CA2968826A1

CA2968826A1 - Wood-metal composite pallet and structures

Info

Publication number: CA2968826A1
Application number: CA2968826A
Authority: CA
Inventors: Alain Belanger
Original assignee: Corruven Canada Inc
Current assignee: Corruven Canada Inc
Priority date: 2017-05-29
Filing date: 2017-05-29
Publication date: 2018-11-29
Also published as: CA3001569A1; WO2018218337A1

Abstract

A wood-metal composite structure includes a wood-metal composite sheet shaped as a body. The body defines an inner cavity. The wood-metal composite sheet includes at least one metal layer having metal protrusions extending away from both sides of the at least one metal layer. The wood-metal composite sheet includes wood veneer layers disposed on both sides of the at least one metal layer. The metal protrusions extend into the wood veneer layers.

Description

WOOD-METAL COMPOSITE PALLET AND STRUCTURES
FIELD
[0001] The improvements generally relate to the field of composite forms, and more particularly, to a wood-metal composite structure.
BACKGROUND

[0002] Wood composites typically consist of one type of wood adhered to another type of wood to provide a structural and/or aesthetic product. Some wood composites do not sufficiently resist moisture on their own, and thus require relatively costly coatings, or relatively complicated moisture barriers, to make them suitable for a given application.
Furthermore, the adhesive used to assemble some wood composites can wear off over time.
SUMMARY

[0003] In accordance with one aspect, there is provided a shipping pallet, comprising: a wood-metal composite sheet shaped as a body, the body defining an inner cavity, the wood-metal composite sheet including at least one metal layer having metal protrusions extending away from both sides of the at least one metal layer, the wood-metal composite sheet including wood veneer layers disposed on both sides of the at least one metal layer, the metal protrusions extending into the wood veneer layers.

[0004] In accordance with another aspect, there is provided a wood-metal composite structure, comprising: a wood-metal composite sheet shaped as a body closed onto itself, the body defining an inner cavity, the wood-metal composite sheet including at least one metal layer having metal protrusions extending away from both sides of the at least one metal layer, the wood-metal composite sheet including wood veneer layers disposed on both sides of the at least one metal layer, the metal protrusions extending into the wood veneer layers.

[0005] In accordance with another aspect, there is provided a method of forming a wood-metal composite structure, comprising: providing a wood-metal composite sheet including wood veneer layers disposed on both sides of at least one metal layer, metal protrusions of the at least one metal layer extending into the wood veneer layers; supplying the wood-metal composite sheet between a compression roller and a mold having a shape of the structure to be formed; and bending the wood-metal composite sheet with the compression roller to wrap the wood-metal composite sheet around an outer surface of the mold.
DESCRIPTION OF THE FIGURES

[0006] Reference is now made to the accompanying figures in which:

[0007] Fig. 1A is a perspective view of a shipping pallet, according to an embodiment of the present disclosure;

[0008] Fig. 1B is a cross-sectional view of the shipping pallet of Fig 1A;

[0009] Fig. 10 is an enlarged view of a portion of the shipping pallet of Fig. 1B;

[0010] Fig. 1D is an enlarged view of another portion of the shipping pallet of Fig. 1B;

[0011] Fig. lE is an enlarged view of another portion of the shipping pallet of Fig. 1B;

[0012] Fig. 2 is a schematic view of a method of forming a wood-metal composite structure;

[0013] Fig. 3A is a cross-sectional view of a wood-metal composite structure, according to an embodiment of the present disclosure;

[0014] Fig. 3B is a cross-sectional view of the wood-metal composite structure of Fig. 3A, having extra layers.

[0015] Fig. 4 is a cross-sectional view of a wood-metal composite structure, according to another embodiment of the present disclosure;

[0016] Fig. 5 is a cross-sectional view of a portion of a wood-metal composite structure, according to another embodiment of the present disclosure; and

[0017] Fig. 6 is a cross-sectional view of a portion of a wood-metal composite structure, according to another embodiment of the present disclosure.

