EP4297953A1

EP4297953A1 - Composite product

Info

Publication number: EP4297953A1
Application number: EP22759066.8A
Authority: EP
Inventors: Roger BERGSTRÖM; Fredrik KÄLLSTRÖM
Original assignee: Stora Enso Oyj
Current assignee: Woodcomposite Sweden AB
Priority date: 2021-02-26
Filing date: 2022-02-25
Publication date: 2024-01-03
Also published as: EP4297953A4; WO2022180589A1

Abstract

A composite product (1) is produced by interposing a cuttable edge seal (40) between a short end (11) of a first solid wood component (10) and a short end (21) of a second solid wood component (20), At least one side (42, 44) of the cuttable edge seal (40) has an indentation (41 43). A polymer-based material is applied onto at least one side (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20) and into the indentation (41, 43) to form a coating layer (60) on the at least one side (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20) and the at least one side (42, 44) of the cuttable edge seal (40) having the indentation (41, 43). The coating layer (60) covers the at least one side of the cuttable edge seal (40) having the indentation (41, 43). A portion (65) of the coating layer (60) covering the indentation (41, 43) has a larger thickness as compared to portions (62) of the coating layer (60) on the at least one side (12, 14, 16, 18, 22, 24, 26, 28) of the first and second solid wood component (10, 20). The composite product (1) can be cut along the cuttable edge seal (40) to obtain cut composite products (1B) having short ends (21, 23) protected by cut edge seals (40B, 50A) protecting the coating layer (60) from delaminating.

Description

COMPOSITE PRODUCT

TECHNICAL FIELD

The present embodiments generally relate to composite products, and in particular to such composite products comprising a solid wood component coated with a polymer-based layer and a method of producing such composite products.

BACKGROUND

Many wood species that are untreated are very susceptible to influences caused by the external environment Untreated wood that is exposed to moisture and/or soil for sustained periods of time will become weakened by attacks by microorganisms and/or insects. It is therefore important to treat the less durable wood in order to increase its resistance against moisture and attacks by microorganisms and/or insects. In addition, wood which is exposed to ultra violet (UV) radiation is susceptible to discoloration and deterioration.

There are a number of different treatments to increase the resistance of wood, including chemical treatment with, for instance, fungicides and heat treatment to thermally modify the wood and remove certain organic compounds found in the wood. Another way to protect solid wood products is by applying paint coatings to the surface of the wood. These paint coatings can be applied by hand or in a factory environment and are normally based on first applying a base (primer) coating and then one or two additional over coat layers to build a protective film on the surface of the wood. This kind of paint coating is, however, susceptible to changing climatic conditions and over time erodes, cracks or peels from the wood, leading to a need for periodic remedial maintenance.

Other known methods include applying a layer of polyvinyl chloride (PVC) polymer on or around a solid wood product as described in WO 2007/057029 or coating a solid wood product with a layer of a composite material comprising thermally modified cellulosic material and a polymer, such as polyethylene terephthalate (PET), polyamide (PA), poly(methyl methacrylate) (PMMA), polypropylene (PP) or high density polyethylene (HD-PE), as described in WO 2016/181258,

Such coatings of solid wood products may, however, be sensitive to delamination caused by, for instance, a shift in temperature together with non-matched thermal expansions of fhe coating and the wood and/or by moisture, Delamination of the coating not only deteriorates the appearance of the product but also exposes the wood to moisture and/or soil that may damage or weaken the wood over time. US 2010/0021677 discloses a method and apparatus enabling a length of wood, such as a post, to be encapsulated in a coating, such as plastic. The method involves placing end caps at the ends of the post and coating the resulting assembly. The method also provides for encapsulating a plurality of posts in a production line. US 2018/0001323 discloses a method for producing an at least two-layered board. The board has a carrier layer, which consists at least partly of wood or lignocellulose-containing particles or fibers, and at least one coating, which consists of a WPC material and which is arranged on at least one face of the carrier layer. The method has the following steps: providing a finished carrier board which forms the carrier layer; providing a WPC coating material, for example in the form of a granulate, on at least one of the two surfaces of the carrier board; and pressing the WPC coating material and the carrier board under the influence of heat and pressure.

There is, thus, a need for a composite product comprising solid wood and a polymer-based coating that reduces the risk of delamination of the coating,

SUMMARY It is a general objective to reduce delamination of coated solid wood products.

This and other objectives are met by embodiments of the present invention.

The present invention is defined in the independent claims. Further embodiments of the invention are defined in fhe dependent claims.

An aspect of the invention relates to a method of producing a composite product. The method comprises interposing a cuttable edge seal between a short end of a first solid wood component and a short end of a second solid wood component. At least one side of the cutable edge seal has an indentation. The method also comprises applying a polymer-based material onto at least one side of the first solid wood component and of the second solid wood component and the at least one side of the cutable edge seal having the indentation and into the indentation to form a coating layer on fhe at least one side of the first solid wood component and of the second solid wood component. The coating layer covers the at least one side of the cutable edge seal having the indentation. A portion of the coating layer covering the indentation has a larger thickness as compared to portions of the coating layer on the at least one side of the first solid wood component and of the second solid wood component. Another aspect of the invention relates to a composite product comprising a first solid wood component and a second solid wood component The composite product also comprises a cuttable edge seal interposed between a short end of the first solid wood component and a short end of the second solid wood component. At least one side of the cutabie edge seal has an indentation. The composite product further comprises a coating layer of a polymer-based material on at least one side of the first solid wood component and of the second solid wood component. The coating layer covers the at least one side of the cutabie edge seal having the indentation. The polymer-based material of the coating layer extends Into the indentation. A portion of the coating layer covering the indentation has a larger thickness as compared to portions of the coating layer on the at least one side of the first solid wood component and of the second solid wood component.

A further aspect of the invention relates to a composite product comprising a solid wood component, a first cut edge seal attached to a first short end of the solid wood component and a second cut edge seal atached to a second short end of the solid wood component. At least one edge of the first cut edge seal is a beveled or chamfered edge and at least one edge of fhe second cut edge seal is a beveled or chamfered edge. The composite product also comprises a coating layer of a polymer-based material on at least one side of the solid wood component. The coating layer covers at least one side of the first cut edge seal and of the second cut edge seal. The polymer-based material of the coating layer extends to cover the beveled or chamfered edges. Portions of the coating layer covering the beveled or chamfered edges have a larger thickness as compared to a portion of the coating layer on the at least one side of the solid wood component.

The present invention solves delamination problems in composite products, or at least reduces the risk of delamination, by applying an edge seal to the solid wood components of composite products. The edge seal is designed to be at least partly mechanically attached to the solid wood components by the polymer-material of the coating layer penetration into at least one Indentation in the edge seal to lock the edge seal in place. Hence, the resulting composite product will be protected from the environment and have a reduced risk of deiamination of the protective polymer-based coating layer. BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments, together with further objects and advantages thereof, may best be understood by making reference to the following description taken together with the accompanying drawings, in which: Fig. 1 A is a cross-sectional view of a composite product according to an embodiment;

Fig. 1B is a cross-sectional view of the composite product taken along the line A-A in Fig. 1A;

Fig. 1C is a cross-sectional view of the composite product taken along the lines B-B and C-C in Fig. 1A;

Fig. 2 schematically illustrates composite products obtained by cuting the composite product in Fig. 1A along the line A-A;

Fig. 3 is a cross-sectional view of a composite product according to another embodiment;

Fig. 4 is a cross-sectional view of a composite product according to a further embodiment;

Fig. 5 schematically illustrates a composite product obtained by cuting the composite product in Fig. 4; Fig. 6 is a cross-sectional view of a composite product according to an embodiment;

Fig. 7 is a flow chart illustrating a method of producing a composite product according to an embodiment; Fig. 8 is a flow chart illustrating an additional, optional step of the method shorn in Fig. 7 according to an embodiment;

Fig. 9 is a flow chart illustrating an additional, optional step of the method shown in Fig. 7 according to a further embodiment;

Fig. 10 is a flow chart illustrating an additional, optional step of the method shown In Fig. 7 according to yet another embodiment; and Fig. 11 is a flow chart illustrating an additional, optional step of the method shorn in Fig. 7 according to an embodiment

DETAILED DESCRIPTION The present embodiments generally relate to composite products, and in particular to such composite products comprising a solid wood component coated with a polymer-based layer and a method of producing such composite products.

Many wood products are protected by a polymer-based coating layer, such as a thermoplastic or composite coating, to protect the wood core from the external environment, including attacks by microorganisms and/or insects, and UV radiation. However, such composite products are sensitive to delamination or creep, in particular at the unprotected edges or short ends of the composite products. Delamination causes the protective polymer-based coating layer to separate from the wood core, in particular at the edges. As a consequence of such a delamination, the wood core is exposed to the environment and may thereby be susceptible to atacks and environmental conditions that negatively affect the wood quality.

