Floor panel with sealing means

Abstract

Floor panels and floor elements therefore are made of sheet-shaped cores which are formed with sealing means for preventing or counteracting changes in the properties of the floor panels caused by moisture. A floor panel, including a body having a core, in which floor panel at least two opposite parallel joint edge portions are provided with connectors for mechanical joining of the floor panel in the horizontal direction with similar floor panels, the connectors having active locking surfaces for cooperation with corresponding active locking surfaces of adjacent floor panels after the floor panel has been joined therewith, the core having an upper surface layer, wherein a material seal of a resilient surface layer covers the upper surface layer of the core.

Claims

1. A floor panel comprising: a core possessing an upper surface, at least two opposite parallel joint edge portions provided with connectors for mechanical joining of the floor panel in the horizontal direction with similar adjacent floor panels, said connectors having active locking surfaces for cooperation with corresponding active locking surfaces of the similar adjacent floor panels after the floor panel has been joined therewith, a resilient sealing layer is disposed on the upper surface of the core, the resilient sealing layer being plastic and providing a material seal of the core, and a surface layer disposed above the resilient sealing layer, wherein at least one joint edge portion further comprises a compressible material seal at the joint edge portion, and wherein the compressible material seal contacts and is located within a corner formed by two surfaces of the floor panel which are adjacent and angled relative to one another, and wherein, when an upper part of one of the joint edge portions of the floor panel directly contacts an upper part of a joint edge portion of another floor panel in a direction of contact, the compressible material seal is compressed in the direction of contact.

2. The floor panel according to claim 1, further comprising a decorative layer.

3. The floor panel according to claim 1, wherein the surface layer directly contacts the plastic.

4. The floor panel according to claim 1, wherein the surface layer comprises an elastic material.

5. The floor panel according to claim 1, wherein the resilient sealing layer covers an entirety of the upper surface of the core.

6. The floor panel according to claim 1, wherein the core is a plastic material.

7. The floor panel according to claim 1, wherein the core is a wood fiber based material.

8. The floor panel according to claim 1, wherein the material seal is sound-reducing.

9. The floor panel according to claim 1, wherein the active locking surfaces are provided in the core of the floor panel.

10. The floor panel according to claim 1, wherein the connectors are configured for joining the floor panel with a previously installed floor panel by inward angling.

11. The floor panel according to claim 1, wherein the connectors are configured for joining the floor panel with a previously installed floor panel by snapping-in to a locked position.

12. The floor panel according to claim 1, wherein the compressible material seal is a compressible material other than that of the body of the floor panel.

13. The floor panel according to claim 12, wherein a portion of the active locking surfaces comprises a recess having therein the compressible material seal other than that of the body of the floor panel, wherein the compressible material is arranged in the recess so the compressible material directly contacts a portion of the corresponding active locking surfaces.

14. The floor panel according to claim 12, wherein the compressible material is a polymeric material.

15. The floor panel according to claim 12, wherein the compressible material is made of a material based on acrylic plastic, synthetic rubber, urethane rubber, silicone rubber or a polyurethane-based hot-melt adhesive.

16. A floor panel comprising: a core possessing an upper surface, at least two opposite parallel joint edge portions provided with connectors for mechanical joining of the floor panel in the horizontal direction with similar adjacent floor panels, said connectors having active locking surfaces for cooperation with corresponding active locking surfaces of the similar adjacent floor panels after the floor panel has been joined therewith, a resilient sealing layer is disposed on the upper surface of the core, the resilient sealing layer being plastic or linoleum, the resilient sealing layer providing a material seal of the core, and a surface layer disposed directly on the resilient sealing layer, the surface layer comprising an elastic material, wherein at least one joint edge portion further comprises a compressible material seal at the joint edge portion, wherein the compressible material seal contacts and is located within a corner formed by two surfaces of the floor panel which are adjacent and angled relative to one another, and wherein, when an upper part of one of the joint edge portions of the floor panel directly contacts and upper part of a joint edge portion of another floor panel in a direction of contact, the compressible material seal is compressed in the direction of contact.

17. The floor panel according to claim 16, further comprising a decorative layer.

18. The floor panel according to claim 16, wherein the resilient sealing layer covers an entirety of the upper surface of the core.

19. The floor panel according to claim 16, wherein the core is a plastic material.

20. The floor panel according to claim 16, wherein the core is a wood fiber based material.

21. The floor panel according to claim 16, wherein the material seal is sound-reducing.

22. The floor panel according to claim 16, wherein the active locking surfaces are provided in the core of the floor panel.

23. The floor panel according to claim 16, wherein the connectors are configured for joining the floor panel with a previously installed floor panel by inward angling.

24. The floor panel according to claim 16, wherein the connectors are configured for joining the floor panel with a previously installed floor panel by snapping-in to a locked position.

25. The floor panel according to claim 16, wherein the compressible material seal is a compressible material other than that of the body of the floor panel.

26. The floor panel according to claim 25, wherein a portion of the active locking surfaces comprises a recess having therein the compressible material seal other than that of the body of the floor panel, wherein the compressible material is arranged in the recess so the compressible material directly contacts a portion of the corresponding active locking surfaces.

27. The floor panel according to claim 25, wherein the compressible material is a polymeric material.

28. The floor panel according to claim 25, wherein the compressible material is made of a material based on acrylic plastic, elastomers of synthetic rubber, urethane rubber, silicone rubber or a polyurethane-based hot-melt adhesive.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The objects and advantages of the invention will become apparent from the following detailed description of preferred embodiments thereof in connection with the accompanying drawings in which like numerals designate like elements and in which:

(2) FIGS. 1a-d illustrate different steps in the production of a floor panel.

(3) FIGS. 2a-e show the composition of a laminate floor with a surface of high pressure laminate and direct laminate.

(4) FIGS. 3a-c illustrate examples of different mechanical joint systems and moisture migration.

(5) FIGS. 4a-d illustrate impregnation of an edge according to prior-art technique.

(6) FIGS. 5a-c show impregnation to form a material seal according to the invention.

(7) FIGS. 6a-c show impregnation of upper joint edges according to the present invention.

(8) FIGS. 7a-d illustrate an embodiment of a material seal according to the invention.

(9) FIGS. 8a-e illustrate the making of a joint seal in a mechanical joint system according to the invention.

(10) FIGS. 9a-d illustrate the making of a mechanical joint system with material seal and joint seal as well as edge reinforcement of parts of the joint system according to the invention.

(11) FIGS. 10a-c illustrate compression of a joint seal according to the invention.

(12) FIGS. 11a-f illustrate alternative embodiments of material and joint seals according to the invention.

(13) FIGS. 12a-b illustrate alternative embodiments of material and joint seals according to the invention.

(14) FIGS. 13a-c illustrate floor panels with a joint seal on two sides according to the invention.

(15) FIGS. 14a-e illustrate mechanical locking systems, FIG. 14a illustrating prior-art technique and FIGS. 14b-e illustrating mechanical locking systems with a compensation seal in the form of an elastic locking means according to the invention.

(16) FIGS. 15a-e illustrate an embodiment of the invention.

(17) FIGS. 16a-f illustrate a joint system which is formed according to the invention and has high strength.

(18) FIGS. 17a-d illustrate sealing of corner portions of neighboring floor panels.

DESCRIPTION OF PREFERRED EMBODIMENTS

(19) FIGS. 1a-d illustrate in four steps the manufacture of a floor panel. FIG. 1a shows the three main components surface layer 31, core 30 and balancing layer 32. FIG. 1b shows a floor element 3, where the surface layer and the balancing layer have been applied to the core. FIG. 1c shows how floorboards 2 are made by dividing the floor element. FIG. 1d shows how the floorboard 2 after edge machining obtains its final shape and becomes a completed floor panel 1 with a joint system 7, 7′ on the long sides 4a, 4b, which joint system in this case is mechanical.

(20) FIG. 2a shows manufacture of high pressure laminate. A wear layer 34 of a transparent material having a high wearing strength is impregnated with melamine with addition of aluminum oxide. A decorative layer 35 of paper impregnated with melamine is placed under this layer 34. One or more layers of reinforcement layers 36a, 36b made of paper core and impregnated with phenol are placed under the decorative layer 35, and the entire packet is placed in a press in which it is caused to cure under pressure and heat to a surface layer 31 of high pressure laminate having a thickness of about 0.5-0.8 mm.

(21) FIG. 2c shows how the surface layer 31 and a balancing layer 32 are then glued to a core 30 so as to form a board element 3.

(22) FIGS. 2d and 2e illustrate direct lamination. A wear layer 34 in the form of an overlay and a decorative layer 35 of decoration paper are placed directly on a core 30, after which all three parts and, also a rear balancing layer 32 are placed in a press where they are caused to cure under heat and pressure to a board element 3 with a decorative surface layer 31 having a thickness of about 0.2 mm.

(23) FIGS. 3a-c illustrate prior-art mechanical joint systems and how moisture, according to studies made by the inventors, affects the joint systems. In FIG. 3a, the floor panel 1 consists of a direct-laminated surface layer 31, a core 30 of fiberboard-based material (HDF) and a balancing layer 32. The vertical locking means which locks the panels 1 and V in the D1 direction, consists of a tongue groove 9 and a tongue 10. The horizontal locking means which locks the panels parallel with the surface layer 31 in the D2 direction consists of a strip 6 having a locking element 8 which cooperates with a locking groove 12. The strip is made by machining of the core 30 of the floor panel and is therefore in this embodiment of the invention formed integrally with the core 30. Dashed arrows MPM indicate how moisture can penetrate from the joint edge into the core 30 as moisture penetrates into the joint system from the front side or upper side of the floor.

(24) FIG. 3b illustrates an embodiment where both the vertical and the horizontal locking means are formed as a tongue groove 9 with a locking groove 12 and a tongue 10 with a locking element 8. The dashed arrow MPJ illustrates how moisture can penetrate through the parts of the locking system.