DETAILED DESCRIPTION

[0018] Fig. 1A illustrates a composite wood structure 10. In the depicted embodiment, the composite wood structure 10 (sometimes simply referred to herein as "structure 10") is in the form of a shipping pallet 11. The shipping pallet 11 shown in Fig. 1A is a bed used to support objects during transport. The shipping pallet 11 can also be used to support stationary objects. The structure 10 can take other forms, and is not limited to the pallet 11 described herein. Some non-limitative examples of alternate forms for the structure 10 include flooring, walls, and panels. Other non-limitative examples of forms for the structure 10 include closed structures, such as a house made from a floor, walls, and a roof. An outer surface of the structure 10 can have a finishing or lining to provide an aesthetically-pleasing appearance.

[0019] In the depicted embodiment, the structure 10 is formed from a sheet of wood composite material. More particularly, the structure 10 is formed from a wood-metal composite sheet 12. The wood-metal composite sheet 12 includes both wood material and metal material arranged in the form of a broad, continuous surface. The structure 10 disclosed herein is a therefore a wood-metal composite structure 10.

[0020] The wood-metal composite sheet 12 (sometimes simply referred to herein as "sheet 12") is folded, bent, curved, or otherwise shaped to provide the form of the structure 10. For example, and as shown in Fig. 1A, the sheet 12 is shaped as a body 14 which provides the form of the shipping pallet 11. The body 14 in Fig. 1A has a substantially tubular or cylindrical shape. More particularly, the body 14 in Fig. 1A has an obround shape, in that the body 14 consists of two semi-circular bodies connected by parallel surfaces that are tangential to the endpoints of the semi-circular bodies. Therefore, the sheet 12 forms a substantially rigid shell body 14 and defines the shape of the shipping pallet 11. The body 14 can have other shapes, such as triangular, circular, and rectangular. In an alternate embodiment, the body 14 has a box-like shape.

[0021] The sheet 12 is shaped to form the body 14 such that the body 14 can be manufactured without using mechanical fasteners and without an adhesive to attach the components of the sheet 12. Stated differently, the body 14 has overlapping portions which are covered by segments or portions of the sheet 12, as described in greater detail below.

The body 14 is therefore, in at least some embodiments, substantially seamless along its circumference or peripheral length, so as to form an relatively uninterrupted surface. This relatively uninterrupted surface of the body 14 helps to reduce the number of points of stress concentrations or weakness. The body 14 in Fig. 1A is closed onto itself.
There is no opening through the sheet 12 which forms the body 14. The expression "closed onto itself' refers to the body 14 being an object without an end. For example, in Fig. 1A, the body 14 is an annular object without an end. In an alternate embodiment, the body 14 is interrupted such that is has at least two ends.

[0022]
Still referring to Fig. 1A, the body 14 of the shipping pallet 11 is at least partially hollow such that it defines an inner cavity 16. The inner cavity 16 reduces the overall weight of the shipping pallet 11, and allows for the insertion of the forks from fork-lifts, for example, to lift and displace the shipping pallet 11 and the objects thereon. The body 14 of the shipping pallet 11 in Fig. 1A extends along a longitudinal axis 18. The body 14 extends along the longitudinal axis 18 between longitudinally opposed extremities 20. An opening 22 is defined in one or both of the extremities 20. In Fig. 1A, the openings 22 are extensions of the inner cavity 16 which extends through the entirety of the body 14. The openings 22 allow the forks of a forklift, for example, to be inserted into the inner cavity 16 to lift or displace the shipping pallet 11.

[0023]
Referring to Figs. 1A to 1D, the shipping pallet 11 of the depicted embodiment includes additional, optional components. The shaped wood-metal composite sheet 12 which forms the shipping pallet 11 includes elongated bumper portions 24. Each bumper portion 24 protects the body 14 of the shipping pallet 11 from impacts. In the depicted embodiment, each bumper portion 24 extends in a direction parallel to the longitudinal axis 18 along a longitudinal side edge of the body 14. Each bumper portion 24 is curved. More particularly, each bumper portion 24 has a semi-circular cross-sectional shape, as shown in Figs. 1B and 10. The bumper portions 24 can have other cross-sectional shapes.
In an alternate embodiment, the cross-sectional shape of one or more of the bumper portions 24 is rectangular. In another alternate embodiment, the cross-sectional shape of one or more of the bumper portions 24 is "S"-shaped. In the embodiment of Figs. 1B and 10, the bumper portions 24 are not hollow. More particularly, one or more of the bumper portions 24 includes a filler member 26 disposed within an inner volume defined by the bumper portion 24. The filler member 26 reinforces the bumper portion 24 and provides strength thereto. In the depicted embodiment, the filler member 26 includes a wood core cut and shaped to fill the semi-circular shape of the bumper portion 24. The filler member 26 can include other components, or be made from other materials.