Delamination of the protective polymer-based coating layer may be due to various reasons, including a shift in ambient temperature causing thermal expansion of the coating layer relative to the wood core, and/or moisture, such as due to precipitation, exposure to cleaning agents, or humidity, entering between the coating layer and the wood core causing a swell of the wood core.

The present invention solves delamination problems in composite products, or at least reduces the risk of delamination, by applying an edge seal to a solid wood component or core of the composite products. This edge seal can be added to the solid wood component prior to or as a part of the process of applying the protective polymer-based coating layer onto the wood component Hence, the resulting solid wood product will be protected from the environment and have a reduced risk of delamination of the protective polymer-based coating layer. An aspect of the invention relates to a method of producing a composite product 1, see Figs. 1A, 1B and 7. The method comprises interposing, in step S1, a cuttable edge seal 40 between a short end 11 of a first solid wood component 10 and a short end 21 of a second solid wood component 20. As is shown in Fig. 1A, at least one side 42, 44 of the cutable edge seal 40 has an indentation 41, 43. The method also comprises applying, in step S2, a polymer-based material onto at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10 and of the second solid wood component 20 and the at least one side 42, 44 of the cuttable edge seal 40 having the indentation 41 , 43 and into the indentation 41, 43 to form a coating layer 60 on the at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10 and of the second solid wood component 20. This coating layer 60 covers the at least one side 42, 44 of the cuttable edge seal 40 having the indentation 41 , 43, According to the invention, a portion 65 of the coating layer 60 covering the indentation 41, 43 has a larger thickness as compared to portions 62 of the coating layer 60 on the at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10 and of the second solid wood component 20. According to the present invention, a cuttable edge seal 40 is interposed between two adjacent solid wood components 10, 20 before applying a polymer-based material onto the solid wood components 10, 20 to form the coating layer 60. This cuttable edge seal 40 is arranged between the opposite short ends 11, 21 of the two solid wood components 10, 20, i.e,, between short ends 11, 21 facing each other when the two solid wood components 10, 20 are arranged or aligned one after the other as shown in Fig. 1 A. The polymer-based material is then applied in step S2 onto at least one respective side 12, 14, 16, 18, 22, 24, 26, 28 of the solid wood components 10, 20 and will thereby also be applied on at least one side 42, 44 of the cutable edge seal 40 having the indentation 41, 43 and into the indentation(s) 41 , 43. Hence, the resulting coating layer 60 made of the polymer-based material covers the at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the solid wood components 10, 20 and the at least one side 42, 44 of the cuttable edge seal 40.

The cuttable edge seal 40 preferably has a size at least substantially corresponding to a size of the short ends 11, 21 of the solid wood components 10, 20. Hence, dimensions of the cuttable edge seal 40, such as length (L) and height (H2), see Fig. 1 B, preferably correspond to the corresponding dimensions, such as length and height, of the short ends 11, 21 of the solid wood component 10, 20, see Fig. 1C. In more detail, the end sides of the cutable edge seal 40 facing the short ends 11 , 21 of the solid wood components 10, 20 preferably have dimensions, such as length (L) and height (H2) corresponding to the dimensions, such as length and height, of the short ends 11, 21 of the solid wood component 10, 20. A section of the cutable edge seal 40, typically the middle section of the cutable edge seal 40, has different dimensions, such as height (H1), due to the indentation(s) 41, 43. This section may then have a different, i.e., smaller, height (H1) as compared to the height (H2) of the end sides of the cuttable edge seal 40 but a same length (L) as indicated in Fig. 1 B. in an alternative embodiment, indentations 41, 43 could be present in ail sides 42, 44, 46, 48 of the cutable edge seal 40. In such an embodiment, the section has both smaller height (H1) and length as compared to the end sides of the eutabie edge seal 40. Correspondingly, the shape of the cutable edge seal 40, in particular the shape of the end sides of the cutable edge seal 40 as seen in hatching in Fig. 1B, preferably corresponds to the shape of the short ends 11, 21 of the solid wood components 10, 20. In other words, the cuttable edge seal 40 is preferably dimensioned and designed to cover the short ends 11 , 21 of the solid wood components 10, 20.

The thickness (T) of the cuttable edge seal 40, see Fig, 1A, is preferably selected to be sufficient thick so that the cuttable edge seal 40 can be cut into a first edge seal 40A and a second edge seal 40B, which is further described below and shown in Fig. 2, For instance, the cuttable edge seal 40 may have a thickness, in an illustrative, but non-limiting, embodiment of from about 2.5 mm, such as from about 5 mm. In illustrative examples, the cuttable edge seal 40 may have a thickness of from about 5 mm to about 50 mm, such as from about 5 mm to about 30 mm. it is also possible to have thicker cuttable edge seals 40. In an embodiment, step S2 in Fig. 7 comprises extruding the polymer-based material onto at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10 and of the second solid wood component 20 to form the coating layer 60 on the at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10 and of the second solid wood component 20. Hence, in this embodiment, the coating layer 60 is obtained by extruding the polymer-based material onto the solid wood components 10, 20 and onto the cuttable edge seal 40 disposed there between.

For instance, the polymer-based material may be fed to an extruder. The first and second solid wood components 10, 20 with the cuttable edge seal 40 disposed between their short ends 11, 21 are conveyed through the extruder while applying a layer of the polymer-based material to form the coating layer 60 on the at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10 and of the second solid wood component 20 and on the at least one side 42, 44, 46, 48 of the cutable edge seal 40 while they are being conveyed through the extruder.

The embodiments are, however, not limited to forming the coating layer 60 by extruding the polymer- based material. The coating layer 60 may, alternatively, be formed in any other conventional known machine configured to apply a layer of a polymer-based material onto solid wood components 10, 20.

The method comprises, in an embodiment and as shown in Fig. 7, an additional, optional but preferred step S3. This step S3 comprises cuting the composite product 1 through the eutabie edge seal 40 to form a first composite product 1 A and a second composite product 1B, see Fig. 2. In such an embodiment the first composite product 1A comprises the first solid wood component 10 comprising the coating layer 60 on at least one side 12, 14, 16, 18 and comprising a first edge seal 40A attached to the short end 11 of the first solid wood component 10. This first edge seal 40A corresponds to a first portion of the cuttable edge seal 40 shown in Fig. 1A. The second composite product 1B, correspondingly, comprises the second solid wood component 20 comprising the coating layer 60 on at least one side 22, 24, 26, 28 and comprising a second edge seal 40B attached to the short end 21 of the second solid wood component 20. The second edge seal 40B corresponds to a second portion of the cuttable edge seal 40.

In this embodiment, the composite product 1 as shown in Fig. 1A is cut through the cuttable edge seal 40 disposed between the short ends 11, 21 of the two solid wood components 10, 20 to form two composite products 1A, 1B each comprising a solid wood component 10, 20 coated on at least one side 12, 14, 18, 18, 22, 24, 26, 28 with the coating layer 60 and having an edge seal 40A, 40B attached to its short end 11 , 21. The respective edge seal 40A, 40B of the composite products 1 A, 1 B is formed by cutting the cuttable edge seal 40, such as along the line A-A as shown in Fig. 1A, to form two respective portions of the cuttable edge seal 40, each atached to a respective composite product 1A, 1 B. The so formed edge seals 40A, 40B form a protective end cap or lid on the short ends 11 , 21 of the solid wood components 10, 20. The edge seals 40A, 40B prevent or at least significantly block moisture from penetrating in between the coating layer 60 and the solid wood components 10, 20. The edge seals 40A, 40B in additional restrict any thermal expansion of the coating layer 60 and thereby also reduce the risk of delamination of the coating layer 60 due to temperature shifts.

The cuttable edge seal 40 can be cut in step S3 using any conventional cutting tool or equipment, such as a saw, a knife, or any other cutting tool.

The cutting in step S3 is typically done perpendicular to main surfaces of the sides 12, 14, 22, 24 of the solid wood components 10, 20, such as along the line A-A as shown in Fig. 1A. It is, however, possible to cut the cuttable edge seal 40 in a non-perpendicular angle, such as by miter sawing.

The polymer-based material is preferably applied to multiple, i.e., at least two, sides 12, 14, 16, 18, 22, 24, 26, 28 of the first and second solid wood components 10, 20 in step S2. In a particular embodiment, step S2 comprises applying the polymer-based material onto ail sides 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10 and of the second solid wood component 20 to form the coating layer 60 on all sides 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10 and of the second solid wood component 20 as shown in Fig. 1C illustrating a cross-sectional view of the composite product 1 as taken along the lines B-B and C-C in Fig. 1A. These sides 12, 14, 16, 18, 22, 24, 26, 28 of the solid wood components 10, 20 are preferably longitudinal sides of the solid wood components 10, 20 as indicated in the figures.

