POLYMER PANEL

Abstract

 A polymer panel (10, 11, 12, 13, 14, 15) comprising a first outer wall (110); and a second outer wall (120) arranged substantially parallel to said first outer wall, wherein the first outer wall and the second outer wall define a hollow closed volume (130) between them; at least one closable opening (135) adapted to provide a liquid in said hollow closed volume from the outside of the panel, wherein the closable opening is liquid tight when closed; a plurality of inner walls (140) extending in a substantially perpendicular direction from the first outer wall to the second outer wall, wherein said inner walls divide the hollow volume in a plurality of cells (150, 151, 152); wherein each cell is in fluid connection with at least one adjacent cell via at least one opening (160) for passing liquids.

Description

Field of the Invention

[0001] The present invention generally relates to polymer panels, and methods to provide polymer panels.

Background of the Invention

[0002] Polymer panels, in particularly wall panels, are known in the art, e.g. from WO2018011393.

[0003] It is generally known that polymers are usually flammable. To restrict the flammability of polymers, the polymer may be blended with fire retardant components, to make the mixture less flammable. However it is a challenge to keep the strength and/or physical properties of such panels with these blends on the same level as the pure polymer, and to keep the weight of these panels made from such blends acceptable. Further, in general, fire retardant components may be toxic to some extent, and little eco-friendly, and may be disturbing the recycling process of the polymers, or may even make recycling impossible.

Summary of the Invention

[0004] The present invention gives a solution to these problems by providing a panel which does not require blending fire retarders in the polymer, while having a prolonged fire resistance.

[0005] According to a first independent aspect of the invention, a polymer panel is provided. The panel comprises:

• a first outer wall; and
• a second outer wall arranged substantially parallel to said first outer wall, wherein the first outer wall and the second outer wall define a hollow closed volume between them;
• at least one closable opening adapted to provide a liquid in said hollow closed volume from the outside of the panel, wherein the closable opening is liquid tight when closed;
• a plurality of inner walls extending in a substantially perpendicular direction from the first outer wall to the second outer wall, wherein said inner walls divide the hollow volume in a plurality of cells; and
• each cell is in fluid connection with at least one adjacent cell via at least one opening for passing liquids.

[0006] The polymer panel according to the first aspect of the invention may preferably be a polymer wall panel, meaning that the polymer panel can be used as a wall in a building construction or a similar facility, such as being used as a wall and/or floor and/or ceiling, e.g. a fire resistant wall and/or floor and/or ceiling.

[0007] According to some embodiments, some or each cell may be in fluid connection with at least one adjacent cell via more than one opening for passing liquids. Some or each cell may be in fluid connection with at least one adjacent cell by two, three, four or more openings in the inner wall or walls, such as by a number of openings in the wall or walls in the range of 1 to 10, e.g. in the range of 1 to 5, e.g. 1 to 3.

[0008] Possibly, some or each cell may be in fluid connection with one adjacent cell via more than one opening for passing liquids. Some or each cell may be in fluid connection with two, three, four or even more adjacent cell, each connection being provided by one or more than one opening for passing liquids in the connecting inner wall, such as each time by one, by two, by three, by four or by even more openings for passing liquids in the connecting inner wall.

[0009] Possibly, the inner wall provided with more than one opening to provide fluid connection with one or more than one adjacent cells, may be provided with a grid-like perforation pattern, thereby providing the more than one openings.

[0010] The openings used over the polymer panel may all be identical, or may all be different one to the other. Alternatively, some of the openings may be identical with some of the other openings, while they are different from the other openings.

[0011] When a cell is in fluid connection with one or more than one adjacent cell via more than one opening, these openings used may all be identical, or may all be different one to the other. Alternatively, some of the openings may be identical with some of the other openings, while they are different from the other openings.

[0012] It is understood that the dimensions, shapes and positions of the various openings may all be identical, or may mutually differ. By varying the dimensions, shapes and positions of the different openings in the inner walls, the flow of the liquid may be controlled, at least to some extent, during filling and/or during use of the polymer panel, e.g. during the time period the polymer panel being subjected to fire.