(25) In FIG. 3c, the floor panel is provided with a surface layer 31 of high pressure laminate, a core 30 of HDF and a balancing layer 32 of high pressure laminate. Also in this embodiment, the vertical locking means consists of a tongue groove 9 and a tongue 10 which are made from the core 30 of the floor panel. The horizontal locking means consists of a strip 6 and the locking element 8, which are made of aluminum and mechanically attached to the core 30.

(26) In the above cases, the joint systems are integrated with the core, i.e., formed or mounted at the factory, and at least part of the joint system is always made by cutting of the core 30 of the floor panel. The locking systems can be joined by angling, horizontal snapping or snapping in an upwardly angled position.

(27) FIGS. 4a-4c illustrate impregnation of joint edges 82, 83 according to prior-art technique, the machined joint being impregnated by an impregnating material 24 being applied sideways by spraying.

(28) To facilitate the understanding, the floor panels are in all figures illustrated with their surface layer directed upwards. In the actual production, the floor panels can however, be oriented with their front side (upper side) directed downwards in the processing machinery and in the subsequent impregnation.

(29) In the prior-art type of impregnation, the floor panel is moved passed a stationary spray nozzle 40. It is difficult to direct the jet of impregnating material 24 so that the edge of the jet is placed immediately under the surface layer 31 in connection with the upper adjoining joint edges 16 with a view to making a material seal 20.

(30) Even if the application can take place using protective plates 43 which protect the surface, it is difficult to provide an efficient protection. The strip 6 and the locking element 8 are in many cases an obstacle, and it is difficult to apply the impregnating material 24 with sufficient accuracy and to obtain sufficiently deep penetration into the area immediately under the surface layer 31 at the upper adjoining joint edges 16. Thus the impregnating depth varies and is smaller immediately under the surface layer and furthest away from the surface layer, as is evident from FIGS. 4a-4d.

(31) FIGS. 5a-5c illustrate impregnation to make a material seal according to the invention. The impregnating material 24 is applied in a suitable fashion in band-shaped areas 44 on the core surface 33, before the remaining layers, i.e., the decorative and the wear layer are applied. The application can take place, for instance, by being sprayed, rolled on etc. conveniently first in the longitudinal direction L in zones where the long sides of the floorboard are later to be formed.

(32) Suitably one long side 4 of the core 30 is used as a guide surface which is then also used as guide surface to facilitate the positioning in connection with application of the surface layer 31, sawing up and machining. In this way, it will be easier to ensure that the material seal 20 is correctly positioned in relation to the completed joint edge.

(33) FIG. 5b illustrates the corresponding impregnation of the parts that will later constitute the short sides 5 of the floorboards. In this impregnation, the core is moved in the transverse direction W perpendicular to the longitudinal direction L. Also in this case, one short side 5 of the core 30 can be used as guide surface in the subsequent manufacture.

(34) FIG. 5c shows an enlargement of a portion that will constitute corners of the floor panel and that will be fully impregnated parallel with the long side to be as well as the short side to be. The parting lines 45 indicate the saw cuts along the long side and the short side for dividing the board element into floorboards.

(35) FIGS. 6a-6c illustrate in greater detail how the impregnation is carried out and penetrates into the core and how the impregnating area is positioned relative to the connecting means to be, which are indicated by dashed lines in FIGS. 6a and 6b. FIG. 6c shows the edges of two floor panels which are made of the board element after this has been cut into individual floorboards by sawing along the line 45.

(36) FIG. 6a shows how the impregnating material 24, when being applied by means of a spray nozzle 40, will penetrate into the core 30 from the core surface 33 and towards the central portion of the core in order to form a material seal 20.

(37) The penetration of the impregnating material 24 into the core 30 can be facilitated by establishing a vacuum on the underside of the core by means of a vacuum device 46. The vacuum device 46 may consist of, for instance, a stationary vacuum table or moving vacuum bands. If the core 30 is stationary during the application of the impregnating material 24, for instance moving spray nozzles 40 are used.

(38) FIG. 6b shows how the impregnating material 24 is positioned in the core 30 of the board element 3 after application of the surface layer 31. The impregnating material then constitutes a material seal 20. The parting line 45 indicates the intended saw cut.

(39) FIG. 6c shows the joint edges 82, 83 of the floor panels 1, 1′ after machining. In order to simplify the illustration, the floor panel has a mechanical joint along one side only. The material seal 20 will be exactly positioned along the two perpendicular sides and in the corner, and in the shown embodiment it is to be found in the upper joint edge portions 80, 81.

(40) A fiberboard-based core 30, e.g. HDF, is produced by ground wood fibers being mixed with a binder, such as melamine, after which a panel is formed by means of pressure and heat. Alternatively, the impregnating material 24 can be applied to the panel in connection with this production, the application taking place within special portions which will later constitute joint portions in the floor panel.

(41) FIGS. 7a-7d illustrate in detail the different production steps to produce a material seal 20 in a mechanical joint system.

(42) According to FIG. 7a, impregnating material 24 is applied from the core surface 33 in the portions 86, 87 (dashed) which in the completed floor panel will constitute joint edge portions which are generally designated 86 and 87 and in which the joint system 9, 10 is formed. A considerable part of the upper joint edge portions 80, 81 is impregnated so as to form a material seal 20.

(43) FIG. 7b shows the floor element 3 with a surface layer 31, a balancing layer 32 and a material seal 20 in the core 30 under the surface layer 31. The Figure also shows the intended saw cut 45 and the contours of the final connecting means by dashed lines.

(44) FIG. 7c shows the edges of the floorboard 2, 2′ after sawing up. The sawing tolerance does not affect the final position of the material seal 20 closest to the joint edge. In the subsequent machining, no additional equipment is required to provide a material seal 20 in the upper joint edge portions 80, 81 of a locking system since this material seal has been provided even before the application of the different surface layers to the core 30.

(45) FIG. 7d illustrates the machined joint with a material seal 20 immediately under the surface layer 31. HP designates a horizontal plane parallel with the surface layer of the panel. The joint edges of the floor panel 1, V are generally designated 82, 83 and can have an optional joint system. In the shown embodiment, the joint edges are formed as a mechanical tongue-and-groove joint which can be locked by inward angling and snapping-in. VP designates a vertical plane (joint plane) which extends perpendicular to the horizontal plane HP at the upper joint edges 80, 81 closest to the surface layer. T indicates the thickness of the floor panel. The largest amount of impregnating material 20 is to be found in the upper joint edge portions 80, 81 immediately under the wear layer 31, i.e. within the area which is most critical in the viewpoint of moisture. This concentration of impregnating material immediately under the wear layer 31 is obtained as a result of the impregnating material being caused to penetrate into the core from the core surface during impregnation.

(46) The material seal 20 in the upper joint edge portions 80, 81 is not only to be found in the core surface 31 closest to the surface layer 31 between the vertical plane or joint plane VP and a lower plane at a distance P2 from the core surface 33, but also all the way in the horizontal direction from the vertical plane VP to a plane at a distance P1 from the vertical plane VP. This entire volume of the core 30 under the core surface 33 is thus impregnated so as to form the material seal 20. Such a location and extent of a material seal cannot be provided by means of the known impregnating methods in which impregnating material 24 is applied to or sprayed onto the upper joint edges 84, 85 at the vertical plane VP when these upper joint edges are already provided with a surface layer 31 and machined to their final shape.

(47) Since the impregnating material 24 penetrates from the core surface 33, the concentration of the impregnating material will be particularly high closest to the core surface 33. In the normal case, the concentration of impregnating material decreases downwards from the core surface 33, as shown schematically in FIGS. 4a-4d.

(48) The material seal 20 can, because of the expense, be limited to a part of the floor panel 1 where the intended connecting means are formed, and therefore, in an exemplary embodiment, does not cover the entire core surface 33.

(49) A material seal 20 can be provided under the surface layer 31 in a considerable portion of the parts of the joint system. Regarding the extent of the material seal in the transverse direction, i.e., transversely of the joint plane VP and along the horizontal plane HP, it can be mentioned that P1 may exceed 0.2 times the floor thickness T and, without difficulty, may amount to 1 time the floor thickness T or more. In many embodiments, the distance P1 can be so great that all parts of the joint edge portion which contain parts of the connecting means of the floor panel are impregnated with the material seal 20.

(50) The impregnating depth, i.e. the distance P2, can conveniently be 0.1-0.3 times the floor thickness T. Preferably, the impregnating depth is such that at least upper parts of the connecting means will consist of impregnated core material.

(51) The material seal 20 of the joint system is located in the core surface 33 at the vertical plane VP and at a distance P1 from VP and that the sealing properties within this area are approximately equivalent or homogeneous, i.e., the core surface 33 has been coated with approximately the same amount of impregnating material 24 per unit of volume of core material 30. As illustrated in FIGS. 4a-4d, the concentration of impregnating material decreases from the joint edge at the vertical plane VP and inwards to the panel parallel with the surface layer 31 at the distance P1 and where the impregnating depth in the horizontal plane will be smaller closest to the core surface 33 and greater at a distance therefrom.

(52) FIGS. 8a-8e illustrate a different embodiment of the invention. In this case, a groove 41 is formed in the core surface 33, for instance in the area where the upper and inner part of the tongue 10 will later be formed. In the groove 41a sealing material 50 is then applied, which has the property that after application it will have a solid form, be moisture-proof, be elastically deformable and may be shaped by cutting.

(53) As shown in FIG. 8b, the core 30 with the groove 41 and the sealing material 50 is then coated with a surface layer 31 and preferably also with a balancing layer 32 to form a floor element. Then the floor element 3 is sawed up in floorboards by cutting along the line 45 and is machined to floor panels 1, 1′ with joint systems. These floor panels are shown in FIGS. 8c-8e, and the joining of the floor panels according to this specific embodiment will be described in more detail below.

