EDGE TRIM FOR FURNITURE

Description

[0001] The invention relates to an edge strip for furniture, comprising a melt layer.

[0002] A furniture panel and a method for its production are known from EP 1 163 864. This describes a generic edge strip in which the molten layer can be welded to wood materials using laser technology.

[0003] When fixing the edge strip to the piece of furniture, it is difficult to ensure that it is securely held to the piece of furniture when using some materials.

[0004] Further related prior art is disclosed in WO 93 / 06995 A1, DD 124 170 A1, DE 101 44 524 A1, WO 02 / 068192 A1, DE 42 08 991 A1 as well as in Wust "Narrow surface coating with the laser - Old technologies in a new light, Part 2: the joining process on the edge banding machine", 01.01.2006, pages 24-29, XP093135309.

[0005] The invention is based on the object of providing an edge strip for pieces of furniture which, regardless of the material of a piece of furniture, can be fixed optically to at least one edge of the piece of furniture without a parting line and without adhesive.

[0006] To achieve this objective, the invention provides an edge strip for furniture according to claim 1, comprising a melt layer, wherein the melt layer contains both polar and non-polar components in its molecular structure, so that the edge strip can be bonded to furniture made of a wide variety of materials by applying energy, for example, light and / or radiation. As a result, the melt layer can be directly bonded to polar and non-polar materials by melting.

[0007] Mechanical adhesion, for example, is achieved by the molten layer penetrating a cell structure of the piece of furniture, enclosing it, and hardening it. Specific adhesion is achieved through various effects: The molten layer, with both polar and non-polar components in its molecular structure, exhibits a good affinity for materials such as wood, facilitating diffusion. For example, the celluloses contained in wood materials, which contain OH groups, exhibit very strong dipole characteristics and thus adhere to polar substances.

[0008] Preferred embodiments of the edge strip according to the invention are claimed in the subclaims.

[0009] According to the invention, the edge strip has a structural layer bonded to the melt layer. This measure has the advantage that the structural layer imparts the actual structure to the edge strip, regardless of the function of the melt layer, whereby the melt layer and the structural layer can each be designed functionally.

[0010] It can be advantageous if the melt layer contains polar and / or reactive molecular groups, allowing adhesive and / or covalent and / or ionic bonds to be achieved. The best results in bonding the edge strip according to the invention are achieved when the polymer of the melt layer exhibits very good flowability.

[0011] Such polar and / or reactive groups can be easily incorporated into the molecular structure of the molten layer, e.g., through appropriate copolymerization and / or grafting and / or subsequent surface treatment (flame treatment, corona or plasma processes). The reactive groups can also form chemical bonds between the molten layer and the respective bonding partner in the piece of furniture, thereby ensuring particularly high bond strength. It can prove helpful if the molten layer contains molecular groups based on carboxylic acids or their esters or salts, in particular acrylic acid, acrylic acid esters, methacrylic acid, methacrylic acid esters, methyl methacrylic acid esters; epoxides, isocyanates, phenol-formaldehyde resin, silanes, titanates, alcohols, amides, imides, ammonium compounds, or sulfonic acids or their esters or salts, or the like.

[0012] According to the invention, the fused layer is based on the material from which the structural layer is made. This measure has the advantage of creating a particularly strong bond between the layers of the edge strip.

[0013] According to the invention, the structural layer is made of a thermoplastic polymer, namely polypropylene. This measure has the advantage that this material is inexpensive and easy to process.

[0014] According to the invention, the material of the melt layer is a graft copolymer. This measure has the advantage that the material composition, in particular the proportion of polar groups in the molecular structure, and thus the material properties, can be specifically adjusted. Specifically, the material of the melt layer according to the invention is maleic acid-grafted polypropylene.

[0015] According to the invention, the fused layer forms the underlayer of the edge strip, which defines the underside or contact side of the edge. This measure has the advantage that the fused layer can be directly welded to the end face of a piece of furniture that is to be covered, e.g., a wood-based panel (chipboard, MDF).

[0016] In a further preferred embodiment, the melt layer is designed as a thermoplastic functional layer, which for the first time makes it possible to fix an edge strip according to the previously described embodiments to a narrow side of a piece of furniture without adhesive and without a visible joint.

[0017] A further preferred embodiment of the invention relates to an edge strip according to one of the preceding embodiments, wherein the structural layer and the melt layer are bonded together. This measure has the advantage that the layers of the edge strip are particularly firmly bonded.