[0013] The circumference of the opening may e.g. be circular, oval, elliptic, track shapes, polygonal or polygonal with rounded corners, like triangular, quadrangular, rectangular or square, or may have a similar circumference.

[0014] Possibly the total surface of the openings in one inner wall may provide a part of the total surface of the inner wall, which part represents 0.01% to 99.99% of the total inner wall surface, more preferably 5% to 90%, even more preferred 10% to 75%, such as 10% to 20% of the total inner walls surface.

[0015] The polymer panel comprises at least one closable opening adapted to provide a liquid in the hollow closed volume from the outside of the panel, which closable opening is liquid tight when closed. Possibly the polymer panel comprises more than one closable opening, each adapted to provide a liquid in the hollow closed volume from the outside of the panel, which closable opening is liquid tight when closed.

[0016] Preferably the one or more closeable openings are provided in one or in both of the outer walls. When two or more closeable openings are provided, these closeable openings may be provided in the same outer wall. Alternatively when two or more closeable openings are provided, each outer wall may be provided with at least one of these closeable openings. Preferably, the position of the closable opening on the surface of the outer wall are about in the middle of one of the length or width of the panel, adjacent the outer edge of the other of the length or width of the panel, or at one of the corners of the panel.

[0017] Alternatively or additionally some or all closeable openings may be provided in the outer side walls of the panel, if any. Such outer side walls are walls encompassing the plurality of inner walls, and connect the first and second outer wall to define the inner volume of the polymer panel.

[0018] According to some embodiments, more than one closeable opening are provided and this in one of the outer walls, like 2, 3, 4, 5, 6 or even more closable openings. Possibly more than one closable opening are provided and each of the of the outer walls, like 2, 3, 4, 5, 6 or even more closable openings in each of the outer walls.

[0019] The circumference of the closeable opening may e.g. be circular, oval, elliptic, track shapes, polygonal or polygonal with rounded corners, like triangular, quadrangular, rectangular or square, or may have a similar circumference. Circular closeable opening are preferred.

[0020] Two or more polymer panels may be interconnected one to the other by a liquid conducting means, like tubes or pipes or alike. Such liquid conducting means may be provided between two closeable openings. As such, the liquid provided to only one of the panels may flow via the liquid conducting means to the connected other panels. Hence as such, when the polymer panel provide a wall, a floor, a ceiling or a whole volume, providing liquid to one closeable opening may be sufficient to provide liquid to all the connected polymer panels. The closeable openings may be provided in the outer walls and/or in side walls. Depending whether or not venting openings are present and opened or closed, the internal pressure in the hollow closed volume can be increased. By filling the hollow closed volume and preventing the air in the hollow closed volume to escape, the air pressure in the hollow closed volume will increase. In case rupture spots are provided in one of both the outer walls, such increased air pressure may assist these spots to work as a sprinkler-like opening once the rupture spot is ruptured. The configuration of the interconnected closeable openings at the walls of the panels will define the sequence and level of filling of the various interconnected panels. Once filled, the closeable openings via which the liquid is provided in the polymer walls may be closed. The closeable openings to which the liquid conducting means are coupled, may also be closed or may stay interconnected by these liquid conducting means.

[0021] The polymer panel preferably has a rectangular or square shape, with a thickness being substantially equal to the height of the inner walls, increased by the thickness of the outer walls. Preferably this thickness is in the range of 10mm to 100mm, such as in the range of 15mm to 75mm, more preferred in the range of 20mm to 60mm, e.g. in the range of 20mm to 50mm. The width and length of the polymer panel may each range from 700mm to 3000mm, but may even be less or more. More preferably the width of the polymer panel is less or equal to 2000m, more preferred less than or equal to 1000m, such as less than or equal to 850mm, e.g. 800mm. Preferably the length of the polymer panel is less or equal to 3000m, more preferred less than or equal to 2800m, such as less than or equal to 2700mm, e.g. 2600mm. Possibly, two or more panels may be combined into a larger polymer panel. E.g. these panels, functioning thus as panel parts, may be connected, like thermally welded, one to the other, forming a larger polymer panel according to the invention. Although the dimensions are not necessarily restricted, panels up to 7m long, and even up to 13m or up to 14m or more, may be provided.