(54) As described above, the groove 41 could also be formed in a floor element or floor board which comprises a surface layer 31, 32 that is bonded to the core 30. This means that the groove 41 may be formed both in the surface layer 31, 32 and in the core 30. This groove 41 could be impregnated and/or provided with a sealing material 50. This method offers the advantages that a standard floor element could be used and impregnation materials could be applied, which may be difficult to use in connection with gluing or lamination of the surface layer 31, 32 to the core 30.

(55) The sealing material 50 is formed to a joint seal 55, preferably by cutting by means of tools which are especially adapted to form elastically deformable synthetic materials.

(56) As mentioned above, a large number of sealing materials that can be used are available on the market. As a non-limiting example, materials having the following properties can be used.

(57) A sealing compound based on acrylic plastics, elastomers of synthetic rubber, silicone rubber or the like, which have the properties that they can be applied in the groove 41 as a compound by extrusion, that they can adhere to the core material (optionally after applying a primer layer thereto), that they have good heat resistance, that they are moisture-proof, that they can resist detergents, and that after application they can be cured or dried and change into a solid, elastically deformable form. The properties of the materials are both sufficiently elastically deformable and preferably at the same time can be machined rationally by means of cutting tools.

(58) Different types of polyurethane-based hot-melt adhesives that are applied by being heated and extruded can also be used to form the joint seal. When such materials solidify, they change into a solid, elastically deformable form. These materials can later be formed by cutting but also by using heated rolls or drag tools of a suitable form, which are moved along and in contact with the sealing material 50 to shape this to a suitable geometry.

(59) Combinations of cutting rough machining and final forming by means of hot scraping or rolling tools are also possible as is also a two-step application, where the first application is carried out with a highly liquid material that penetrates into the core, and where the subsequent second application takes place with a material which is more viscous and has good adherence to the former material. It is also possible to use different types of primer system to improve the adhesion of the joint sealing material to the floor panel.

(60) Different materials, methods of application and methods of forming can be used on opposite joint edges and respectively on the long side and the short side for the purpose of optimizing function and cost.

(61) FIG. 8c shows the machined joint edge with a mechanical locking system 9, 10, 6, 8, 12 and an elastically deformable joint seal 55. The joint seal 55 is compressed in connection with the laying of the floor panel. In this embodiment, which shows inward angling, the compression and the deformation begin only when the locking element 8 is already in initial engagement with the locking groove 12 and when the tongue 10 is already in engagement with the tongue groove 9. Both the vertical and horizontal locking functions in the mechanical locking system are thus active as the compression proceeds. As a result, the compression in connection with laying can take place by applying an extremely small amount of force, and the need for compression therefore does not render laying difficult.

(62) FIG. 8d shows how two floor panels 1, 1′ are joined by snapping-in, where compression of the joint seal 55 can take place in the same manner as described above by interaction between a tongue groove 9 and a tongue 10 and where lateral displacement along the joint plane has been facilitated and where a flexible strip 6, a locking element 8 and a locking groove 12 cooperate in the compression of the joint seal and therefore will compress the joint seal in connection with snapping-in.

(63) The joint seal 55 can be formed so that the compression can start when the guide part 11 of the locking element 8 engages the guide part 13 of the locking groove 12. This engagement can be facilitated if the guide part 11 of the locking element is formed as a rounded or beveled part in the upper portions of the locking element. The guiding as well as the compression can also be facilitated if the locking groove 12 is formed with a correspondingly rounded guide part 13 in the lower part of the locking groove 12 closest to the joint edge.

(64) In connection with laying, the joint seal 55 is pressed against an opposite cooperating joint surface 56 in the joint system. In the embodiment illustrated in FIGS. 8a-8e, this joint surface 56 has an inclination of 45 (to the horizontal plane HP of the panel. This is illustrated in FIG. 8e. The pressure applied by the joint seal 55 will therefore be uniformly distributed on the vertical 9, 10 and horizontal 6, 8, 12 locking means of the joint system. This is advantageous since it is desirable to reduce the pressure both in connection with laying and in the locked position. Excessive pressure horizontally in the locked position may result in the floor panels separating and the joint obtaining an undesired joint gap at the adjoining upper joint edges 16. Excessive vertical pressure in the locked position may result in rising of the joint edge portion 80 in the upper part of the tongue groove 9.

(65) FIGS. 9a-9d show how the material seal 20 and the joint seal 55 can be combined to a moisture-proof locking system. In this case, a groove 41 has been formed in the upper side of the core 30 after impregnation to form the material seal 20.

(66) In this embodiment, both the tongue groove side 9 and the tongue side 10 have been provided with sealing material 50a, 50b. The impregnating material 24 serves as binder and increases the strength of the core 30. In this embodiment (see FIG. 9a) the impregnating material 24 has been applied in several areas on the core 30. These areas will constitute a material seal 20 and also a material reinforcement of the upper joint edge portions 80, 81. The impregnation can also provide an edge reinforcement 21a, 21b in the portions where the strip 6 is attached and in an area 21c in the core 30 adjacent to the locking groove 12 where the locking groove 12 cooperates with the locking element 8.

(67) FIG. 9b shows how the sealing material 50a, 50b can be applied in the groove 41. Once the core 30 has been provided with a surface layer 31 and a balancing layer 32 (FIG. 9c), the joint edge and the sealing material 50a, 50b are formed to a joint seal 55a, 55b (FIG. 9d). As mentioned above in connection with FIG. 8b, the sealing material could be provided in a groove that is made in both the surface layer 31, 32 and in the core 30.

(68) The strip 6 can be formed and fixed to the core 30 in different ways [for instance as shown and described in EP1061201 (Valinge Aluminium AB) or WO9824995 (Valinge Aluminium AB)], so that the mechanical locking system for locking together the floor panels 1, V in the vertical and horizontal directions will comprise the tongue 10 and the tongue groove 9; the joint seals 55a and 55b; the material seal 20; the strip 6 with its locking element 8; the edge-reinforced fixing parts 21a, 21b for the strip 6; and an edge-reinforced locking surface 14 in the locking groove 12.

(69) The floor panels 1, 1′ according to this embodiment will then have upper joint edge portions 80, 81 which in the vertical plane VP have a reinforced material seal 20 immediately under the surface layer 31 and joint seals 55a, 55b in connection with the material seal 20. The material seal 20 and the joint seals 55a, 55b together with the moisture-proof surface layer 31 counteract that moisture penetrates into the core 30 and that moisture penetrates through the joint system. This results in a moisture-proof floor. As mentioned above, the vertical 9, 10 and horizontal 6, 8, 12 locking means should be designed in such manner that they can hold the elastically deformable joint seals 55a, 55b compressed and elastically deformed during the life of the floor without the locking means being deformed. The tongue groove 9 is not to be too deep in the horizontal direction and for the upper part or lip 15 of the tongue groove can be rigid so as not to rise. Moreover the locking element 8 and the strip 6 can be designed in such manner that they can resist the pressure applied by the joint seals 55a, 55b without the floor panels 1, 1′ separating while forming a visible joint gap adjacent to the upper joint edge portions 81, 82. The sealing material 50a, 50b can also be selected so that during the entire life of the floor it exerts a pressure and prevents moisture migration through the joint system.

(70) As appears from FIG. 9d, the core 30 is impregnated and reinforced in the areas 21a, 21b and 21c where the strip 6 is fixed and where the locking element 8 locks against the locking groove 12. This can allow use of less expensive core material 30, which can be of lower quality and which by means of impregnation is reinforced to obtain greater strength in the critical areas. In this manner, high quality can be combined with low cost.

(71) A plurality of variants of this moisture-proof locking system are conceivable. The joint seals 55a, 55b can be optionally arranged in the joint system, but it is advantageous if the joint seal is arranged invisibly from the surface close to the surface layer 31. They can be optionally arranged on the tongue groove side 9 or on the tongue side 10, and they can, like in the embodiment shown, be found in both joint parts. Of course, several joint seals 55 can be arranged on each joint part above and beside each other. Moreover, the contact surface between the joint seal 55 and the opposite part in the joint system can be designed in an optional manner with geometries that are, for instance, toothed, triangular, semicircular and the like. Basically all the forms that are normally used when designing sealing strips of elastic synthetic material or rubber can be used.

(72) Using vacuum technique as described in connection with the embodiment according to FIG. 6b, the entire joint system from the surface layer 31 to the balancing layer 32 can be provided with a material seal and edge reinforcement 20. This can increase the joint's strength and protection against moisture, give the machined strip better flexibility, enable machining to obtain smoother surfaces and enable a reduction of the frictional forces when displacing one floor panel relative to another in the locked position. It is also possible to impregnate wood fibers with plastic material in such manner that the wood fibers, together with the impregnating material, will have such properties that they can be formed to a joint seal.

(73) As described above, the sealing material 50a, 50b and/or 20 can alternatively be arranged in grooves which can also be made in the floor element 3 or in the floorboard 2 before the connecting parts are made. The groove 41 can then be made in both the core 30 and the surface layer 31.

(74) Sealing material 50a, 50b can also be arranged at the edge of the floorboard 2 or the floor panel 1 when the entire joint system or parts thereof have been made, and the final forming of the joint seal 55a, 55b can also take place in a separate manufacturing step when the floor panel 1 has already obtained its final shape.

(75) By changing the angle of the pressure surfaces between the elastically deformable joint seals 55a, 55b, the direction and distribution of the compression pressure can be adjusted between fully horizontal and fully vertical direction. It is an advantage if the pressure surfaces are not perpendicular but are inclined in relation to the horizontal plane HP, so that the pressure is distributed with vertical and horizontal components, so that the distribution of pressure is optimized in relation to the possibilities, afforded by the combinations of materials, of forming a rigid upper tongue groove part 15 and a strong horizontal joint 6, 8, 12.

(76) FIGS. 10a-10c illustrate in detail how compression can be achieved in connection with inward angling. The active part 54 of the joint seal 55 is formed with a convex outer part which starts to be compressed when the locking groove 12 engages the locking element 8. Such a position is shown in FIG. 10b. In connection with the final downward angling and locking, the final compression of the joint seal takes place against an opposite cooperating joint surface 56. The joint surface 56 can be coated with, for instance, wax or other similar materials after the joint system has been formed. This can facilitate displacement along the joint edge in the locked position and contribute to improving the functions of the material seal and the joint seal.