[0018] A further preferred embodiment of the invention relates to an edge strip according to one of the preceding embodiments, wherein the structural layer and the melt layer are coextruded. This measure has the advantage that the shaping of the edge strip is particularly simple.

[0019] A further preferred embodiment of the invention relates to an edge strip according to one of the preceding embodiments, wherein the melt layer contains energy-absorbing additives, preferably light- and / or radiation-absorbing additives, e.g., laser pigments. This measure has the advantage that the melt layer can be subjected to targeted energy and heated above its melting point. Preferably, the energy-absorbing additives are contained in specific melt sections in the melt layer, which are melted in a targeted manner. The melt sections can be arranged in any desired pattern, e.g., as parallel lines along the longitudinal edges of the edge strip.

[0020] A further preferred embodiment of the invention relates to an edge strip according to one of the preceding embodiments, wherein the structural layer forms the upper layer of the edge strip, which defines a top or visible side of the edge strip. This measure has the advantage that the appearance of the edge strip remains unchanged on the visible side even after the melted layer is melted and welded to a piece of furniture, e.g., a wood-based panel (chipboard, MDF).

[0021] A further preferred embodiment of the invention relates to an edge strip according to one of the preceding embodiments, wherein the upper side of the edge strip has a decorative finish. This feature has the advantage that the edge strip can have different decorations despite a substantially identical structural design, e.g., a decoration tailored to a storage surface of the piece of furniture.

[0022] In a further advantageous embodiment of the invention, the fused layer contains additives, such as dyes, pigments, and the like, which result in a favorable color match between the fused layer and the cover layer, as well as the upper surface of the piece of furniture. The visually visible joint between the edge of the piece of furniture and the cover layer, known from the prior art, is thus avoided.

[0023] A further preferred embodiment of the invention relates to an edge strip according to one of the preceding embodiments, wherein the structural layer has a thickness of 0.8 to 1.6 mm, preferably 1.0 to 5.0 mm. This measure has the advantage that the structural layer imparts a sufficiently rigid structure to the edge strip.

[0024] A further preferred embodiment of the invention relates to an edge strip according to one of the preceding embodiments, wherein the fused layer has a thickness of 0.1 to 0.5 mm, preferably 0.2 to 0.5 mm. This measure has the advantage that the fused layer is only made to the thickness required to achieve the connection to the piece of furniture. This eliminates the need for the fused layer material, which is more expensive than the structural layer material.

[0025] A further preferred embodiment of the invention relates to a piece of furniture with an edge strip according to one of the preceding embodiments, wherein the molten layer is at least partially bonded to an edge of the piece of furniture by a material fit and / or chemical bond. This measure has the advantage that the molten layer is bonded to the piece of furniture by a material fit and / or chemical bond, and possibly also by a form fit. Due to the partial welding, whereby the molten layer is only partially welded to the edge of the piece of furniture, but the edge is completely covered by the edge strip, the molten layer only needs to be exposed to energy at selected points, thus saving time and energy. The term "chemically bonded" refers to a chemical bond resulting from a chemical reaction between a reactive molecular group contained in the molten layer and a corresponding bonding partner or the edge of the piece of furniture.The reactive molecular group contained in the melt layer and the bonding partner are not restricted, as long as they are capable of chemically bonding with each other. The chemical bond between the molecular group in the melt layer and the respective bonding partner in the piece of furniture ensures a particularly high bond strength.

[0026] A further preferred embodiment of the invention relates to a piece of furniture according to the preceding embodiment, wherein the underside of the edge strip is fully bonded to the edge of the piece of furniture by a material bond and / or chemical bond. This measure has the advantage that the melt layer is securely and permanently bonded to the piece of furniture.

[0027] A further preferred embodiment of the invention relates to a piece of furniture according to one of the preceding embodiments, wherein the material of the piece of furniture is selected from the group of wood materials, wood substitute materials, metals, glasses, plastics, stones, ceramics, or combinations thereof. This measure has the advantage of allowing the greatest possible freedom with regard to the material selection of the piece of furniture. Wood, for example, contains approximately 40% cellulose, approximately 25% holocellulose, and approximately 30% lignin. Cellulose is a linear chain molecule (up to 8 µm long) and is particularly responsible for the tensile strength of wood. Holocelluloses are composed of different sugars; the chains are significantly shorter and have side groups and branches. The holocelluloses are linked to the lignin in the cell wall by covalent bonds.Celluloses, in particular, contain numerous OH groups, which are necessary for the internal cohesion of the wood, but are also useful for the external bonding of the enamel layer. These OH groups are particularly suitable for forming a chemical bond with reactive molecular groups contained in the enamel layer.

