges of the fluted member, which is resistant to deformation under load.

[0073] The ribs 14 can be fixed, for example by gluing or welding, to the outside walls 12, to form the bridges at the fixing locations. The bridges are generally parallel to the outside walls. For example, with reference to the embodiments described herein, the respective fluted members can be welded or glued between the outside walls 12 or, at least along one side, be welded or glued to each other, for example, in the embodiment shown in figure 2.

[0074] Broadly, the plastics material can be any plastics material capable of extrusion in sheet form and the density of the material used can depend on the intended application.

[0075] The plastics material can include further additives such as, but not limited to, one or more of material related to anticounterfeiting, antimicrobials/bio-stabilisers, antioxidants, antistatic agents, biodegradable plasticisers, degradable plasticisers, blowing agents, external lubricants, fillers/extenders, flame retardant, fragrances, heat stabilisers, impact modifiers, internal lubricants, light stabilisers, pigments, plasticisers, process aids and reinforcements.

[0076] It will be appreciated that the various parameters described herein can be varied depending on the desired application for the sheeting. Thus, the sheeting embodiments are not limited to spacing, layer thickness, type of plastics material, weight (for example, in grams per square metre) of the plastics material, or method of production.

[0077] The sheeting can have multiple applications and is not limited to any single application. For example, the sheeting can be used for packaging and construction building material such as void fills, and printing and display applications, where the inherent resistance to moisture damage of the plastics material is useful. Such applications can also be those in which the inherent resistance to damage by insects of the plastics material is useful.

[0078] The appended claims are to be considered as incorporated into the above description.

[0079] Throughout the specification, the use of common reference numerals is intended to indicate like parts or components across the drawings, unless otherwise indicated. However, such use of common reference numerals is for convenience only and is not intended to indicate that the like parts or components need to be identical. The inventor(s) envisages that, where feasible, various components described throughout the drawings can be interchanged to provide further embodiments that are not specifically described herein.

[0080] Throughout the specification, including the claims, where the context permits, the term "comprising" and variants thereof such as "comprise" or

"comprises" are to be interpreted as including the stated integer or integers without necessarily excluding any other integers.

[0081] It is to be understood that the terminology employed above is for description and should not be regarded as limiting. The described embodiments are intended to be illustrative of the invention, without limiting the scope thereof. The invention is capable of being practised with various modifications and additions as will readily occur to those skilled in the art.

[0082] When any number or range is described herein, unless clearly stated otherwise, that number or range is approximate. Recitation of ranges of values herein are intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value and each separate subrange defined by such separate values is incorporated into the specification as if it were individually recited herein. [0083] Words indicating direction or orientation, such as "front", "rear", "back", etc, are used for convenience. The inventor(s) envisages that various embodiments can be used in a non-operative configuration, such as when presented for sale. Thus, such words are to be regarded as illustrative in nature, and not as restrictive.