(77) As is evident from FIG. 10c, the joint system can have one of more expansion spaces 53a, 53b where the joint seal 55 can swell when being pressed together. The joint seal 55 can thus be formed to have some excess, and if the joint system has been formed with appropriate expansion spaces 53a, 55b, the joint seal 55 can be formed with lower tolerance requirements and maintained function.

(78) The material seal 20 in the upper joint edges has in this embodiment been made with a considerable depth from the core surface 33, which means that the entire area from the upper parts of the joint seal 55 to the core surface 33 is moisture-proof. In this embodiment, the major part of the joint edge portion between the tongue groove 9 and the core surface 33 will constitute a material seal 20.

(79) FIGS. 11a-11c illustrate different embodiments of the invention. FIG. 11a shows an embodiment according to the invention where the joint seal 55 has been formed to minimize edge rising and separation of the joint edges. The contact surface of the joint seal 55 with the opposite cooperating joint surface 56 has a small angle to the plane of the panel, which means that the major part of the compression force will be directed approximately vertically in the direction of the arrow A. The joint edge above the tongue, however, is rigid and the risk of edge rising is small.

(80) In the embodiment in FIG. 11b, the elastically deformable joint seal 55a, 55b is arranged immediately under the surface layer 31, which surface layer thus covers the joint seal. The upper part of the seal 55a, 55b can constitute the material seal which prevents moisture from penetrating into the core 31, while the lower parts of the seal 55a, 55b can constitute the actual joint seal. The sealing 58a, 58b may also cover part of the surface layer 31, 32 closest to the core.

(81) The embodiment according to FIG. 11c is characterized in that separate materials 58a, 58b, which can constitute a material seal, are arranged above the elastically deformable joints seals 55a, 55b. These separate materials 58a, 58b can also be used for the purpose of decoration by the surface layer 31, for instance, being a beveled portion 60, so that the separate materials 58a, 58b will be visible in the joint. Such a decorative material may also be applied in a grove formed in the core 30 and in the surface layer 31, 32 of the floorboard before the final machining of the edges of the floor panel.

(82) The principles of sealing function also without the mechanical joint system if glue is applied between the tongue groove and the tongue 10.

(83) FIG. 1d shows an embodiment where one edge of a floor panel has a material seal 20 and the other edge a joint seal 55a. The joint seal covers the lower part of the surface layer 31. FIGS. 11e and 11f show how the sealing material 55a and 20 may be applied in groves 41a and 41b, which are made in the floor board. The advantage of this method is mainly that the sealing material may be applied with great accuracy. Furthermore, application on the surface may be avoided, a considerable amount of impregnation could be applied, and the locking system may be formed to its final shape with great accuracy in a second machining operation where a reference surface such as 10a may be used to position the floor board.

(84) It is obvious that the application of a material seal and a joint seal could be combined in several ways. Both sides could, for example, have material seal and joint seal, or only join seal or material seal, etc. In this embodiment, a considerable amount of impregnating material 20 is to be found in the upper joint edge portions, immediately under the wear layer 31, i.e., within the area that is most critical in the viewpoint of moisture. This concentration of impregnating material immediately under the wear layer 31 is obtained as a result of the impregnating material being caused to penetrate into the core, from the groove 41b closest to the surface during impregnation. No protection of the surface closest to the final edge is necessary, since the surface is protected by the remaining part 31a of the surface layer and since a considerable amount of impregnation material could be applied. The core part which is closest to the surface could be impregnated to a horizontal depth of about 1 mm or more and the impregnation could be made with this depth over substantially the whole edge of the floor panel. The vertical concentration of impregnating material 20 under the wear layer 31 is higher at the joint surface than in the core. Naturally, the procedure above, which was described with reference to the upper surface 33 of the floor panel, may also be applied to the lower surface of the floor panel.

(85) FIG. 12a shows an embodiment according to the invention where the core 30 has been coated with three different surface layers having different functions. The surface of the floor panel 1, V comprises a transparent, hard and durable wear layer 34 of plastic material, an intermediate decorative layer 35 of plastic film and a reinforcement layer 36 which is made of an elastic material and which can be both moisture-proof and sound-absorbing. The decorative layer 35 of plastic film can be replaced with decorative patterns which are printed directly on the underside of the transparent wear layer 34 or on the upper side of the elastic reinforcement layer 36. This embodiment could also be produced without a seal and may then constitute a floating floor panel with a wood based core such as HDF/MDF, a resilient surface and a mechanical locking system for locking the floor panels horizontally and vertically at its long and short sides through angling and/or snapping. The seal could even in this embodiment be applied in a grove that is formed in the core and in the surface layer of the floor board.

(86) The joint seal 55a on the tongue side has an active part 54 in the form of a convex bulge which presses against the opposite elastic cooperating joint surface 56. The active part 54 of the joint seal 55a has been made small, and this contributes to reducing the friction in connection with lateral displacement when the short sides of the floor panels are to be locked by snap action. Friction can also be reduced by the joint seals 55a, 55b being coated with different types of friction-reducing agents.

(87) FIG. 12b shows an embodiment with the same surface layer 31 as in FIG. 12a, but the joint seals 55a, 55b have been formed in the elastic and deformable reinforcement layer 36 closest to the core 30. If the wear layer 34 is harder than the reinforcement layer 36, on the one hand the deformation of the joint seal 55b will take place in the lower part 57 of the joint seal closest to the core 30 and, on the other hand, no significant deformation of the wear layer 34 will take place. This can result in a moisture-proof and sound-absorbing floor. Also in this embodiment, the sealing means in the form of material seal and joint seal can be designed in many different ways as described above.

(88) It is obvious that the above-described embodiments according to FIGS. 6-12 can be combined. For instance, the sealing means according to FIGS. 12a and 12b or 10a and 10b can be arranged in same joint system. The strip 6 can be made of aluminum etc.

(89) FIG. 13 shows a floor panel 1 with a mechanical joint system on the long sides 4a, 4b and on the short sides 5a, 5b and with a joint seal 55a and 55b on one short side 5a and one long side 4b. When the floor panel 1 is connected with other similar floor panels V on both long sides 4a, 4b and on both short sides 5a, 5b to form a floor, there will be a joint seal on all sides.

(90) If, besides, the joint edges have a material seal 20 according to the embodiments described above, the joint system of the floor panels will counteract penetration of moisture into the joint system on all sides 4a, 4b, 5a, 5b and in all corner portions 38a, 38b, 38c, 38d.

(91) Linear machining of long sides and short sides makes it possible to design the corner portions 38a, 38b, 38c, 38d with the same narrow tolerances as the sides 4a, 4b, 5a, 5b of the floor panels 1. The joint seal in the corners 38a, 38b, 38c, 38d can have an exact fit, and the angular displacements between the short sides 5a, 5b and the long sides 4a, 4b as well as the deviations from parallelism between the long sides 4a, 4b that may appear can be compensated for if it is ensured that the possibility of the joint seals 55a, 55b being deformed when the floor panels have been joined, can exceed these manufacturing tolerances.

(92) FIG. 14a is a cross-sectional view of conventionally designed floor panels 1, V, transversely of a joint along one long side of a wooden floor. The floor panels 1, V have a surface layer 31 of wood with a main direction of fibers parallel to the long side and a core 30 having a different direction of fibers approximately perpendicular to the long side. The longitudinal side edges of the floor panel 1, 1′ have a mechanical joint system 9, 10, 6, 8, 12. In moist surroundings, the upper joint edge portions 80, 81 swell transversely of the direction of fibers (i.e. transversely of the joint between the neighboring floor panels 1, V) more than does the core 30. This means that the floor panels 1, 1′ along the long sides are pressed apart and that the strip 6 is bent backwards. This involves a risk of the upper joint edge portions 80, 81 or the cooperating locking surfaces 14, 18 being compressed or damaged. As the floor panels 1, 1′ dry and shrink in winter (when the relative humidity falls), this may in turn result in a joint gap arising between the upper joint edge portions 80, 81.

(93) FIGS. 14b-14e show how it is possible to compensate for this risk of joint gaps arising by utilizing according to the invention an elastic compensation seal 52 which is inserted into the horizontal locking means 6, 8, 12 for counteracting the effects of swelling and shrinking of the upper joint edge portions 80, 81.

(94) FIG. 14b shows an embodiment of a floorboard 2′ which is suitable to form a joint system with a compensation seal according to the invention. The contour lines of the joint system to be have been indicated by dashed lines in FIG. 14b. The surface layer 31, the core 30 and the balancing layer 32 are laterally offset on both the tongue groove side 9 and the tongue side 10 to minimize the waste when machining the joint edges. In the underside of the floorboard 2 a groove 40 is formed in the core 30. An elastic material 51 is arranged and fixed in the groove 41 by, for instance, extrusion or the like according to the previously described methods or alternatively by gluing or mechanical fixing by, for instance, pressing material into a groove.

(95) In the subsequent machining, the elastic material 51 is removed or reshaped only partially and is formed to an elastic compensation seal 52 which constitutes the active locking surface in the locking groove 12 and which is operative in the horizontal direction D2. This is illustrated in FIG. 14c.

(96) As the joint edge portions 80, 81 swell, the elastic compensation seal 52 will be compressed by its locking surface 14 pressing against the locking surface 18 of the locking element 8. As a result, the mechanical looking system can compensate for the great movements due to moisture in the upper joint edge portions 80, 81 without the joint system being damaged or a visible joint gap appearing in winter when the floor has dried and shrunk.

(97) The problem with the upper joint edges swelling will be greater if the thickness WT of the surface layer 31 is considerable and if this thickness is more than, for instance, 0.1 times the floor thickness T.

