Method and system for attaching a lower element to a panel element and related panel element

Abstract

A method for attaching a sublayer element (23) to a reduced-weight panel element (1) is disclosed. The method comprises providing a panel element and a sublayer element, wherein a back side (4) of the panel element comprises a grooved portion and a residual portion. The grooved portion comprises at least one groove (10). An adhesive (20) is applied to at least a portion of the residual portion of the sublayer element and / or at least a portion of a corresponding residual portion, and the sublayer element is arranged on the back side of the panel element such that the adhesive contacts the sublayer element and the back side.

Description

Technical Field

[0001] The present disclosure generally relates to a lower layer element of a panel element such as a panel. More specifically, the present disclosure relates to a method and system for applying a lower layer element to a panel element such as a panel, wherein the back of the panel element includes at least one groove. The present disclosure also relates to the panel element itself, such as a panel. The panel can be a building panel, a floor panel, a wall panel, a ceiling panel or a furniture panel. Typically, a panel such as a floor panel can include a thermoplastic material or a thermosetting material. The floor panel can be a luxury vinyl tile (LVT tile), a stone plastic (polymer) composite panel (SPC panel), an expanded polymer core board (EPC panel) or a wood plastic composite panel (WPC panel). Alternatively, the panel can include a HDF core board and optionally at least one wood fiber-based layer. In some embodiments, the panel can be a mineral-based panel, such as a cement panel or a panel such as comprising magnesium oxide and optionally magnesium chloride and / or magnesium sulfate. Background Art

[0002] It is known that underlayments can be provided beneath panels, such as floor panels, in order to improve some of their characteristics. For example, the acoustic characteristics, feel, elasticity, thermal characteristics, permeability characteristics and energy absorption of the panel may be affected.

[0003] The backing may be loosely arranged on the substructure onto which the panels are mounted, such as a subfloor, but may also be glued to the panels and / or the substructure.

[0004] Patent US 9,109,108 B1 discloses a method of installing a floor on a floor substrate, wherein a first adhesive layer is applied to the floor substrate. A certain hybrid substrate including an extruded thermoplastic sheet having a plurality of air-filled expanded thermoplastic microspheres distributed therein is placed on the first adhesive layer. A second adhesive layer is applied to the hybrid substrate, and then a plurality of interface LVT floor units are placed on the second adhesive layer.

[0005] Publication US 2012 / 0291387 A1 discloses a floor system comprising an upper floor, a lower floor and / or a backing material disposed between the lower floor and the upper floor. The upper floor may comprise a plurality of luxury vinyl tiles configured such that corresponding tile joints may be formed between adjacent luxury vinyl tiles. The backing material may comprise a cross-linked polyolefin foam.

[0006] Recently, there has been an increasing interest in panels with reduced weight. One way to obtain reduced weight is to remove material from the back of the panel. WO 2013 / 032391 discloses floor panels, such as LVT floor panels, comprising a plastic core layer, comprising flex grooves for increasing their flexibility and for reducing their weight. Furthermore, WO 2014 / 007738 discloses building panels, such as floor panels, comprising a thermosetting resin or a thermoplastic material, preferably comprising a filler, and provided with core grooves.

[0007] WO 2013 / 032391 generally describes that a substrate such as foam may cover the flex grooves. Furthermore, WO 2014 / 007738 describes that a separate covering layer - such as paper, plastic foil, foam, cork or real wood veneer - may cover the core grooves to provide a moisture seal or reduce sound. However, there is still room for improvement, particularly with respect to methods for providing a substrate on a panel. Summary of the invention

[0008] It is therefore an object of at least embodiments of the inventive concept to provide a method for attaching a substructure element, such as a substructure unit, to a weight-reducing and / or flexible board element, such as a panel, which method may require a reduced amount of adhesive.

[0009] It is another object of at least embodiments of the present inventive concept to provide such a method in a more cost-effective manner.

[0010] At least another object of embodiments of the present inventive concept is to provide a corresponding system.

[0011] Furthermore, it is an object of at least embodiments of the inventive concept to provide a corresponding panel element, such as a panel, wherein a lower element, such as a lower unit, is attached thereto.

[0012] At least some of these and other objects and advantages that will be apparent from the description have been achieved by the various aspects described below.

[0013] According to a first aspect of the inventive concept, a method for attaching a lower layer element such as a lower layer unit to a panel element such as a panel is provided. The method comprises: providing a panel element, wherein a back side of the panel element comprises a groove portion and a remaining portion, the groove portion comprising at least one groove; providing a lower layer element; applying an adhesive on at least a portion of the remaining portion and / or on at least a portion of a corresponding remaining portion of the lower layer element; and arranging the lower layer element on the back side of the panel element so that the adhesive contacts the lower layer element and the back side.

[0014] The method may comprise, in sequence, providing a panel element and / or a lower element, applying an adhesive and arranging the lower element on the back side.

[0015] Typically, an adhesive can adhere or attach the underlying component to the backing surface.

[0016] The grooves can reduce the weight of the panel element. With the help of the grooved portion, the surface area of ​​the back side becomes smaller. Thus, the contact area between the back side and the lower layer element can be reduced. Therefore, by selectively applying the adhesive according to the first aspect and embodiments thereof, a smaller amount of adhesive may be required to attach the lower layer element to the panel element.

[0017] On the remaining part and / or residual part, the adhesive may be applied only or substantially only to, for example, 95% of the surface area. Thus, application of adhesive in the groove part may be avoided. The groove part may be free of adhesive.

[0018] The panel element can be a panel itself, such as a floor panel, or it can be split into at least one panel, such as at least two panels, such as floor panels. The panels can be substantially similar. It should be emphasized that throughout the present disclosure, any embodiment involving a panel element can also be an embodiment involving a panel itself. However, it should be noted that the panel can include or can be intended to include a locking system for horizontal and / or vertical locking, preferably a mechanical locking system. The locking system of the panel can be preformed before applying the adhesive and attaching the lower element to the panel, or it can be post-formed after the lower element is attached to the panel.

[0019] The mechanical vertical locking system may include a tenon tongue and a tenon groove, which are configured to cooperate with the tenon groove and the tenon provided on the adjacent panel, respectively. In a first example, the tenon is formed integrally with the panel. In a second example, the tenon is formed separately from the panel. The separately formed tenon may be a preferably flexible removable tenon provided in the insertion groove. The mechanical horizontal locking system may include a locking element provided on the locking strip and a locking groove configured to cooperate with the locking groove and the locking element provided on the locking strip on the adjacent panel, respectively.

[0020] The panel element may extend in first (X) and second (Y) horizontal directions which may be perpendicular to each other. In a first example, the first and second horizontal directions extend parallel to the long side portion and the short side portion of the panel element, respectively. In a second example, the first and second horizontal directions extend parallel to the short side portion and the long side portion of the panel element, respectively. The vertical direction (Z) of the panel element may be perpendicular to the first and second horizontal directions. The thickness of the panel element may be the extension of the panel element in the vertical direction.

[0021] The at least one groove may have a longitudinal extension and a transverse extension. The longitudinal extension may be greater than the transverse extension. The longitudinal extension may be parallel to the first horizontal direction.

[0022] At least one groove of the panel may be arranged in an inner portion of the rear face, spaced from a pair of opposing edge portions of the panel (eg opposing short edge portions), preferably spaced from all edge portions of the panel.

[0023] Likewise, the lower element may extend in first and second horizontal directions that are perpendicular to each other. The first and second horizontal directions of the lower element may be parallel to the first and second horizontal directions of the panel element, respectively.

[0024] The panel element may further comprise a front side arranged at an opposite side relative to the back side. The front side may be adapted to be visible and, at least in some embodiments, the back side may be adapted to be hidden in the installed state of the panel element or panel. Typically, the panel may be a building panel, a floor panel, a wall panel, a ceiling panel or a furniture panel.

[0025] The panel element or panel may comprise a pair of opposing edge portions. The panel element or panel may comprise a first and a second pair of opposing edge portions, for example comprising a long side portion and a short side portion of the panel element / panel, respectively. A locking system for horizontal and / or vertical locking, preferably a mechanical locking system, may be provided on the long side portion and / or the short side portion of the panel.

[0026] Typically, the panel elements or panels such as floor panels may comprise a thermoplastic material or a thermosetting material. In a first example, the panels such as floor panels may be LVT tiles, SPC panels, EPC panels or WPC panels. In a second example, the panels may comprise a core panel, such as an HDF core panel, and optionally at least one wood fiber based layer attached to the core panel. The at least one wood fiber based layer may comprise a powder mix, the powder mix comprising wood powder or wood fibers. Furthermore, the wood fiber based layer may comprise a thermosetting resin, such as a melamine-formaldehyde resin or a urea-formaldehyde resin, and optionally a pigment. The thermosetting resin and / or the pigment may be provided in the powder mix. Optionally, a wood covering, such as wood chips, may be provided on at least one wood fiber based layer. The floor panel may be Paneling or panel.

[0027] In some embodiments, the panel may be a mineral-based panel, such as a cement panel, or a panel comprising magnesium oxide and optionally magnesium chloride and / or magnesium sulfate, for example. For example, the panel may be or may include a magnesium oxide (MgO) panel, a cement board, or a fiber cement board. In particular, the back side may include any of the above materials.

[0028] Providing that the underlying element is attached to the rear face, at least some of the grooves, preferably all of the grooves, may be concealed.

[0029] The groove portion may be formed integrally with the plate element.Thus, the material composition of the back surface and the material composition of at least some parts of the groove portion may be substantially similar.

[0030] Typically, the groove portion may be formed by removing material from the back side. Alternatively, the groove portion may be formed when forming the board element or panel, for example by heat and pressure.

[0031] The remaining portion may be in a horizontal plane extending along the back side of the panel element. Thereby, increased adhesion between the back side and the underlying element may be provided. In a first example, the remaining portion is smooth. In a second example, the remaining portion comprises a certain surface roughness, for example comprising peaks and valleys, the peaks preferably extending vertically from the valleys by less than 0.5 mm, for example less than 0.35 mm. For example, adhesive may be provided on the peaks, preferably such that no or substantially no adhesive is applied in the valleys.

[0032] Throughout this disclosure it should be understood that each embodiment and example etc. discussed in relation to the panel elements in the first, second, third, fourth and fifth aspects are equally applicable to the panels.

[0033] In some embodiments, a panel, such as a furniture panel or a building panel, can be configured to be a component in a panel arrangement, such as a furniture arrangement. In some embodiments, a panel, such as a building panel, a floor panel, a wall panel, or a ceiling panel, can be configured to be mounted in and / or connected to a substructure, such as a profile grid or a subfloor.

[0034] When provided as flooring, the panel with the underlying element attached thereto can be configured to be installed in a floating manner on the underlying floor.Thereby, it may not be necessary to apply an attachment member such as an adhesive to the underside of the underlying element.

[0035] Panels such as floor panels can be configured to be attached to a lower structure such as a subfloor, for example, by adhesive. In some embodiments, the panels can be configured to be loosely installed on a base structure such as a subfloor, without using any locking system that interlocks the panels.

[0036] In some embodiments, adhesive may be applied over substantially the entire remaining portion and / or substantially the entire corresponding residual portion.

[0037] The adhesive may be applied to the upper side of the lower element. Thus, the upper side may be attached to the back side. The adhesive may contact at least a portion of the lower element and may be disposed between the lower element and the back side.

[0038] When the lower element is attached to the back side, the corresponding residual portion may be configured to face and align with the remaining portion of the back side. The lower element may further include a cover portion configured to face and align with the groove portion when the lower element is attached to the back side. The cover portion may cover the groove portion. Preferably, no adhesive is applied in the cover portion. The corresponding residual portion and the cover portion may be corresponding surface portions of the upper side.

[0039] The adhesive may be any known adhesive known in the art, such as glue, which is preferably compatible with the material of the panel element (eg the material of the back side) and the material of the underlying element (eg the material of the upper side thereof).

[0040] The method may further include curing or hardening the adhesive.

[0041] The adhesive may be applied by an adhesive applicator.

[0042] The adhesive can be applied during the displacement of the panel element and / or the underlying element along the feed path. As a result, the method can be made more time-saving. Furthermore, the method can be implemented in a continuous process. The adhesive can be applied in-line.

[0043] The arrangement of the lower element on the back side can be carried out during the displacement of the panel element and / or the lower element in the feed path.

[0044] The application of the adhesive and / or the arrangement of the lower element on the back side can be carried out in a continuous process, for example during the feeding of the lower element and / or the panel element in a continuous process, for example by using rollers. A continuous process may be suitable, for example, when the lower element comprises an elastic material such as foam, but can also be used when the lower element, preferably in the form of at least one lower unit, is configured for individual delivery.

[0045] In some embodiments, the application of adhesive and / or the arrangement of the lower element on the back side can be carried out in a discontinuous process. For example, a discontinuous process may be suitable when the lower element (preferably in the form of at least one lower unit) can be delivered individually, for example in the form of at least one cork board.

[0046] The adhesive may be applied at least to a peripheral portion of the back side and / or a peripheral portion of the upper side of the lower element, any one or both of the peripheral portions preferably extending along a short side portion and / or a long side portion of the board element (or panel) and / or the lower element (or lower unit). The peripheral portion may be arranged in the remaining portion and / or the corresponding residual portion. The peripheral portion of the back side and the upper side may be located in the horizontal outer portion of the back side and the upper side, respectively, preferably close to an edge portion thereof, such as a short side portion or a long side portion. The peripheral portion may be positioned within a distance of 10%, preferably 5%, of the total length of the board element or the lower element from the horizontal outermost portion of the back side or the upper side. Alternatively or additionally, the peripheral portion may be positioned within a distance of 20 mm, preferably 10 mm, from the horizontal outermost portion.

