System comprising a wood layer and method of manufacturing

Abstract

According to an example aspect of the present invention, there is provided a system (1) comprising a wood layer (2) including a first surface (3) and an opposite second surface (4), an adhesive layer (6) arranged on at least a 5 part of the first surface (3) of the wood layer (2), a non- load bearing top layer (7) arranged on top of the adhesive layer (6), and a plurality of rigid particles (8), wherein at least some of the particles of the plurality of rigid particles (8) are partially embedded in the adhesive layer 10 (6) and partially embedded in the top layer (7).

Description

SYSTEM COMPRISING A WOOD LAYER AND METHOD OF MANUFACTURINGFIELD

[0001] The present invention relates to a system comprising a wood layer.

[0002] Further, the present invention relates to use of a system comprising a wood layer in connection with a floor structure of a building or a frame structure of a transportation system.

[0003] Additionally, the present invention relates to a method of manufacturing a system comprising a wood layer.BACKGROUND

[0004] Building structures such as floor structures are often made of reinforced concrete having a thickness in a range between 25 cm and 35 cm. Manufacturing of such reinforced concrete structures is CO2-intensive. Composite structures made of a wood layer and a concrete layer have been therefore developed to reduce the amount of concrete used. For example, such composite structures have a load bearing layer of reinforced concrete with a thickness of about 10 cm screwed to the wood layer, thus providing a more environmentally friendly solution. The reinforced concrete in such known composite structures comprises steel reinforcement bars, thus providing a load bearing layer.

[0005] Dimensions of such composite floor structures are typically limited by vibration requirements, thus resulting in a maximum admissible span for such structures.

[0006] In view of the foregoing, it would be beneficial to provide a system comprising a wood layer. The system should be particularly useful in connection with a floor structure of a building or a frame structure of a transportation system.SUMMARY OF THE INVENTION

[0007] The invention is defined by the features of the independent claims. Some specific embodiments are defined in the dependent claims.

[0008] According to a first aspect of the present invention, there is provided a system comprising a wood layer including a first surface and an opposite second surface, an adhesive layer arranged on at least a part of the first surface of the wood layer, a nonload bearing top layer arranged on top of the adhesive layer, and a plurality of rigid particles, wherein at least some of the particles of the plurality of rigid particles are partially embedded in the adhesive layer and partially embedded in the top layer.

[0009] Certain embodiments of the first aspect may include at least one feature from the following bulleted list:• the system comprises a beam structure attached to the second surface of the wood layer• the adhesive layer comprises or consists of epoxy, polyurethane, phenol resorcinol formaldehyde, phenol formaldehyde or acrylic material the top layer comprises or consists of concrete or gypsum• the top layer comprises or consists of at least one of a screed, concrete or gypsum• the top layer is made of a self-levelling pump screed, a self-levelling screed, a selflevelling concrete or a self-levelling gypsum• at least some of the particles of the plurality of rigid particles comprise or consist of crushed stone or stone chips or gravel, metal or metal alloy, crushed glass, recycled composite material, ceramic material, porcelain material, hardwood, adhesive waste material, phenolic resin, or phenolic adhesive• the rigid particles each comprise one or more sharp edges• a particle size of at least some of the particles of the plurality of particles is in a range between 1 mm and 16 mm, 2 mm and 10 mm, or 3 and 6 mm• a thickness of the adhesive layer is less than 3 mm, less than 2 mm or less than 1 mm at least 10 %, at least 20 %, at least 30 %, or at least 50 % of a volume of a particle of the plurality of rigid particles is embedded in the adhesive layer• at least 10 %, at least 20 %, at least 30 %, or at least 50 % of a surface area of a particle of the plurality of rigid particles is embedded in the adhesive layer• a thickness of the top layer is in a range between 20 mm and 100 mm• elements of the wood layer comprise or consist of laminated veneer lumber, glued laminated timber, oriented strand board, or plywood• elements of the beam structure comprise or consist of an engineered wood product or sawn timber

[0010] According to a second aspect of the present invention, there is provided a use of the system according to any one of claims 1 - 14 in connection with a floor structure of a building or a frame structure of a transportation system.