[0022] According to some embodiments, both first and second outer wall may have an inner surface oriented towards the hollow closed volume, for at least one cell, possibly all cells, the at least one opening of said cell is arranged such that the perimeter of each opening is distant from the inner surface of one of the two outer walls. As such at least a part of the inner wall remains in contact with the inner surface of the outer wall. The provision of at least a part of the inner wall in contact with the inner surface of the outer wall may provide be more strong, and/or show less flexibility.

[0023] According to some embodiments, the at least one opening of a cell may be arranged such that the perimeter of each opening is distant from both inner surfaces of the two outer walls.

[0024] Possibly for all openings in one and the same inner wall, the distance between all openings and one of the inner surfaces of one of the outer walls is identical. Possibly for all openings in all inner walls of one cell, the distance between all openings and one of the inner surfaces of one of the outer walls is identical. Possibly for all openings in all inner walls of all cells, the distance between all openings and one of the inner surfaces of one of the outer walls is identical.

[0025] Possibly for all openings in one and the same inner wall, the distance between all openings and both the inner surfaces of both the outer walls is identical. Possibly for all openings in all inner walls of one cell, the distance between all openings and both the inner surfaces of both the outer walls is identical. Possibly for all openings in all inner walls of all cells, the distance between all openings and both the inner surfaces of both the outer walls is identical.

[0026] According to some embodiments, the at least one opening of a cell may intersect with at least one imaginary plane parallel to the first and second outer wall, thereby providing two parts of the at least one opening, said two parts of the at least one opening each define a concave opening, concave towards this at least one imaginary plane. According to some embodiments, this imaginary plane parallel to the first and second outer wall may be the imaginary plane parallel to and at half the height between the first and second outer wall. According to some embodiments, the two parts may be mirrored one to the other relative to said at least one imaginary plane.

[0027] Possibly, the two parts, each being delimited by an edge, have at least a part of its edge coinciding with this imaginary plane, which imaginary plane preferably is positioned at half the height between the first and second outer wall. The two parts may even be congruent one to the other.

[0028] Alternatively, the inner wall may comprise two or more, but preferably two openings, whose edges are free of any coinciding point or part, which openings are congruent one to the other, and which are rotated 180° over a point, hereinafter the rotation point, of at least one imaginary plane parallel to the first and second outer wall, this plane preferably being at half the height between the first and second outer wall. The rotation point may be positioned at half the width of the inner wall. The two openings hence are point-symmetrical in view of this rotation point at half the width of the inner wall.

[0029] Optionally, the inner wall may comprise two or more, but preferably two openings, whose edges are free of any coinciding point or part, which openings are congruent one to the other, and which openings are mirrored over at least one imaginary plane parallel to the first and second outer wall, this plane preferably being at half the height between the first and second outer wall, and which are translated in a direction parallel to the imaginary plane. More preferred, the two openings are point-symmetrical in view of a point at half the width of the inner wall.

[0030] The distance between an openings and the inner surfaces of an outer walls is to be understood as the minimum length measurable between the perimeter of the opening and the inner surface, measured in a direction perpendicular to the inner surface of the outer wall.

[0031] These distances between an opening and an inner surfaces of an outer walls is in the range of 0 to 100%, possibly in the range of 0.01% to 75%, more preferred in the range of 1% to 25% of the total height of the inner wall. The height of the inner wall is understood the length measured between the two inner surfaces of the two outer walls in a direction perpendicular to the two inner surfaces of the two outer walls.

[0032] Alternatively, for at least one cell, and possibly for all cells, the at least one opening of the cell extends from the inner surface of one of the two outer walls up to the inner surface of the second of the two outer walls.

[0033] According to some embodiments, the cell may comprise at least a first inner wall, a third inner wall and a second inner wall arranged between the first inner wall and the third inner wall, the opening is provided in at least the second inner wall, wherein the perimeter of the opening is distant from the first inner wall and/or third inner wall.

[0034] According to some embodiments, the opening of inner wall may be arranged distantly, possibly equidistantly from the first and third inner wall.