[0047] The peripheral portion of the panel element may comprise a peripheral portion of at least one panel, such as at least two panels, into which the panel element is configured to be divided. Alternatively or additionally, the peripheral portion of the lower element may comprise a peripheral portion of at least one lower unit, such as two lower units, into which the lower element is configured to be cut. The peripheral portion of at least one panel and / or lower unit may extend along a short side portion and / or a long side portion of the panel / lower unit.

[0048] As further described below, the application of adhesive can be controlled so that no adhesive is applied or substantially not applied in at least one cut portion and / or at least one segmented portion. Optionally, the application of adhesive can be controlled so that no adhesive is applied or substantially not applied in, for example, the back portion in which the locking system of at least one panel is configured to be formed. Optionally again, the application of adhesive can be controlled so that no adhesive is applied or substantially not applied in the upper side portion of at least one lower unit, which is configured to contact a portion of the at least one panel, in which the locking system is configured to be formed. Therefore, the need to apply adhesive in some parts may become redundant because they are intended to be processed, such as segmented, cut, or processed to form a locking system. Thus, the amount of adhesive used can be further reduced.

[0049] The peripheral portion may extend continuously around the periphery of the back and / or upper side, for example along the short side portion and / or long side portion of the panel element and / or the lower element. For example, the groove portion may be separated from the peripheral portion of the back and / or the cover portion may be separated from the peripheral portion of the upper side.

[0050] Alternatively or additionally, to apply adhesive on the peripheral portion, the adhesive may be applied on the remaining portion of the interior of the back side, e.g., the interior of the peripheral portion. For example, the adhesive may be applied on the inside of a pair of outermost grooves extending along a first horizontal direction, e.g., along the long side portions of the panel, preferably longitudinally.

[0051] The method may further comprise controlling the application of the adhesive based on a feature of at least one groove. Thereby, the adhesive may be selectively applied in desired areas, such as on the remaining part and / or on the corresponding residual part. The feature may be the shape of the at least one groove and / or the extension length of the at least one groove in the first and / or second horizontal direction of the panel element. Alternatively or additionally, the feature may be the position of the at least one groove in the back side and / or the distance between at least one pair of grooves in the first and / or second horizontal direction or the distance between at least one pair of grooves in the first and / or second horizontal direction, each groove arrangement comprising at least one groove, preferably comprising a plurality of grooves.

[0052] The application may be controlled by a control unit. The control may include controlling the position of the adhesive on the panel element and / or the underlying element, and optionally the amount of adhesive. By varying the amount applied, the thickness and / or width of the adhesive may be varied, for example along the application direction of the adhesive. The application direction may be parallel to the feed direction of the panel element and / or the underlying element.

[0053] The control can be based on data related to the characteristics of at least one groove. In some embodiments, the data related to the characteristics can be retrieved by the control unit from a data storage unit, and the data can be stored in the data storage unit. In some embodiments, the data can be collected by a data collection unit during the operation of the system implementing the method disclosed herein or before the operation. For example, the data can be obtained by scanning the back with a scanner. In some embodiments, the data related to the characteristics can be predetermined. For example, data related to shape, extension, any position, etc. can be predetermined. In some embodiments, collected and predetermined data can be combined. In some other embodiments, the data related to the characteristics can determine the position of the adhesive applicator (e.g., a roller coater or a slot die coater) relative to the plate element and / or the underlying element during the application of the adhesive. For example, and as outlined above, the data can be predetermined data and / or collected data.

[0054] Generally, the method may include retrieving data related to characteristics of at least one groove to control application of the adhesive.

[0055] The position of the lower element may have to be controlled with the position of the plate element, e.g. in synchronization, so that the lower element may become aligned with the plate element. In a first example, the cover portion may be aligned with the groove portion and the corresponding residual portion may be aligned with the remaining portion. Preferably, no adhesive is applied in the cover portion. Synchronization may be particularly important in embodiments where adhesive has already been applied on the lower element. In a second example, the lower element and the horizontal outermost portion of the back side may be aligned, e.g. as described elsewhere herein. The first and second examples may be combined. Synchronization may be controlled by a control unit.

[0056] The adhesive can be applied by contact application, for example by slot die coating or by roller coating. Roll coating and slot die coating can be applied by a roller coater and a slot die coater, respectively. By the contact method, the amount of adhesive applied can be more accurately controlled. An advantage of roller coating is that the adhesive can be applied mainly in the remainder. An advantage of slot die coating is that the adhesive can be applied more uniformly. In some embodiments, when the surface structure of the back side is too rough, it may be preferred to use slot die coating on the lower element.

[0057] Throughout this disclosure, the panel element and / or the underlying element may generally be referred to as a substrate. Thus, the adhesive may be applied to a substrate, such as a panel element and / or an underlying element.

[0058] The adhesive can be applied to the substrate by slot die coating from any direction. For example, the adhesive can be applied from above or from below when the substrate is provided in an inclined, vertical or horizontal position or fed in an inclined, vertical or horizontal direction.

[0059] Slot die coating or roller coating can be used when the substrate is fed continuously, for example by rollers, for example when the substrate, such as the panel element and / or the underlying element, is flexible and / or soft.

[0060] Roller coating can apply the adhesive in a wide variety of applications, as described in detail below.

[0061] The adhesive can be applied by non-contact application, for example by spraying or curtain coating. Spraying and curtain coating can be applied by a sprayer and a curtain coater, respectively. By non-contact methods, the adhesive can be applied at a distance from the substrate. Thus, dirt accumulation in the adhesive applicator can be reduced or even avoided.

[0062] The adhesive may be applied continuously or intermittently, for example, along the feed path of the panel element and / or the underlying element. The continuous or intermittent application may result in the adhesive extending continuously or discontinuously along at least a portion of the panel element and / or the underlying element in the first or second horizontal direction, respectively, e.g. along the entire panel element. By intermittent application, less adhesive may be required. The continuous or intermittent application may be controlled according to any of the control embodiments described herein.

[0063] Intermittent application is contemplated in any of the contact or non-contact applications described herein. In a first example, intermittent application can be achieved by contacting and separating a roller coater from the panel element and / or underlying element while displacing it along a feed path. In a second example, intermittent application can be implemented by transfer application, such as by utilizing a combination of a transfer roller and an adhesive unit (e.g., a slot die and a roller coater). In a third example, intermittent application can be implemented by intermittent non-contact application (e.g., by spraying or curtain coating) while displacing the panel element and / or underlying element along a feed path.

[0064] The adhesive may be applied in a linear application or in a wide application. The linear application may apply the adhesive along a first and / or second horizontal direction of the panel element and / or the underlying element. In addition, the linear application may apply the adhesive over at least a portion of the width of the back or upper side, such as between its corresponding short side portions or long side portions. For example, the linear application may cover less than 20% of the width, such as less than 10% or less than 5%. The wide application may apply the adhesive over substantially the entire width of the back and / or upper side, such as between its short side portions and / or long side portions. Obviously, as in any embodiment disclosed herein, the adhesive is preferably applied only to the remaining portion and / or the corresponding residual portion.

[0065] Linear application can be achieved, for example, by spraying or slot die coating or roller coating. Wide-width application can be achieved, for example, by roller coating, spraying, slot die coating or curtain coating.

[0066] Either of the continuous application or the intermittent application can be a linear application or a wide application.In addition, the continuous application can extend between a pair of edges of the panel element and / or the underlying element that can be transported along the corresponding feed path.

[0067] A continuous wide application may completely cover the remaining portion with adhesive, for example by using a roller coating.A continuous or intermittent linear application or an intermittent wide application may partially cover the remaining portion with adhesive.

[0068] Typically, the adhesive can be applied only in dedicated areas, such as in a controlled manner. Thus, the amount of adhesive used can be further reduced. The adhesive can be applied in a pattern arrangement, such as on the remaining part and / or on the corresponding residual part. For example, the pattern arrangement can be obtained by continuous or intermittent application of the adhesive or even a combination thereof.

[0069] The pattern arrangement may be a primary pattern. The primary pattern may include the same basic applied design that appears repeatedly. For example, the basic applied design may be arranged in the form of a grid, or may be circular, oval or polygonal, such as a triangle, square or star.

[0070] Optionally, the pattern arrangement may further include at least one additional pattern, such as a secondary pattern. The secondary pattern may include at least two primary patterns. In a first example, the at least two primary patterns may be spaced apart from each other. In a second example, the at least two primary patterns may be juxtaposed or interlaced.

[0071] The pattern arrangement can be a predetermined pattern arrangement. In a first example, the pattern arrangement can be applied by controlling the spraying of the adhesive, for example, in pulses and / or patterned application, for example, in a swirl pattern. In a second example, the pattern arrangement can be applied by an engraved roller coater. For example, the applied adhesive can be provided as an embossing or texture. The surface of the engraved roller coater can include multiple structural elements, such as indentations and / or protrusions. The structural elements, such as their position on the roller coater and / or their shape, can correspond to the pattern arrangement, such as an embossing or texture, including its basic application design. In a third example, the pattern arrangement can be applied by an intermittently operated slot die coater and / or by linear application. In a fourth example, the pattern arrangement can be applied by a slot die coater in combination with at least one mask.

[0072] The adhesive can be applied to the plate element and / or the underlying element by transfer application, for example by utilizing a transfer roller and an adhesive unit configured to distribute the adhesive on the transfer roller. For example, the adhesive unit can be a slot die coater. Thus, a more flexible adhesive application operation can be obtained, for example while maintaining the benefits of roller coating. Moreover, an engraved roller for obtaining a pattern arrangement may not be required. In addition, the application of the adhesive may be more easily controlled. For example, by changing the distribution of the adhesive from the adhesive unit on the transfer roller, the pattern arrangement and / or the intermittent application of the adhesive may be easily changed.

[0073] The thickness of the remaining portion may be greater than the thickness of the groove portion, and the main part of the remaining portion preferably has a constant thickness. The thickness may be the distance between the front and back sides in the remaining portion and / or the groove portion, such as the maximum thickness. The main part may be at least 50% of the back side area, such as at least 70% or at least 90%. In some embodiments, substantially the entire or the entire remaining portion may have a constant thickness.

[0074] The at least two grooves may have been formed discontinuously. The application of adhesive may comprise applying adhesive between the discontinuous grooves, for example along the first and / or second horizontal direction of the panel element. Obviously, alternatively or additionally, the application of adhesive may comprise applying adhesive between corresponding cover parts of the lower element, for example along the first and / or second horizontal direction of the lower element.

[0075] The discontinuous grooves may be spaced apart from one another in the first and / or second horizontal direction of the panel element.

[0076] The longitudinal extension of the discontinuous grooves may be parallel to the long side portions of the panel elements.

[0077] The groove portion may comprise at least two groove arrangements, each groove arrangement comprising at least two grooves, such as a plurality of grooves. Preferably, the grooves are discontinuous grooves of the panel element. The groove arrangements may be separated by a partition, which preferably extends continuously along the second horizontal direction, such as between the long side portions of the panel element. For example, the partition may comprise a rectangular portion. By means of the partition, a more stable panel element may be provided.

[0078] In some embodiments, the longitudinal extension of the grooves, such as discontinuous grooves, may be parallel to the short side portions of the panel elements.

[0079] The panel element may comprise at least one layer, and the at least one groove may at least partially penetrate the at least one layer, for example at least the lower layer. The at least one layer may comprise an upper layer. Furthermore, in some embodiments, the lower layer may be a backing layer. The backing layer may be a balancing layer. The backing layer may be provided in the lower layer of the at least one layer, for example in the backing layer. In general terms herein, the at least two layers of the panel element may be laminated together, for example by heat and pressure, or bonded together by an adhesive.

[0080] The panel element may comprise at least two layers, and at least one reinforcement layer, such as a glass fibre layer, may be provided between the at least two layers, for example as a mesh.

[0081] The at least one groove may completely penetrate the underlying layer, such as the backing layer.

[0082] At least one layer optionally including an upper layer and / or a lower layer (eg a backing layer) may each include a polymer-based material, preferably a thermoplastic material or a thermosetting material. Preferably, at least one layer optionally including an upper layer and / or a lower layer each includes a filler.

[0083] The lower unit can be arranged or attached on the back side of the plate element or panel. The plate element or panel and the lower unit can have specifications that are adapted to each other, such as area and / or shape. The area and / or shape of each lower unit can correspond to the area and / or shape of the back side of the plate element or panel, for example, be substantially the same. The shape can be a rectangle or a square. In a first example, before the lower unit is attached to the back side, the area and / or shape of the lower unit corresponds to the area and / or shape of the back side. In a second example, the lower element is attached to the back side and then cut into the lower unit so that its area and / or shape corresponds to the area and / or shape of the back side.

[0084] The lower layer element itself may be at least one lower layer unit. For example, at least one lower layer unit may be stored in an lower layer applicator, which may be configured to arrange the at least one lower layer unit on the back side.

[0085] The lower layer element may be cut into at least one lower layer unit. The method may further include cutting the lower layer element along at least one cutting portion into at least one lower layer unit. For example, the lower layer element may be stored on a roll and may be transferred therefrom to the lower layer applicator.

[0086] When the lower element is attached to the panel element, the lower element may be cut. In some embodiments, the method may include cutting only the lower element without processing or substantially processing - for example at least partially segmenting - the panel element. The panel element may be segmented after cutting. Thereby, a simple separation of the removed material elements may be provided, for example in the case where they are to be recycled. In some embodiments, the method may include cutting the lower element and segmenting the panel element, for example performing the cutting and segmenting in the same operation. Thereby, an efficient treatment may be provided. However, the removed material elements may have to be separated, for example in the case where they are to be recycled.

[0087] The lower layer element may be cut before attaching it to the panel element, for example before the lower layer element is arranged on the panel element.