[0011] According to a third aspect of the present invention, there is provided a method comprising providing a wood layer including a first surface and an opposite second surface, attaching a beam structure to the first surface of the wood layer, applying an adhesive layer on at least a part of the first surface of the wood layer, distributing a plurality of rigid particles prior to complete hardening of the adhesive layer such that at least some particles of the plurality of rigid particles are partially embedded in the adhesive layer, and applying a non-load bearing top layer on top of the hardened adhesive layer such that a remaining part of the particles of the plurality of rigid particles partially embedded in the adhesive layer is further embedded in the top layer.

[0012] Certain embodiments of the first aspect may include at least one feature from the following bulleted list:• the method comprising attaching a beam structure to the second surface of the wood layer• the method comprising applying the adhesive layer by spraying or utilizing a roller or a brush the method comprising distributing the plurality of rigid particles such that an absorbtivity of the adhesive layer is saturated or substantially saturatedthe method comprising applying the top-layer by pumping a self-levelling screed onto the adhesive layer• the method comprising removing excess material utilizing pressurized air, a brush, suction, or movement of the wood layer prior to applying the top layer

[0013] Considerable advantages can be obtained by the present invention. A system comprising a wood layer, an adhesive layer, a non-load bearing top layer and a plurality of embedded rigid particles as well as a method of manufacturing such system are provided. Vibration performance can be improved due to the composite structure of the system. As a consequence, longer spans and / or thinner structures can be provided. For example, the span can be about 40 % longer or up to 37 % less laminated veneer lumber has to be used with the same span according to certain embodiments in comparison to a laminated veneer lumber structure having a floating screed thereon. Additionally, sound insulation can be improved according to certain embodiments.

[0014] According to certain embodiments, a self-levelling pump screed is used as the top layer for fast installation and short curing time.

[0015] A stiff, rigid and cost-efficient composite connection can be achieved using crushed stone such as granite chips as the rigid particles according to certain embodiments. However, also other materials, particularly recycling materials, can be used as the rigid particles according to other embodiments.

[0016] Additionally, the system may be manufactured manually at the installation site or at least parts of the manufacturing process may be performed off site. In other words, the system may be pre-manufactured in a manufacturing plant or a part of the system may be pre -manufactured in a manufacturing plant and a remaining part of the system may be finalized at an installation site. In particular, applying the adhesive layer and distributing the plurality of rigid particles in a manufacturing plant enables high quality control.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIGURE 1 illustrates a schematic view of a system in accordance with at least some embodiments of the present invention, and

[0018] FIGURE 2 illustrates a schematic view of another system in accordance with at least some embodiments of the present invention.EMBODIMENTS

[0019] In FIGURE 1 a schematic view of a system 1 in accordance with at least some embodiments of the present invention is illustrated. The system 1 comprises a planar wood layer 2 including a first surface 3 and an opposite second surface 4. The wood layer 2 may be, for example, made of laminated veneer lumber panels, glued laminated timber panels, oriented strand board panels, or plywood panels. The wood layer 2 may be made of a plurality of Kerto® LVL Q-panels, for instance. In other words, the wood layer 2 is typically made of a plurality of elements. A thickness of the wood layer 2 may be, for example, in a range between 27 mm and 75 mm.

[0020] The system 1 further comprises an adhesive layer 6 arranged on at least a part of the first surface 3 of the wood layer 2. The adhesive layer 6 may comprise or consist of epoxy, polyurethane, phenol resorcinol formaldehyde, phenol formaldehyde or acrylic material, for instance. A thickness of the adhesive layer 6 is typically less than 3 mm, less than 2 mm or less than 1 mm. The thickness of the adhesive layer 6 may, for example, depend on the selected adhesive layer material.

[0021] Even further, the system 1 comprises a non-load bearing top layer 7 arranged on top of the adhesive layer 6. The top layer 7 may, for example, comprise or consist of at least one of a screed, concrete or gypsum. Typically, the top layer 7 is made of a selflevelling pump screed, a self-levelling screed, a self-levelling concrete or a self-levelling gypsum. A thickness of the top layer 7 is typically in a range between 20 mm and 100 mm. The top layer 7 is not reinforced. This means that reinforcements such as steel reinforcing bars typically used for concrete or bolts, screws or similar reinforcements are not present in the top layer 7. In other words, the top layer 7 is typically a homogenous layer consisting of merely the selected top layer material. For example, the top layer 7 may be produced by applying 40 mm of Weber Plaano having a curing time of 2 h to 4 h.