[0035] According to some embodiments, the opening in the second inner wall may be arranged substantially equidistant to the first and third inner wall.

[0036] According to some embodiments, the opening in the second inner wall may extend from the first to the third inner walls.

[0037] According to some embodiments, the opening in the second inner wall may extend from the first to the third inner walls and from the inner surface of the first to the inner surface of the second outer walls.

[0038] The inner walls may define cells having a given 3D shape.

[0039] Preferably the cells are oblique or right prisms, preferably right prisms, having a ground surface or bases defined by the outer walls, the inner walls defining sides of the prisms. The angle between the inner and outer walls are preferably in the range of 90° and 45°, and preferably are substantially 90°.

[0040] The bases of the cells are preferably polygonal, like triangular, rectangular, square, quadrangular in general, hexagonal (regular or irregular), and alike. Most preferred, all cells have an identical base.

[0041] According to some embodiments, the opening in the second inner wall may extend through at least one of the first and third inner wall .

[0042] According to some embodiments, the opening in the second inner wall may extend through both the first and third inner wall.

[0043] According to some embodiments, one or more of said cells may be in fluid connection with more than one, possibly all adjacent cell, and each connection between adjacent

[0044] According to some embodiments, all cells may be in fluid connection with more than one, possibly all adjacent cell, and each connection between adjacent cells being provided by at least one opening for passing liquids.

[0045] According to some embodiments, at least two groups of cells may be defined, wherein the walls separating these at least two groups are free of openings.

[0046] According to some embodiments, the groups may form rows of cells, such as rows extending from one side of the panel to another, preferably opposite side of the panel. Each row may comprise one, two or more cells adjacent in a direction non-parallel to the direction of the row. The rows are preferably a number of adjacent cells, forming a line parallel top one of the width of height of the panel.

[0047] Possibly, within each group, such as each row, each cell may be in fluid communication with one, more than one or all adjacent cells in the row.

[0048] The openings in the plurality of inner walls preferably are not distributed over the polymer panel surface in a symmetrical way. When too many openings are provided in one defined zone of the panel surface or when too many openings are aligned according to a pine parallel to the width or length of the panel, this may cause the panel to have a weak spot or a weal zone, causing the strength of the panel to decrease locally. Therefore, although the openings may be distributed according to a distribution scheme, more preferred the openings in a series of three or more adjacent inner walls are not all aligned. The openings are to be distributed more asymmetrically over the wall pane.

[0049] Hence when cells comprise more than one opening in more than one inner wall, for these openings, for each pair of openings, the imaginary plane coplanar with the two lines, each line passing through a center of one of the pair of openings and being parallel with the inner wall, is not parallel to the width or length of the panel. This is in particular the case when the openings extend from one outer wall to the other outer wall.

[0050] Even more preferred, when cells comprise more than one opening in more than one inner wall, for each pair of these openings, when projections are made of one opening on the inner wall comprising the other opening, this projection is free of overlap with the opening in the other inner wall, and this both in the direction of the width of the panel and the direction of the length of the wall.

[0051] By ensuring the openings are distributed asymmetrically, weak zones or spots may be avoided to a large extent. According to some embodiments, each group of cells further may comprise at least one closable opening.

[0052] The polymer panel may comprise thermoplastic polymer or thermohardening polymer.

[0053] According to some embodiments, the panel may be made of a thermoplastic polymer material.

[0054] The thermoplastic material may be polyamide, polyethylene, polypropylene, polyethylene terephthalate, polyvinylchloride and/or combinations thereof.

[0055] According to some embodiments, the panel may be made of polypropylene.

[0056] Alternatively, the polymer panel is provided from a composite material, the polymer used in this composite may be thermoplastic polymer or thermohardening polymer, in combination with reinforcing fibers, such as but not restricted to glass fibers. These reinforcements may be provided as fibers, as one or more webs or as a woven or knitted fabric or fabrics.

[0057] Turning to the polymer panel itself, the polymer panel preferably has a rectangular or square shape.