[0088] In some embodiments, the horizontal outermost portions of the lower element, preferably its upper side, and the back face may be aligned, for example, along their first and / or second horizontal directions. Thereby, a tighter fit between the lower elements of adjacent mounted panels may be obtained, for example, thereby improving their waterproof sealing effect, etc. For example, the extension length of the lower element in the first and / or second horizontal direction may be the same or substantially the same as the extension length of the panel in the first and / or second horizontal direction.

[0089] In some embodiments, the underlying element disposed on the back surface may include at least one chamfer. The chamfer may be pre-formed, or it may be formed after the underlying element has been disposed on the back surface.

[0090] It is emphasized again that throughout this disclosure, it should be understood that when referring to a lower layer element, it can be at least one lower layer unit itself, or it can be cut into at least one lower layer unit.

[0091] The lower layer element can be cut by a cutting tool such as a rotary cutting device, a carving device or a cutter device. In some embodiments, each cutting portion can correspond to the width of the cutting tool.

[0092] The method may further include dividing the panel element into at least one panel, such as at least two panels, along at least one dividing portion. The panel element may be divided by, for example, a dividing tool including a rotating cutting element such as a circular saw blade. In some embodiments, each dividing portion may correspond to the width of the dividing tool.

[0093] Each segmentation portion may be arranged along the first or second horizontal direction of the panel element. In the first example, each segmentation portion may be arranged parallel to the long side portion of the panel element. In the second example, each segmentation portion may be arranged parallel to the short side portion of the panel element.

[0094] The panel elements can be divided after the action of arranging the lower layer elements on the back side.

[0095] Obviously, in some embodiments, the panel elements may be segmented before arranging the underlying element on the back side of the at least one panel segmented thereby.

[0096] Typically, the method may further comprise controlling the application of adhesive so that no or substantially no adhesive is applied to the back side portion of the panel element and / or the upper side portion of the lower element, the upper side portion of the lower element being configured to be further processed, for example by cutting the lower element, dividing the panel element or forming a locking system. This may result in a simpler separation and / or recycling of the material elements of the panel element and the lower element.

[0097] The method may further comprise controlling the application of adhesive so that no or substantially no adhesive is applied in at least one cut portion and / or at least one segmented portion, whereby in these portions the underlying element may be more easily separated from the panel element.

[0098] The method may further include controlling the application of the adhesive so that no or substantially no adhesive is applied to the back portion or the upper portion of the at least one lower unit, preferably the locking system of at least one panel is configured to be formed at the back portion and the upper portion is configured to be arranged along (e.g. in contact with) the back portion.

[0099] During processing, e.g. during segmentation and cutting, and optionally when forming the locking system, the panel elements and the underlying elements, the removed material will typically be a mixture of material elements from the panel elements, the adhesive and the underlying elements, complicating, e.g., recycling. Therefore, the method may further comprise separating material elements removed from the underlying elements and the panel elements, e.g., chips, shavings or strips, during or after processing the panel elements and the underlying elements, e.g., by separating said material elements based on at least one property of the underlying elements and the panel elements, respectively. The processing may comprise cutting the underlying elements into at least one underlying unit and segmenting the panel elements into at least one panel. Alternatively or additionally, the processing may comprise forming the locking system on the panel elements. Optionally, material elements contacting the adhesive of the panel elements and / or the underlying elements may also be separated, e.g., based on at least one property of the adhesive.

[0100] The property may be a physical characteristic of the underlying element, the panel element and the adhesive. More specifically, the separation may be based on at least one selected from the group consisting of material composition of the material element, size of the material element, weight of the material element, shape of the material element and density of the material element.

[0101] The method may comprise screening or sieving the material elements. This may be advantageous when the sizes of the material elements, for example the sizes of the underlying elements and the plate elements, are different.

[0102] The method may comprise gravity separation of the material elements, for example specific gravity separation. It may be advantageous when the size and / or shape of the material elements, for example the size of the material elements of the underlying element and the panel element, are substantially the same.

[0103] The density of the underlying element may be less than the density of the block element or panel.

[0104] The separation may be based on density separation or cyclonic separation. Alternatively or additionally, the materials may be separated by using an air classifier. The separation may employ a dry separation method.

[0105] The adhesive may be applied to the back and / or underlying element at an application temperature of the adhesive. In a non-limiting example, the application temperature may be 5-150° C., such as 10-120° C. Typically, in a non-limiting example, 10-200 g / m 2 , such as 10-40g / m 2 or 60-120g / m 2 An amount of adhesive may be applied to the backside and / or underlying element.

[0106] The adhesive may be a hot melt adhesive. Preferably, the hot melt adhesive is applied at an application temperature between 100°C and 140°C, such as 110-130°C.

[0107] The method may comprise heating an adhesive, such as a hot melt adhesive, thereby achieving an application temperature of the adhesive.

[0108] The hot melt adhesive may be used in any of the application methods described herein, such as slot die coating, roller coating, spray coating, or curtain coating.

[0109] In a non-limiting example, 10-150 g / m 2 , preferably 60-110g / m 2 , more preferably 70-90g / m 2 The amount of hot melt adhesive is applied to the back and / or lower layer element. In some embodiments, the preferred amount of alternative is 10-100 g / m 2 , more preferably 10-50g / m 2 .

[0110] Generally speaking herein, hot melt adhesives can be reactive or non-reactive. In non-limiting examples, hot melt adhesives can be reactive polyurethane (PUR) hot melt adhesives, ethylene vinyl acetate (EVA) hot melt adhesives, polyolefin (PO) hot melt adhesives, copolyamide (CoPA) hot melt adhesives, or rubber-based pressure sensitive adhesives (PSA). EVA hot melt adhesives and rubber-based PSA can be non-reactive. PO hot melt adhesives can be reactive.

[0111] PUR hot melt adhesives can provide strong adhesion between the panel elements and the underlying elements. A non-limiting list of examples of PUR hot melt adhesives are KLEIBERIT 711.2.00, KLEIBERIT 706.1.38, HB Fuller Rapidex NP2075LT, Coating P. Material PR-6620 and Jowatherm-Reaktant 609.40. In non-limiting examples, PUR hot melt adhesives can be applied at 50-100 g / m 2 , preferably 70-90g / m2 Or sometimes 10-100g / m 2 , preferably 10-50g / m 2 amount applied.

[0112] In some embodiments, the adhesive can be a cold adhesive. The cold adhesive can be a one-component (1C) adhesive or a two-component (2C) adhesive. The two-component adhesive can include an adhesive and a hardener. The cold adhesive can be a solvent-based adhesive. However, in some embodiments, a water-based cold adhesive is conceivable. The cold adhesive can be a polyurethane (PUR), such as a 1C PUR or 2C PUR, a styrene copolymer (SBS), a chloroprene rubber (CR), a two-component epoxy resin adhesive, or EVA. 1C PUR can be wet cured. 2C PUR can contain isocyanates and polyols. In some applications, cold adhesives are too slow to be used in fast production lines. As a result, the cold adhesive may have to be post-processed, see discussion below. In a non-limiting example, 120-180 g / m 2 An amount of cold adhesive is applied to the back and / or underlying element.

[0113] In fact, the universal adhesive can be post-treated, for example after the adhesive is applied. The method may further include drying the adhesive and / or exposing the adhesive to radiation, such as infrared or ultraviolet radiation. The post-treatment can be performed before and / or after the lower element is arranged on the back. Preferably, the adhesive is exposed to UV radiation before the lower element is arranged on the back. For example, the adhesive can be a UV curable adhesive, such as an acrylic adhesive. Alternatively or additionally, the method may further include post-heating the adhesive, that is, heating the adhesive when or after the adhesive is applied on the back and / or on the lower element. Preferably, the adhesive is heated before the lower element is arranged on the back. Thus, the adhesion properties of the adhesive can be increased. For example, the applied adhesive can be post-heated when its temperature is reduced to below the operating temperature. The operating temperature can be a temperature above which the adhesion properties of the adhesive exceed a certain threshold. The operating temperature can be higher than the glass transition temperature Tg of the adhesive and / or higher than the melting point Tm of the adhesive. In a non-limiting example, the working temperature may typically be 5-150° C., such as 10-120° C., and for a hot melt adhesive the working temperature may be 100-140° C., such as 110-130° C. For example, the hot melt adhesive may be a PUR adhesive. For example, the adhesive applied to the panel elements may be post-heated after the panel elements are segmented and / or after the locking system is formed on the panel. This may simplify the handling of the panel elements and / or the underlying elements.

[0114] In certain embodiments, post-processing may include exposing at least a portion of the adhesive to moisture / water. Thus, the curing of the moisture-curing adhesive may be activated and / or accelerated. In fact, the method may further include controlling the moisture content and / or relative ambient humidity (RH) applied. Preferably, the adhesive is exposed to moisture before the lower layer element is arranged on the back side.

[0115] The adhesive may be a pressure sensitive adhesive, such as an acrylic based adhesive or a rubber based adhesive. In a non-limiting example, the PSA may be applied at 10-100 g / m 2 , preferably 15-50g / m 2 , more preferably 20-30g / m 2 amount applied.

[0116] Typically, the method may further comprise applying pressure on the lower element and / or the panel element, preferably during the curing or hardening of the adhesive. Such application of pressure is conceivable for any type of adhesive, including pressure-sensitive adhesives and hot-melt adhesives. Pressure may be applied to the lower element and / or the panel element, preferably such that at least a portion of the upper side, such as the entire upper side, is pressed towards and / or against the back side. By applying pressure, the adhesion of the lower element to the panel element may be increased.

[0117] The lower element may be formed continuously without any slots therein. However, in some embodiments, the lower element may be formed discontinuously, including perforations and / or at least one slot. Thereby, heat transfer from a lower structure such as a lower floor to the facade may be improved. For example, when attached, the at least one slot may be aligned with the at least one groove. This alignment may be controlled when synchronizing the position of the lower element with the position of the panel element.

[0118] The lower element may comprise an elastic material. Thus, the lower element may be arranged on rollers and may be transported on rollers more easily. Optionally, the lower element may be compressible.

[0119] The lower element may comprise a rigid material.

[0120] The lower element may comprise a thermoplastic material.

[0121] The underlying element may be a foam, such as a closed cell foam or an open cell foam.

[0122] The lower element may comprise or may be any of irradiated cross-linked polyethylene or polypropylene foam (IXPE foam or IXPP foam), EVA foam, preferably provided as closed-cell foam, polyolefin (PO) foam such as cross-linked polyolefin foam (XLPO) or foam rubber. In addition, the lower element may be a polystyrene (PS) foam, such as extruded polystyrene (XPS), or a polyethylene (PE) foam, such as expanded polyethylene (EPE) or cross-linked polyethylene foam (XLPE), or a PET foam.

[0123] The lower layer element can be a cork-based lower layer element, such as a cork sheet. For example, a cork-based lower layer element such as a cork sheet can be stored on a roller and can be conveyed from the roller to the lower layer applicator.

[0124] The lower element may include a thermosetting resin, such as polyurethane (PU). For example, the lower element may be PU foam.

[0125] The thickness of the underlying element, such as a foam or cork based underlying element, may be between 0.5 mm and 4 mm, for example between 1 mm and 2 mm. The thickness of a panel element, such as a panel, may be between 2 mm and 1 mm. to The depth of the groove may be greater than 0.5 mm, for example greater than 2 mm.

[0126] The panel element may be a panel, and the method may further comprise forming a locking system, preferably a mechanical locking system, for horizontal and / or vertical locking on at least one edge portion of the panel, preferably on two opposite edge portions thereof, for example on all edge portions. In a first example, the locking system is formed before the lower element is arranged on the back side. The area and / or shape of the lower element may correspond to the area and / or shape of the back side of the panel comprising the locking system. In a second example, the locking system is formed after the lower element is arranged on the back side. When forming the locking system, it may be necessary to remove a part of the lower element.

[0127] It should be noted that the steps of the method according to any of the above embodiments are exemplary and do not have to be performed in the exact order disclosed.

[0128] According to a second aspect of the inventive concept, there is provided a panel element, such as a panel, obtainable by a method according to any embodiment of the first aspect. For example, the panel element in the method according to the first aspect may be a panel. Embodiments and examples of the panel element according to the second aspect are largely similar to the embodiments and examples of the first, third, fourth and fifth aspects of the panel element in which it is mentioned.

[0129] According to a third aspect of the inventive concept, there is provided a system for attaching a lower layer element, such as a lower layer unit, to a panel element, such as a panel. The system comprises an adhesive applicator and a lower layer applicator.

[0130] The adhesive applicator may be a contact applicator, such as a roll coater or slot die coater, or a non-contact applicator, such as a spray coater or curtain coater.

[0131] The adhesive applicator may be configured to apply the adhesive by transfer application.

[0132] The system may comprise a conveying device configured to convey the panel elements and / or the underlying elements along the respective feed paths.

[0133] The system may comprise a pressure device configured to exert pressure on the underlying element and / or the panel element. For example, the pressure device may be provided by at least one roller and / or at least one conveyor belt.

[0134] The system may include a post-processing device for post-processing the adhesive after application. The post-processing device may be located upstream and / or downstream of the lower layer applicator along the feed path. In some embodiments, the post-processing device is located at the lower layer applicator. The post-processing device may include a drying device and / or a radiation device, such as an infrared or ultraviolet radiation device, which is configured to dry the adhesive and / or reduce the curing time or hardening time of the adhesive. Alternatively or additionally, the post-processing device may include a post-heating device, which is configured to heat the adhesive after applying the adhesive to the panel element and / or the lower layer element. In some embodiments, the system may include a moisture regulator / humidity regulator for adjusting the applied moisture and / or RH value. The moisture regulator may be located upstream of the lower layer applicator along the feed path.