Fig. 1C is a cross-sectional view of Fig. 1A taken along the lines B-B and C-C. in this illustrated embodiment, the polymer-based material is applied in step S2 onto all four longitudinal sides 12, 14, 16, 18, 22, 24, 26, 28 of the solid wood components 10, 20, As a consequence, polymer-based material will also be applied onto ail four sides 42, 44, 46, 48 of the cutabie edge seal 40 as shown in Fig. 1 B, which is a cross-sectional view of Fig. 1A taken along the line A-A. Hence, all four sides 42, 44, 46, 48 of the cuttabie edge seal 40 will be coated with the coating layer 60.

In the embodiments above and as shown in Figs. 1B and 1C, the cross-sectional shape of the solid wood components 10, 20 is rectangular or quadratic and the solid wood components 10, 20 thereby have four longitudinal sides 12, 14, 16, 18, 22, 24, 26, 28. The embodiments are, however, not limited thereto. The solid wood components 10, 20 may have other cross-sectional shapes with more than or fewer than four (longitudinal) sides 12, 14, 16, 18, 22, 24, 26, 28. In these other embodiments, the polymer-based material could be applied to ail or a portion of the sides of the solid wood components 10, 20.

The solid wood components 10, 20 generally have an elongated and oblong form with two short ends 11, 21 at either end of the solid wood components 10, 20. A side 12, 14, 16, 18, 22, 24, 26, 28 of a solid wood component 10, 20 as used herein is a side 12, 14, 16, 18, 22, 24, 26, 28 of the solid wood component 10, 20 extending between its two short ends 11, 21. The number of such sides 12, 14, 16,

18, 22, 24, 26, 28 of the solid wood component 10, 20 depends on the cross-sectional configuration of the solid wood component 10, 20. For instance, a solid wood component 10, 20 having a quadratic or rectangular cross-section generally has four longitudinal sides 12, 14, 16, 18, 22, 24, 26, 28, a solid wood component 10, 20 having a triangular cross-section typically has three longitudinal sides, and a solid wood component 10, 20 having a circular cross-section has one longitudinal side corresponding to the lateral surface of the solid wood component 10, 20,

In this embodiment, the first composite product 1A formed by cutting the composite product 1 through the cuttabie edge seal 40 in step S3 comprises the first solid wood component 10 comprising the coating layer 60 on all four (longitudinal) sides 12, 14, 16, 18 and comprising the first edge seal 40A attached to the short end 11 of the first solid wood component 10. The first edge seal 40A corresponds to a first portion of the cuttable edge seal 40. Correspondingly, the second composite product 1B formed in step S3 comprises the second solid wood component 20 comprising the coating layer 60 on ail four (longitudinal) sides 22, 24, 26, 28 and comprising the second edge seal 40B attached to the short end 21 of the second solid wood component 20. The second edge seal 40B corresponds to a second portion of the cuttab!e edge seal 40.

In this embodiment, the coating layer 60 as applied to all four (longitudinal) sides 12, 14, 16, 18, 22, 24, 26, 28 of the solid wood components 10, 20 and the first and second edge seal 40A, 40B form a protective enclosure around the solid wood components 10, 20 thereby protecting and sealing the solid wood components 10, 20 from the environment.

In an embodiment, the cuttable edge seal 40 is a first cuttable edge seal 40, see Fig. 4. In such an embodiment step S1 of Fig. 7 comprises interposing the first cutable edge seal 40 between the short end 11 of the first solid wood component 10 and a first short end 21 of the second solid wood component 20 and interposing a second cuttable edge seal 50 between a second short end 23 of the second solid wood component 20 and a short end 31 of a third solid wood component 30. At least one side 52, 54 of the second cuttable edge seal 50 has an indentation 51, 53. Step S2 comprises, in this embodiment, applying the polymer-based material onto at least one side 12, 14, 16, 18, 22, 24, 26, 28, 32, 34 of the first solid wood component 10, of the second solid wood component 20 and of the third solid wood component 30 and the at least one side 42, 44 of the first cutable edge seal 40 having the indentation 41, 43, the at least one side 52, 54 of the second cuttable edge seal 50 having the indentation 51, 53 and into the indentations 41, 43, 51, 53 of the first and second cutable edge seals 40, 50 to form the coating layer 60 on the at least one side 12, 14, 16, 18, 22, 24, 26, 28, 32, 34 of fhe first solid wood component 10, of the second solid wood component 20 and of the third solid wood component 30. The coating layer 60 covers the at least one side 42, 44, 46, 48, 52, 54 of the first cuttable edge seal 40 and of the second cuttable edge seal 50. In this embodiment, portions 65 of the coating layer 60 covering the indentations 41, 43, 51, 53 have a larger thickness as compared to portions 62 of the coating layer 60 on the at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10, of the second solid wood component 20 and of fhe fhird solid wood component 30. Hence, in this embodiment, at least one of the solid wood components 10, 20, 30 of the composite product 1 comprises a respective cuttable edge seal 40, 50 at each of its two opposite short ends 21, 23, This process of having alternating solid wood components 10, 20, 30 and cutable edge seals 40, 50 may be extended further with a third cuttable edge seal (not shown) interposed between the third solid wood component 30 and a fourth solid wood component (not shorn) and so on. Hence, in a preferred embodiment, each solid wood component 10, 20, 30 of the composite product 1 preferably comprises a cuttable edge seal 40 in connection with one of its short ends 21 and then another cuttable edge seal 50 in connection with its other, opposite short end 23.

The first solid wood component 10 in the composite product 1 may lack a preceding cuttable edge seal, i.e,, having a non-sealed short end, or may be preceded by a cuttable edge seal or an edge seal as obtained by cuting a cutable edge seal in step S3 in Fig. 7. In the later cases, both short ends 11 of the first solid wood component 10 may be sealed by a cutable edge seal and the first edge seal 40A, or by two edge seals 40A.

Step S3 of Fig. 7 comprises, when applied to a composite product 1 as shown in Fig. 4, cutting the composite product 1 through the first cuttable edge seal 40 and the second cuttable edge seal 50 to form a cut composite product 1B, see Fig. 5, comprising the second solid wood component 20 comprising the coating layer 60 on at least one side 22, 24, 26, 28 and comprising a first edge seal 40B atached to the first short end 21 of the second solid wood component 20 and a second edge seal 50A atached to the second short end 23 of the second solid wood component 20. The first edge seal 40B corresponds to a portion of the first cuttable edge seal 40 and the second edge seal 50A corresponds a portion of the second cuttable edge seal 50.

The cut composite product 1B as shown in Fig, 5 comprises two edge caps or lids 40B, 50A, each atached to a respective short end 21, 23 of the second solid wood component 20. The cutable edge seals 40, 50 are at least partly attached to the solid wood components 10, 20 by having an indentation 41, 43, 51, 53 in at least one side 42, 44, 52, 54 of the cutable edge seals 40, 50. The indentation 41, 43, 51, 53 is designed to allow the polymer-based material to flow into and fill up the indentation 41, 43, 51, 53. The polymer-based material will thereby lock the cutable edge seals 40, 50 to the solid wood components 10, 20, 30 by “gripping” into the indentation 41, 43, 51, 53 and thereby preventing the cutabie edge seals 40, 50 from unintentionally slipping away from the short ends 11, 21, 23, 31 of the solid wood components 10, 20, 30. As is shown in Figs. 1 and 4, a cuttabie edge seal 40, 50 preferably has respective indentations 41, 43, 51, 53 on opposite sides 42, 44, 52, 54 of the cuttabie edge seal 40, 50. Hence, in an embodiment, opposite sides 42, 44, 52, 54 of the cuttabie edge seal 40, 50 have a respective indentation 41, 43, 51, 53. This means that the cutabie edge seal 40, 50 has a first side 42, 52 with a first indentation 41, 51 and a second, opposite side 44, 54 with a second indentation 43, 53, It is possible to have indentations 41, 43, 51, 53 on more than two sides 42, 44, 52, 54 if the cuttabie edge seal 40, 50 has more than two sides 42, 44, 52, 54. For instance, indentations 41, 43, 51, 53 could be present on three or four sides 42, 44, 46, 48, 52, 54 of the cutabie edge seal 40, 50, such as on all sides 42, 44, 46, 48, 52, 54 of the cutabie edge seal 40, 50.