[0058] The thickness of the outer walls is preferably in the range of 1mm to 10mm, such as in the range of 3mm to 5mm. The thickness of the inner walls is preferably in the range of 0.5mm to 8mm, such as in the range of 1mm to 4mm.

[0059] Preferably the cells are oblique or right prisms, the bases of the cells are preferably polygonal, like triangular, rectangular, square, quadrangular in general, hexagonal (regular or irregular), and alike.

[0060] Most preferably rectangular, square of hexagonal bases are provided. The maximum span between two inner walls is preferably in the range of 5mm to 200mm, such as in the range of 25mm to 150mm, e.g. in the range of 50mm to 100mm.

[0061] Turning to the closeable openings, preferably in the outer wall or outer walls, these openings are preferably liquid tight closable by means of a physical closing system. Possibly such physical closing system may comprise a plug, like a ribbed plug, may be a cork-like closure, or may be a cap, such as a screw cap or a flip cover. Most preferably the closing system comprises a valve, most preferably a pressure valve.

[0062] Possibly however, closeable openings may be closable by welding, such as thermal welding. A part of polymer or a plug may be welded to cover and close the closeable opening.

[0063] In fact, the closeable openings may be provided to the outer wall or outer walls during manufacturing of the polymer panel. The polymer panel may comprise one or more injection moulded parts. The closeable openings may be provided already during this injection moulding process, moulding the part comprising the outer wall in which the closeable opening or openings are to be provided. Alternatively the closeable openings may be provided after having produced or provided the part comprising the outer wall in which the closeable opening or openings are to be provided. As an example, the closeable openings may be provided may be provide in the outer walls by drilling, pinching, perforating and alike.

[0064] According to some embodiments, at least one of the closable openings may be configured as a pressure release valve.

[0065] According to some embodiments, more than one, even all the closable openings are configured as a pressure release valve.

[0066] During filling of the liquid in the polymer panel, one, some or all the closeable openings may function as a venting hole to allow the air or gas in the hollow closed volume to vent or escape to ambient. Alternatively one or both the outer walls, and/or one or more of the side walls of the polymer panel, may comprise air venting holes to allow the air or gas in the hollow closed volume to vent or escape to ambient. These venting holes preferably are also closeable venting holes. These specific venting holes may have dimensions being smaller than the closeable openings for providing liquid into the polymer panel. The dimensions of these venting holes may preferably be in the range of 1mm to 50mm. The venting holes may be closeable by closing them by welding, or may be provided with a plug, like a ribbed plug, e.g. a cork-like closure, or a cap, such as a screw cap or a flip cover, or may be provided with a valve, most preferably a pressure valve.

[0067] According to some embodiments, a liquid may be provided in at least one of the cells.

[0068] Most preferably this liquid is a water-based liquid, like tap water, or demin water.

[0069] The polymer panels according to the first aspect of the invention have the advantage that, when being empty, i.e. free of liquid, they are lightweight seen their polymer nature. However, once installed, they can be partially or completely filled with a liquid, like water. Surprisingly it was found that these at least partially filled panels resist a fire significantly longer in case the outer wall subjected to the fire is contacted at the inner surface by the liquid, such as water. Whereas a non-filled panel would resist a fire exposure of nearly 1.5 - 2 minutes, the very same panel with water present at the inner surface of the outer wall exposed to the fire, resist the same fire exposure typically about 10 times longer, such as for a time period in the range of 10 minutes to 25 minutes, e.g. in the range of 10 minutes to 20 minutes, although the resistance time may be dependent on the liquid level and the type of liquid, which is preferably water-based liquid, even water.

[0070] The polymer panels thus have outer walls defining a hollow closed volumes and an inner structure of inner walls defining cells. The cells hence are to the outer side of the polymer panel delimited by the outer walls. Possibly, for one, some or all cells, one or both outer wall part delimiting the cell, comprises at least one rupture spot with a reduced wall thickness. When a polymer panel is subjected to heat or fire, the polymer panel will first fail at these rupture spot or spots. Possibly the spots may function at that moment as a sprinkler sprinkling the liquid from the outer side of the outer wall of the polymer panel towards the source of fire or heat. To have a preferred sprinkling effect, the rupture spots may have the shape of a truncated cone, the top being delimited by polymer material having a thickness less than he average thickness of the outer wall, and preferably having its outer side flush with the outer walls outer surface.