[0135] The system may include a separation device configured to separate material elements such as chips, shavings or strips removed from the lower element and the panel element during or after processing the panel element and the lower element, for example by separating the material elements based on at least one property of the lower element and the panel element, respectively. The processing may include cutting the lower element into at least one lower unit and dividing the panel element into at least one panel. Alternatively or additionally, the processing may include forming a locking system on the panel element. In a first example, the locking system may be formed after arranging the lower element on the back side and dividing the panel element into at least one panel. In a second example, the locking system of the panel itself may be formed before arranging the lower element on the back side. Optionally, material elements contacting the adhesive of the panel element and / or the lower element may also be separated, for example based on at least one property of the adhesive.

[0136] The system may include a processing tool, such as a cutting tool and / or a parting tool.

[0137] The system may comprise a control unit. Furthermore, the system may comprise a data storage unit and optionally a data collection unit.

[0138] Embodiments and examples of the system according to the third aspect are largely similar to the embodiments and examples of the first, second, fourth and fifth aspects of the system in which they are addressed.

[0139] According to a fourth aspect of the present inventive concept, a panel assembly is provided, comprising a panel and a lower unit. The back side of the panel comprises a groove portion and a remaining portion, the groove portion comprising at least one groove. The lower unit is attached to the back side of the panel by an adhesive contacting at least a portion of the remaining portion and a corresponding remaining portion of the lower unit.

[0140] Embodiments and examples of the panel according to the fourth aspect are largely similar to the embodiments and examples of the first, second, third and fifth aspects of the panel in which it is mentioned. In particular, embodiments and examples of at least one of the group selected from the material composition of the panel, the material composition of the underlying unit, the design of the panel and the design of the underlying unit may be the same. In addition, at least the following embodiments and examples are conceivable.

[0141] The lower unit may be pre-installed on the panel.

[0142] The thickness of the remaining portion may be greater than the thickness of the groove portion, and a major portion of the remaining portion preferably has a constant thickness.

[0143] The adhesive may be applied in a pattern.

[0144] The at least two grooves may have been formed discontinuously.The adhesive may be provided between the discontinuous grooves, for example along the first and / or second horizontal direction of the panel.

[0145] The panel may comprise at least one layer, and the at least one groove may at least partially penetrate the at least one layer, such as at least the lower layer.

[0146] The at least one layer, optionally including an upper layer and / or a lower layer, such as a backing layer, may each comprise a polymer-based material, such as a thermoplastic material, and preferably comprises a filler.

[0147] The lower layer unit may be foam, such as closed-cell foam or open-cell foam, or may be embodied as any other embodiment described with respect to the first aspect.

[0148] According to a fifth aspect of the inventive concept, there is provided a method for attaching a lower layer element such as a lower layer unit to a panel element such as a panel. The method comprises: providing a panel element, wherein a back surface of the panel element comprises a groove portion and a remaining portion, the groove portion comprising at least one groove; providing a lower layer element comprising a pre-applied adhesive; and arranging the lower layer element on the back surface of the panel element so that the adhesive contacts the lower layer element and the back surface.

[0149] The adhesive may be applied to at least a portion of the corresponding remaining portion of the lower element. For example, the adhesive may be applied only to the corresponding remaining portion.

[0150] The method may further comprise synchronising the position of the lower element with the position of the panel element such that the lower element becomes aligned with the panel element, preferably such that the cap portion is aligned with the groove portion and the corresponding residual portion is aligned with the remaining portion.

[0151] The lower element may be provided with a releasable liner, such as a releasable film, and the method may further comprise removing the releasable liner before arranging the lower element on the back surface.

[0152] Embodiments and examples of the method according to the fifth aspect are largely similar to the embodiments and examples of the first aspect of the method in which it is mentioned. In particular, embodiments and examples of at least one of the group consisting of the material composition of the plate element / panel, the material composition of the underlying element / unit, the design of the plate element / panel and the design of the underlying element / unit may be the same. Furthermore, the application details of the pre-applied adhesive, such as the pattern arrangement, may be the same as in the first aspect.

[0153] Embodiments and examples of other aspects of the inventive concept and each of the first, second, third, fourth and fifth aspects are provided in the following embodiments section. It should be emphasized that the embodiments and examples of any aspect can be combined with the embodiments and examples of any other aspect.

[0154] Generally, all terms used in the claims should be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / an / the [element, device, part, means, step, etc.]" should be openly interpreted as referring to at least one instance of the element, device, part, means, step, etc., unless explicitly stated otherwise. BRIEF DESCRIPTION OF THE DRAWINGS

[0155] The present disclosure will be described in more detail below in conjunction with exemplary embodiments and with reference to the attached exemplary drawings, in which:

[0156] Figure 1a-1c An embodiment of a system for attaching a substructure element to a panel element is shown in a perspective view.

[0157] Figure 2a-2e An embodiment of an adhesive applicator is shown in perspective view, and an embodiment of a system for attaching a subjacent element to a panel element is shown in side view.

[0158] Figure 3a-3d An embodiment of an adhesive applicator is shown in perspective view, and an embodiment of a system for attaching a subjacent element to a panel element is shown in side view.

[0159] Figure 3e In the side view an enlarged cross section around the back side of a panel element is shown which includes some surface roughness.

[0160] Figures 4a-4f Embodiments of board elements and panels are shown in perspective, bottom and side views, and in top view the underlying element is shown.

[0161] Figure 5a-5l An embodiment of attaching a lower unit to a panel is shown in a side view and an embodiment of a system and method for attaching a lower element to a panel element is shown in a bottom view and a side view.

[0162] Figure 6 is a flow chart illustrating one embodiment of a method for attaching a subjacent element to a panel element.

[0163] Figure 7a-7c An embodiment of a method for cutting a lower element to be attached to a panel and one embodiment of a method for forming a locking system on a panel are shown in a side view.

[0164] Figure 7d One embodiment of an arrangement of a lower element on a panel element is shown in a side view, wherein the lower element comprises a pre-applied adhesive and is provided with a releasable liner.

[0165] Figures 8a-8f An embodiment of a panel to which adhesive has been applied is shown in bottom view.

[0166] Figures 9a-9f An embodiment of a panel to which adhesive has been applied is shown in a top view and an embodiment of an adhesive applicator is shown in a top view and a perspective view.

[0167] Figure 9g-9h An embodiment of the underlying element is shown in a top view.

[0168] Figures 10a-10d In the top view an embodiment of a lower element is shown and in the bottom view an embodiment of a panel is shown.

[0169] Figure 10e-10f Embodiments of panel elements and lower elements are shown in a bottom view and a top view and in a side view, respectively. DETAILED DESCRIPTION

[0170] Next, we will refer in particular to Figure 1a-1c , 2a-2e, 3a-3e, 5a-51, 6 and 7a-7c describe an embodiment of a method for attaching a lower element 23, such as lower units 23a, 23b, to a back side 4 of a panel element 1, such as a panel 1', comprising at least one groove 10 and an embodiment of a system 30 configured to implement the method. The panels referred to are typically floor panels, such as planks or tiles, but it should be understood that in some embodiments the panels may be building panels, wall panels, ceiling panels or furniture panels.

[0171] Figure 1a-1c An embodiment of a system 30 for attaching a lower layer element 23 to a board element 1 such as a panel 1' is schematically shown in a side view. The system 30 comprises an adhesive applicator 40 and an underlayer applicator 31. The application of the adhesive 20 and / or the arrangement of the lower layer element on the back side can be performed in a continuous process.

[0172] like Figure 1a As shown, the system may further include conveying devices 50, 51, which are configured to convey the plate elements along the feed path FP and / or to convey the lower layer elements along the feed path FP'. The feed direction FD of the plate elements and the feed direction FD' of the lower layer elements may be parallel along at least a portion of the feed paths, for example at the position where the lower layer elements are arranged on the back side 4. The conveying devices 50, 51 may be any conveying devices known in the art. For example, it may include at least one roller 50a, 50b, 51a, 51b, 51c, which rotates along directions R1, R2, R3 and optionally includes a drive mechanism (not shown) for driving at least one roller 50a-50b, 51a-51c, at least one conveyor belt 50c or the like. For clarity, in the embodiments disclosed herein, the conveying device 50 is sometimes omitted. At least one component of the lower layer applicator 31 may be provided by the conveying device 51, for example, by at least one roller 51c.

[0173] The speed of the panel element and the speed of the underlying element along the feed path FP, FP' may be synchronized, eg substantially identical, during operation of the system 30. For example, the speed may be 3-130 m / min, such as 15-100 m / min or 20-50 m / min.

[0174] The system 30 may further include a frame 32 in which the lower layer applicator and the adhesive applicator and optionally the conveying device are arranged. Preferably, the lower layer applicator and the adhesive applicator and optionally the conveying device are fixedly mounted in the frame. It can be understood that the frame 32 exists in the following, but it is not repeated for the sake of clarity.

[0175] The lower layer applicator 31 can be loaded with a lower layer element 23, which is configured to be arranged on the back of the panel element. Generally, the lower layer element can include at least one lower layer unit 23a, 23b itself or it can be cut into at least one lower layer unit 23a, 23b. The lower layer element can be cut to a suitable size by a cutting tool 52, which can be provided in the system 30, see e.g. Figure 1a-1c and 2d. The cutting tool may comprise a rotary cutting device, an engraving device or a knife device comprising at least one knife. In a first example, the cutting tool is fixedly mounted in the frame 32. In a second example, the cutting tool is displaceably mounted in the frame. The cutting tool 52 may be positioned downstream of the lower layer applicator 31FP' along the feed path. Alternatively, as described above, the lower layer applicator may comprise at least one lower layer unit 23a, 23b, which may be stored therein and may be transported therefrom, see e.g. Figure 3d .

[0176] The adhesive applicator 40 may include or may be connected to an adhesive reservoir 42. Furthermore, a control unit 44 may control the application of the adhesive.

[0177] Figure 1a The embodiment in FIG. 1 schematically shows a general adhesive applicator 40, which can be a contact applicator, such as a roller coater 43 or a slot die coater 41, or a non-contact applicator, such as a spray coater 45 or a curtain coater 46. Figure 1a As shown, the adhesive applicator can be configured to apply adhesive 20 to a panel element 1 such as a panel 1'. Figure 1b As shown, the adhesive applicator can be configured to apply adhesive to the lower layer element 23, such as the lower layer units 23a, 23b. Figure 1c As shown, the adhesive applicator may be configured to apply adhesive to the panel element 1, such as the panel 1', and to the lower layer element 23, such as the lower layer units 23a, 23b.

[0178] The position of the lower element may have to be synchronized with the position of the panel element so that the lower element becomes aligned with the panel element. The synchronization may be controlled by the control unit 44.

[0179] The adhesive may be a hot melt adhesive, such as a PUR hot melt adhesive, although other adhesives suitable for the intended purpose are also contemplated as will be apparent from the discussion herein.

[0180] In a first example, the panel may be an SPC panel, the PUR hot melt adhesive may be KLEIBERIT 711.2.00, and the underlying element may be IXPE foam, EVA foam, or a cork board. In a second example, the panel may be an EPC panel, the PUR hot melt adhesive may be HBFuller Rapidex NP 2075LT, and the underlying element may be IXPE foam, EVA foam, or a cork board. In a third example, the panel may be an LVT tile, the PUR hot melt adhesive may be HBFuller Rapidex NP 2075LT, and the underlying element may be IXPE foam, EVA foam, or a cork board.

[0181] like Figure 1a As shown, the system 30 disclosed herein may further include a heating device 33 for heating an adhesive, such as a hot melt adhesive, prior to application. For example, the heating device may heat the adhesive to an application temperature. The system 30 in any embodiment disclosed herein may further include a post-processing device 34, such as a drying device and / or a radiation device, such as an infrared or ultraviolet radiation device. The post-processing device may be located at the lower layer applicator 31 and / or downstream thereof along the feed path FP'. However, alternatively or additionally, in some embodiments, the post-processing device 34, such as an ultraviolet radiation device, may be located upstream of the lower layer applicator 31. Alternatively or additionally, the system may include a post-heating device 36 configured to heat the adhesive after the adhesive is applied. Such an embodiment is, for example, Figure 1c Shown in.

[0182] In some embodiments, and as Figure 1b As shown, post-treatment may include exposing the adhesive to moisture, for example, via a moisture conditioner 39. In fact, the method may further include controlling the applied moisture content and / or RH value. Preferably, the moisture conditioner is disposed upstream of the lower layer applicator 31 along the feed path FP and / or FP'.

[0183] Optionally, the system 30 may further comprise a pressure device 35 configured to exert pressure on the lower layer element and / or the panel element, preferably located at the lower layer applicator 31 and / or downstream thereof along the feed path FP'. At least one component of the pressure device 35 may be provided by the conveying device 50, 51, for example by at least one roller 50b, 51c, or by at least one roller 51c and a portion of the conveying device 50, such as at least one conveyor belt 50c, or the like. For example, the distance between the components of the conveying device, such as a pair of rollers or a portion of a roller and a conveyor belt, between which the panel element may be fed, may be smaller than the combined thickness of the panel element and the lower layer element (preferably including the adhesive).

[0184] like Figure 1b-1c , 2a-2b and 2e schematically show that the adhesive can be applied by contact application, such as by slot die coating or roller coating. As described above, Figure 1a The adhesive applicator 40 in the embodiment may be a contact applicator, such as a roller coater 43 or a slot die coater 41. Figure 1c Any one or both of the adhesive applicators 40 in may be a contact applicator, such as a roller coater 43 or a slot die coater 41 .