(98) A joint system according to the above embodiment is especially suitable for use together with underfloor heating and in surroundings where the relative humidity varies significantly during the year. The elastic locking means or compensation seal 52 can be arranged optionally on the locking element 8 (as in FIG. 14d) or in the locking groove 12 (as in FIGS. 14c and 14e) or in both these parts, and it can be formed with many different geometries having different angles and radii which can facilitate inward angling and displacement. The elastic locking means or compensation seal 52 can also be combined with a material seal 20 and a joint seal 55 according to the previously described embodiments of the invention.

(99) FIG. 14d illustrates an embodiment where the elastic locking means or compensation seal 52 also serves as a joint seal, sealing against moisture. In this case, the seal 52 will, when compressed, also take up the movements that are caused by swelling and shrinking of the upper joint edge portions 80, 81. The compression and, thus, sealing capacity of the elastic seal 52 can thus increase when the floor panels are located in moist surroundings. In this case, there is a material seal 20 which, however, has not been illustrated specifically in this Figure but which extends down to at least the upper parts of the connecting means in the same way as shown in, for instance, FIG. 7d.

(100) FIG. 14e illustrates an embodiment where the elastic compensation seal 52 is compressed by a locking element 8 which is made of a material other than that of the core 30. In this embodiment, the strip 6 and the locking element 8 can be made of aluminum or some other convenient metal. This construction has a flexibility which is greater than in the case where the strip 6 is formed integrally with the core of the floor panel. The invention can also be used in this embodiment. One of the advantages of this embodiment is that the friction is low during lateral displacement in the locked position.

(101) FIGS. 15a-15e illustrate a embodiment of a joint system with a joint seal 55 which has been arranged in the groove 41 in the core 30 adjacent to the upper and inner part of the tongue 10 and which has been formed using a tool 70.

(102) FIGS. 15a and 15b show the critical tolerance which lies in the position of the tool 70 when forming, for instance, a groove 41 in the core 30 or the board element relative to the vertical plane VP to be in the floor panel 1′. The innermost position of the tool 70 is defined by a plane TP1. FIG. 15b shows the outer position of the tool 70 which is defined by a plane TP2 outside the vertical plane VP. As is evident from these two Figures, the contact surfaces of the joint seal 55 for contact with the opposite cooperating joint portion 56 can be formed with great accuracy although the manufacturing tolerance TP1-TP2 for the horizontal positioning of the groove 41 relative to the joint edge to be at the vertical plane VP is fairly great and may exceed 0.2 times the floor thickness T. Using modern production equipment it is possible to manage a horizontal lateral positioning with these tolerances in the entire production chain from production of the surface layer 31 and the board element 3 to the completed floor panel V. The positioning of the tool 70 in the vertical direction is less critical since the tolerance mainly depends on the thickness tolerances of the materials and since these as a rule are small in relation to the tolerances in connection with the lateral positioning.

(103) In this embodiment, it is also possible to use the core surface 33 or the surface of the surface layer 31 as reference surface. The groove 41 and the sealing material 50, which is then formed into the joint seal 55, can therefore be positioned with great accuracy in the vertical direction. The active contact surfaces of the joint system and the joint seal 55 can therefore be made with very narrow manufacturing tolerances, which may be below 0.01 times the floor thickness T although the original positioning of the sealing material 50 is effected with significantly lower tolerance requirements.

(104) In an exemplary embodiment, the manufacturing tolerance between the active part 54 of the joint seal and the upper adjoining joint edges 16 can be significantly lower than the tolerance between another part of the joint seal which is not active, and the above-mentioned upper adjoining joint edge 16. This facilitates rational manufacture and enables high quality manufacture.

(105) If the groove is formed in the core of the floor board and in the surface layer 31, 32, the outer part of the tongue 10 could be formed in the same machining step and this part of the tongue or some other parts of the floor board could be used as a reference surface when forming the locking system and the seal 55. In this case, the vertical and horizontal tolerances could be reduced to as little as 0.01 mm.

(106) FIG. 15c shows the joint seal 55 in its compressed state with expansion spaces 53a and 53b on both sides of the joint seal.

(107) FIG. 15d shows how the joint seal 55 can be formed to facilitate machining of the surface layer 31 when this consists of a laminate. When machining the upper joint edge 80 using a diamond cutting tool 71 which operates horizontally, i.e., perpendicular to the vertical plane VP according to the arrow R, great wear arises at the point 72 on the diamond cutting tool that works on the laminate wear layer 35 which contains aluminum oxide. In order to utilize a greater part of the active surface of the diamond cutting tool, the tool is moved from its starting position 71, for example, step by step downwards in the direction of the tongue 10. The starting position of the tool is indicated by the position 71 and its end position by the position 71′. If the joint seal 55 is located adjacent to the upper and inner part of the tongue 10 in the shown groove 41 and if its upper boundary UP is located at a distance SD from the surface of the surface layer 31 that exceeds, for instance, 0.2 times the floor thickness T, it is possible to provide a joint seal 55 which is designed in such manner that the machining of the joint edge adjacent to and under the surface layer 31 can be facilitated. This form and location of the joint seal 55 at a distance from the surface layer 31 also makes it possible to form, by simple machining of the tongue 10 using the tool 73 (see FIG. 15e) and the opposite and cooperating joint portion 56 on the opposite joint edge, the locking system with radii and angles in a manner that facilitates a snapping-in and/or inward angling function of the locking system.

(108) FIGS. 16a-16e show locking systems that have a plurality of horizontal locking means. These locking systems can be used in connection with moisture-proof locking systems but also merely as ordinary mechanical locking systems to provide a locking system with great horizontal strength. The basic principles can be used in locking systems which are joined by inward angling or snapping-in and using strips 6 which are optionally formed integrally with the core 30 or made of a separate material, such as aluminum, and then secured to the core.

(109) Various combinations of the systems can be used on the long and short sides. The locking elements 8a, 8b, 8c and the locking grooves 12a, 12b, 12c can be made with different angles and radii of, for instance, wood, fiberboard-based materials, plastic materials and like panel materials with strips which are machined from the core or which consist of separate materials, and the locking elements can be designed for installation of the floor panels by angling or snapping-in.

(110) The locking system according to FIG. 16a has two strips 6a and 6b, two locking elements 8a, 8b and two locking grooves 12a, 12b. The locking element 8a and the locking groove 12a enable locking with great strength as well as good guiding in connection with, for example, inward angling. The locking element 8b results above all great in strength and can significantly increase the horizontal locking force. The locking element can be designed so as to be operative when the horizontal tensile force is so great that the upper joint edges begin to move apart, for instance when a joint gap of 0.05 mm or 0.10 mm arises.

(111) FIG. 16b illustrates a locking system with three horizontal locking means with the locking elements 8a, 8b, 8c and the locking grooves 12a, 12b, 12c which can be made according to these basic principles. This embodiment consists of a locking means with good guiding capacity 8a, 12a, and two locking means 8b, 12b and 8c, 12c which contribute to increasing the strength of the joint system in connection with horizontal tension load. This joint system can hold together the joint edges during compression of the joint seal 55. Several locking elements can be formed according to this method in the upper and lower parts of the tongue 10 and in the strip 6, and they can be adjusted to facilitate inward angling, snapping-in and guiding and to increase strength.

(112) FIG. 16c illustrates that a separate locking means 8b, 12b and/or 8c, 12c, for example, can be used to limit separation in a joint system where parts of the locking groove 12a can consist of an elastic locking means 52.

(113) The locking systems according to FIGS. 16a and 16b are mainly intended for snapping-in but they can be adjusted, with minor changes of the angles and radii of the locking system, so as to be easier to angle.

(114) FIG. 16d shows a locking system with two horizontal locking means 8a, 12a and 8b, 12b which are convenient for, e.g., the long side which may be laid by inward angling.

(115) FIG. 16e illustrates a locking system for e.g. the short side which may be laid by snapping-in. The locking system according to FIG. 16e differs from that in FIG. 16f among other things by the locking element being smaller and having a greater inclination in relation to the surface layer, the strip 6a being longer and more flexible, the tongue groove 9 being deeper, and the upper locking element 8b having a locking surface which is more inclined in relation to the surface layer.

(116) The locking grooves 12b and 12c can be made to have advanced forms by means of tools which need not necessarily rotate. FIG. 16f illustrates manufacture of the undercut groove 12c in a joint system according FIG. 16b. The panel can, according to prior-art technique in metal working, be moved past a stationary grooving tool 74 which in this embodiment has teeth 75 which operate perpendicular to the surface layer 31. When the floor panel 1 moves in the direction of the arrow B, the floor panel can pass the grooving tool 74 which is inserted into the tongue groove 9 and the teeth of which make the final forming of the undercut groove 12 with its locking surface. The major part of the tongue groove 9 is formed in a conventional manner using large rotating diamond cutting tools before the panel comes to such a position that the grooving tool 74 is operative. In this manner, geometric shapes can be formed in the same way as in extrusion of plastic or aluminum sections. This technique can also be used to form the groove 41 in the core where the sealing material is arranged.

(117) FIGS. 17a-17d illustrate an enlargement of the corner portion 38a of the floor panel, which has previously been illustrated in FIG. 13, and show a joining of three floor panels 1, 1′ and 1″. Precisely the corner portions constitute one of the critical parts in a moisture-proof floor. To counteract penetration of moisture into the joint system through the corner, the joint seal 55a, 55b can be unbroken in at least one corner 38a according to FIG. 17a. Moreover, the joint seal in the corner 38d of the floor panel 1′ can be positioned and formed in such manner that its active part 54 is not completely removed in connection with the machining of the different parts, specifically the tongue groove 9, of the joint system.

(118) FIGS. 17c and 17d illustrate the joint system in a cross-sectional view along the line C1-C2 in FIG. 17b, i.e., the short side and the corner portion 38a of the panel 1′ are shown in an end view whereas the panel 1 is shown in cross-section along this line C1-C2. In this embodiment, the active part 54 of the joint seal is intact in the panel V at the outer end of the upper lip of the tongue groove 9b. This is due to the fact that the active part 54 is placed in a plane SA which is positioned between the surface layer 31 and the upper part of the tongue groove which in this case is an undercut groove 9b. The active part 54 of the joint seal can thus in this plane be in contact with an opposite cooperating joint surface 56 of the third floor panel 1″.