[0071] According to a second aspect of the invention, the polymer panels according to the first aspect of the invention may be used to construct at least part of a fire resistant wall or fire resistant floor or fire resistant ceiling.

[0072] According to a third aspect of the invention, a method is provided for using the polymer panel according to the first aspect of the invention for providing a fire resistant wall, floor or ceiling, or for improving the fire resistance of a wall, floor or ceiling. The method comprises the steps of

• mounting one or more polymer panels according to the first aspect of the invention;
• providing liquid in the at least one closable opening ;
• close the at least one closable opening liquid tight.

[0073] Preferably the liquid is water-based liquid, such as tap water.

[0074] According to some embodiments, at least some of the polymer panels are mounted horizontally, i.e. in horizontal direction.

[0075] According to some embodiments, at least some of the polymer panels are mounted vertically, i.e. in vertical direction.

[0076] Possibly the volume of water provided in the hollow closed volume is 10% to 90% of the total volume of the hollow closed volume, such as 20% to 90%, Even a limited liquid layer may have a significant effect. A liquid layer of 10mm of water is sufficient to extend the resistance to fire exposure by a factor of about 10.

[0077] According to a further fourth independent aspect of the invention, a polymer panel is provided, the polymer panel comprising:

• a first outer wall; and
• a second outer wall arranged substantially parallel to said first outer wall, wherein the first outer wall and the second outer wall define a hollow closed volume between them;
• a plurality of inner walls extending in a substantially perpendicular direction from the first outer wall to the second outer wall, wherein said inner walls divide the hollow volume in a plurality of cells; wherein each cell is in fluid connection with at least one adjacent cell via at least one opening for passing liquids;
• a liquid being provided in said hollow closed volume.

[0078] Preferably the liquid is a water bases liquid, like tap water or demi water. The setup of the inner walls and the setup of the at least one opening for passing liquids, may be similar even identical to the ones as set out to the first aspect of the invention.

[0079] The liquid which is provided in the hollow closed volume may be provided through one or more closeable opening in the outer walls and/or the side walls of the polymer panel, or may be provided in the hollow closed volume during production of the polymer panel prior to sealing the polymer panel.

[0080] Indeed, possibly but not necessarily, the polymer panel according to this fourth aspect of the invention may comprise one or more closeable opening in the outer walls and/or the side walls of the polymer panel.

[0081] Also all other details and features set out for the polymer panels according to the first aspect of the invention, are applicable for the polymer panel according to this fourth aspect of the invention.

[0082] According to a fifth aspect of the invention, the polymer panels according to the fourth aspect of the invention may be used to construct at least part of a fire resistant wall or fire resistant floor or fire resistant ceiling, such as walls, floors or ceilings of any kind of construction.

[0083] According to a sixth aspect of the invention, a polymer wall according to the first or fourth aspect of the invention is used as a wall, floor and/or ceiling of a building construction, such as houses, offices, agricultural buildings like staples, e.g. for housing animals and/or livestock such as chickens, pigs, cattle, and alike.

[0084] In relation to the invention, when reference is made to a range, the range is to be understood inclusive. Further, it is understood that a feature of one aspect of the invention may be combined with one or more features of one or more other aspect of the invention.

Brief Description of the Drawings

[0085] 

Fig. 1a illustrates schematically a top view of a polymer panel according to the invention. A cross sections and details of this polymer panel are shown in figures 1b to 1d.

Fig. 2a to 2c illustrate schematically alternative polymer panels according to the invention.

Fig. 3 illustrate schematically two polymer panels according to the invention being connected by a liquid conducting means.

Fig. 4 shows schematically half of a polymer panel used to provide polymer panels according to the invention.

Fig 5 shows schematically the action to convert two halves of a polymer panel of figure 4 into a polymer panel according to the invention.

Fig 6a to 6e show schematically the polymer panel obtained from the actions shown in figure 5, as well as various cross sections of this polymer panel.