[0185] Figure 1b A slot die applicator 41 is shown applying adhesive 20 on, for example directly on, the underlying element 23. The adhesive may be applied from below, for example, while the underlying element is fed in a horizontal or inclined direction. Figure 2a In general, a slot die coating on a substrate 60 is shown in perspective view, which substrate 60 can be a panel element 1, such as a panel 1', or a lower layer element 23, such as a lower layer unit 23a, 23b. The slot die coater can form an adhesive coating on the substrate 60, which adhesive coating can be continuous in a direction TD or TD' transverse to the feed direction FD or FD', respectively, and in operation, the directions TD, TD' are preferably parallel to the back side 4. However, in some embodiments, the adhesive coating on the substrate 60 can be discontinuous in the direction TD or TD', see Figure 2e , wherein a slot die coater is used in combination with at least one mask 40a. The adhesive may be deposited from at least one nozzle 41a extending in a transverse direction TD or TD', depending on whether the substrate is a plate element or an underlying element, respectively.

[0186] Figure 2b, an embodiment is shown in the side view in which the adhesive applicator 40 includes at least one roller applicator 43, such as an application roller 43a and a metering roller 43b, and preferably includes a scraper 43c. The adhesive applicator can apply the adhesive 20 to the panel element 1, such as directly thereon. Generally speaking in this document, it should be understood that at least one roller applicator 43 can be rotated during the application of the adhesive. Preferably, a rotating mechanism (not shown) can be configured to rotate at least one roller applicator 43.

[0187] As in Figure 2c-2d In the embodiments of 3a-3b, schematically shown in side and perspective views, the adhesive can be applied by non-contact application, such as by spraying or curtain coating. It should be remembered that Figure 1a The adhesive applicator 40 in FIG. 4 may be a non-contact applicator, such as a spray coater 45 or a curtain coater 46. In operation, the non-contact applicator may generally be spaced apart from the underlying element.

[0188] Figure 2c The non-contact application of adhesive 20 onto panel element 1 by adhesive applicator 40 , such as sprayer 45 or curtain coater 46 , is generally shown.

[0189] also, Figure 2d The non-contact application of adhesive 20 on the lower element 23 by an adhesive applicator 40, such as a sprayer 45 or a curtain coater 46, is generally shown. The application of adhesive and / or the placement of the lower element on the back side can be performed in a continuous process. The conveying device 50, 51 configured to convey the panel element along the feed path FP and / or convey the lower element along the feed path FP' can be implemented as described elsewhere in the present disclosure, for example by at least one roller 50a, 50b, 51a, 51b, which rotates in the directions R1, R2, R3 and optionally includes a drive mechanism (not shown) for driving at least one roller, at least one conveyor belt or the like. Figure 2c Other features of the embodiments in the present invention may be similar to those described in the Figure 1a-1c Any embodiment described in the embodiments.

[0190] Figure 3a yes Figure 2d 4. An enlarged perspective view of the area around the adhesive applicator 40 in FIG. 4, where the adhesive applicator 40 is provided in the form of a sprayer 45. Obviously, the sprayer 45 can apply the adhesive 20 to the back side 4, for example, to the remaining portion 4b described below, such as Figure 3b As shown schematically, Figure 3b Can be Figure 2c FIG. 4 is an enlarged perspective view of the area surrounding the adhesive applicator 40 in FIG.

[0191] In some embodiments, and as discussed elsewhere in this disclosure, the non-contact applicator 40 may be a curtain coater 46 that coats the surface of the substrate. Figure 3c Schematically shown in operation on a substrate 60, here the substrate 60 is a panel element 1, such as a panel 1'. However, it should be understood that in some embodiments, the substrate 60 on which the adhesive 20 is applied may be a lower layer element. Figure 3c As shown, adhesive 20 may be stored in an adhesive reservoir 42 .

[0192] In some embodiments, Figure 2d The adhesive applicator 40 in FIG. 4 may be a contact applicator, such as a roller coater 43 or a slot die coater 41 .

[0193] It should be understood that Figure 2b-2c In the embodiments of 3c and 3d, after applying the adhesive, the lower layer element can be arranged on the panel element 1 by the lower layer applicator 31, which can be done according to the text, for example, in Figure 1a-1c , 2d, 3d or 5f.

[0194] Arranging the lower layer element on the back side can be performed in a discontinuous process, for example by operating the lower layer applicator 31 intermittently. Figure 3d As schematically shown in any embodiment herein, for example, Figure 1a-1c , 2b-2c, 3c and 5f, the lower layer applicator 31 may include at least one lower layer unit 23a, 23b that can be stored therein. The area and / or shape of the lower layer unit 23a, 23b may correspond to the area and / or shape of the back side of the plate element 1 or the panel 1'. The lower layer applicator may be suitable for arranging at least one lower layer unit on the back side 4 of the plate element 1 or the panel 1'. The at least one lower layer unit may be arranged thereon sequentially, for example, individually thereon. Any known method in the art may be adopted, for example, a method using a suction cup 55. The control unit 44 may control the operation of the lower layer unit.

[0195] Optionally, Figure 2d The system 30 in or 3d may further comprise a pressurizing device 35 configured to apply pressure on the lower layer element and / or the plate element, which is preferably located at the lower layer applicator 31 and / or downstream thereof along the feed path FP'.

[0196] Figures 4a-4f An embodiment of a panel element 1 such as a panel 1' that can be obtained by at least some embodiments of the methods disclosed herein is shown. In fact, embodiments of the system 30 described herein, such as Figure 1aThe embodiments of any one of 2a-2e, 3a-3d and 5a-5l can be used to implement a method for attaching a lower layer element 23 such as a lower layer unit 23a, 23b to a lower layer element 23 respectively. Figure 4a and Figure 4b The method is shown in perspective on a panel element 1 or panel 1 ′.

[0197] The panel 1 ' and the lower unit 23b may be referred to as a panel assembly. Figure 4c An embodiment of the back side 4 of a panel 1' is shown in a bottom view, the panel 1' comprising a grooved portion 4a having at least one groove 10 and a remaining portion 4b without any grooves. The remaining portion may be in a horizontal plane HP extending along the back side. The horizontal plane HP may be parallel to a horizontal plane extending along the front side 2 of the panel 1'.

[0198] like Figure 4c As shown, at least one groove 10 is preferably arranged in the inner space of the back side 4 so as to be spaced apart from a pair of opposite edge portions of the panel, such as opposite short side portions 1c, 1d, preferably all edge portions 1a, 1b, 1c, 1d.

[0199] As in Figure 4d The embodiment in FIG. 1 is shown in a top view, wherein the lower element 23 or the lower units 23a, 23b comprises an upper side 21 configured to face the plate element or panel and an opposite lower side 22, see Figure 4e The upper side 21 includes a cover portion 21a and a corresponding residual portion 21b, which are configured to face and align with the groove portion 4a and the remaining portion 4b, respectively, when a lower layer element is attached to the back surface.

[0200] Figure 4e and 4f In a side view, an embodiment of a panel 1' is schematically shown, comprising long side portions 1a, 1b and short side portions 1c, 1d, respectively, wherein a lower unit 23b is attached to the back side 4 of the panel. For example, the panel and the lower unit may correspond to Figure 4c-4d The adhesive 20 contacts at least a portion of the remaining portion 4b and a corresponding remaining portion 21b of the lower element, thereby attaching the lower unit to the back surface.

[0201] The panel 1' or in general the board element 1 may comprise a layer arrangement 3 comprising at least one layer 3a, 3b, 3c. Optionally, the layer arrangement 3 may comprise a lower layer 3c which may be a backing layer. Thereby, at least one groove 10 at least partially penetrates at least one layer 3a, 3b, 3c, for example at least the lower layer 3c.

[0202] Typically, the panel 1 ' may comprise a locking system 9 for horizontally and / or vertically locking a preferably mechanical locking system on at least one edge portion, preferably on two opposing edge portions thereof. Figure 4c-4e A mechanical vertical locking system is shown, which comprises a tongue 9a, 9a' and a tongue groove 9b, 9b' formed on the long side parts 1a, 1b and the short side parts 1c, 1d. In addition, Figure 4c-4e A mechanical horizontal locking system is shown, which comprises locking elements 8, 8' arranged on locking strips 6, 6' and locking grooves 14, 14' formed on the long side parts 1a, 1b and the short side parts 1c, 1d. The tongue 9a on the long side part 1a can be formed integrally with the panel, while the tongue 9a' on the short side part 1d can be formed separately from the panel and arranged in the insertion groove 15. The tongue 9a' can be a displaceable tongue, preferably flexible. Obviously, Figure 4c-4f The locking systems in are exemplary and other locking systems are also conceivable.

[0203] In some embodiments, the locking system 9 may include at least one connecting element configured to be attached to the back side 4 of adjacent panels, for example in their corners, to connect them to each other. Each connecting element may include an adhesive layer configured to contact the back side of the adjacent panels. For example, the connecting element may be an adhesive tape.

[0204] The panel may extend in a first horizontal direction X and a second horizontal direction Y which may extend parallel to the long side portions 1a, 1b and the short side portions 1c, 1d of the panel, respectively.

[0205] The groove length GL of at least one groove 10, for example along the first horizontal direction X, can be less than the distance between the components of the locking system 9, for example the distance between the short side portions 1c, 1d. In one embodiment, the groove length GL can be at least 75% of the distance between the components of the locking system 9, for example at least 85% of the distance, for example at least 90% of the distance. In a first example, the groove length GL is less than the distance from the inner wall of the locking groove 14' to a vertical plane VP extending along an edge portion of the panel, for example the short side portion 1d including the locking strip 6'. The vertical plane VP can be arranged along the upper part of the short side portion 1d and can extend perpendicular to the horizontal plane HP. In a second example, the groove length GL is less than the distance from the inner wall of the locking groove 14' to the innermost wall portion of the insertion groove 15 that can be arranged on the short side portion 1d including the locking strip 6'.

[0206] However, if Figure 4b As shown, it is conceivable that in some embodiments the panel 1' is not provided with a mechanical locking system. For example, it may be adapted to be loosely arranged on the subfloor, or it may be glued to the subfloor.

[0207] The remaining part 4b may have a thickness Tb greater than the thickness Ta of the groove part 4a. Furthermore, a major part of the remaining part preferably has a constant thickness, for example in an area spaced apart from the edge parts 1a-1d in which the locking system 9, preferably a mechanical locking system comprising a tongue 9a, 9a' and a tongue groove 9b, 9b' and / or a locking element 8, 8' and a locking groove 14, 14' is formed.

[0208] Preferably, the shape of the end 16 of the groove 10 along its longitudinal direction is curved. Such a shape can be obtained, for example, when the groove is formed by a rotary cutting device.

[0209] At least one layer 3a, 3b, 3c of the layer arrangement 3 may each comprise a polymer-based material, such as a thermoplastic material, and preferably a filler. The layers may be (co)extruded. In this embodiment, the thermoplastic material is PVC, but other thermoplastic materials may obviously be used, such as PE, PP, PET or ABS. The filler of any layer may be a mineral material, such as calcium carbonate (CaCO3) or a stone, such as stone powder, or the like. Optionally, at least some of the layers - such as all the layers - may contain plasticizers and / or additives. For example, the floor panels may be LVT tiles, SPC panels, EPC panels or WPC panels.

[0210] In other embodiments, the polymer-based material may be a thermosetting material. For example, the panel may include a HDF core and optionally at least one wood fiber-based layer attached to the core. For example, a floor panel or a wall panel may be Paneling or panel.

[0211] In further embodiments, the panel may be a mineral based panel, such as a cement panel or a panel comprising magnesium oxide and optionally magnesium chloride and / or magnesium sulfate. For example, a panel such as a floor panel or a wall panel may be or may comprise a MgO panel, a cement board or a fiber cement board.

[0212] The lower layer element 23, such as the lower layer units 23a, 23b, may include an elastic material. Figure 1a-1c , 2d, 3d-3e, 4a-4b, 4d-4f, 5a-5d, 5f-5l and 7a-7c. The lower layer element in any of the embodiments disclosed is a foam, such as a closed-cell foam, such as IXPE foam, EVA foam, XLPE foam, foam rubber or PU foam. However, in some embodiments, such as in any of the accompanying drawings, the lower layer element may include cork, such as cork sheets. In some further embodiments, the lower layer element may include a thermosetting resin, such as PU.

[0213] It should be understood that Figure 4b-4f Similar features as described in relation to the panel 1 ' and the lower unit 23b may also be used for the panel element 1 and the lower unit 23a.

[0214] Embodiments of the system 30 and method for attaching a lower element, such as a lower unit, to a panel element, such as a panel, are respectively described in Figure 5a-5l is schematically shown in Figure 6 The flowchart (block S10) in FIG. 1 is used for explanation. Figure 1a-1c , the systems described in 2a-2e and 3a-3d, and Figures 4a-4f and embodiments of the board elements / panels in 7a-7c.

[0215] Figure 5a-5d The arrangement of the lower unit 23b on the back side of the panel 1' is schematically shown in the side view. Figure 5e-5f The arrangement of the lower layer unit 23a on the back side of the panel element 1 is shown, preferably in a continuous processing process, whereby the panel element and the lower layer element are fed along a feed path FP, FP', for example along a feed direction FD, FD'.

[0216] Typically, the method comprises providing Figure 5e The plate element 1 shown or Figure 4c or Figure 5a The panel 1' shown and Figure 4d or Figure 5a The lower layer elements 23 or lower layer units 23a, 23b are shown. Figure 5a (Block S11), wherein the board element or panel comprises a groove portion 4a. Furthermore, the method comprises applying an adhesive 20 on at least a portion of the remaining portion 4b and / or on at least a portion of a corresponding residual portion 21b of the underlying element (Block S12), see Figure 5b and 5f The application can also be as in, for example, Figure 1a-1c , 2a-2e and 3a-3c as in any of the embodiments described.