[0022] Additionally, the system comprises a plurality of rigid particles 8. At least some of the particles of the plurality of rigid particles 8 are partially embedded in the adhesive layer 6 and partially embedded in the concrete layer 7. In other words, a first portion of at least some of the particles of the plurality of particles 8 is embedded in the adhesive layer 6 and a remaining second portion of the particles of the plurality of particles8 protruding from the adhesive layer 6 is embedded in the top layer 7. Consequently, a particle size of a particle of the plurality of rigid particles 8 is greater than a thickness of the adhesive layer 6. Typically, at least 10 %, at least 20 %, at least 30 %, or at least 50 % of a volume of a respective particle of the plurality of rigid particles 8 is embedded in the adhesive layer 6 and the remaining volume of the respective particle of the plurality of rigid particles 8 is embedded in the top layer 7. Alternatively, at least 10 %, at least 20 %, at least 30 %, or at least 50 % of a surface area of a respective particle of the plurality of rigid particles 8 is embedded in the adhesive layer 6 and the remaining surface area of the respective particle of the plurality of rigid particles 8 is embedded in the top layer 7. The particles of the plurality of rigid particles 8 typically each comprise one or more sharp edges. In other words, such particles typically comprise at least two surfaces arranged at an angle in the range between 5 degrees and 160 degrees. Consequently, such particles are non-round. Such particles may, for example, comprise or consist of crushed stone or stone chips or gravel, metal or metal alloy, crushed glass, recycled composite material, ceramic material, porcelain material, hardwood, adhesive waste material, phenolic resin, or phenolic adhesive.

[0023] The function of the plurality of particles 8 and the adhesive layer 6 lies in mechanically connecting the non-load bearing top layer 7 to the wood layer 2, thus resulting in a system 1 having reduced vibration characteristics in comparison to known systems having a floating screed. Instead or in addition, a maximum span between two fixation points arranged at a first end 9 and at a second end 10 of the system 1 can be increased due to the structure of the system 1.

[0024] In this document, alternatives are given for various parameters such as a material of the wood layer, a material of the plurality of the rigid particles, a material of the top layer, a thickness of the wood layer, a thickness of the adhesive layer, a thickness of the top layer, a volume of a particle of the plurality of rigid particles 8 embedded in the adhesive layer, and a surface area of a particle of the plurality of rigid particles 8 is embedded in the adhesive layer. According to this document, any possible combination of such parameters is disclosed herein. Specific examples are described below:

[0025] Example 1 : Wood layer 2 comprising panels made of laminated veneer lumber, adhesive layer made 6 of epoxy, thickness of adhesive layer 6 is less than 1 mm, particles of the plurality of rigid particles 8 consist of crushed stone or stone chips or gravel, at least 10 % of a volume of a particle of the plurality of rigid particles 8 isembedded in the adhesive layer, and top layer 7 made of a self-levelling pump screed without additional reinforcements.

[0026] Example 2: Wood layer 2 comprising panels made of laminated veneer lumber, adhesive layer made 6 of acrylic material, thickness of adhesive layer 6 is less than 2 mm, particles of the plurality of rigid particles 8 consist of crushed granite or other crushed stone or gravel, at least 20 % of a volume of a particle of the plurality of rigid particles 8 is embedded in the adhesive layer, and top layer 7 made of concrete without additional reinforcements.

[0027] Example 3: Wood layer 2 comprising panels made of laminated veneer lumber, adhesive layer made 6 of polyurethane, thickness of adhesive layer 6 is less than 3 mm, particles of the plurality of rigid particles 8 consist of ceramic material, at least 30 % or at least 50 % of a volume of a particle of the plurality of rigid particles 8 is embedded in the adhesive layer, and top layer 7 made of self-levelling gypsum without additional reinforcements.