(119) This embodiment makes the corner 38a have an area SA where the sealing material 55a is positioned in one or more planes and where the joint seal 55a is unbroken. There can thus be no gaps or hollows where moisture can penetrate from the surface and spread in the joint system. The exemplary embodiment of the floor panel has two corners 38b, 38d where the joint seals 55a, 55b are in unbroken contact with the opposite cooperating joint surface. The active part 54 of the joint seal 55 is thus continuous along one entire long side and one entire short side as well as in the corners between these long and short sides.

(120) Hence, a system has been described, for forming a joint between two adjoining edges 4a, 4b; 5a, 5b of floor panels 1, 1′ which have a fiberboard core 30 and a surface layer 31 applied to the upper side 53 of the core and consisting of at least one layer, and which at their adjoining joint edges 82, 83 have connecting means 9, 10 for joining the floor panels with each other in the vertical direction D1, the upper adjoining joint edges 16 of said floor panels 1, 1′ meeting in a vertical joint plane VP. In the system, adjoining joint edge portions 80, 81 of the floor panels 1, 1′ have a material seal 20 for counteracting penetration of moisture into the cores 30 of the floor panels from the joint edges 82, 83, said material seal 20 comprising an impregnation of the core 30 within said joint edge portions with a moisture-sealing agent and/or an agent counteracting or significantly reducing swelling caused by moisture, from the upper side 33 of the core 30 and at least a distance down towards the connecting means 9, 10.

(121) In the system, the concentration of the moisture-sealing agent in the joint edge portion may be higher at the core surface 33 than at a distance therefrom.

(122) In the system, the impregnation of the core 30 may extend down to a depth P2 which is at least 0.1 times the thickness T of the floor panel.

(123) In the system, the impregnation of the core 30 may extend down to a depth P2 which corresponds to at least half the distance between the surface 33 of the core and the upper surfaces of the connecting means 9, 10.

(124) In the system, the impregnation may extend down to at least upper parts of the connecting means 9, 10.

(125) In the system, the impregnation may extend from the joint plane VP inwards in the core 30 a distance P1 which is at least 0.1 times the thickness of the floor panel.

(126) In the system, the impregnation may extend from the joint plane VP inwards in the core 30 a distance P1 which corresponds to at least half the width of the connecting means 9, 10, seen from the joint plane.

(127) In the system, the impregnation may extend from the joint plane VP inwards in the core 30 a distance P1 which corresponds to the width of approximately the entire connecting means 9, 10, seen from the joint plane.

(128) In the system, the core 3 within at least its joint edge portions may be impregnated with a property-improving agent also from its underside.

(129) In the system, the adjoining joint edges 82, 83 may also have connecting means 6, 8, 12 for joining the floor panels 1, 1′ with each other in the horizontal direction HP perpendicular to the joint plane VP.

(130) In the system, the core 30 within at least said joint edge portions may be impregnated with a property-improving agent also from its underside and at least a distance up towards the connecting means 9, 10, 6, 8, 12.

(131) In the system, the impregnation may extend up to at least lower parts of the connecting means 6-10, 12, 14, 18.

(132) In the system, the impregnating agent may be an agent improving the mechanical properties of the core 30.

(133) In the system, the impregnating agent may be an agent improving the elasticity properties of the core 30.

(134) In the system, the core 30 may be impregnated over less than half the distance between said opposite joint edge portions.

(135) In the system, the core 13 may be impregnated within said joint edge portions within which at least parts of the connecting means 6-10, 12, 14, 18 are formed.

(136) In the system, the connecting means 9, 10, 6, 8, 12 may be designed for mechanical joining of neighboring floor panels 1, 1″ at a vertical joint plane VP both perpendicular to the same and perpendicular to the front side of the floor panel.

(137) In the system, the floor panels 1, V may be quadrilateral and have all their opposite joint edge portions impregnated.

(138) In the system, the entire core surface 33 at the joint edge portion of the corner portions 38a-d may be impregnated.

(139) In the system, the floor panels 1, V may be quadrilateral and have mechanical joint systems 9, 10, 6, 8, 12 for vertical and horizontal joining on all sides.

(140) In the system, the connecting means 9, 10, 6-8-12 may be designed for joining a floor panel 1 with a previously installed floor panel V by inward angling and/or snapping-in to a locked position.

(141) In the system, the connecting means 9, 10, 6, 8, 12 may comprise a lower lip or locking strip 6 which may be formed integrally with the core and is included in the mechanical connecting means.

(142) In the system, the lower lip or locking strip 6 is impregnated with an elasticity-improving agent.

(143) In the system, the connecting means 9, 10, 6, 8, 12 may comprise an integrated locking strip 6 which is made of a material other than that of the core 30 and which is fixed to fixing elements 21a, 21b which are formed along one of the opposite parallel joint edge portions of each floor panel.

(144) In the system, the fixing elements 21a, 21b made in the core 30 for the locking strip 6 may be impregnated with a property-improving agent.

(145) In the system, the fixing elements 21a, 21b may be impregnated with a strength-increasing agent.

(146) In the system, the connecting means 9, 10, 6, 8, 12 may be made by cutting.

(147) In the system, the opposite joint edge portions 86, 87 of the floor panels 1, 1′ may also have a joint seal 55 for counteracting penetration of moisture along the joint surfaces of the joint edges between neighboring floor panels when joined, and that this joint seal 55 is formed at the joint edge portions 86, 87 and is made of an elastic sealing material 50, 50a, 50b, which is secured in at least one of the floor panels 1, 1′ and which is compressed, when neighboring floor panels are joined together.

(148) In the system, the joint seal 55 may be formed of parts of the connecting means 9, 10, 6, 8, 12 and/or portions of the floor panel parts above and/or below the connecting means.

(149) In the system, the joint seal 55 may be designed in such manner that the tolerance within a floor panel and/or between different floor panels is smaller between the active part and the upper adjoining joint edges 16 of the joint seal 55 than between another part of the joint seal 55 and said upper adjoining joint edges.

(150) In the system, the joint seal 55 may be made of parts of the vertical connecting means 9, 10 and/or portions of the floor panel parts positioned above the vertical connecting means.

(151) In the system, the joint seal 55 may be made by machining of the elastic sealing material 50, 50a, 50b in connection with the designing of one of the joint edges 82, 83.

(152) In the system, the joint seal 55 may be made by machining of the elastic sealing material 50, 50a, 50b in connection with the designing of one of the vertical connecting means 9, 10.

(153) In the system, the active part 54 of the joint seal 56 may be designed in such manner that the compression is begun approximately when the locking element 8 during inward angling comes into contact with the active locking surface of the locking groove 12.

(154) In the system, the active part 54 of the joint seal 56 may be designed in such manner that the compression is begun approximately when the locking element 8a during snapping-in comes into contact with the active locking surface of the locking groove 12.

(155) In the system, the floor panels may have a joint seal 56 with an active part 54 on a long side and a short side, and that this active part 54 is continuous and covers all these long sides and short sides as well as the corner portion between these long sides and short sides.

(156) The system may further comprise an impact sound insulating layer 36 of plastic between the core 30 and the decorative and wear layer 34. Also, in the system, the free surface portions of the impact sound insulating layer 36 facing the joint VP may be designed by cutting in connection with the designing of the joint edge and are formed as joint sealing means 55a, 55b which are compressed when neighboring floor panels 1, V are joined together.

(157) In the system, the joint sealing means 55, 55a, 55b may be formed with contact surfaces which are inclined to the upper side of the floor panels 1, V in the joined state.

(158) The system may comprise more than one locking means 8a, 8b, 8c for horizontal joining of neighboring floor panels 1, 1′.

(159) In the system, the locking means 8a, 8b, 8c for horizontal joining, one may be placed on one side of the vertical joint plane VP and another on the other side of the vertical joint plane VP.

(160) In the system, the locking means 8a, 8b, 8c for horizontal joining may be arranged at different levels relative to the front side of the floor panels 1, V.

(161) Furthermore, a floor panel has been described, which has a fiberboard core 30 and at least one surface layer 31 applied to the upper side of the core and which at least at two opposite parallel joint edge portions 86, 87 has connecting means 9, 10 for joining of the floorboard in the vertical direction D1 with similar floorboards. In the floorboard, the core 30 within at least said upper joint edge portions 80, 81 is impregnated with a property-improving agent all the way from its upper side 33 and at least a distance down towards the connecting means 9, 10.

(162) In the floor panel, the concentration of the property-improving agent in the joint edge portion may be higher at the core surface 33 than at a distance therefrom.

(163) In the floor panel, the impregnation may extend to a depth which is at least 0.1 times the thickness of the floor panel.

(164) In the floor panel, the impregnation of the core 30 may extend down to a depth P2 corresponding to at least half the distance between the surface 33 of the core and the upper parts of the connecting means 9, 10.

(165) In the floor panel, the impregnation may extend down to at least upper parts of the connecting means 9, 10.

(166) In the floor panel, the impregnation may extend inwards from the joint plane VP in the core 30 a distance which is at least 0.1 times the thickness of the floor panel.

(167) In the floor panel, the impregnation may extend inwards from the joint plane VP in the core 30 a distance corresponding to at least half the width of the connecting means 9, 10, seen from the joint plane VP.

(168) In the floor panel, the impregnation extends inwards from the joint plane VP in the core 30 a distance P1 corresponding to at least half the width of the connecting means 9, 10, seen from the joint plane.

(169) In the floor panel, the impregnation may extend down to at least upper parts of the connecting means 9, 10.

(170) In the floor panel, the core 30 within at least said joint edge portions may be impregnated with a property-improving agent also from its underside and at least a distance up towards the connecting means 610, 12, 14, 18.