Fig 7 shows schematically the action to convert two other halves of a polymer panel into a polymer panel according to the invention.

Fig 8 shows schematically the polymer panel obtained from the actions shown in figure 7, as well as various cross sections of this polymer panel.

[0086] In the different figures, the same reference number refers to the same or a similar feature.

Detailed Description of Embodiment(s)

[0087] A top view of a polymer panel 10, adapted to be used as a floor, wall or ceiling of a building construction, is shown in figure 1a. A cross section according to the plane AA' is shown in figure 1b. A detail of the panels outer wall is shown in figure 1c. as will be set out, the thin zone may function as a rupture spot. Figure 1d shows the functioning of this rupture spot when the outer side of the polymer panel is heated and this spot is ruptured, and takes its function as a sprinkler.

[0088] The polymer panel 10 is delimited by four side walls 101, 102, 103 and 104, in this embodiment delimiting the rectangular shaped or cuboid volume, together with two outer walls 110 and 120. Between the two outer walls 110 and 120, the hollow closed volume 130 is provided. Within this hollow closed volume 130, a plurality of inner walls 140 separate the hollow closed volume 130 into a plurality of cells 150, the liquid being provided in this cell 150, 151 and 152, in this embodiment substantially cubic cells. Each of the walls 140 is provided with one opening 160. As such each cell is in fluid connection with each of the adjacent cells.

[0089] The polymer panel 10 is in this embodiment provided with one closeable opening 135, which is adapted to allow liquid to pass into the hollow closed volume 130 in cell 150, will flow through the openings 160 towards the adjacent cells 151 and 152. The liquid further will pass to adjacent cells of the cells 151 and 152. Hence by providing sufficient liquid in the closeable opening 135, all cells of the hollow closed volume 130 may be partially or completely filled with the liquid, e.g. water. The closeable opening may be liquid-tight closed by screwing the screw cap 136 being internally threaded on the external collar 137 of the closeable opening 135. This collar 137 is provided with the matching external thread. Alternatively, the closeable opening may have an internal collar, threaded at the inner side of the collar. A plug, with matching screw thread may be screwed in this internally oriented flange to liquid-tight close the closeable opening.

[0090] The closeable opening 135 may have a diameter in the range of 1mm to 50mm, such as 20mm. Possibly more than one closeable opening 135 may be provided to allow providing liquid in other cells. This may speed up the provision of the required amount of liquid in the hollow volume 130. The closeable openings 135 may also be provided on both sides of the polymer panel 10, i.e. at both outer walls 110 and 120. Depending on the orientation of the polymer panel in e.g. the building construction, the most appropriate closeable openings 135 may be used to provide liquid in the hollow volume 130. As an example, when the polymer panel 10 is used as a flooring panel, the closeable openings 135 at the outer wall oriented upwards may be used, while the closeable openings 135 on the downwards oriented outer wall may stay liquid tight closed.

[0091] In general the polymer panel 10 may have a substantially cuboid shape, with a width and length which may be up to 7m, preferably being in the range of 0.5m to 5 meter, and as a mere example in this embodiment about 2m. This length and width may be the dimensions of the two outer walls 110 and 120. The thickness of the polymer panel, this is the distance between the two outer surfaces defined by the outer walls 110 and 120, may be in the range of 20mm to 100mm, such as e.g. 50mm. The outer walls and side walls may have a wall thickness of about 2m to 5m. the side walls and outer walls may be provided from a thermoplastic polymer, such as polypropylene optionally but not necessarily reinforced by reinforcing fibers, such as but not restricted to glass fibers.

[0092] During filling of the liquid in the polymer panel 10 one or more of the closeable openings 135 may function as a venting hole to allow the air or gas in the hollow closed volume to vent or escape to ambient. In this embodiment, the polymer panel 10 is provided with a dedicated venting hole 170, which is provided at the same outer wall 110 as the closeable opening 135. This venting hole 170 is closeable by a lid or a plug 171. The plug may also function as a pressure safety valve, popping out of the net hole 170 when the pressure inside the hollow volume 130 becomes above a threshold level. The dimensions of these venting holes may be in the range of 1mm to 50mm.