[0028] Manufacturing of the system 1 takes place by providing a wood layer 2 including a first surface 3 and an opposite second surface 4 and applying an adhesive layer 6 on at least a part of the first surface 3 of the wood layer 2. The adhesive layer 6 may be, for example, applied by spraying or utilizing a roller or a brush. Subsequently, a plurality of rigid particles 8 is distributed prior to complete hardening of the adhesive layer 6 such that at least some particles of the plurality of rigid particles 8 are partially embedded in the adhesive layer 6. The plurality of rigid particles 8 may be distributed such that an absorbtivity of the adhesive layer 6 is saturated or substantially saturated, for instance. In such a case, excess material can be removed utilizing pressurized air, a brush, suction, or movement of the wood layer 2 prior to applying the top layer 7. After hardening of the adhesive layer 6, a non-load bearing top layer 7 is applied on top of the hardened adhesive layer 6 such that a remaining part of the particles of the plurality of rigid particles 8 partially embedded in the adhesive layer is further embedded in the top layer 7. The top- layer 7 may be, for example, applied by pumping a self-levelling screed onto the adhesive layer 6. The above manufacturing process is typically done manually. However, at least parts of the manufacturing process may be performed by a robot or a manufacturing line may be provided for manufacturing of the system 1. Further, the system 1 may be premanufactured in a manufacturing plant or a part of the system 1 may be pre-manufactured in a manufacturing plant and a remaining part of the system 1 may be finalized at aninstallation site. In particular, applying the adhesive layer and distributing the plurality of rigid particles in a manufacturing plant enables high quality control.

[0029] In FIGURE 2 a schematic view of another system 1 in accordance with at least some embodiments of the present invention is illustrated. The system 1 includes the features described and illustrated in connection with FIGURE 1.

[0030] Additionally, the system 1 further comprises a beam structure 5 attached to the second surface 4 of the wood layer 2. The beam structure 5 may, for example, comprise a plurality of beams such as T-shaped beams as shown in FIGURE 2. The beam structure 5 or elements thereof may be, for example, made of an engineered wood product or sawn timber. The engineered wood product may, for example, comprise laminated veneer lumber or glued laminated timber. The beam structure 5 or elements thereof may be made of a plurality of Kerto® LVL S-beams, for instance.

[0031] The function of the plurality of particles 8 and the adhesive layer 6 lies in mechanically connecting the non-load bearing top layer 7 to the wood layer 2, thus resulting in a system 1 having reduced vibration characteristics in comparison to known systems having a wood layer, a beam structure and a floating screed arranged on the wood layer. As a consequence, a maximum span dspan between two load bearing fixation points arranged at a first end 9 and at a second end 10 of the system 1 and / or a distance d between two adjacent beams can be increased due to the structure of the system 1. A height h of the beam structure 5 can be further decreased. In other words, less material, for example laminated veneer lumber, has to be used per m2of the wood layer 2. For example, the amount of laminated veneer lumber can be reduced from 54 kg / m2to 41 kg / m2in comparison to a system having a wood layer made of laminated veneer lumber, a beam structure made of laminated veneer lumber and a floating screed applied on the wood layer (calculated according to Finnish national annex to EC5).

[0032] The manufacturing process described above in connection with FIGURE 1 can additionally include a step of attaching a beam structure 5 to the second surface 4 of the wood layer 2. For example, a beam structure 5 may be provided in a building and the wood layer 2 is then placed on the beam structure 5 prior to applying the adhesive layer 6, distributing the plurality of rigid particles 8 and applying the top layer 7. Alternatively, a pre-manufactured unit comprising the wood layer 2, the hardened adhesive layer 6 and partially embedded rigid particles 8 may be placed on top of the beam structure 5 provided in a building. Applying the top layer 7 can then be manually performed at the installationsite in order to finalize the system 1.

[0033] It is to be understood that the embodiments of the invention disclosed are not limited to the particular structures, process steps, or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting.

[0034] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment.

[0035] As used herein, a plurality of items, structural elements, compositional elements, and / or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. In addition, various embodiments and example of the present invention may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as de facto equivalents of one another, but are to be considered as separate and autonomous representations of the present invention.

[0036] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the description, numerous specific details are provided, such as examples of lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.

[0037] While the forgoing examples are illustrative of the principles of the presentinvention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.

[0038] The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of "a" or "an", i.e. a singular form, throughout this document does not exclude a plurality.INDUSTRIAL APPLICABILITY

[0039] At least some embodiments of the present invention find industrial application in construction of buildings, particularly in construction of floors.REFERENCE SIGNS LIST1 system2 wood layer3 first surface 4 second surface5 beam structure6 adhesive layer7 top layer8 rigid particles 9 first end10 second end d distance between adjacent beams dspan span of system h height of beam structure

Claims

CLAIMS:

1. A system (1) comprising: o a wood layer (2) including a first surface (3) and an opposite second surface (4), o an adhesive layer (6) arranged on at least a part of the first surface (3) of the wood layer (2), o a non-load bearing top layer (7) arranged on top of the adhesive layer (6), and o a plurality of rigid particles (8), wherein at least some of the particles of the plurality of rigid particles (8) are partially embedded in the adhesive layer (6) and partially embedded in the top layer (7).