[0028] In principle, all materials with corresponding reactive groups on their surface that come into contact with the edges of, for example, furniture pieces are suitable for chemical bonding. If necessary, the materials can first be surface-modified if a chemical bond between the edgeband and the furniture material is desired and the materials themselves do not have any or insufficiently chemically reactive bonding partners.

[0029] A further preferred embodiment of the invention relates to a piece of furniture according to one of the preceding embodiments, wherein the material of the structural layer is selected from the group of wood materials, wood substitute materials, metals, glasses, plastics, stones, ceramics, or combinations thereof. This measure has the advantage of allowing the greatest possible freedom with regard to the material selection of the structural layer. Short description of the characters:

[0030] Figure 1 shows a schematic sectional view of a piece of furniture edge and an edge strip according to the invention to be attached thereto. Figure 2 shows a schematic sectional view of a piece of furniture edge and the edge strip according to the invention attached thereto. Figure 3 shows a schematic and perspective view of a piece of furniture edge with a partially attached edge strip according to the invention, to explain a method for attaching the edge strip to the piece of furniture edge. Detailed description of the preferred embodiments

[0031] The edge strip 1 according to the invention is described below with reference to the accompanying figures.

[0032] The edge strip 1 according to the invention for pieces of furniture 4 comprises a melt layer 3 that contains both polar and non-polar components in its molecular structure. For this purpose, the melt layer 3 is made of a material that is chemically modified to contain both polar and non-polar components in its molecular structure. This allows the melt layer 3 to be directly bonded to polar or non-polar materials by melting. In the simplest variant, the edge strip 1 comprises only the melt layer 3, i.e., the edge strip 1 is made of the chemically modified material that contains both polar and non-polar components in its molecular structure.

[0033] The edge strip 1 according to the invention for pieces of furniture 4 comprises a structural layer 2 and the melt layer 3 made of the chemically modified material, which contains both polar and non-polar components in its molecular structure. Between the structural layer 2 and the melt layer 3, there can be no intermediate layers, one intermediate layer, or several intermediate layers, so that the structural layer 2 and the melt layer 3 are at least indirectly, preferably directly, connected. The structural layer 2 can be omitted if the melt layer 3 is sufficiently thick to impart the necessary rigidity to the edge strip 1. Since the chemically modified material of the melt layer 3 is generally more expensive than the material of the structural layer 2, the variant with the structural layer 2 is preferred.

[0034] Figure 1 shows a schematic sectional view of a piece of furniture edge 4 and an edge strip 1 according to the invention to be connected thereto.

[0035] For the purposes of the invention, a structural layer 2 refers to a layer that essentially imparts its structure to the edge strip 1. A material for the structural layer 2 can be selected from any materials, e.g., wood-based materials, wood substitute materials, metals, glass, plastics, stones, ceramics, or combinations thereof.

[0036] In a preferred embodiment, the structural layer 2 is made of a thermoplastic polymer, preferably polypropylene, acrylonitrile-butadiene-styrene copolymer, polyvinyl chloride, polymethyl methacrylate, polyethylene terephthalate and the like.

[0037] In the illustrated embodiments, the structural layer 2 simultaneously forms the upper layer 2 of the edge strip 1, which defines a top or visible side 20 of the edge strip 1. Alternatively, one or more layers are arranged above the structural layer 2, for example, a decorative layer or decorative film with a decorated surface. The structural layer 2 has a thickness of 0.8 mm to 5.0 mm, preferably 1.0 to 3.0 mm.

[0038] In the context of this description, melt layer 3 refers to a layer consisting of a meltable material which preferably softens when the temperature is increased above the melting point and assumes a viscous or viscoplastic state, and solidifies again when cooled.

[0039] The material of the melt layer 3 is chemically modified in such a way that it contains polar and / or non-polar and / or reactive molecular groups. Accordingly, the material of the melt layer 3 is also referred to as a phase compatibilizer. By melting, the material of the melt layer 3 can be directly bonded to polar and non-polar materials. According to the invention, the melt layer 3 is based on the same material as the structural layer 2, i.e. on a non-polar material, preferably plastic, more preferably polypropylene, acrylonitrile-butadiene-styrene copolymer, polyvinyl chloride, polymethyl methacrylate, polyethylene terephthalate and the like, but is chemically modified. According to the invention, the material of the melt layer 3 is a graft copolymer, preferably a polypropylene grafted with maleic anhydride.The material of the melt layer 3 contains a proportion of up to four percent polar and / or reactive groups in the molecular structure, preferably between 0.5 and 2%, more preferably 1%. The melt layer 3 has a thickness of 0.1 mm to 1.5 mm, preferably 0.2 mm to 0.5 mm. The melt layer preferably contains one or more molecular groups based on carboxylic acids or their esters or salts, in particular acrylic acid, acrylic acid esters, methacrylic acid, methacrylic acid esters, methyl methacrylic acid esters; epoxides, isocyanates, phenol-formaldehyde resin, silanes, titanates, alcohols, amides, imides, ammonium compounds or sulfonic acids or their esters or salts, or the like.