[0024] Still referring to Figs. 1A to 10, the shipping pallet 11 can have optional internal reinforcements to further reinforce the surfaces of the shipping pallet 11 to better resist the loads generated by the objects stored thereon. In the embodiment of Figs. 1B
and 10, the inner cavity 16 of the body 14 is defined between opposed inner surfaces 28 of the body 14.
One or more support members 30 are disposed within the inner cavity 16 and extend between the opposed inner surfaces 28. In the depicted embodiment, at least one of the support members 30 includes a support post 32. The support post 32 is cylindrical in shape.
The cylindrical support post 32 in Figs. 1B and 10 is also made from the same wood-metal composite material that makes up the sheet 12. It will be appreciated that the support post 32 can be made from other materials, and have other shapes. In Fig. 1A, the supports posts 32 are spaced apart from one another in a direction that is parallel to the longitudinal axis 18.

[0025] The wood-metal composite sheet 12 which makes up the body 14 of the structure 10, and in some embodiments some of its components, is now discussed in greater detail with reference to Figs. 1B and 1E. The sheet 12 is composed of one or more metal layers 34 attached to one or more wood veneer layers 36. Each metal layer 34 is textured, enhanced, or otherwise treated to improve its engagement with the wood veneer layers 36 to which it is attached. In the depicted embodiment, the metal layer 34 has multiple metal protrusions 38 which extend outwardly from one or both sides 40 of the metal layer 34. Each metal protrusion 38 is an extension from the corresponding side 40 of the metal layer 34 which is adapted to mechanically engage with another material (e.g. the wood material of the wood veneer layer 36). Each metal protrusion 38 can therefore take any suitable shape, or form any suitable non-parallel angle with a plane of the side 40, to achieve such functionality.
Some non-limitative examples of shapes for one or more of the metal protrusions 38 include spikes, hooks, ribs, bumps, and teeth. In the depicted embodiment, each metal protrusion 38 is a burr which is integral with the corresponding side 40 of the metal layer.
The metal protrusion 38 burr is formed by machining the side 40 the metal layer 34 to cut or plow a path/groove/channel/furrow into the side 40 and displace the material from the groove or channel to a position generally above the plane of the side 40, while permitting the material to remain attached to the side 40. Examples of treated metal materials are described in US
patent 5,376,410 to Macke!vie, the entirety of which is hereby incorporated by reference.
One or more of the metal layers 34 may include the product commercialised under the name GRIP Metal TM by GRIPmetal Limited of Toronto, Ontario, Canada.

[0026] The one or more wood veneer layers 36 are disposed on one or both of the sides 40 of the metal layer 34. When disposed on both sides 40 of a metal layer 34, the wood veneer layers 36 sandwich the metal layer 34. One or more of the wood veneer layers 36 are composed of a relatively thin slice of wood, and is relatively easy to produce because it does not require the deconstruction or reconstruction of pieces of wood.
Indeed, the wood veneer layer 36 may be made by "peeling" a circular wood log or by slicing large blocks of wood. Other techniques are possible. The type of wood used for the wood veneer layer 36 can vary. For example, where the wood veneer layer 36 will be visible and serve an aesthetic function, the wood used to make the wood veneer layer 36 can be a hardwood or a wood having an aesthetically pleasing growth ring pattern. Conversely, where the wood veneer layer 36 will be hidden and serve a primarily structural function, a relatively inexpensive softwood can be used. The wood veneer layers 36 are relatively thin, for example thinner than about 3 mm or 0.125 in.

[0027] One or more of the wood veneer layers 36 has wood fibers or grains which have an orientation. The orientation of the wood fibers may depend on the manner by which the wood veneer layer 36 is made. It is observed that the wood veneer layer 36 provides a relatively stiff resistance to bending in the direction of the orientation of its wood fibers, while being relatively pliable in a direction that is transverse to the orientation of its wood fibers. It can thus be appreciated that the orientation of the wood fibers can be selected to optimise bending and/or pliability of the sheet 12 along any desired direction. The wood veneer layer 36 can be provided so that the majority of its wood fibers are substantially parallel to one another, and oriented in the same direction. For example, at least 70% of the wood fibers of the wood veneer layer 36 can be oriented along one direction.