(171) In the floor panel, the adjoining joint edges 82, 83 may also have connecting means 6, 8, 12 for joining the floor panel 1 in the horizontal direction HP with another similar floor panel 1′ perpendicular to the joint plane VP.

(172) In the floor panel, the impregnation may extend up to at least lower parts of the connecting means 6-10, 12, 14, 18.

(173) In the floor panel, the impregnating agent is an agent improving the mechanical properties of the core 30.

(174) In the floor panel, the impregnating agent may be an agent improving the elasticity properties of the core 30.

(175) In the floor panel, the impregnating agent may be a moisture-sealing agent and/or an agent counteracting or significantly reducing swelling caused by moisture and intended to form a material sealing means 20.

(176) In the floor panel, the core 30 may be impregnated over less than half the distance between said opposite joint edge portions.

(177) In the floor panel, the core 30 may be impregnated within said joint edge portions, within which at least part of the connecting means 6-10, 12, 14, 18 are formed.

(178) In the floor panel, the connecting means 6-10, 12, 14, 18 may be formed for mechanical joining of the floor panel 1 with a neighboring similar floor panel V at a vertical joint plane VP both perpendicular to the same and perpendicular to the front side of the floor panel.

(179) The floor panel may be quadrilateral and have all its opposite joint edge portions impregnated.

(180) In the floor panel, the connecting means 610, 12, 14, 18 may be formed for joining a floor panel 1 with a previously installed floor panel 1′ by inward angling and/or snapping-in to a locked position.

(181) In the floor panel, the connecting means 6-10, 12, 14, 18 may comprise a lower lip or locking strip 6 which is formed integrally with the core 30 and is included in the mechanical connecting means 6-10, 12, 14, 18.

(182) In the floor panel, the lower lip or locking strip 6 may be impregnated with an elasticity-improving agent.

(183) In the floor panel, the connecting means 610, 12, 14, 18 may comprise an integrated locking strip 6 which is made of a material other than that of the core 30 and which is fixed to fixing elements 21a, 21b which are formed along one of the opposite parallel joint edge portions of the floor panel.

(184) In the floor panel, the fixing elements 21a, 21b formed in the core 30 and intended for the locking strip 6 may be impregnated with a property-improving agent.

(185) In the floor panel, the fixing elements 21a, 21b may be impregnated with a strength-increasing agent.

(186) In the floor panel, the connecting means 6-10, 12, 14, 18 may be made by cutting.

(187) In the floor panel, parts of the connecting means 6-10, 12, 14, 18 and/or adjoining portions of the core 30 within the upper parts of the joint edge portions may be made of an elastic sealing material 50, 50a, 50b, which is secured in the core 30 and designed by machining in connection with the designing of the connecting means 6-10, 12, 14, 18 and which is made to form a joint sealing means 55, 55a, 55b for counteracting penetration of moisture between neighboring joined floor panels 1, V.

(188) In the floor panel, the joint seal 55 may be made of parts of the connecting means 9, 10, 6, 8, 12 and/or portions of the floor panel parts positioned above and/or below the connecting means.

(189) In the floor panel, the joint seal 55 may be designed in such manner that the tolerance within a floor panel and/or between different floor panels is smaller between the active part of the joint seal 55 and upper adjoining joint edges 16 than between another part of the joint seal 55 and said upper adjoining joint edges.

(190) In the floor panel, the joint seal 55 may be made of parts of the vertical connecting means 9, 10 and/or portions of the floor panel parts positioned above the vertical connecting means.

(191) In the floor panel, the joint seal 55 may be made by machining of the elastic sealing material 50, 50a, 50b in connection with the designing of one of the joint edges 82, 83.

(192) In the floor panel, the joint seal 55 may be made by machining of the elastic sealing material 50, 50a, 50b in connection with the designing of one of the vertical connecting means 9, 10.

(193) In the floor panel, the active part 54 of the joint seal 56 may be designed in such manner that the compression is begun approximately when the locking element 8, during inward angling, comes into contact with the active locking surface of the locking groove 12 when the floor panel is joined with a similar floor panel.

(194) In the floor panel, the active part 54 of the joint seal 56 may be designed in such manner that the compression is begun approximately when the locking element 8, during snapping-in, comes into contact with the active locking surface of the locking groove 12 when the floor panel is joined with a similar floor panel.

(195) In the floor panel, there may be a joint seal 156 with an active part 54 on a long side and a short side and that this active part 54 is continuous and covers the entire long sides and short sides as well as the corner portion between said long sides and short sides.

(196) The floor panel may comprise an impact sound insulating layer 36 of plastic between the core 30 and the decorative and wear layer 34. In that floor panel, the free surface portions of the impact sound insulating layer 36 facing the joint VP may be designed by cutting in connection with the designing of the connecting means 6-10, 12, 14, 18 and be made as joint sealing means 55a, 55b which are compressed, when neighboring floor panels 1, V are joined together.

(197) Also described is a method of making a fiberboard core 30 which is intended for production of floorboards 2 or board elements 3 to be divided into floorboards 2 which have opposite joint edge portions 86, 87. The fiberboard core 30 in the exemplary method is impregnated with at least one property-improving agent within defined band-shaped areas 44 which comprise joint edge portions 86, 87 to be of the floorboards 2.

(198) In the method, the impregnation of the wood-based panel may take place from its front side to be.

(199) In the method, the impregnation may be carried out in such manner that the concentration of the property-improving agent in the joint edge portion is higher at the core surface 33 of the core than at a distance from the core surface.

(200) In the method, the impregnation of the wood-based panel may take place from its rear side to be.

(201) In the method, the impregnation may be carried out to a depth corresponding to at least 0.1 times the panel thickness T.

(202) In the method, the impregnation may be carried out at least to such a depth that parts of the connecting means 9, 10 to be of the floor panels will be impregnated.

(203) In the method, the impregnation may be carried out by applying a liquid impregnating agent over the band-shaped areas 44.

(204) In the method, the impregnation may take place with an agent improving the mechanical properties of the core 30.

(205) In the method, the impregnation may take place with an agent improving the elasticity properties of the core 30.

(206) In the method, the impregnation may take place with a moisture-sealing agent.

(207) In the method, the impregnation may take place with a swelling-reducing agent.

(208) In the method, the core 30 may be impregnated over less than half the distance between said opposite joint edge portions.

(209) In the method, grooves 41 may be formed in the panel within the band-shaped areas 44 to a depth on a level with the connecting means 6-10, 12, 14, 18 to be of the floorboards, and an elastic sealing material may be inserted in said grooves.

(210) In the method, the elastic sealing material may be cast in said grooves 41.

(211) There is also described a method of producing a floorboard 2 or a floorboard element 3 which is intended to be divided into floorboards, which have opposite joint edge portions 86, 87, in which method a fiberboard core 30 is coated with a surface layer 31 on its front side and preferably also a balancing layer 32 on its rear side. Before the coating with the surface layer 31 and a possible balancing layer 32, the fiberboard core 30 is impregnated with at least one property-improving agent within defined band-shaped areas 44 comprising joint edge portions 86, 87 to be of the floorboards.

(212) In the method, the impregnation of the wood-based panel 30 may take place from its upper side to be.

(213) In the method, the impregnation of the wood-based panel 30 may take place from its underside to be.

(214) In the method, the impregnation may be carried out at least to such a depth that parts of connecting means 9, 10, 6-8-12 to be of the floorboards will be impregnated.

(215) In the method, the impregnation may be carried out by applying a liquid impregnating agent over the band-shaped areas 44.

(216) In the method, the impregnation may take place with an agent improving the mechanical properties of the core 30.

(217) In the method, the impregnation may take place with an agent improving the elasticity properties of the core 30.

(218) In the method, the impregnation may take place with a moisture-sealing agent and/or an agent counteracting or significantly reducing swelling caused by moisture.

(219) In the method, the core 30 may be impregnated over less than half the distance between said opposite joint edge portions.

(220) In the method, grooves 41 may be formed in the panel 30 within the band-shaped areas 44 to a depth on a level with the connecting means 9, 10 to be of the floorboards and an elastic sealing material 50, 50a, 50b may be inserted into said grooves.

(221) There is also described a floorboard which is intended as semi-manufacture for producing a floor panel 1 and which has a fiberboard core 30 and a surface layer 31 applied to the upper side 33 of the core and which has at least two opposite parallel joint edge portions 86, 87 which are intended for cutting to form connecting means 9, 10 of the floor panel. The core 30 within at least said joint edge portions 86, 87 is impregnated with a property-improving agent all the way from its upper side 33 and at least a distance down towards the connecting means 9, 10.

(222) In the floorboard, the concentration of the moisture-sealing agent in the joint edge portion may be higher at the core surface 33 than at a distance therefrom.

(223) In the floorboard, the impregnation may extend to a depth which is at least 0.1 times the thickness of the floorboard.

(224) In the floorboard, the impregnation of the core 30 may extend to a depth P2 which corresponds to at least half the distance between the surface 33 of the core and the upper surfaces of the connecting means 9, 10.

(225) In the floorboard, the impregnation may extend down to at least upper parts of the connecting means 6-10, 12, 14, 18 to be.

(226) In the floorboard, the core 30 within at least said joint edge portions may be impregnated with a property-improving agent also from its underside and at least a distance up towards the connecting means 6-10, 12, 14, 18.

(227) In the floorboard, the impregnation may extend up to at least lower parts of the connecting means 6-10, 12, 14, 18.

(228) In the floorboard, the impregnating agent may be an agent improving the mechanical properties of the core 30.

(229) In the floorboard, the impregnating agent may be an agent improving the elasticity properties of the core 30.

(230) In the floorboard, the impregnating agent may be a moisture-sealing agent and/or an agent counteracting or significantly reducing swelling caused by moisture.

(231) In the floorboard, the core 30 may be impregnated over less than half the distance between said opposite joint edge portions.

(232) In the floorboard, the core 30 may be impregnated within said joint edge portions, within which at least parts of the connecting means 6-10, 12, 14, 18 of the floor panel are to be formed.