[0040] The structural layer 2 and the melt layer 3 are preferably bonded, preferably coextruded. The material of the melt layer 3 preferably has a lower melting point than the material of the structural layer 2. If the edge strip 1 is heated to a predetermined temperature that is above the melting point of the material of the melt layer 3 but below the melting point of the structural layer 2, only the material of the melt layer 3 is softened or melted, which is desirable.

[0041] Figure 3 shows a schematic and perspective view of a piece of furniture 4 with the edge strip 1 according to the invention, wherein the melt layer 3 of the edge strip 1 is or will be directly connected to an edge 40 of the piece of furniture 4 in a materially bonded manner.

[0042] The piece of furniture 4 comprises a plate (e.g. table top, kitchen worktop, etc.) made of a material selected from any materials, e.g. the group of wood materials, wood substitute materials, metals, glasses, plastics, stones, ceramics or combinations thereof.

[0043] In the present example, the piece of furniture 4 is a panel made of a wood-based material, in particular a chipboard or an MDF board. The piece of furniture 4 comprises edges 40, which are defined and bordered by edge edges 41, a top or storage side 42, and a bottom (not shown).

[0044] The edge strip 1 comprises in the embodiment according to Fig. 3 the preferred construction with a structural layer 2 defining the visible side 20 and a melt layer 3 defining the contact side 30, and has a flexible structure.

[0045] The material of the structural layer 2 is polypropylene. The material of the fused layer 3 is maleic anhydride-grafted polypropylene. The edge strip 1 is moved to the edge 40 of the piece of furniture 4 to be covered using a largely conventional process, with the contact side 30 of the fused layer 3 being subjected to energy by an energy application means 6 immediately before the edge strip 1 is moved to the edge 40. The fused layer 3 is heated by the energy application.

[0046] The energy is supplied in any desired form, preferably in the form of laser light, hot air, microwaves, ultrasound, etc., wherein an energy absorption agent (e.g. laser pigments) preferably contained in the melt layer 3 absorbs the energy supplied by the energy application agent 6 and heats the melt layer 3 above the melting point. In this case, it is not necessary for the melt layer 3 to be completely melted, but rather that the melt layer 3 is only softened on the contact side 30, so that the melt layer 3 assumes a viscous or viscous-plastic state at least in sections and, when the edge strip 1 is pressed against the edge 40 of the piece of furniture 4, mechanically engages the preferably rough surface structure of the edge 40 of the piece of furniture 4. Due to the adjusted chemical properties of the edge strip 1, the melt layer 3 is additionally bonded to the edge 40 of the workpiece 4 in a material-to-material manner.

[0047] A melt layer 3, which has reactive molecular groups, is preferably supplied with sufficient energy by the energy application means 6 to exceed an activation energy to trigger a chemical reaction and create a chemical bond between the melt layer 3 and the respective connecting partner, here the piece of furniture 4. Applying energy to the melt layer 3 to bring about a chemical reaction between the melt layer 3 and the edge 40 of the piece of furniture 4, in order to chemically bond the melt layer 3 and the edge 40 of the piece of furniture 4, occurs optionally simultaneously or independently of applying energy to the melt layer 3 to melt the melt layer 3.

[0048] The activation energy required to create a chemical bond between the melt layer 3 and the respective bonding partner, here the piece of furniture 4, is influenced by the following parameters, among others: Temperature Radiation (laser, UV light) Contact force Joint gap Layer thickness Curing time Ambient air (humidity, oxygen content) Substrate surface Pretreatment

[0049] For a melt layer 3 made of maleic anhydride-grafted polypropylene (PP-MAH), for example, the melt layer 3 is heated to a temperature greater than + 135°C. This temperature is usually sufficiently high for the maleic anhydride (MAH) to react with the OH groups of the wood to create a chemical bond.