[0028]
Referring to Fig. 1E, the metal protrusions 38 of the metal layer 34 extend into the neighbouring wood veneer layers 36. The metal protrusions 38 penetrate into the wood material of the wood veneer layers 36 to mechanically engage the wood material and provide a mechanical interlocking action. The metal protrusions 38 are therefore firmly affixed within the adjacent wood veneer layers 36. This helps the wood veneer layers 36 to resist shear forces which may act to separate the wood veneer layers 36 from the metal layer 34. The penetration of the metal protrusions 38 within the wood material of the wood veneer layers 36 acts as a mechanical adhesive, thus reducing or eliminating the need for a chemical adhesive to bond the metal layer 34 to the wood veneer layer 36. If the wood-metal composite sheet 12 is free of adhesive, it can also be immersed in water or exposed to humidity.

[0029] A sheet 12 having a specific configuration of metal and wood veneer layers 34,36 is shown in Fig. 1E. The wood-metal composite sheet 12 includes three metal layers 34 and four wood veneer layers 36. Each metal layer 34 is disposed between two of the wood layers 36. At least some of the metal protrusions 38 of immediately adjacent metal layers 34 extend into the same wood veneer layer 36. For example, in the configuration shown in Fig. 1E, the metal layer 34A is immediately adjacent to the metal layer 34B on one side 40A
of the metal layer 34A, and is immediately adjacent to the metal layer 340 on the other side 40B of the metal layer 34A. The metal protrusions 38 extending outwardly from the side 40A of the metal layer 34A penetrate into the wood material of the wood veneer layer 36A, and the metal protrusions 38 extending outwardly from one side 40 of the metal layer 34B penetrate into the same wood material of the same wood veneer layer 36A. Similarly, the metal protrusions 38 extending outwardly from the side 40B of the metal layer 34A
penetrate into the wood material of the wood veneer layer 36B, and the metal protrusions 38 extending outwardly from one side 40 of the metal layer 340 penetrate into the same wood material of the same wood veneer layer 36B. In the configuration of the sheet 12 shown in Fig. 1E, the middle metal layer 34A reinforces the sheet 12 and gives it rigidity. The sheet 12 in other embodiments can have more or fewer metal layers 34 and wood veneer layers 36.
The orientation of the metal protrusions 38 of one or more of the metal layers 34 can be selected to facilitate the shaping of the sheet 12 into the form of the body 14. For example, the metal protrusions 38 can be oriented in the direction along which the sheet 12 will be folded or bent.

[0030]
There is also disclosed a method of forming a wood-metal composite structure.
Referring to Fig. 2, the method includes providing the wood-metal composite sheet 12 described above. In the depicted embodiment, the sheet 12 is conveyed along direction D.
The method also includes supplying the sheet 12 between a compression roller 40 and a mold 42 having the shape of the structure 10 to be formed from the sheet 12.
In the depicted embodiment, the shape of the mold 42 is substantially obround so as to form the substantially obround shape of the shipping pallet 11 described above. The method also includes bending the sheet 12 with the compression roller 40 to wrap the sheet 12 around an outer surface 44 of the mold 42. The method may also include moving the mold 42 and/or the compression roller 40 to maintain the application of a suitable pressure on the sheet 12 being conveyed between the compressor roller 40 and the mold 42. In the depicted embodiment, the mold 42 is rotatable in direction R about a rotation axis 46.

[0031] Fig. 3A shows the sheet 12 wrapped around the outer surface 44 of the mold 42 to create the body 14. The sheet 12 includes a first sheet assembly 12i consisting of a metal layer 34 sandwiched between, and attached to, a first wood veneer layer 36i and a second wood veneer layer 36ii. The first sheet assembly 12i is fed between the compression roller 40 and the mold 42. The first sheet assembly 12i wraps around the outer surface 44 of the mold 42. Once the outer surface 44 has been substantially covered by the first wood veneer layer 36i, the first wood veneer layer 36i is cut. Alternatively, the first wood veneer layer 36i can be supplied in a predetermined length. The metal layer 34 continues to be wound about the outer surface of the second wood veneer layer 36ii. The second wood veneer layer 36ii continues to be wound about the outer surface of the metal layer 34. The sheet 12 can be wound in this fashion to form the body 14 having as many layers 34,36 as desired, and thus can spiral outwardly in a continuous fashion. Fig. 3B shows an example of a sheet 12 created in this manner. The body 14 is formed from a single metal layer 34, a first wood veneer layers 36i and a second wood veneer layer 36ii.