The polymer-based material is applied into the indentation 41, 43, 51, 53 of the cuttabie edge seal 40, 50 and thereby mechanically locks the cuttabie edge seal 40, 50 in place between the short ends 11, 21, 23, 31 of the solid wood components 10, 20, 30. Hence, a portion of the coating layer 60 extends or protrudes into the at least one indentation 41 , 43, 51 , 53 of the cuttabie edge seal 40 as shown in Figs. 1 and 4. In a preferred embodiment, the cutabie edge seal 40, 50 comprises at least two such indentations 41, 43, 51, 53 in opposite sides 42, 44, 52, 54 of the cutabie edge seal 40, 50 to interlock the cutabie edge seal 40, 50 between the coating layer 60 as applied to opposite (longitudinal) sides 12, 14, 16, 18, 22, 24, 26, 28, 32, 34 of the solid wood components 10, 20, 30,

The at least one indentation 41, 43 can have various shapes and forms including, but not limited to, wedge-shaped indentation(s), concave indentation(s), slot(s), slit(s), quadratic or rectangular indentation(s), etc. In an embodiment, the thickness T1 of a portion 5 of the composite product 1 comprising the cutabie edge seal 40 is substantially the same as a thickness T2 of a portion 2 of the composite product 1 comprising the first solid wood component 10. This means that in a preferred embodiment the thickness of the composite product 1 is substantially the same over the first solid wood component 1, such as along the line B-B in Fig. 1A, as over the cutabie edge seal 40, such as along the line A-A in Fig. 1A. in a particular embodiment, the thickness of a portion 3 of the composite product 1 comprising the second solid wood component 10, such as along the line C-C in Fig. 1A, is also substantially the same as the thickness along the lines A-A and B-B. This means that in a preferred embodiment, the composite product 1 preferably has substantially the same thickness throughout its length, i.e., both at the first and second solid wood components 10, 20 and at the cuttable edge seal 40. However, as is clearly seen in Fig. 1A, the thickness of the coating layer 60 is not the same or uniform along the length of the composite produce 1. in clear contrast the thickness of the portion 65 of the coating layer 80 covering the indentation(s) 41, 43 of the cuttabie edge seal 40 is thicker, due to the indentation(s) 41, 43, as compared to the thickness of the portions 62 of the coating layer 60 on the solid wood components 10, 20.

The cutabie edge seal 40 and also the edge seals 40A, 40B formed by cutting the cutabie edge seal 40 in step S3 in Fig. 7 can be further attached to the coating layer 60 and/or the short end 11 , 21 of the solid wood component 10, 20 in various embodiments. These further embodiments are described with reference to the cuttabie edge seal 40 interposed between the first and second soiid wood components 10, 20 but also apply to the cuttabie edge seal 50 interposed between the second and third solid wood components 20, 30.

In an embodiment, step S1 in Fig. 7 comprises applying the polymer-based material onto at least one side 12, 14, 16, 18, 22, 24, 28, 28 of the first solid wood component 10 and of the second solid wood component 20 to form the coating layer 60 on the at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the first soiid wood component 10 and of the second solid wood component 20 while melting the coating layer 60 together with the at least one side 42, 44, 46, 48 of the cutabie edge seal 40 covered by the coating layer 80.

Hence, in this particular embodiment, the cutabie edge seal 40 is melted or fused together with the coating layer 60. For instance, the polymer-based material may be applied onto the at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the soiid wood components 10, 20 by extrusion as previously described herein. In such a case, this extrusion can be performed at an elevated temperature. Hence, the polymer-based material applied to the solid wood components 10, 20 and to the cutabie edge seal 40 and into the indentation(s) 41, 43 in step S2 is preferably heated to a temperature causing at least partly melting of the at least one side 42, 44, 46, 48 of the cutabie edge seal 40 and/or of the polymer- based material to allow the formed coating layer 60 to be melted or fused together with the at least one side 42, 44, 46, 48 of the cutabie edge seal 40, For instance, and depending on the particular material of the cutabie edge seal 40 and of the polymer-based material, the temperature of the polymer-based material being applied to the solid wood components 10, 20 and the cutabie edge seal 40 in the extruder is preferably equal to or above 150°C, preferably equal to or above 180°C, such as equal to or above 200°C, or even higher.

Fig. 6 is a cross-sectional view of a composite product 1 showing another embodiment of attaching the cuttable edge seal 40 to the solid wood components 10, 20 and/or the coating layer 60. In this embodiment the cutable edge seal 40 comprises protrusions 45 extending into the short end 11 of the first solid wood component 10 and the short end 21 of the second solid wood component 20.

The protrusions 45 thereby extend from opposite sides of the cuttable edge seal 40 and from the sides facing the respective short ends 11 , 21 of the solid wood components 10, 20. The protrusions 45 are designed to extend into the solid wood components 10, 20 to thereby attach or anchor the cuttable edge seal 40 to the solid wood components 10, 20.

The protrusions 45 can be any protrusion or protruding or extending element that can pierce into the short ends 11, 21 of the solid wood components 10, 20. Non-limiting, but illustrative, examples of such protrusions 45 include studs, spikes, pins, plugs, thorns, etc.

Fig. 8 is a flow chart illustrating an embodiment of an additional step to atach the cutable edge seal 40 to the solid wood components 10, 20 and/or the coating layer 60 according to an embodiment The method continues from step S2 in Fig. 7. A next step S10 comprises heat treating a portion of the coating layer 60 aligned with the cuttable edge seal 40, i.e,, covering the at least one side 42, 44 of the cuttable edge seal 40 having the indentation 41, 43, to fuse the portion of the coating layer 60 and the least one side 42, 44 of the cuttable edge seal 40 covered by the coating layer 60. The method then ends or continues to step S3 in Fig. 7.

In this embodiment the cuttable edge seal 40 is fused to the coating layer 60 by beat treating at least a portion of the coating layer 60 aligned with and covering the at least one side 42, 44 of the cutable edge seal 40 having the indentation 41, 43. The heat treatment preferably causes at least partly melting of the polymer-based material in this portion 65 of the coating layer 60 and of the material of the cutable edge seal 40 adjacent to this portion 65 of the coating layer 60.

Fig. 9 is a flow chart illustrating an embodiment of an additional step to atach the cutable edge sea! 40 to the solid wood components 10, 20 and/or the coating layer 60 according to another embodiment. The method continues from step S1 in Fig. 7. A next step S20 comprises ataching the cutable edge seal 40 to the short end 11 of the first solid wood component 10 and the short end 21 of the second solid wood component 20 with an adhesive. The method then continues to step S2 in Fig, 7. In this embodiment, an adhesive is used to at least partly attach the cuttable edge seal 40 to the short ends 11 , 21 of the solid wood components 10, 20. The adhesive may then be applied to the short ends 11, 21 of the solid wood components 10, 20, to the opposite sides of the cuttable edge seal 40 facing the respective short ends 11 , 21 of the solid wood components 10, 20 or applied to both the short ends 11, 21 of the solid wood components 10, 20 and to the opposite sides of the cuttable edge seal 40.

The adhesive may be any adhesive or glue that is selected at least partly based on the material of the cuttable edge seal 40 to thereby be able to attach the cuttable edge seal 40 to the wood surface of the short ends 11, 21 of the solid wood components 10, 20. An alternative to applying adhesive or glue directly onto the short ends 11, 21 and/or the cutable edge seal 40 is to use a double-sided tape coated with adhesive on both sides.

In a further embodiment, step S1 of Fig. 7 comprises interposing the cutable edge seal 40 between the short end 11 of the first solid wood component 10 and the short end 21 of the second solid wood component 20 while applying a force onto at least the second solid wood component 20 to maintain the cuttable edge seal 40 pressed between the first solid wood component 10 and the second solid wood component 20.

In this further embodiment, the cutable edge seal 40 is maintained between the solid wood components 10, 20 by pressure, i.e., by pressing the second solid wood component 20 towards the first solid wood component 10 or by pressing both solid wood components 10, 20 towards each other. For instance, as previously mentioned herein, the polymer-based material may be applied onto the solid wood components 10, 20 in an extruder, in such an embodiment, a force can be applied onto the second solid wood component 20 while feeding the first solid wood component 10, the cutable edge seal 40 and the second solid wood component 20 into and through the extruder. The design of the extruder and the extrusion of the polymer-based material onto the solid wood components 10, 20 provide a counter force on the first solid wood component 10 to maintain the cutable edge seal 40 disposed between the two solid wood components 10, 20. The various embodiments of ataching the cutable edge seals 40, 50 to the solid wood components 10, 20, 30 and/or the coating layer 60 described above may be combined.

In an embodiment, step S2 in Fig. 7 comprises applying a composite material comprising ceilulosic material and at least one polymer onto at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10 and of the second solid wood component 20 to form the coating layer 60 on the at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10 and of the second solid wood component 20. Hence, in this embodiment, the polymer-based material applied in step S2 onto the solid wood components 10, 20 is a composite material comprising ceilulosic material and at least one polymer, such as at least one thermoplastic polymer. The composite material will be further described below.