[0217] Figure 5fThe adhesive applicator 40 in may comprise at least one roller applicator 43. The adhesive 20 may be applied during displacement of the panel element 1 and / or the lower layer element 23 along the feed paths FP, FP'. Preferably, at least two roller applicators 43 are spaced apart from each other in the transverse direction TD. Thus, no or substantially no adhesive is applied in at least one cutting portion 12a, in which the lower layer element is configured to be cut into at least one lower layer unit, for example at least two lower layer units, and / or no or substantially no adhesive is applied in at least one segmentation portion 12b, in which the panel element is configured to be segmented into at least one panel, for example at least two panels. Moreover, preferably, no or substantially no adhesive is applied in the back portion 4d, in which the locking system 9 of at least one panel 1' is configured to be formed. The segmented panels may be substantially similar.

[0218] After applying the adhesive as described above, the lower layer element 23 is arranged on the back side of the board element or panel by the lower layer applicator 31 (block S13) so that the adhesive contacts the lower layer element and the back side, see e.g. Figure 5c and 5f Preferably, the arrangement of the lower element on the back side is performed during the displacement of the panel element and / or the lower element along the feed path FP and / or FP', such as Figure 1a-1c and any of 2d, but it is also conceivable that the arrangement may be as for example with respect to Figure 3d The process is performed as described in a discontinuous process.

[0219] In the first case, the panel element is a panel 1' and the lower element is a lower unit 23b, wherein no segmentation and / or cutting is required (block S14), e.g. Figure 4b-4d , 5c, 5j, 5l and 7a. Thus, the panel and the underlying unit may have specifications that match each other. For example, the panel may be adapted to be loosely arranged on the underlying floor, or it may be glued to the underlying floor. In other examples, the locking system 9, preferably a mechanical locking system comprising a tongue 9a, 9a' and a tongue groove 9b, 9b' and / or a locking element 8, 8' and a locking groove 14, 14', may be preformed on at least one edge portion, for example all edge portions, of the panel 1a, 1b, 1c, 1d, see for example 4c-4f, 5d and 7c. Optionally, however, a locking system 9, preferably a mechanical locking system comprising a tongue 9a, 9a' and a tongue groove 9b, 9b' and / or a locking element 8, 8' and a locking groove 14, 14', may be post-formed (block S15) on at least one edge portion of the panels 1a, 1b, 1c, 1d, e.g. on all edge portions according to principles known in the art, see e.g. Figure 4c-4f, 5d and 7b-c. Figure 5d A panel 1 ' is shown which comprises a mechanical locking system for horizontal and / or vertical locking, such as a folding mechanical locking system. In any embodiment of the panel described herein with or without a locking system, the horizontal outermost parts and the back side of the lower element can be aligned, for example, along their first horizontal direction X and / or second horizontal direction Y.

[0220] In the second case, and as in e.g. Figure 1a-1c As shown in the embodiments of , 2d, 3d, 5g-5l and 7a-7c, the panel elements and / or underlying elements may be segmented and / or cut (block S14). Figure 5g-5i and Figure 5k The example in FIG. Figure 5f The panel element 1 shown in FIG. 1 is a sectional side view along the section AA.

[0221] In a first example, the attached underlying element may be processed separately from the board element or panel (block S20), as in Figure 5g-5j Or as shown in the embodiments in 7a-7c. Figure 5g-5h As shown in Figures 7a-7b, the lower element 23 or the lower unit 23a can be cut into at least one lower unit 23b along at least one cutting portion 12a, preferably by means of a cutting tool 52. For example, the cutting tool 52 can be a rotary cutting device, a carving device or a knife device. Thus, the material element 23c can be removed from the lower element. For example, the specifications / design of the cut lower unit, such as its length along its first horizontal direction X and / or second horizontal direction Y, can be adapted to the specifications of the panel, such as along its first and / or second horizontal direction. The interior of the lower element can be as shown in Figures 7a-7b. Figure 5g-5h as shown, and / or the exterior of the underlying element may be as Figure 7a-7b Optionally, preferably after the underlying element has been arranged on the back side, at least one chamfer 28 may be formed.

[0222] Optionally, and as Figure 5i As shown, the panel element may be divided along at least one dividing portion 12b into at least one panel, for example at least two panels 1' (block S22), preferably by a dividing tool 54, for example comprising a rotating cutting element such as a circular saw blade.

[0223] In the second example, and as Figure 5k-5l As shown in the embodiment of FIG. 2 , the segmentation of the panel elements and the cutting of the attached underlying elements can be performed jointly (block S24 ), preferably by the same processing tool 56 , which can include a cutting tool 52 and / or a segmentation tool 54 .

[0224] In some embodiments, for example, Figure 5j , 5l In 7a, no further processing of the panel or underlying element may be required, thereby Figure 5j , 5l or 7a may be in their final form. For example, the panels may be suitable for being loosely laid on or glued to the underlying floor. However, optionally, as in Figure 7c In and still Figure 5d As shown in , a locking system 9, preferably a mechanical locking system, may be formed on at least one edge portion of the panels 1a, 1b, 1c, 1d, for example on all edge portions according to principles known in the art (block S23).

[0225] Optionally, material elements 23c, 4c such as chips, shavings or strips removed from the lower layer elements and the panel elements during or after cutting and dividing can be separated from each other (box S25). In some embodiments, material elements that contact the adhesive of the panel elements and / or the lower layer elements can also be separated. In a first example, the method includes cutting only the lower layer elements and then dividing the panel elements. Thereby, the removed material elements can be easily separated, for example by a separate vacuum device. In a second example, the method includes performing cutting and dividing in the same operation, the method optionally also includes forming a locking system 9. The separation of the material elements can then be based on at least one property of the lower layer elements and the panel elements and the optional adhesive. The separation can be implemented by a separation device 37 in the system 30, which is Figure 5k Schematically shown in FIG. The separation device 37 can be configured to screen or sieve the material elements, or it can use gravity separation of the material elements, such as specific gravity separation. For example, density separation or cyclone separation can be used. In any of the first and second examples above, optionally, no or substantially no adhesive is applied to the cutting portion 12a and / or the segmenting portion 12b.

[0226] In some embodiments, during or after forming the locking system 9 on the panel element, the material elements 23c, 4c removed from the underlying element and the panel element can be separated from each other. At least part of the locking system can be formed by removing material from the back portion 4d, see Figure 7a .

[0227] Figures 8a-8f 9a - 9b show an embodiment of a panel 1 ′ including an applied adhesive 20 in a bottom view.

[0228] Typically, in e.g. Figure 1a-1cIn any of the above-mentioned embodiments, the adhesive may be applied continuously or intermittently along the feed paths FP, FP', for example along the feed directions FD, FD', on at least a portion of the panel element 1 and / or the lower layer element 23. Thus, the applied adhesive may extend continuously or discontinuously along the first horizontal direction X and / or the second horizontal direction Y.

[0229] Any continuous or intermittent application of the adhesive disclosed herein can be, for example, Figure 5f , 8a , 8e-8f and 9a-b as shown in the embodiments and / or as in the wide range of Figure 8b-8e and the linear application shown in the embodiment in 9b. Figure 8a , 8e In FIGS. 8a - 8f and 9a - 9b , at least a portion of the adhesive 20 is applied over substantially the entire width of the remaining portion 4b along the second horizontal direction Y between the long side portions 1a , 1b . Figure 8a and 9a An embodiment is shown in which the adhesive is applied substantially over the entire remaining portion 4b. Figure 5f In the embodiment, the adhesive is applied as at least two, for example three, wide applications, which may be spaced apart from one another as described above. Figure 8b-8f In 9b, the adhesive is applied along the first horizontal direction X and / or the second horizontal direction Y over at least a portion of the width of the remaining portion 4b, and is therefore preferably applied between the short side portions 1c, 1d and / or between the long side portions 1a, 1b.

[0230] exist Figures 8a-8f In 9a-9b, the adhesive 20 is applied to the peripheral portion 5 of the back surface 4. Figure 8b As shown by dashed lines in FIG. 2 , the peripheral portion 5, 5' of the back side 4 or upper side 21 can be positioned within a distance of 10%, preferably 5%, of the total length LX, LY of the panel element or underlying element from the horizontally outermost portion of the back side or upper side. The adhesive can be applied along the long side portions 1a, 1b and / or along the short side portions 1c, 1d.

[0231] Figure 8a-8c , 8e-8f and 9b show that the application may be a linear application or a wide application, whereby the adhesive is applied along, ie parallel to, the first horizontal direction X and / or the second horizontal direction Y. Figure 8d and 9a It is shown that the application may be a linear application or a wide application, whereby the adhesive is applied at an angle relative to the first horizontal direction X and / or the second horizontal direction Y, respectively.

[0232] In e.g. Figure 8c and9a In any of the embodiments disclosed herein as shown in -9b, adhesive 20 can be applied in a pattern arrangement 26 on remaining portion 4b and / or corresponding residual portion 21b. Figure 9a The embodiment in FIG. 4 shows an adhesive provided on the remaining portion 4 b , wherein the basic application design 27 of the adhesive in the pattern arrangement 26 is arranged in the form of a grid.

[0233] The pattern arrangement can be e.g. Figure 8c or Figure 9a The main pattern 24 in FIG. Figure 9b As shown, the pattern arrangement 26 may further include at least one additional pattern, such as a secondary pattern 25. The secondary pattern may include at least two primary patterns 24 that may be spaced apart from each other, for example, along the first horizontal direction X and / or the second horizontal direction Y. Figure 9b , the main patterns 24 are spaced apart from each other along the first horizontal direction X. Optionally, an additional adhesive 20 may be applied between the main patterns, which may be applied, for example, by linear application, in the peripheral portions 5, 5' as described above. Figure 9b The basic application design 27 of the adhesive in the embodiment forms a circle. However, as Figure 9d As shown in the embodiment of FIG. , other basic application designs are also conceivable, such as an ellipse, or a polygon, such as a triangle, square or star, etc.

[0234] Usually, and if Figure 8f and 9b As shown, the groove portion 4a may include at least two groove arrangements 11, each of which includes at least one groove 10, preferably a plurality of grooves. The grooves may be formed discontinuously in the back surface 4 and their longitudinal extensions may be parallel to the long side portions 1a, 1b. The extensions of the grooves in each groove arrangement, such as the longitudinal extensions, are preferably parallel to each other. The groove arrangements may be spaced apart from each other in the first horizontal direction X and / or the second horizontal direction Y of the plate element or panel. The groove arrangements may be spaced apart by a partition 13 provided in the back surface 4, which preferably extends continuously along the second horizontal direction Y, for example between the long side portions 1a, 1b. For example, the partition may include a rectangular portion.

[0235] like Figure 8f As shown, the adhesive 20 can be applied, for example, along the first horizontal direction X, preferably controlled to be applied between the groove arrangement structures 11. The adhesive can be applied in the partition 13, for example, covering the entire partition. Optionally, and as Figure 8f As shown, the adhesive may also be applied between the grooves 10 of the groove arrangement 11 , for example along the second horizontal direction Y. For example, the adhesive may be applied between the ends 16 of the grooves 10 .

[0236] For example, Figure 9b The adhesive 20 provided by the main pattern 24 as in FIG. 1 may be applied, for example, along the first horizontal direction X between the trench arrangements 11 .

[0237] Typically, the pattern arrangement 26 can be applied by contact application, such as by a slot die coater 41 or by a roller coater 43, or by non-contact application, such as by a spray coater 45 or a curtain coater 46. For example, as described elsewhere in this disclosure, Figure 1a-1c The embodiments in , 2a-2e, 3a-3d and 5a-5l can be used to achieve contact application or non-contact application.

[0238] in addition, Fig.9c and 9e The embodiment in FIG. 4 shows in top view and perspective view an engraved roller coater 43 comprising a plurality of structural elements 47 , such as indentations and / or protrusions. Fig.9c and 9e The structural elements of the roller coater in the embodiment may correspond to Figure 9a The pattern arrangement in 26 and Figure 9b The main pattern 24 in. Fig.9c The structural element 47 is arranged along the circumference of the roller coater, and Fig.9e The structural elements 47 in the coating are arranged in groups 48, each group preferably being spaced apart from each other along the circumference of the coating roller. Fig.9c The adhesive applicator 40 in 9e can be connected to an adhesive reservoir 42 as described elsewhere herein. Typically, the adhesive applicator can include at least one roller applicator, whereby Fig.9c Or the roller coater in 9e can be a coating roller 43a, see Figure 2b The embodiments in .

[0239] Fig.9c and 9e The roller coating embodiment in the embodiment can achieve continuous or intermittent application of adhesive. Continuous application can be such as Figure 2b For example, the roller coater 43 and the conveying device 50 can be fixedly installed in, for example, the frame 32. In addition, as Figure 2b As shown by the dashed arrow in FIG. 1 , intermittent application can be generally performed by making the roller coater 43 contact and separate from the panel element 1 and / or the lower layer element 23 while displacing along the feed paths FP, FP'. In a first example, the roller coater 43 is displaceably mounted, for example, in the frame 32. In a second example, the conveying device 50 is movably mounted, for example, in the frame 32.

[0240] Typically, the adhesive may be applied by transfer application. Figure 9fThe embodiment in the figure shows in a perspective view a part of an adhesive applicator 40, which comprises an adhesive unit 49 in the form of a slot die coater 41 and a transfer roller 49' capable of applying the adhesive 20 intermittently and / or in a pattern arrangement 26 on a substrate 60, which substrate 60 can be conveyed along a feed path FP, FP' in a feed direction FD, FD'. As described above, the substrate 60 can be a panel element 1, such as a panel 1', or a lower layer element 23, such as a lower layer unit 23a, 23b. The slot die coater 41 can apply the adhesive 20 on the roller coater 43 along its circumferential and longitudinal extension dimension L, for example intermittently and / or by applying the adhesive in a pattern arrangement and preferably during its rotation. For example, it can be Figure 9f The adhesive applicator 40 in the embodiment described herein can be used to obtain the adhesive applicator 40 described herein. Figure 8f and Fig.10b In addition, the adhesive may be applied intermittently. Figure 9f The adhesive applicator 40 in the embodiment described herein can be used to obtain the adhesive applicator 40 described herein. Figure 8b , 8e and the application of the adhesive shown in 10e-10f. In some embodiments, Figure 9f The adhesive coating on the substrate 60 in the direction TD or TD' can be discontinuous. For example, a slot die coater can be used with a Figure 9f At least one mask 40a indicated by a dotted line is used in combination.