[0032]
Fig. 4 shows an embodiment of the sheet 112 wrapped around the outer surface 44 of the mold 42 to create the body 114. The sheet 112 includes a first sheet assembly 112i consisting of a first metal layer 34i sandwiched between, and attached to, two wood veneer layers 36. The first sheet assembly 112i is fed between the compression roller 40 and the mold 42. The first sheet assembly 112i wraps around the outer surface 44 of the mold 42 until a leading extremity 112A of the first sheet assembly 112i approaches the feed between the compression roller 40 and the mold 42. The first sheet assembly 112i is then cut to form a trailing extremity 112B, and a gap 113 is formed between the leading and trailing extremities 112A,112B of the first sheet assembly 112i. The sheet 112 also includes a second sheet assembly 112ii wrapped around the first sheet assembly 112i. More particularly, the second sheet assembly 112ii is wrapped around the outermost wood veneer layer 36 of the first sheet assembly 112i. In the depicted embodiment, the second sheet assembly 112ii consists of a second metal layer 34ii which engages the outermost wood veneer layer 36 of the first sheet assembly 112i, and another wood veneer layer 36 which forms the outermost wood veneer layer 36 of the sheet 112 when the second sheet assembly 112ii covers the first sheet assembly 112i. In the depicted embodiment, the second sheet assembly 112ii is pressed into the gap 113 at least partially by the compression roller 42 and/or the mold 42, and covers the gap 113.

[0033] Fig. 5 shows an embodiment of a portion of the sheet 212 forming the body 214.
The sheet 212 includes a first sheet assembly 212i consisting of a first metal layer 34i sandwiched between, and attached to, two wood veneer layers 36. The first sheet assembly 212i has a first gap 213A between its leading and trailing extremities 212A,212B. The sheet 212 also includes a second sheet assembly 212ii wrapped around the first sheet assembly 212i. More particularly, the second sheet assembly 212ii is wrapped around the outermost wood veneer layer 36 of the first sheet assembly 212i. In the depicted embodiment, the second sheet assembly 212ii consists of a second metal layer 34ii which engages the outermost wood veneer layer 36 of the first sheet assembly 212i, and another wood veneer layer 36. In the depicted embodiment, the second sheet assembly 212ii is pressed into the first gap 213A at least partially, and covers the first gap 213A. The second sheet assembly 212ii has a second gap 213B defined between its leading and trailing extremities 212A,212B. The sheet 212 also includes a third sheet assembly 212iii wrapped around the second sheet assembly 212ii. More particularly, the third sheet assembly 212iii is wrapped around the outermost wood veneer layer 36 of the second sheet assembly 212ii.
The third -sheet assembly 212iii consists of a third metal layer 34iii which engages the outermost wood veneer layer 36 of the second sheet assembly 212ii, and another wood veneer layer 36 which forms the outermost wood veneer layer 36 of the sheet 212 when the third sheet assembly 212iii covers the second sheet assembly 212ii. The third sheet assembly 212iii is 5 pressed into the second gap 213B at least partially, and covers the second gap 213B.