In an embodiment, the cuttable edge seal 40 is made of a polymer material, i.e., a material comprising or consisting of a polymer, such as a thermoplastic polymer. In a particular embodiment, the polymer- based material applied in step S2 comprises this polymer, such as in the form of a composite material comprising the polymer. Hence, in a particular embodiment, the polymer-based material, and thereby the coating layer 60, and the cuttabie edge seal 40 both comprise or are made of a polymer, such as a thermoplastic polymer, and preferably a same type of polymer. This embodiment is in particular suitable for attaching the cutabie edge seal 40 to the coating layer 60 by melting or fusing the cuttabie edge seal 40 to the coating layer 60. For instance, the cutabie edge seal 40 may comprise or be made of a thermoplastic polymer or a composite material comprising ceilulosic material and a polymer, such as a thermoplastic polymer. Also, the coating 60 may comprise or be made of, for instance, a thermoplastic polymer or a composite material comprising ceilulosic material and a polymer, such as a thermoplastic polymer.

In an embodiment step S1 in Fig. 7 comprises interposing the cutabie edge seal 40 between the short end 11 of a first thermally modified solid wood component 10 and the short end 21 of a second thermally modified solid wood component 20.

In this embodiment, the method may therefore optionally comprise an additional step S30 as shown in Fig. 10. This step S30 comprises thermally modifying the first solid wood component 10 and the second solid wood component 20 by heat treatment at a temperature between 160°C and 250°C, preferably between 170°C and 230°C, at atmospheric pressure. Alternatively, the heat treatment applied in step S30 could be performed at a lower temperature, such as at a temperature above 100°C, preferably above 120°C, at an elevated pressure that is higher than atmospheric pressure, l.e., above 1 bar, preferably between 1.5 and 13 bar. The method then continues to step S1 in Fig. 7. In an embodiment, thermally modified wood as used herein, such as the thermally modified solid wood component 10, 20 and/or thermally modified cellulosic material, is wood or cellulosic material at which the composition of the cell wail material and its physical properties are modified by the exposure to a temperature higher than 160 °C and conditions of reduced oxygen availability. The wood or cellulosic material is altered in such way that at least some of the properties are permanently affected through the cross section of the solid wood component or cellulosic material. In particular, the thermally modified wood has a lower number of hydroxyl groups (OH) as compared to non-thermally modified wood. In a particular embodiment, thermally modified wood is as defined in SID-CEN/TS 15679:2008 Thermally modified Timber - Definitions and characteristics. Thermally modified wood is wood that has been modified by a controlled pyrolysis process of wood being heated, preferably in the absence of oxygen or at least in reduced oxygen atmosphere. Such a heat treatment induces chemical changes to the chemical structures of cell wall components, including lignin, cellulose and hemiceliulose, in the wood resulting in increased durability. Low oxygen content during the heating process prevents the wood from burning at these high temperatures. Various beat treating processes are known to produce thermally modified wood including, but not limited to, Westwood process, Plato process, Retification process, Les Bois Perdure process, Oil heat treatment and THERMOWOOD® process.

The heat treatment process removes certain organic compounds, often denoted volatile organic compounds (VOCs), which reduces the possibility for fungi and rot to thrive on the wood. In addition, the chemical changes to the chemical structures of the cell wail components make these less appetizing to fungi and insects. The heat treatment may, additionally, improve properties of the wood with respect to moisture, e.g., lower equilibrium moisture content, less moisture deformation and improved weather resistance.

The heat treatment as applied in step S30 of Fig. 10 is preferably performed for at least 5 hours, preferably at least 15 hours, more preferably at least 20 hours, such as at least 25 hours or even longer, such as at least 30 hours or at least 35 hours. The heat treatment applied to the solid wood components in step S30 may also, or alternatively, be applied to the cellulosic material in the composite material of the coating layer 60 and/or of the cuttable edge seal 40,

Fig, 11 is a flow chart illustrating an additional, optional step of the method shorn in Fig, 7, In this embodiment the first solid wood component 10 and the second solid wood component 20 are treated in step S40 with a fire retardant, also referred to as flame retardant In the art. The method then continues to step S1 in Fig, 7,

Any fire retardant traditionally used in wood products could be used in step S40 to treat the solid wood components 10, 20. Illustrative, but non-limiting, examples of fire retardants are based on phosphorus, nitrogen, boron, silica and/or their combinations, for instance, mono-ammonium phosphate, diammonium phosphate, ortho-phosphoric acid, ammonium sulphate, borax, boric acid, boric oxide, disodium octoborate, melamine phosphate, etc.

Another aspect of the invention relates to a composite product 1. The composite product 1 comprises a first solid wood component 10, a second solid wood component 20, a cuttable edge seal 40 and a coating layer 60. The cuttable edge seal 40 is interposed between a short end 11 of the first solid wood component 10 and a short end 21 of the second solid wood component 20. At least one side 42, 44 of the cuttable edge seal 40 has an indentation 41, 43, The coating layer 60 is made of a polymer-based material and is provided on at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10 and of the second solid wood component 20, in addition, the coating layer 60 covers the at least one side 42, 44 of the cuttable edge seal 40 having the indentation 41, 43. The polymer-based material of fhe coating layer 60 extends into the indentation 41 , 43 and a portion 65 of the coating layer 65 covering the indentation 41, 43 has a larger thickness as compared to portions 62 of the coating layer 60 on the at least one side 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10 and of the second solid wood component 20. In an embodiment, the composite product 1 comprises the coating layer 60 on all (longitudinal) sides 12, 14, 16, 18, 22, 24, 26, 28 of the first solid wood component 10 and of the second solid wood component 20. In an embodiment, see Fig, 3, the cuttable edge seal 40 comprises protrusions 45 extending into the short end 11 of the first solid wood component 10 and the short end 21 of the second solid wood component 20, In an embodiment, opposite sides 42, 44 of the cuttable edge seal 40 has a respective indentation 41, 43, in this embodiment, polymer-based material of the coating layer 60 extends into the indentations 41, 43.

In an embodiment, the portion 65 of the coating layer 60 aligned with the cuttable edge seal 40, i.e., covering the indentation 41, 43, is fused to the least one side 42, 44, 46, 48 of the cuttable edge seal 40 covered by the coating layer 60.

In an embodiment, the cuttable edge seal 40 is attached to the short end 11 of the first solid wood component 10 and the short end 21 of the second solid wood component 20 with an adhesive,

The various embodiments described above of attaching the cuttable edge seal 40 to the solid wood components 10, 20 and/or to the coating layer 60 can be combined. These various embodiments also apply to attaching the second cuttable edge seal 50 to the second and third solid wood components 20, 30,

In an embodiment, the cuttable edge seal 40 is a first cuttable edge seal 40 interposed between the short end 11 of the first solid wood component 10 and a first short end 21 of the second solid wood component 20, The composite product 1 further comprises, in this embodiment, a third solid wood component 30 and a second cutable edge seal 50 interposed between a second short end 23 of the second solid wood component 20 and a short end 31 of the third solid wood component 30. At least one side 52, 54 of the second cuttable edge seal 50 has an indentation 51, 53,

In an embodiment, a thickness T1 of a portion 5 the composite product 1 comprising the cuttable edge seal 40 is substantially the same as a thickness T2 of a portion 2 of the composite product 1 comprising the first solid mod component 10. in an embodiment, the polymer-based material of the coating layer 60 comprises a polymer and the cuttable edge seal 40 is made of a polymer material comprising the polymer. For instance, the coating layer 60 may be made of a composite material comprising cellulosic material and the polymer and the cuttable edge seal 40 may also be made of a composite material comprising cellulosic material and the polymer or may be made of the polymer, such as made of a thermoplastic polymer material.

In an embodiment, the first solid wood component 10 is a first thermally modified solid wood component 10 and the second solid wood component 20 is a second thermally modified wood component 20.

A further aspect of the invention relates to a composite product 1 B, see Fig. 5, comprising a solid wood component 20, a first cut edge seal 40B, a second cut edge seal 50A and a coating layer 60. At least one edge 47, 49 of the first cut edge seal 40B is a beveled or chamfered edge 47, 49 and at least one edge 57, 59 of the second cut edge seal 50A is a beveled or chamfered edge 57, 59. The first cut edge seal 40B is atached to a first short end 21 of the solid wood component 20 and the second cut edge seal 50A is atached to a second short end 23 of the solid wood component 20. The coating layer 60 is made of a polymer-based material and is provided on at least one side 22, 24, 26, 28 of the wood component 20. In addition, the coating layer 60 covers at least one side 42B, 44B, 52A, 54A of the first cut edge seal 40B and of the second cut edge seal 50A. The polymer-based material of the coating layer 60 extends to cover the beveled or chamfered edges 47, 49, 57, 59 and portions 67 of the coating layer 60 covering the beveled or chamfered edges 47, 49, 57, 59 have a larger thickness as compared to a portion 62 of the coating layer 60 on the at least one side 22, 24, 26, 28 of the solid wood component 20.

In an embodiment, the composite product 1B comprises the coating layer 60 on all four (longitudinal) sides 22, 24, 26, 28 of the solid wood component 20. In this embodiment, the coating layer 60, the first cut edge seal 40B and the second out edge seal 50A form a protective enclosure around the solid wood component 20.