[0241] It should be understood that the application of adhesive to the panel elements - for example, as described with respect to broad application, linear application, peripheral application, patterned arrangement, etc. Figures 8a-8f and any of the applications described in 9a-9f - can also be envisaged as an adhesive application on the corresponding residual portion 21b of the underlying element. An example of such an application is shown in Figure 10a-10b middle, Figure 10a-10b An embodiment of the lower element 23b is shown in top view. These are similar to Figure 8a and Figure 8f Preferably, adhesive 20 is not applied in cover portion 21a. However, in some embodiments herein, a major portion (eg, more than 50%) of the cover portion may be free of adhesive.

[0242] As in Fig.10c It should be noted that in some embodiments, the longitudinal extension of the groove 10 may be parallel to the short side portions 1c, 1d. Fig.10d The embodiment in the embodiment is shown in top view configured to be attached to Fig.10c 2 . The lower unit 23b on the panel 1 ' in FIG. 1 is shown, wherein the cover part 21a and the corresponding residual part 21b are indicated. Fig.10c and10d It is shown that the adhesive 20 is applied on substantially the entire remaining portion 4b and / or the corresponding residual portion 21b, respectively. Preferably, the adhesive is not applied in the groove portion 4a or the cover portion 21a.

[0243] In some embodiments, Figure 9g and 9h As shown, the lower layer element 23, such as the lower layer units 23a, 23b, may be formed discontinuously, including perforations 21d and / or at least one slot 21e. The at least one slot 21e may be configured to align with the groove portion 4a of the panel. Thus, less adhesive may be required for attachment. Other features may be similar to those described elsewhere herein, such as Figure 3e , 4a -4f, 5a-5l, 7a-7d, 8a-8f, 9a-9b and 10a-10f.

[0244] The method may include controlling the application of adhesive 20 so that no or substantially no adhesive is applied in at least one cut portion 12a and / or at least one segmented portion 12b. Furthermore, the method may include controlling the application of adhesive so that no or substantially no adhesive is applied in a back portion 4d in which the locking system 9 of at least one panel 1' is configured to be formed, and / or no or substantially no adhesive is applied in an upper portion 21c of at least one lower unit that is configured to contact the back portion 4d. An example of such a back portion 4d is shown in FIG. Figure 7a The embodiment is shown in FIG.

[0245] Fig.10e An embodiment of a panel element 1 including an applied adhesive 20 is shown in a bottom view and a lower layer unit 23a is shown in a side view. Fig.10f An embodiment of a lower layer unit 23b including an applied adhesive 20 is shown in a top view and a panel element 1 is shown in a side view. In each of these embodiments, no or substantially no adhesive is applied in at least one cut portion 12a and / or at least one segmented portion 12b. For example, Fig.10e The adhesive in 10f can be applied by a slot die coater 41 or a spray coater 45 or even by an engraved roller coater 43. Figure 10e-10f In the embodiment, the lower layer unit 23a or the lower layer unit 23b can be attached to the corresponding board element 1 or panel 1 '.

[0246] like Fig.10e As shown, the adhesive may be applied in the peripheral portion 7 of at least two panels 1' into which the panel element 1 is configured to be divided. Fig.10fIt is shown that the adhesive may be applied in the peripheral portion 7' ​​of at least two lower layer units 23b into which the lower layer element 23a is configured to be cut. Fig.10e and 10f As shown for the rightmost panel 1' and the lower unit 23b, the peripheral portions 7, 7' may be defined similarly to the peripheral portions 5, 5' described above. For example, in any of these embodiments, the adhesive may be applied in a linear application, which extends, for example, along a first horizontal direction X of the panel 1' or the lower unit 23b, for example, along a long side portion. Optionally, as Fig.10e As shown, the adhesive 20 can also be applied in a linear application, which extends, for example, along the second horizontal direction Y of the panel 1' or the lower unit 23b, for example along the short edge portion, preferably, no or substantially no adhesive is applied in at least one cutting portion 12a and / or at least one segmenting portion 12b. The adhesive is preferably applied in the peripheral portion 5, 5'.

[0247] Typically, the adhesive can be controlled to be applied only on the remaining portion 4b and / or the residual portion 21b. The method may include an action of controlling the application of the adhesive 20 based on the characteristics of at least one groove 10. For example, the control unit 44 may control the application. The adhesive may be applied by spraying, curtain coating, slot die coating or roller coating. The characteristics may be at least one selected from the group consisting of the shape, extension, position of at least one groove 10 or at least one groove arrangement structure 11 in the first horizontal direction X and / or the second horizontal direction Y, and the distance between at least one pair of grooves or between a pair of groove arrangements along the first and / or second horizontal direction. Control may include controlling the positioning of the adhesive on the plate element and / or the lower element and optionally the amount of the adhesive.

[0248] In any of the embodiments described herein, and if Figure 1a-1b As shown schematically, the control unit 44 can retrieve data about the features from a data storage unit 57, which can store predetermined data and / or collected data. For simplicity, the data storage unit 57 is usually hidden in the figure. For example, data can be obtained or collected by scanning the back side 4 with a scanner 58 preferably connected to the data storage unit 57. The scanner 58 may include a horizontal scanning unit 58a and / or a vertical scanning unit 58b, which is configured to determine data about grooves along at least one direction X, Y, Z, such as along at least one horizontal direction X, Y and / or along the vertical direction Z. The scanning device 58 may include an image sensor, such as a digital camera and / or a laser triangulation device. For example, a scanner 58 optionally including a horizontal scanning unit 58a and / or a vertical scanning unit 58b can be provided in a visual inspection system.

[0249] In some embodiments, the data about the feature, which may be predetermined data and / or collected data, may determine the position of adhesive applicator 40 , such as roller applicator 43 or slot die applicator 41 , relative to position 1 of panel element and / or underlying element 23 .

[0250] The adhesive 20 may be applied between at least one groove arrangement 11 and / or between discontinuous grooves 10, for example Figure 9b shown.

[0251] Typically, the adhesive 20 can be post-treated by a post-treatment device 34 such as a drying device and / or a radiation device as described above. Alternatively or additionally, the method can further include post-heating the adhesive by a post-heating device 36 and / or exposing the adhesive to moisture by a moisture conditioner 39.

[0252] The method may further include applying pressure on the adhesive 20, preferably during the curing or hardening of the adhesive. For example, a pressurizing device 35 may be used, such as Figure 1a and 3d The pressurizing device described.

[0253] In some embodiments, adhesive 20 may be pre-applied to underlying element 23. For example, the underlying element may be delivered to system 30 with the pre-applied adhesive. In such an embodiment, for example, Figure 1a-1c In any of the embodiments of , 2d, 3d, 4a-4f, 5a-5l, 7a-7c, the applicator of the adhesive applicator 40 may become redundant, but the other features may be the same. However, it should be noted that in any of the embodiments described herein that describe the application of adhesive on the panel element 1, 1' or the underlying element 23, 23a, 23b, such as in 8a-8f and 9a-9b, 9d, 10a-10f, a pre-applied adhesive 20 may be embodied. For example, the adhesive may be applied in a linear application, a wide application, a pattern arrangement 26, etc.

[0254] like Figure 7d As schematically shown in , the lower layer element with pre-applied adhesive may be provided with a releasable liner 29, such as a releasable film. The releasable liner may be removed before the lower layer element is arranged on the back surface 4, for example by a lower layer removal device 38 provided in the system 30. In some embodiments, the releasable liner 29 may be removed during continuous processing, for example when the panel element and / or the lower layer element is fed along the feed path FP, FP', for example along the feed direction FD, FD'.

[0255] Figure 3e The embodiments in any embodiment of the present invention are described in Figure 1a-1cThe remaining portion 4b in any of the embodiments of 10a-10e, 11a-12e, 12a-13d, 13a-14f, 14a-15l, 15a-16d, 16a-17d, 17a-18f, 18a-19b, 19c and 20e-21f may comprise surface roughness, for example comprising peaks 4e and valleys 4f. For example, the surface roughness may be provided by embossing of the back side 4. The peaks may be in the horizontal plane HP. The adhesive 20 attaching the lower element 23 to the panel element 1 may be provided on the peaks 4e, preferably such that no or substantially no adhesive is applied in the valleys 4f.

[0256] The inventive concept has been described above mainly with reference to several embodiments. However, as will be readily appreciated by a person skilled in the art, other embodiments than those disclosed above are equally possible within the scope of the inventive concept as defined in the appended patent claims and in the items in the following example section. For example, it can be clearly understood that: Figure 1a-1c , 2a-2e, 3c-3e, 4a-4b, 5a-5l, 7a-7d, 8a-8f and 9a-9b, the board element or panel may include a layer arrangement 3, the layer arrangement 3 including at least one layer 3a, 3b, 3c, similar to Figures 4a-4f At least one layer of the layer arrangement 3 may each comprise a polymer-based material, such as a thermoplastic material or a thermosetting material, and preferably a filler. Furthermore, it is clear that any system described herein, such as Figure 1a-1c , 2a-2e, 3a-3d, 5a-5l, 7a-7c and 9c-9f, may include a post-treatment device 34, such as a drying device, a radiation device or a moisture conditioner 39, or a post-heating device 36. Optionally, the system may include a separation device 37. Finally, and as mentioned above, it is clear that in some embodiments, the panel 1 ', such as Figure 1a-1c , 2b-2d, 3c-3e, 4a-4b, 5a-5l, 7a-7c, 8a-8f, 9a-9b, 10c and 10e-10f in any one of the panels 1 ', can alternatively be a building panel, a wall panel, a ceiling panel or a furniture panel. However, it is clear that the panel 1 ' in these embodiments can include a locking system different from that shown in the figures, or it can even have no locking system.

[0257] Example 1

[0258] Use a roller coater to apply a layer of 20g / m 2Reactive PUR hot melt coating P. Material PR-6620 is applied on the back side of the SPC panel provided with a plurality of grooves. EVA foam is arranged on the back side of the panel so that the hot adhesive contacts the foam and the back side. The panel is subsequently pressed in a calender. The line speed is set to 30 m / min and the calendering pressure is set to 3 Bar. The adhesive is applied at an application temperature of 110°C, an ambient temperature of 25°C and an RH value of 55%.

[0259] Example 2

[0260] Use a sprayer to apply a layer of 20g / m 2 Reactive PUR hot melt KLEIBERIT 711.2.00 is applied on the back of an LVT tile provided with a plurality of grooves. IXPE foam is arranged on the back of the tile so that the hot adhesive contacts the foam and the back. The tile is subsequently pressed in a calender. The line speed is set to 15 m / min and the calendering pressure is set to 3 Bar. The adhesive is applied intermittently in a pattern arrangement at an application temperature of 120°C, an ambient temperature of 25°C and an RH value of 55%.

[0261] Example

[0262] Further aspects of the inventive concept are provided below. The embodiments, examples, etc. of these aspects are largely similar to the embodiments, examples, etc. described above, and therefore reference is made to the above for detailed description.

[0263] Item 1. A method for attaching a lower element (23), such as a lower unit (23a; 23b), to a panel element (1), such as a panel (1'), comprising:

[0264] A panel element is provided, wherein the back side (4) of the panel element comprises a groove portion (4a) and a remaining portion (4b), the groove portion comprising at least one groove (10),

[0265] Providing the lower element (23),

[0266] applying an adhesive (20) to at least a portion of the remaining portion (4b) and / or to at least a portion of a corresponding remaining portion (21b) of the underlying element, and

[0267] The lower element is placed on the back side of the panel element so that the adhesive contacts the lower element and the back side.

[0268] Item 2. The method according to item 1, wherein the adhesive is applied during displacement of the panel element and / or the underlying element along the feed path (FP; FP').

[0269] Item 3. A method according to Item 1 or 2, wherein arranging the lower-layer element on the back side is performed during displacement of the panel element and / or the lower-layer element along the feed path (FP; FP').

[0270] Item 4. A method according to any one of the preceding items, wherein the adhesive is applied at least to a peripheral portion (5) on the back side and / or a peripheral portion (5') on the upper side of the lower element, any one or both of the peripheral portions preferably extending along a short side portion (1c, 1d) and / or a long side portion (1a, 1b) of the panel element and / or the lower element.

[0271] Item 5. A method according to Item 4, wherein the peripheral part of the panel element includes the peripheral part (7) of at least one panel, such as at least two panels, and the panel element is configured to be divided into the panels, and / or the peripheral part of the lower layer element includes the peripheral part (7') of at least one lower layer unit, such as two lower layer units, and the lower layer element is configured to be cut into the lower layer units.

[0272] Item 6. A method according to any one of the preceding items, wherein the method further comprises controlling the application of the adhesive based on the characteristics of the at least one groove, wherein the control preferably causes the adhesive to be selectively applied, for example, on the remaining portion and / or the corresponding residual portion.

[0273] Item 7. The method of Item 6, further comprising retrieving data regarding characteristics of the at least one groove to control application of the adhesive.

[0274] Item 8. The method according to any of the preceding items, wherein the adhesive is applied by contact application, such as by slot die coating or by roller coating, and / or by non-contact application, such as by spraying or curtain coating.

[0275] Item 9. The method according to any of the preceding items, wherein the adhesive is applied continuously or intermittently, for example along a feed path (FP; FP') of the panel element and / or underlying element.