[0050] The edge strip 1 is usually manufactured with an oversize and is positioned against the edge 40 of the piece of furniture 4 in such a way that an overhang area is created on both sides of the edge strip 1 between the dashed lines 21 and the edges of the edge strip 1 in the connected state. This material overhang is removed by machining, so that the longitudinal edges of the edge strip 1 and the storage surface 42 as well as the underside (not shown) of the piece of furniture 4 are flush.

[0051] It is sufficient if the contact side 30 of the edge strip 1 is at least partially materially and / or chemically connected or welded to the edge 40 of the piece of furniture 4. Spot-shaped, line-shaped or checkerboard-like welding patterns are possible, which can be achieved, for example, by specifically applying energy-absorbing additives to the melt layer 3. However, it is preferred that the melt layer 3 be connected or welded over its entire surface to the edge 40 of the piece of furniture 4. This applies in particular to the corner regions of the piece of furniture 4, where the edge strips 1 are arranged adjacently, for example at an angle, in order to prevent the edge strips 1 from detaching from the corner regions of the piece of furniture 4.

[0052] Figure 2shows the connected state of the edge strip 1 according to the invention and the piece of furniture 4. It is shown how the initially melted and subsequently solidified material of the melt layer 3 engages in the rough or porous or microporous surface structure on the edge 40 of the piece of furniture 4, so that the melt layer 3 is connected to the piece of furniture 4 in a material-locking and - if the surface structure of the piece of furniture 4 permits it - also in a form-fitting manner.

[0053] Variants of the edge strip 1 are listed below with details of the respective materials: Variant 1 (PP edge) Structural layer: Polypropylene (PP); Melt layer: PP-maleic anhydride Variant 2 (ABS edge) Structural layer: Acrylonitrile-butadiene-styrene copolymer (ABS); Melt layer: Ethylene vinyl acetate, ethylene vinyl acetate maleic anhydride, ethylene methacrylate, polyurethane (thermoplastic), ABS maleic anhydride or styrene-ethylene-butylene-styrene block copolymer maleic anhydride, adhesion-modified copolyamide; Variant 3 (PVC edge) Structural layer: Polyvinyl chloride (PVC); Melt layer: PVC-ethylene vinyl acetate copolymer or PVC-polyacrylate, adhesion-modified copolyamide; ABS-maleic anhydride Variant 4 (PMMA / PET edge) Structural layer: Polymethyl methacrylate (PMMA) or polyethylene terephthalate (PET); Melt layer: Ethylene butylene acrylate, ethylene methacrylate, ethylene vinyl acetate, epoxidized acrylate, polyester (maleic anhydride grafted). Variant 5 (PP edge) Structural and melt layer: PP-maleic anhydride grafted

Claims

1. An edge strip (1) for pieces of furniture, comprising a melting layer (3) and a structural layer (2) of plastic connected to the melting layer (3), wherein the melting layer (3) defines an abutting side (30) of the edge strip (1) and the material of the melting layer (3) contains both polar and non-polar components in the molecular structure, characterised in that the melting layer (3) is based on a material from which the structural layer (2) is produced, wherein the structural layer (2) is produced from polypropylene and the material of the melting layer (3) is a maleic acid anhydride-grafted polypropylene.

2. The edge strip (1) according to claim 1, wherein the structural layer (2) and the melting layer (3) are directly connected.

3. The edge strip (1) according to any one of the preceding claims, wherein the structural layer (2) and the melting layer (3) are connected in a material-bonded manner.

4. The edge strip (1) according to any one of the preceding claims, wherein the structural layer (2) and the melting layer (3) are co-extruded.

5. The edge strip (1) according to any one of the preceding claims, wherein the melting layer (3) contains light- and / or radiation-absorbing additives, preferably laser pigments.

6. The edge strip (1) according to any one of the preceding claims, wherein the structural layer (2) forms the upper layer of the edge strip (1), which defines an upper side or visible side (20) of the edge strip (1).

7. The edge strip (1) according to any one of the preceding claims, wherein the melting layer (3) has a thickness of 0.1 to 1.5 mm, preferably 0.2 to 0.5 mm.

8. A piece of furniture (4) with an edge strip (1) according to any one of the preceding claims, wherein the melting layer (3) is connected in a material-bonded manner at least in sections to an edge (40) of the piece of furniture (4).

9. The piece of furniture (4) according to claim 8, wherein the underside (30) of the edge strip (1) is connected in a material-bonded manner over its entire surface to the edge (40) of the piece of furniture (4).