In an embodiment, portions of the coating layer 60 aligned with the first cut edge seal 40B and with the second cut edge seal 50A, i.e,, covering the beveled or chamfered edges 47, 49, 57, 59, are fused to the at least one side 42B, 44B, 52A, 54A of the first cut edge seal 40B and of the second cut edge seal 50A covered by the coating layer 60.

In an embodiment, see Fig. 6, the first cut edge seal 40B and the second cut edge seal 50A comprise protrusions 45, 55 configured to extend into the first short end 21 and into the second short end 23 of the solid wood component 20. In an embodiment, opposite edges 47, 49, 57, 59 of the first cut edge seal 40B and of the second cut edge seal 50A are beveled or chamfered edges 47, 49, 57, 59, in this embodiment, polymer-based material of the coating layer 60 extends to cover the beveled or chamfered edges 47, 49, 57, 59, The beveled or chamfered edge(s) 47, 49, 57, 59 is(are) obtained by cuting a composite product 1 comprising a cutable edge seal 40 comprising at least one indentation 41, 43 and a cuttable edge seal 50 comprising at least one indentation 51, 53 as shown in Fig, 4,

The polymer-based material thereby extends, in this embodiment, to cover the beveled or chamfered edge(s) 47, 49, 57, 59 thereby mechanically locking the cut edge seals 40B, 50A to the coating layer 60 and thereby to the solid wood component 20.

In an embodiment, the first cut edge seal 40B is atached to the first short end 21 with an adhesive and the second cut edge seal 50A is attached to the second short end 23 with an adhesive.

The various embodiments described above of attaching the cut edge seals 40B, 50A to the solid wood component 20 and/or to the coating layer 60 can be combined.

In an embodiment, a thickness of portions 5 the composite product 1B comprising the first or second cut edge seals 40B, 50A is substantially the same as a thickness of a portion 2 of the composite product 1 comprising the solid wood component 20.

In an embodiment, the polymer-based material of the coating layer 60 comprises a polymer and the first cut edge seal 40B and the second cut edge seal 50A are made of a polymer material comprising the polymer. For instance, the coating layer 60 may be made of a composite material comprising celiuiosic material and the polymer and the cut edge seals 40B, 50A may also be made of a composite material comprising celiuiosic material and the polymer or may be made of the polymer, such as made of a thermoplastic polymer material, In an embodiment, the solid wood component 20 is a thermally modified solid wood component 20.

In an embodiment, the polymer-based material of the coating layer 60 in the composite product 1 , 1B is a composite material comprising celiuiosic material and at least one polymer. The celiuiosic material preferably comprises natural fibers.

The natural fibers used in accordance with the present invention are natural fibers that contain cellulose and, in many cases, lignin and/or hemicelluloses. The natural fibers may be produced by chemical pulping, mechanical pulping, chemo-mechanical pulping or mechanical milling/crushing of celiuiosic or lignoceilulosic raw materials. They are, typically, wood fibers produced by chemical pulping, mechanical pulping, chemo-mechanical pulping or mechanical milling/crushing of softwood or hardwood. Examples of such pulps are chemical pulp such as sulfate or sulfite pulp, dissolving pulp, thermomechanical pulp (TMP), high temperature thermomechanical pulp (HTMP), mechanical fiber intended for medium density fiberboard (MDF-fiber), chemo-thermomechanical pulp (CTMP), high temperature chemo- thermomechanical pulp (HTCTMP), and combinations thereof. The fibers can also be produced by other methods such as steam explosion pulping, milling/crushing and/or from other celiuiosic or lignoceilulosic raw materials such as flax, jute, hemp, kenaf, bagasse, coton, bamboo, straw or rice husk, it is also possible to use celiuiosic material that is a mixture of fibers from different raw materials, such as a mixture of wood and any of the materials mentioned above.

The celiuiosic material may alternatively consist of, or may comprise, microfibrillated cellulose.

The celiuiosic material may alternatively consist of, or may comprise, milled wood fibers. in an embodiment, the celiuiosic material is thermally modified celiuiosic material, i.e., the celiuiosic material has been thermally modified. In an embodiment, all celiuiosic material is thermally modified celiuiosic material. In another embodiment, parts of the celiuiosic material is thermally modified celiuiosic material. Thus, in an embodiment, the composite material comprises thermally modified celiuiosic material and non-thermally modified celiuiosic material,

Microfibriiiated cellulose (MFC) as used herein means a cellulose particle, fiber or fibril having a width or diameter of from 20 nm to 1000 nm. Various methods exist to make MFC, such as single or multiple pass refining, pre-hydrolysis followed by refining or high shear disintegration or liberation of fibrils. One or several pre-treatment steps is usually required in order to make MFC manufacturing both energy efficient and sustainable. The cellulose fibers of the pulp used when producing MFC may thus be native or pre-treated enzymatically or chemically, for example to reduce the quantity of hemiceilulose or lignin. The cellulose fibers may be chemically modified before fibrillation, wherein the cellulose molecules contain functional groups other (or more) than found in the original cellulose. Such groups include, among others, carboxymethyl (CM), aldehyde and/or carboxyl groups (cellulose obtained by N-oxyl mediated oxidation, for example "TEMPO"), or quaternary ammonium (cationic cellulose). After being modified or oxidized in one of the above-described methods, it is easier to disintegrate the fibers into MFC.

MFC can be produced from wood cellulose fibers, both from hardwood or softwood fibers, it can also be made from microbial sources, agricultural fibers such as wheat straw pulp, bamboo, bagasse, or other non-wood fiber sources, it can be made from pulp, including pulp from virgin fiber, e.g. mechanical, chemical and/or thermomechanical pulps. If can also be made from broke or recycled paper.

In an embodiment, the composite material comprises less than 50% by weight of the ceilulosic material. In a particular embodiment, the composite material comprises less than 45 % by weight of the ceilulosic material, preferably less than 30 % by weight of the ceilulosic material, and more preferably less than 25 % by weight of the ceilulosic material. It is also possible to have a composite material comprising even less ceilulosic material, such as less than 20 % by weight of the ceilulosic material or less than 15 % by weight of the ceilulosic material. In an embodiment, the composite material comprises at least 1 % by weight of the ceilulosic material, preferably at least 2.5 % by weight of the ceilulosic material, and more preferably at least 5 % by weight of the ceilulosic material. In particular embodiment, the composite material comprises between 15 and 45 % by weight of the ceilulosic material, preferably between 15 and 30 % by weight of the ceilulosic material, and more preferably between 15 and 25 % by weight of the ceilulosic material.

In an embodiment, the ceilulosic material in the composite material comprises ceilulosic fibers having a length weighted average fiber length of up to 5 mm, preferably of up to 4 mm, more preferably of up to 3 mm, and most preferably up to 2 mm. In a particular embodiment, the length weighted average fiber length is equal to or below 1 ,7 mm, such as equal to or below 1.5 mm, preferably equal to or below 1 mm. Length of fibers, such as ceilulosic fibers, as referred to herein, is length weighted average fiber length. Length weighted average fiber length is calculated as the sum of individual fiber lengths squared divided by the sum of the individual fiber lengths as described in e.g., IS0 16065-1 or ISO 16065-2. In an embodiment the cellulosic material may be in the form of a powder. For instance, the cellusosic material may comprise ceilulosic fibers that have been mechanically treated to a powder. The size of the ceilulosic material is of importance in order to be able to achieve composite material where the ceilulosic material is evenly distributed, it was found that if the celiuiosic material is in the form of a powder it is easy to achieve a good dispersion and mixture with the polymer.

In an embodiment, the powder particles have an average size (diameter) of up to 5 mm, preferably of up to 4 mm, more preferably of up to 3 mm, and most preferably up to 2 mm. in a particular embodiment, the average size (diameter) is equal to or below 1.7 mm, such as equal to or below 1.5 mm, preferably equal to or below 1 mm, or even smaller.

In an embodiment, the polymer of the polymer-based material, such as of the composite material, is a thermoplastic polymer. Non-limiting, but illustrative, examples of such thermoplastic polymers include polyethylene terephthalate (PET), polystyrene (PS), polyamide (PA), poly(methyl methacrylate) (PMMA), polypropylene (PP), polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), styrene- acrylonitrile (SAN), polyacrylic acid (PAA), polylactic acid (PLA), polycarbonate (PC) and polyethylene (PE), such as high-density PE (HOPE) or low-density PE (LDPE), and combinations thereof, preferably PET. It is also possible to have a polymer-based material, such as the composite material, comprising two or more different polymers, such as a mixture of two or more of PET, PS, PA, PMMA, PP, PVC, ABS, SAN, PAA, PLA, PC and PE.