[0276] Item 10. The method of any of the preceding items, wherein the adhesive is applied in a pattern arrangement (26).

[0277] Item 11. The method according to any one of the preceding items, wherein a thickness of the remaining portion (Tb) is greater than a thickness of the groove portion (Ta), a major portion of the remaining portion preferably having a constant thickness.

[0278] Item 12. A method according to any of the preceding items, wherein at least two grooves are formed discontinuously, and applying the adhesive comprises: for example, applying the adhesive between the discontinuous grooves along the first horizontal direction (X) and / or the second horizontal direction (Y) of the panel element.

[0279] Item 13. A method according to any of the preceding items, wherein the panel element comprises at least one layer (3a, 3b, 3c), and the at least one groove at least partially penetrates the at least one layer, for example at least partially penetrates at least one lower layer (3c).

[0280] Item 14. A method according to Item 13, wherein the at least one layer, optionally including the upper layer (3a) and / or the lower layer (3c), each comprises a polymer-based material, preferably a thermoplastic material or a thermosetting material, and preferably also comprises a filler.

[0281] Item 15. The method according to any one of the preceding items, further comprising:

[0282] The lower layer element (23) is cut into at least one lower layer unit (23a; 23b) along at least one cutting portion (12a).

[0283] Item 16. The method according to any one of the preceding items, further comprising:

[0284] The panel element (1) is divided along at least one dividing portion (12b) into at least one panel (1'), for example at least two panels.

[0285] Item 17. The method according to Item 16, wherein the panel elements are divided after the operation of arranging the lower layer elements on the back side.

[0286] Item 18. The method according to any of the preceding items further comprises controlling the application of the adhesive so that no or substantially no adhesive is applied to the back portion (4d) of the panel element and / or the upper portion (21c) of the lower element, the upper portion being configured to be further processed, for example by cutting, splitting or forming a locking system.

[0287] Item 19. According to the method of any one of the preceding items, the application of the adhesive is further controlled so that no adhesive is applied or substantially no adhesive is applied in at least one cutting portion (12a) and / or at least one segmenting portion (12b).

[0288] Item 20. The method according to any one of the preceding items, further comprising controlling the application of the adhesive so that no adhesive is applied or substantially no adhesive is applied to the following parts:

[0289] A rear part (4d), for example a locking system (9) of at least one panel (1') is configured to be formed in said rear part (4d), and / or

[0290] An upper portion (21c) of the at least one lower layer unit (23a; 23b) is configured to be disposed along the back portion (4d), for example, to contact the back portion (4d).

[0291] Item 21. The method according to any of the preceding items further includes separating material elements such as fragments, shavings or strips removed from the lower layer elements and the panel elements during or after processing the panel elements and the lower layer elements, for example by separating the material elements based on at least one property of the lower layer elements and the panel elements, respectively.

[0292] Item 22. A method according to Item 21, wherein the processing comprises cutting the lower layer element (23) into at least one lower layer unit (23a; 23b) and dividing the panel element into at least one panel and / or forming a locking system (9) on the panel element.

[0293] Item 23. The method of any one of the preceding items, wherein the adhesive is a hot melt adhesive.

[0294] Item 24. The method according to any of the preceding items, further comprising drying the adhesive and / or exposing the adhesive to radiation, such as infrared or ultraviolet radiation.

[0295] Item 25. The method of any of the preceding items, further comprising post-heating the adhesive, ie, heating the adhesive while or after the adhesive is applied to the backing surface.

[0296] Item 26. The method according to any of the preceding items, further comprising applying pressure on the underlying element and / or the panel element, preferably during curing or hardening of the adhesive.

[0297] Item 27. A method according to any of the preceding items, wherein the lower layer element is a foam such as a closed-cell foam, for example, IXPE foam, IXPP foam, EVA foam, XLPO foam, XLPE foam, foam rubber or PU, PO, PE or PS foam, or the lower layer element is a cork board.

[0298] Item 28. A method according to any of the preceding items, wherein the panel element is a panel (1'), the method further comprising forming a locking system (9), preferably a mechanical locking system, for horizontal and / or vertical locking on at least one edge portion of the panel, preferably on all edge portions (1a, 1b; 1c, 1d).

[0299] Item 29. The method of any one of the preceding items, wherein the panel is a floor panel or a wall panel.

[0300] Item 30. A panel element (1), such as a panel (1'), obtainable by a method according to any one of the preceding items 1-29.

[0301] Item 31. A system (30) for attaching a lower element (23), such as a lower unit (23a; 23b), to a panel element (1), such as a panel (1'), comprising:

[0302] an adhesive applicator (40), and

[0303] Lower layer applicator (31).

[0304] Item 32. A panel assembly, comprising a panel (1') and a lower unit (23b),

[0305] The back side (4) of the panel comprises a groove portion (4a) and a remaining portion (4b), wherein the groove portion comprises at least one groove (10), and

[0306] Therein, the lower unit (23b) is attached to the back side of the panel by means of an adhesive (20) contacting at least a portion of the remaining portion and a corresponding remaining portion (21b) of the lower unit.

[0307] Item 33. A panel assembly according to Item 32, wherein the thickness of the remaining portion (Tb) is greater than the thickness of the groove portion (Ta), and a major portion of the remaining portion preferably has a constant thickness.

[0308] Item 34. The panel assembly of Item 32 or 33, wherein the adhesive is applied in a pattern arrangement (26).

[0309] Item 35. The panel assembly according to any one of the preceding items 32-34, wherein at least two grooves are formed discontinuously, and the adhesive is disposed between the discontinuous grooves, for example along a first horizontal direction (X) and / or a second horizontal direction (Y) of the panel.

[0310] Item 36. A panel assembly according to any one of the preceding items 32-35, wherein the panel comprises at least one layer (3a, 3b, 3c), and the at least one groove at least partially penetrates the at least one layer, for example at least partially penetrates at least one lower layer (3c).

[0311] Item 37. A panel assembly according to Item 36, wherein the at least one layer, optionally including the upper layer (3a) and / or the lower layer (3c), each comprises a polymer-based material, such as a thermoplastic material, and preferably comprises a filler.

[0312] Item 38. A method for attaching a lower element (23), such as a lower unit (23a; 23b), to a panel element (1), such as a panel (1'), comprising:

[0313] A panel element is provided, wherein the back side (4) of the panel element comprises a groove portion (4a) and a remaining portion (4b), the groove portion comprising at least one groove (10),

[0314] providing a lower element (23) comprising a pre-applied adhesive (20),

[0315] as well as

[0316] The lower element is placed on the back side of the panel element so that the adhesive contacts the lower element and the back side.

[0317] Item 39. The method according to Item 38, wherein the adhesive (20) is applied to at least a portion of the corresponding residual portion (21b) of the underlying element, for example, only to the corresponding residual portion.

[0318] Item 40. The method according to Item 38 or 39 further includes synchronizing the position of the lower element with the position of the plate element so that the lower element becomes aligned with the plate element, preferably so that the cover part (21a) is aligned with the groove part and the corresponding residual part (21b) is aligned with the remaining part.

[0319] Item 41. A method according to any one of the preceding items 38 to 40, wherein the lower element is provided with a peelable liner (29), such as a peelable film, and the method further comprises removing the peelable liner before arranging the lower element on the back side.

[0320] Item 42. A method according to any one of the preceding items 38 to 41, wherein no or substantially no pre-applied adhesive is applied to the upper portion (21c) of the lower element which is configured for further processing, for example by cutting or forming a locking system.

[0321] Item 43. The method according to any one of the preceding items 38 to 42, wherein no or substantially no pre-applied adhesive is applied in at least one cut portion (12a).

[0322] Item 44. A method according to any one of the preceding items 38 to 43, wherein no or substantially no pre-applied adhesive is applied to the upper portion (21c) of at least one lower layer unit (23a; 23b), the upper portion being configured to be arranged along a back portion (4d), for example, a locking system (9) of at least one panel (1') being formed in the back portion, for example, configured to contact the back portion (4d).

[0323] Item 45. A method according to any one of the preceding items 38 to 44 and further according to any one of the preceding items 3-5, 10-17, 21-29.

Claims

1. A method for attaching a lower element (23) to a weight-reduced panel element (1) comprising at least one groove (10), the panel element itself being a panel (1') or the panel element being divisible into at least one panel (1'), wherein each panel (1') is a floor panel or a wall panel, the method comprising: A panel element (1) is provided, the panel element (1) comprising a front face (2) adapted to be visible and a rear face (4) arranged on the opposite side of the front face (2), wherein the rear face (4) of the panel element comprises a groove portion (4a) and a remaining portion (4b), the groove portion (4a) comprising the at least one groove (10) and the remaining portion (4b) being in a horizontal plane (HP) extending along the rear face (4) of the panel element, providing the lower layer element (23), the lower layer element (23) being a foam or cork sheet, applying an adhesive (20) on at least a portion of the remaining portion (4b) and / or on at least a portion of a corresponding remaining portion (21b) of the underlying element (23), and placing the lower element on the back side (4) of the panel element so that the adhesive contacts the lower element and the back side, wherein the panel element comprises at least one layer (3a, 3b, 3c), each of the at least one layer comprising a thermoplastic material, wherein the at least one groove (10) at least partially penetrates the at least one layer, wherein the method further comprises controlling the application of the adhesive (20) based on the characteristics of the at least one groove (10), wherein the control causes the adhesive to be selectively applied, wherein the adhesive (20) is applied at least to a peripheral portion (5) of the back side (4) and / or a peripheral portion (5') of an upper side (21) of a lower element (23), said upper side (21) being configured to face the panel element (1) or the panel (1'), any one or both of said peripheral portions (5; 5') extending along short side portions (1c, 1d) and / or long side portions (1a, 1b) of the panel element and / or the lower element, The upper side (21) includes a cover portion (21a) and the residual portion (21b), wherein the cover portion (21a) is configured to face the groove portion when the lower layer element (23) is attached to the back surface (4). (4a) and aligned with the groove portion (4a), the residual portion (21b) being configured to face the remaining portion (4b) and aligned with the remaining portion (4b) when the lower layer component (23) is attached to the back surface (4). Alignment, and The groove portion (4a) is separated from the peripheral portion (5) of the back side (4) and / or the cover portion (21a) is separated from the peripheral portion (5') of the upper side (21).

2. The method according to claim 1, wherein: The characteristic is the shape of the at least one groove (10) and / or the extension of the at least one groove in the first horizontal direction (X) and / or the second horizontal direction (Y) of the panel element (1).

3. The method according to claim 1, wherein: The features are: the position of the at least one groove (10) in the back side (4), and / or the distance between at least one pair of grooves along the first horizontal direction (X) and / or the second horizontal direction (Y), or The distance between at least one pair of groove arrangement structures (11) along the first horizontal direction (X) and / or the second horizontal direction (Y), each groove arrangement structure comprising at least one groove.

4. The method according to any one of claims 1 to 3, wherein: The control is based on data relating to characteristics of the at least one groove (10).

5. The method according to any one of claims 1 to 3, further comprising retrieving data related to characteristics of the at least one groove (10) to control the application of adhesive.

6. The method according to claim 5, wherein: The data is obtained by scanning the back side (4) using a scanner (58).

7. The method according to any one of claims 1 to 3, wherein: The lower layer element (23) is a lower layer unit (23a; 23b).

8. The method according to any one of claims 1 to 3, wherein: The peripheral part (5) of the panel element (1) comprises the peripheral part (7) of at least one floor panel or wall panel (1') into which the panel element is configured to be divided, and / or the peripheral part (5') of the lower layer element (23) comprises the peripheral part (7') of at least one lower layer unit (23b) into which the lower layer element is configured to be cut.

9. The method according to any one of claims 1 to 3, wherein: The adhesive is applied in a pattern arrangement (26).

10. The method according to any one of claims 1 to 3, wherein: At least two grooves (10) are formed discontinuously, and applying the adhesive comprises: applying adhesive between the discrete grooves along a first horizontal direction (X) and / or a second horizontal direction (Y) of the panel element (1), and / or The adhesive is applied between the corresponding cover portions (21a) of the lower element (23) along the first horizontal direction and / or the second horizontal direction of the lower element.

11. The method according to any one of claims 1 to 3, further comprising: The lower layer element (23) is cut into at least one lower layer unit (23a) along at least one cutting portion (12a); 23b), and / or The panel element (1) is divided into at least one floor panel or wall panel (1') along at least one dividing portion (12b).

12. The method according to any one of claims 1 to 3, further comprising controlling the application of the adhesive (20) so that no adhesive is applied to the back side portion (4d) of the panel element (1) and / or the upper side portion (21c) of the lower element (23), which is configured to be further processed by cutting, segmenting or forming the locking system (9).

13. The method according to any one of claims 1 to 3, further comprising controlling the application of the adhesive (20) such that no adhesive is applied in at least one cut portion (12a) and / or at least one segmented portion (12b).

14. The method according to any one of claims 1 to 3, further comprising controlling the application of the adhesive (20) so that no adhesive is applied in the following parts: a rear part (4d) in which the locking system (9) of at least one floor panel or wall panel (1') is formed, and / or An upper side portion (21c) of the at least one lower layer unit (23a; 23b), the upper side portion being configured to be disposed along the back side portion (4d) to contact the back side portion (4d).

15. The method according to any one of claims 1 to 3, further comprising separating material elements (23c; 4c) removed from the underlying elements and the panel elements during or after machining the panel elements and the underlying elements.

16. The method according to claim 15, wherein: The material elements (23c; 4c) are chips, shavings or strips.

17. The method according to claim 15, wherein: The material elements are separated based on at least one property of the underlying elements and the slab elements, respectively.

18. The method according to any one of claims 1 to 3, wherein: The at least one layer each further comprises a filler.

19. The method according to claim 3, wherein: Each groove arrangement includes a plurality of grooves.

Images