2. The system (1) according to claim 1, wherein the system (1) comprises a beam structure (5) attached to the second surface (4) of the wood layer (2).

3. The system (1) according to claim 1 or 2, wherein the adhesive layer (6) comprises or consists of epoxy, polyurethane, phenol resorcinol formaldehyde, phenol formaldehyde or acrylic material.

4. The system (1) according to any one of claims 1 - 3, wherein the top layer (7) comprises or consists of at least one of a screed, concrete or gypsum.

5. The system (1) according to any one of claims 1 - 4, wherein the top layer (7) is made of a self-levelling pump screed, a self-levelling screed, a self-levelling concrete or a selflevelling gypsum.

6. The system (1) according to any one of claims 1 - 5, wherein at least some of the particles of the plurality of rigid particles (8) comprise or consist of: o crushed stone, stone chips or gravel, o metal or metal alloy, o crushed glass, o recycled composite material, o ceramic material, o porcelain material, o hardwood,o adhesive waste material, o phenolic resin, or o phenolic adhesive.

7. The system (1) according to any one of claims 1 - 6, wherein the rigid particles (8) each comprise one or more sharp edges.

8. The system (1) according to any one of claims 1 - 7, wherein a particle size of at least some of the particles of the plurality of particles (8) is in a range between 1 mm and 16 mm, 2 mm and 10 mm, or 3 and 6 mm.

9. The system (1) according to any one of claims 1 - 8, wherein a thickness of the adhesive layer (6) is less than 3 mm, less than 2 mm or less than 1 mm.

10. The system (1) according to any one of claims 1 - 9, wherein at least 10 %, at least 20 %, at least 30 %, or at least 50 % of a volume of a particle of the plurality of rigid particles (8) is embedded in the adhesive layer.

11. The system (1) according to any one of claims 1 - 9, wherein at least 10 %, at least 20 %, at least 30 %, or at least 50 % of a surface area of a particle of the plurality of rigid particles (8) is embedded in the adhesive layer.

12. The system (1) according to any one of claims 1 - 11, wherein a thickness of the top layer (7) is in a range between 20 mm and 100 mm.

13. The system (1) according to any one of claims 1 - 12, wherein elements of the wood layer (2) comprise or consist of laminated veneer lumber, glued laminated timber, oriented strand board, or plywood.

14. The system (1) according to any one of claims 1 - 13, wherein elements of the beam structure (5) comprise or consist of an engineered wood product or sawn timber.

15. Use of the system (1) according to any one of claims 1 - 14 in connection with a floor structure of a building or a frame structure of a transportation system.

16. A method comprising: o providing a wood layer (2) including a first surface (3) and an opposite second surface (4),o applying an adhesive layer (6) on at least a part of the first surface (3) of the wood layer (2), o distributing a plurality of rigid particles (8) prior to complete hardening of the adhesive layer (6) such that at least some particles of the plurality of rigid particles (8) are partially embedded in the adhesive layer (6), and o applying a non-load bearing top layer (7) on top of the hardened adhesive layer (6) such that a remaining part of the particles of the plurality of rigid particles (8) partially embedded in the adhesive layer is further embedded in the top layer (7).

17. The method according to claim 16, the method comprising attaching a beam structure(5) to the second surface (4) of the wood layer (2).

18. The method according to claim 16 or 17, the method comprising applying the adhesive layer (6) by spraying or utilizing a roller or a brush.

19. The method according to any one of claims 16 - 18, the method comprising distributing the plurality of rigid particles (8) such that an absorbtivity of the adhesive layer(6) is saturated or substantially saturated.

20. The method according to any one of claims 16 - 19, the method comprising applying the top-layer (7) by pumping a self-levelling screed onto the adhesive layer (6).

21. The method according to any one of claims 16 - 20, the method comprising removing excess material utilizing pressurized air, a brush, suction, or movement of the wood layer (2) prior to applying the top layer (7).

Images