In a particular embodiment, the polymer is a high melt polymer having a melting temperature above 180°C, preferably above 200°C. Such high melt polymers are in particular useful if the solid wood component(s) 10, 20 of the composite product 1 , 1 B is thermally modified solid wood component(s) 10, 20 since such thermally modified solid wood components 10, 20 are more temperature resistant as compared to normal kiln dried solid wood components. This higher temperature resistance in turn enables using higher temperatures when applying the composite material onto the solid wood component(s) 10, 20, such as in an extruder.

In another embodiment, the polymer-based material of the coating layer 60 is a thermoplastic polymer material comprising one or more thermoplastic polymers. In a particular embodiment, the at least one thermoplastic polymer is then selected from the group consisting of PET, PS, PA, PMMA, PP, PVC, ABS, SAN, PAA, PLA, PC and PE, including any combination of two or more of these polymer materials.

In an embodiment, the coating layer 60 of the composite product 1, 1B has a thickness between 0.25 mm and 5 mm, preferably between 0.5 mm and 2.5 mm. Too thick coating layers 60 may be more prone to creep.

In an embodiment, the coating layer 60 comprises a fire retardant. In such a case, the fire retardant can be selected among the fire retardants described in connection with Fig. 11.

The cutable edge seal 40, 50 of the composite product 1 and the cut edge seals 40B, 50A of the composite product 1B are preferably made of a polymer material.

In an embodiment, the polymer material is a thermoplastic polymer material comprising one or more thermoplastic polymers. In a particular embodiment, the at least one thermoplastic polymer is selected from the group consisting of PET, PS, PA, PMMA, PP, PVC, ABS, SAN, PAA, PLA, PC and PE, preferably PET. In an embodiment the thermoplastic polymer of cuttable edge seal 40, 50 and of the cut edge seals 40B, 50A is the same polymer as in the coating layer 60, or if the cuttable edge seal 40, 50 and the cut edge seals 40B, 50A and/or the coating layer 60 comprises multiple different polymers, at least one polymer is preferably the same in the cuttable edge seal 40, 50 and in the cut edge seals

40B, 50A as in the coating layer 60,

In another embodiment, the polymer material of the cuttable edge seal 40, 50 and of the cut edge seals 40B, 50A is a composite material comprising a cellulosic material and at least one polymer. The discussion above of a composite material for the coating layer 60 also applies to the cuttable edge seal

40, 50 and of the cut edge seals 40B, 50A.

The polymer material of the cuttable edge seals 40, 50 and thereby of the cut edge seal 40A, 40B, 50A could comprise the same or different polymers as the polymer-based material of the coating layer 60. In an embodiment, the cuttable edge seals 40, 50 and thereby the cut edge seal 40A, 40B, 50A is made of a composite material comprising a cellulosic material and at least one polymer, such as at least one thermoplastic polymer, in another embodiment, the coating layer 60 is made of a composite material comprising a cellulosic material and at least one polymer, such as at least one thermoplastic polymer. In a further embodiment, both the coating layer 60 and the cutable edge seals 40, 50 and thereby the cut edge seal 40A, 40B, 50A are made of a composite material comprising a cellulosic material and at least one polymer, such as at least one thermoplastic polymer. In this further embodiment, the coating layer 60 and the cuttable edge seals 40, 50 and thereby the cut edge seal 40A, 40B, 5GA could be made of the same or different composite materials.

The solid wood component(s) 10, 20, 30 of the composite product 1, 1B is an engineered wood component 10, 20, 30, sometimes also referred to as wood core or engineered wood core. The solid wood component 10, 20, 30 can be of any kind of wood, e.g. softwood or hardwood or even bamboo. The solid wood component 10, 20, 30 can be any piece of wood, such as plank or board, including a piece of wood having holes, indentations, protrusions, tongue and grooves or other engineered structures.

The composite product 1, 1B can be used for the production of many different products, such as cladding, decking, window and door profiles, light poles, jetties, joinery, furniture, joists, wall elements, sound barriers, fencing, products used in flooring, parquetry, paneling, etc.

The embodiments described above are to be understood as a few illustrative examples of the present invention, it will be understood by those skilled in the art that various modifications, combinations and changes may be made to the embodiments without departing from the scope of the present invention. In particular, different part solutions in the different embodiments can be combined in other configurations, where technically possible.

Claims

1. A method of producing a composite product (1 ), the method comprising: interposing (S1) a cutabie edge seal (40) between a short end (11) of a first solid wood component (10) and a short end (21) of a second solid wood component (20), wherein at least one side (42, 44) of the cuttabie edge seal (40) has an indentation (41 , 43); and applying (S2) a polymer-based material onto at least one side (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20) and the at least one side (42, 44) of the cuttabie edge seal (40) having the indentation (41, 43) and into the indentation (41, 43) to form a coating layer (60) on the at least one side (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20), wherein the coating layer (60) covers the at least one side (42, 44) of the cuttabie edge seal (40) having the indentation (41, 43) and a portion (65) of the coating layer (60) covering the indentation (41, 43) has a larger thickness as compared to portions (62) of the coating layer (60) on the at least one side (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20).

2. The method according to claim 1, wherein applying (S2) the polymer-based material comprises extruding the polymer-based material onto at least one side (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20) to form the coating layer (60) on the at least one side (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20).

3. The method according to claim 1 or 2, further comprising cutting (S3) the composite product (1) through the cutabie edge seal (40) to form a first composite product (1A) and a second composite product (1B), wherein the first composite product (1A) comprises the first solid wood component (10) comprising the coating layer (60) on at least one side (12, 14, 16, 18) and comprising a first edge seal (40A) attached to the short end (11) of the first solid wood component (10), wherein the first edge seal (40A) corresponds to a first portion of the cuttabie edge seal (40); and the second composite product (1B) comprises the second solid wood component (20) comprising the coating layer (60) on at least one side (22, 24, 26, 28) and comprising a second edge seal (40B) atached to the short end (21) of the second solid wood component (20), wherein the second edge seal (40B) corresponds to a second portion of the cutabie edge seal (40).

4. The method according to any one of the claims 1 to 3, wherein applying (S2) the polymer-based material comprises applying (S2) the polymer-based material onto at least one side (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20) to form the coating layer (60) on the at least one side (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20) while melting the coating layer (60) together with the at least one side (42, 44) of the cuttable edge seal (40) covered by the coating layer (60).

5. The method according to any one of the claims 1 to 4, wherein interposing (S1) the cuttable edge seal (40) comprises interposing (S1) a cuttable edge seal (40) comprising protrusions (45) configured to extend into the short end (11) of the first solid wood component (10) and the short end (21) of the second solid wood component (20).

6. The method according to any one of the claims 1 to 5, wherein opposite sides (42, 44) of the cuttable edge seal (40) has a respective indentation (41, 43).

7. The method according to any one of the claims 1 to 6, further comprising heat treating (S10) the portion (65) of the coating layer (60) covering the indentation (41, 43) to fuse the portion (65) of the coating layer (60) and the least one side (42, 44, 46, 48) of the cutable edge seal (40) covered by the coating layer (60).

8. The method according to any one of the claims 1 to 7, further comprising attaching (S20) the cuttable edge seal (40) to the short end (11) of the first solid wood component (10) and the short end (21) of the second solid wood component (20) with an adhesive.

9. The method according to any one of the claims 1 to 8, wherein interposing (S1) the cuttable edge seal (40) comprises interposing (S1) the cuttable edge seal (40) between the short end (11) of the first solid wood component (10) and the short end (21) of the second solid wood component (20) while applying a force onto at least the second solid wood component (20) to maintain the cuttable edge seal (40) pressed between the first solid wood component (10) and the second solid wood component (20).

10. The method according to any one of the claims 1 to 9, wherein the cuttable edge seal (40) is a first cutable edge seal (40); interposing (S1) the cuttable edge seal (40) comprises interposing (S1) the first cuttable edge seal (40) between the short end (11) of the first solid wood component (10) and a first short end (21) of the second solid wood component (20) and interposing (S1) a second cuttabie edge seal (50) between a second short end (23) of the second solid wood component (20) and a short end (31 ) of a third solid wood component (30), wherein at least one side (52, 54) of the second cuttabie edge seal (50) has an indentation (51, 53); and applying (S2) the polymer-based material comprises applying (S2) the polymer-based material onto at least one side (12, 14, 16, 18, 22, 24, 26, 28, 32, 34) of the first solid wood component (10), of the second solid wood component (20) and of the third solid wood component (30), the at least one side (42, 44) of the first cuttabie edge seal (40) having the indentation (41, 43), the at least one side (52, 54) of the second cuttabie edge seal (50) having the indentation (51, 53) and into the indentations (41, 43, 51, 53) of the first and second cuttabie edge seals (40, 50) to form the coating layer (60) on the at least one side (12, 14, 16, 18, 22, 24, 26, 28, 32, 34) of the first solid wood component (10), of the second solid wood component (20) and of the third solid wood component (30), wherein the coating layer (60) covers the at least one side (42, 44) of the first cutabie edge seal (40) having the indentation (41, 43) and the at least one side (52, 54) of the second cuttabie edge seal (50) having the indentation (51, 53) and portions (65) of the coating layer (60) covering the indentations (41, 43, 51, 53) have a larger thickness as compared to portions (62) of the coating layer (60) on the at least one side (12, 14, 16, 18, 22, 24, 26, 28, 32, 34) of the first solid wood component (10), of the second solid wood component (20) and of the third solid wood component (30).