(233) The floorboard may be quadrilateral and have all its opposite joint edge portions impregnated.

(234) In the floorboard, the joint edge portions on the upper side of the floorboard may be impregnated with a moisture-sealing agent and/or an agent counteracting or significantly reducing swelling caused by moisture.

(235) In the floorboard, the joint edge portions on the underside of the floorboard may be impregnated with a strength-increasing agent.

(236) In the floorboard, the joint edge portions on the underside of the floorboard may be impregnated with an elasticity-improving agent.

(237) The floorboard may comprise an elastically deformable sealing material 54, which is secured in the core in such positions thereof as, in machining the floorboard to a floor panel, will form parts of the connecting means 6-10, 12, 14, 18 of the floor panel and/or adjoining portions of the core 30 of the floor panel within the upper parts of the joint edge portions.

(238) In the floorboard, the elastic joint sealing material 56 may be secured in the core 30 within areas which are intended to form a long side and a short side of a floor panel to be and which are continuous along the entire long sides and short sides as well as a corner portion between said long sides and short sides.

(239) The floorboard may comprise an impact sound insulating layer 36 of plastic between the core 30 and the decorative and wear layer 34.

(240) According to this embodiment, a system is provided for forming a joint between two adjoining edges of floor panels which have a fiberboard core and a surface layer applied to the upper side of the core and consisting of at least one layer, and which adjacent to their adjoining joint edge portions have connecting means for joining the floor panels with each other in the vertical direction and which meet in a vertical joint plane. According to this aspect of the invention, the adjoining joints edge portions of the floor panels have a material seal for counteracting penetration of moisture into the cores of the floor panels from the joint plane. This material seal comprises an impregnation of the core within said joint edge portions with a moisture-sealing agent and/or an agent counteracting or significantly reducing swelling caused by moisture all the way from the upper side of the core and at least a distance down towards the connecting means.

(241) This impregnation may extend to a depth which is at least 0.1 times the thickness of the floor panel, seen from the upper side of the core. More preferably, the impregnation extends down to at least upper parts of the connecting means of the floor panels. The extent of the impregnation seen from the joint plane and inwards in the core is preferably also at least 0.1 times the thickness of the floor panel. More preferably, the impregnation, seen from the joint plane, extends a distance corresponding to at least half the width of the connecting means.

(242) It is also preferred for the core to be impregnated from its underside and at least a distance up towards the connecting means. The impregnation of the underside of the core can be effected using a property-improving agent, especially an agent which improves the mechanical properties of the core.

(243) In some connecting systems, it is possible to choose to improve the strength and elasticity properties of the core for the core to better satisfy its function as starting material for mechanical connecting means.

(244) Through this embodiment, the properties of the core are obtained within those parts of the floor panels which are most exposed to influence, i.e., the edge portions. This causes great economic advantages since the impregnation of the core has been limited to precisely the portions that need be improved so as to obtain a floor having the desired properties as regards resistance to the influence of penetrating moisture. The impregnation of the core therefore preferably takes place to less than half the distance between the opposite edges of the core. The impregnation is restricted to those parts of the edge portions within which at least parts of the connecting means are formed.

(245) As mentioned above, the embodiment is particularly usable in connection with systems which are based on mechanical joining of neighboring floor panels, i.e., systems where the mechanical locking means join the floor panels at a vertical joint plane both perpendicular thereto and perpendicular to the front side of the floor panels. The connecting means can particularly advantageously be designed for joining a floor panel with a previously installed floor panel by inward angling and/or snapping-in to a locked position.

(246) When utilizing the embodiment for floor panels with mechanical locking means, the connecting means may comprise a lower lip or locking strip which is formed integrally with the core. In such a case, it is particularly advantageous, as mentioned above, to impregnate the lower parts of the core with a property-improving agent, especially an elasticity-improving agent, so that this lower lip or locking strip obtains optimal properties for its intended function. Within the scope of the invention, however, such a locking strip can also be made of a different material, for instance aluminum, and in that case the parts of the core which form the attachment for the separate locking strip can advantageously be impregnated with such a property-improving agent in order to further increase the core's capability of retaining the attached locking strip.

(247) According to this embodiment, the problem of providing a material seal has thus been solved by the core, and thus not the completed joint edge, being impregnated in the areas where the joint system will later be formed. The impregnating agent can be caused to penetrate so that the upper part of the core closest to the front side will be impregnated in an area where the joint edge will later be formed. Then the core is coated with a surface layer on its front side and preferably also a balancing layer on its rear side. The board element or the floorboard will thus contain parts where the core under the surface layer is impregnated. The board element is sawn, where appropriate, into floorboards having edge portions within which the core under the surface layer is impregnated. The edges of the floorboards are then machined and the completed floor panels will have upper joint edge portions which are impregnated.

(248) An impregnating agent can be applied to the surface of the core and/or in the parts of the core under the surface using methods which do not require the impregnation to take place from the joint edge of the machined joint systems.

(249) The main advantage of a joint system made according to this manufacturing method is that the impregnating agent can be applied without actually requiring tolerances. A further advantage is that the production line in the manufacture of board elements may have a high capacity although the impregnation is carried out at a relatively low speed since the impregnation takes place in connection with the production of the large board elements which are later divided into a plurality of floorboards, and not in connection with the individual edge machining of the floorboards. The impregnating material can also be allowed to penetrate into the core during a relatively long time.

(250) Further advantages are that the method allows impregnating material to be applied directly under the surface layer in areas adjacent to the completed joint edge, i.e., in the upper joint edge portion, and to have a significantly greater extent horizontally from the joint edge towards the floor panel compared with what can be achieved by impregnation from the joint edge of the floor panel after this has been machined for making the connecting means. A further advantage is that all corners will have joint edge portions that are impregnated. Since the joint is formed after impregnation, any swelling in connection with the impregnation will not affect the joint geometry, nor will there be any impregnating residues on the joint surfaces or on the surface layer closest to the joint edge.

(251) One more advantage is that the impregnating result can be checked by measuring the swelling of the core, the board element or the floorboard in portions where the joint edge will be made and in another, not impregnated, part of the panel at a distance from this joint edge, for instance closest to the central part of the floor panel to be.

(252) The impregnating result can be ensured before the final machining of the floor panels is made and this can result in a higher capacity and a considerable saving in costs in the form of a smaller amount of rejects.

(253) This method of providing a material seal is suitable for all fiberboard-based core materials such as homogeneous wood, plywood consisting of a plurality of veneer layers, materials consisting of wood blocks glued together, fiberboard of the type HDF and MDF, particle board, flake board (OSB) and the like. The method can also be used in other core materials which, for instance, do not contain wood fibers and which do not swell when exposed to moisture but where the intention above all is to obtain impregnation of certain parts with a view to providing an edge reinforcement.

(254) In principle, impregnating materials available on the market can be used which contribute to increasing the protection against moisture in wood or fiberboard-based materials. However, it should preferably be possible to apply them in liquid form, and they should have such properties as to allow surface layers to be applied to the core using such prior-art application methods as gluing, direct lamination, varnishing, calendaring or coating of plastic films or the like by extrusion, optionally in connection with grinding or application of primer layers and the like with a view to improving adhesion. As non-restrictive examples of usable impregnating materials, polyurethane, phenol and melamine can be mentioned.

(255) The impregnating liquid can be applied in different ways, for example, by spraying. Other methods, which are very difficult to use in the systems that are used today for impregnating machined joint edges of a completed floor panel, such as rolling, spreading, injecting and the like, function in an excellent fashion in connection with the present invention. The penetration of impregnating agent into the core can be facilitated by applying heat, vacuum, pressure or the like, optionally in combination with, e.g., grinding of the surface of the core before application of the impregnating agent. Grinding of the impregnated core can also take place before applying the surface layer so as thus to remove any swollen surface parts before applying the surface layer. Vacuum and grinding of surface parts cannot be used when impregnation is carried out from the joint edge, and several of the methods described above are also considerably more difficult to use when impregnating from the joint edge.

(256) It is also possible to make grooves in the core in areas that will later constitute joint portions of the floor panel. The impregnating agent can then be applied both from the surface of the core and from the edges of the groove. Different layers having different properties can also be applied. Rolling or spreading is particularly advantageous in the cases where the impregnating agent contains substances which are not environment-friendly such as polyurethane (PUR) with isocyanate. When rolling on the impregnating agent, it is possible to use, within valid limits, up to 10 times more isocyanate than if application takes place by spraying.

(257) The impregnating method can also be used to reinforce the edge. Various chemicals, such as those mentioned above, can be supplied in liquid form which after curing or solidification reinforce the wood fibers and give the joint edge a higher compression, shearing or impact strength or elasticity. The preferred method is particularly suitable to provide a moisture-proof but also strong joint edge with the aid of e.g. thermosetting plastics such as melamine or phenol which as a rule require both heat and pressure to cure. Direct lamination of the surface layer in fact takes place at a high temperature and under high pressure, and in connection with this operation also the impregnating layer can be cured. Hot-gluing of surface layers can also cause curing or drying. This method can be used in combination with moisture impregnation.

(258) Different layers can also be produced by, for instance, a two-step impregnation where the first impregnating step is made with an agent that penetrates deep under the surface of the core and gives increased protection against moisture, while the second impregnating step is carried out with an agent which, for instance, has a different viscosity or other curing properties and which results in a strong joint edge immediately under the surface layer. In this way, for instance direct-laminated floor panels can be produced which have reinforced joint edge portions, whose properties can be equivalent to or better than the considerably more expensive laminate floors which have a surface layer of high pressure laminate.

(259) The embodiment above is intended to be used in order to change the properties of the core by adding different materials before application of the surface layer in those parts of the core which will constitute the joint edge portions of the floor panel.

(260) While the present invention has been described by reference to the above-mentioned embodiments, certain modifications and variations will be evident to those of ordinary skill in the art. Therefore, the present invention is to be limited only by the scope and spirit of the appended claims.