[0034] Fig. 6 shows an embodiment of a portion of the sheet 312 forming the body 314. In the depicted embodiment, the sheet 312 includes a single metal layer 34 that engages each of the wood veneer layers 36. The sheet 312 therefore includes a single sheet assembly 312i consisting of a single metal layer 34 and multiple wood veneer layers 36.
Beginning at a 10 first end 34D of the single metal layer 34, the single metal layer 34 is wrapped around and engaged with an innermost wood veneer layer 36i. A second wood veneer layer 36ii is supplied, and an inner surface thereof is applied against the single metal layer 34. The single metal layer 34 is also wrapped around an outer surface of the second wood veneer layer 36ii. A third wood veneer layer 36iii is supplied, and an inner surface thereof is applied against the single metal layer 34. The single metal layer 34 is also wrapped around an outer surface of the third wood veneer layer 36iii, and the single metal layer 34 terminates at a second end 34E thereof. Finally, an outermost wood veneer layer 36iv is supplied, and an inner surface thereof is applied against the single metal layer 34. The sheet 312 and the body 314 formed thereby in Fig. 6 is substantially free of joints. Stated differently, the body 314 has overlapping portions which are covered by segments or portions of the sheet 312.
The body 314 is therefore substantially seamless along its circumference or peripheral length, so as to form a relatively uninterrupted outer and inner surface. This relatively uninterrupted surface of the body 314 helps to reduce the number of points of stress concentrations or weakness. The body 314 in Fig. 6 is closed onto itself.
There is no opening through the sheet 312 which forms the body 314.

[0035] Referring to Figs. 3 to 6, the embodiments of the sheet 12,112,212,312 do not have a mechanical fastener to join the different sheet assemblies together.
Instead, the sheet assemblies are wrapped over one another, and the metal layers 34 of each sheet assembly mechanically attach one sheet assembly to an adjacent sheet assembly.

[0036] As can be understood, the examples described above and illustrated are intended to be exemplary only. The scope is indicated by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A shipping pallet, comprising: a wood-metal composite sheet shaped as a body, the body defining an inner cavity, the wood-metal composite sheet including at least one metal layer having metal protrusions extending away from both sides of the at least one metal layer, the wood-metal composite sheet including wood veneer layers disposed on both sides of the at least one metal layer, the metal protrusions extending into the wood veneer layers.

2. The shipping pallet as defined in claim 1, wherein the body is closed onto itself.

3. The shipping pallet as defined in claim 1, wherein the wood-metal composite sheet includes at least two metal layers and at least three wood veneer layers, each metal layer being disposed between two of the wood layers, at least some of the metal protrusions of immediately adjacent metal layers extending into the same wood veneer layer.

4. The shipping pallet as defined in claim 1, wherein the body includes two longitudinally opposed extremities, an opening being defined in at least one of the extremities.

5. The shipping pallet as defined in claim 1, wherein the shaped wood-metal composite sheet includes elongated bumper portions each extending along longitudinal side edges of the body.

6. The shipping pallet as defined in claim 5, wherein at least one of the bumper portions includes a filler member disposed within an inner volume defined by the bumper portion.

7. The shipping pallet as defined in claim 1, wherein the inner cavity of the body is defined between opposed inner surfaces of the body, at least one support member being disposed within the inner cavity and extending between the opposed inner surfaces.

8. The shipping pallet as defined in claim 7, wherein the at least one support member includes a cylindrical support post, the cylindrical support post being composed of an inner wood-metal composite sheet including wood veneer layers disposed on both sides of at least one metal layer, metal protrusions of the at least one metal layer extending into the wood veneer layers.

9. A wood-metal composite structure, comprising: a wood-metal composite sheet shaped as a body closed onto itself, the body defining an inner cavity, the wood-metal composite sheet including at least one metal layer having metal protrusions extending away from both sides of the at least one metal layer, the wood-metal composite sheet including wood veneer layers disposed on both sides of the at least one metal layer, the metal protrusions extending into the wood veneer layers.

10. The structure as defined in claim 9, wherein the wood-metal composite sheet includes at least two metal layers and at least three wood veneer layers, each metal layer being disposed between two of the wood layers, at least some of the metal protrusions of immediately adjacent metal layers extending into the same wood veneer layer.

11. The structure as defined in claim 9, wherein the inner cavity of the body is defined between opposed inner surfaces of the body, at least one support member being disposed within the inner cavity and extending between the opposed inner surfaces.

12. A method of forming a wood-metal composite structure, comprising:
providing a wood-metal composite sheet including wood veneer layers disposed on both sides of at least one metal layer, metal protrusions of the at least one metal layer extending into the wood veneer layers;
supplying the wood-metal composite sheet between a compression roller and a mold having a shape of the structure to be formed; and bending the wood-metal composite sheet with the compression roller to wrap the wood-metal composite sheet around an outer surface of the mold.