11. The method according to claim 10, further comprising cutting (S3) the composite product (1) through the first cuttabie edge seal (40) and the second cuttabie edge seal (50) to form a cut composite product (1B) comprising the second solid wood component (20) comprising the coating layer (60) on at least one side (22, 24, 26, 28) and comprising a first edge seal (40B) attached to the first short end (21) of the second solid wood component (20) and a second edge seal (50A) atached to the second short end (23) of the second solid wood component (20), wherein the first edge seal (40B) corresponds to a portion of the first cuttabie edge seal (40) and the second edge seal (50A) corresponds to a portion of the second cutabie edge seal (50).

12. The method according to any one of the claims 1 to 11 , wherein applying (S2) the polymer-based material comprises applying (S2) the polymer-based maieriai onto all sides (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20) to form a coating layer (60) on all sides (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20).

13. The method according to any one of the claims 1 to 12, wherein the polymer-based material comprises a polymer and the cuttable edge seal (40) is made of a polymer material comprising the polymer, preferably a composite material comprising the polymer.

14. The method according to any one of the claims 1 to 13, wherein applying (S2) the polymer-based material comprises applying (S2) a composite material comprising cellulosic materia! and at least one polymer onto at least one side (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20) to form the coating layer (60) on the at least one side (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20).

15. The method according to any one of the claims 1 to 14, wherein a thickness of a portion (5) of the composite product (1) comprising the cuttable edge seal (40) is substantially the same as a thickness of a portion (2) of the composite product (1) comprising the first solid wood component (10).

16. A composite product (1 ) comprising: a first solid wood component (10); a second solid wood component (20); a cuttable edge seal (40) interposed between a short end (11) of the first solid wood component (10) and a short end (21) of the second solid wood component (20), wherein at least one side (42, 44) of the cuftabie edge seal (40) has an indentation (41, 43); and a coating layer (60) of a polymer-based material on at least one side (12, 14, 16, 18, 22, 24, 26,

28) of the first solid wood component (10) and of the second solid wood component (20), wherein the coating layer (60) covers the at least one side (42, 44) of the cuttable edge seal (40) having the indentation (41, 43), the polymer-based material of the coating layer (60) extends into the indentation (41, 43) and a portion (65) of the coating layer (60) covering the indentation (41, 43) has a larger thickness as compared to portions (62) of the coating layer (60) on the at least one side (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20),

17. The composite product according to claim 16, wherein the composite product (1) comprises the coating layer (60) on all sides (12, 14, 16, 18, 22, 24, 26, 28) of the first solid wood component (10) and of the second solid wood component (20).

18. The composite product according to claim 16 or 17, wherein the cuttable edge seal (40) comprises protrusions (45) extending info the short end (11) of the first solid wood component (10) and the short end (21) of the second solid wood component (20).

19. The composite product according to any one of the claims 16 to 18, wherein opposite sides (42, 44) of the cuttable edge seal (40) has a respective indentation (41 , 43).

20. The composite product according to any one of the claims 16 to 19, wherein the portion (65) of the coating layer (60) covering the indentation (41, 43) is fused to the least one side (42, 44, 46, 48) of the cuttable edge seal (40) covered by the coating layer (60).

21. The composite product according to any one of the claims 16 to 20, wherein the cuttable edge seal (40) is atached to the short end (11 ) of the first solid wood component (10) and the short end (21 ) of the second solid mod component (20) with an adhesive.

22. The composite product according to any one of the claims 16 to 21 , wherein the cutable edge seal (40) is a first cutable edge seal (40) interposed between the short end (11) of the first solid wood component (10) and a first short end (21) of the second solid wood component (20); and the composite product (1) further comprises: a third solid wood component (30); and a second cutable edge seal (50) interposed between a second short end (23) of the second solid mod component (20) and a short end (31) of the third solid mod component (30), wherein at least one side (52, 54) of the second cuttable edge seal (50) has an indentation (51, 53).

23. The composite product according to any one of the claims 16 to 22, wherein the polymer-based material comprises a polymer and the cuttable edge seal (40) is made of a polymer material comprising the polymer, preferably a composite material comprising the polymer.

24. The composite product according to any one of claims 16 to 23, wherein a thickness of a portion (5) of the composite product (1) comprising the cutabie edge seal (40) is substantially the same as a thickness of a portion (2) of the composite product (1) comprising the first solid wood component (10).

25. A composite product (1 B) comprising: a solid wood component (20); a first cut edge seal (40B) attached to a first short end (21) of the solid wood component (20), wherein at least one edge (47, 49) of the first cut edge seal (40B) is a beveled or chamfered edge (47, 49); a second cut edge seal (50A) attached to a second short end (23) of the solid wood component

(20), wherein at least one edge (57, 59) of the second cut edge seal (50A) is a beveled or chamfered edge (57, 59); and a coating layer (60) of a polymer-based material on at least one side (22, 24, 26, 28) of the solid wood component (20), wherein the coating layer (60) covers at least one side (42B, 44B, 52A, 54A) of the first cut edge seal (40B) and of the second cut edge seal (50A), the polymer-based material of the coating layer (60) extends to cover the beveled or chamfered edges (47, 49, 57, 59) and portions (67) of the coating layer (60) covering the beveled or chamfered edges (47, 49, 57, 59) have a larger thickness as compared to a portion (62) of the coating layer (60) on the at least one side (22, 24, 26, 28) of the solid wood component (20).

26. The composite product according to claim 25, wherein the composite product (1B) comprises the coating layer (60) on ail sides (22, 24, 26, 28) of the solid wood component (20); and the coating layer (60), the first cut edge seal (40B) and the second cut edge seal (50A) form a protective enclosure around the solid wood component (20).

27. The composite product according to claim 25 or 26, wherein the portions (67) of the coating layer (60) covering the beveled or chamfered edges (47, 49, 57, 59) are fused to the at least one side (42B, 44B, 52A, 54A) of the first cut edge seal (40B) and of the second cut edge seal (50A) covered by the coating layer (60).

28. The composite product according to any one of the claims 25 to 27, wherein the first cut edge seal (40B) and the second cut edge seal (50A) comprise protrusions (45, 55) extending into the first short end (21) and into the second short end (23) of the solid wood component (20).

29. The composite product according to any one of the claims 25 to 28, wherein opposite edges (47, 49, 57, 59) of the first cut edge seal (40B) and of the second cut edge seal (50A) are beveled or chamfered edges (47, 49, 57, 59).

30. The composite product according to any one of the claims 25 to 29, wherein the first cut edge seal (40B) is attached to the first short end (21) with an adhesive; and the second cut edge seal (50A) is attached to the second short end (23) with an adhesive.

31. The composite product according to any one of claims 25 to 30, wherein a thickness of portions

(5) of the composite product (1B) comprising the first or second cut edge seals (40B, 50A) is substantially the same as a thickness of a portion (2) of the composite product (1) comprising the solid wood component (20).

32. The composite product according to any one of the claims 25 to 31, wherein the polymer-based material comprises a polymer and the first cut edge seal (40B) and the second cut edge seal (50A) are made of a polymer material comprising the polymer, preferably a composite material comprising the polymer.

33. The composite product according to any one of the claims 16 to 32, wherein the polymer-based material is a composite material comprising cellulosic material and at least one polymer.

34. The composite product according to claim 33, wherein the cellulosic material comprises natural fibers produced by chemical, mechanical or chemo-mechanical pulping.

35. The composite product according to claim 33 or 34, wherein the ceiiuiosic material comprises microfibrillated cellulose.

36. The composite product according to any one of claims 33 to 35, wherein the ceiiuiosic material comprises milled wood fibers.

37. The composite product according to any one of the claims 16 to 36, wherein the polymer is selected from the group consisting of polyethylene terephthalate (PET), polystyrene (PS), polyamide (PA), poly(methyl methacrylate) (PMMA), polypropylene (PP), polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), styrene-acrylonitrile (SAN), polyacrylic acid (PAA), polylactic acid (PLA), polycarbonate (PC) and polyethylene (PE), preferably PET.

38. The composite product according to any one of the claims 16 to 37, wherein the coating layer (6G) has a thickness between 0.25 and 5 mm, preferably between 0.5 and 2.5 mm.