[0093] As shown in figure 1c, the outer wall 120 or the outer walls 110 and 120 may be proved with one, or possibly more than one, rupture spots 180 with a reduced wall thickness. Liquid, 300 such as water, is provided at the inner side of the outer wall 120. When a polymer panel is subjected to heat or fire, the polymer panel will first fail at these rupture spot or spots. In this embodiment, at least the cell 151 is provided with a rupture spot 180. Possible more than one, or even all cells are provided with one rupture spot 180 at one or at both outer walls 110 and 120. When the rupture spots 180 rupture as is shown figure 1d, the liquid 300, e.g. water may spread out to the outer side of the polymer panel. The spot 180 functions as a sort of sprinkler.

[0094] In the polymer panel 10, all cells are in fluid communication with all other cells of the polymer panel.

[0095] Alternative setups of polymer panels 11, 12 and 13 are shown in figure 2a to 2c. In these polymer panels 11, 12 and 13, cells 150 are grouped in groups of cell 191, 192, 193, 194, 195, 196 and 197, each group of cells being provided with at least one closeable opening 135, optionally one venting hole 170. The cells in each group of cells are in fluid communication with each other through the openings in the inner walls 140 of the cells. The groups of cells may provide aligned groups as shown in figure 2a and 2b, or may be grouped in a dedicated manner to provide particular properties over specific zones of the polymer panel 13, as shown in figure 2c. also in these embodiments 11, 12 and 13, rupture spots 180 with a reduced wall thickness may be provided to some or all cells at one or both outer walls 110 and 120.

[0096] In figure 3, two alternative but identical polymer panels 19 are positioned one adjacent to the other. the panels 19 are identical to the panel 10 of figure 1a to 1d, but have two closeable openings 135 and 139. One closable opening 139 of each of the two panels 19, are interconnected by means of a tube 190, being connected to the flanges 137 of the closeable openings 139 by means of appropriate coupling means. One of the other closeable openings 135 may be used to provide liquid, like water, in the void spaces 130 of both panels 19, whereas the other closeable opening 135 of the other panel 19 may stay closed by a cap 136. Once filled, both closeable openings 135 may be closed by a cap 136. The other two closeable openings 139 may stay interconnected by means o the tube 190, or may be closed by a cap 136 after the tube 190 is removed from the flanges 137. As an alternative, the closeable openings 139 may be provided in side walls of the polymer panels 19, such as in the walls 101 and/or 102.

[0097] Turning to figure 4 and further, a method to provide a polymer panel according to the invention is elaborated. As shown in figure 4, a half of a polymer panel 201 may be provided by e.g. injection moulding. This part 201 may serve as the upper or lower half of a polymer panel. an upper view is provided, as well as two cross sections according to the planes CC' and DD'.

[0098] In this embodiment, one closeable opening 135 is provided and one venting hole 170 in the closed side 203 of this half part 201, which will serve as the outer wall 110 or 120 of the polymer panel. All cells, delimited by the inner walls 140 are in fluid communication with each other through openings 160. In this example, the openings 160 are not aligned in direction of the side walls, but are shifted in position one compared to the other. The openings 160 in this embodiment extend from the open side 202 of this half part 201 up to the inner surface of the closed side 203. It is understood that opening extending less far from the open side 202 may be provided as well in the same way.

[0099] As shown in figure 5, two identical half parts 201, referred to as 201a and 201b, are provided. The open sides 202 may be mirror welded one to the other. The outer edges of the walls at one or both open sides are heated by the welding mirror, and thereafter brought in contact with each other. As such, the two identical half parts are in fact flipped one on top of the other (the open sides 202 oriented to each other) by a rotation along an axis E", parallel to one of the side walls of the half parts 201.

[0100] The effect of this is shown in figures 6a to 6e. The outer edges of the inner walls 140 and the outer side walls were heated and pressed one to the other in the thickness direction of the polymer panel. cooling cause the two half parts 201 to adhere. As the inner and side walls are aligned, a firm bonded polymer panel 14 is provided with openings as shown in the cross sections according to the planes FF', GG', HH' and II' in figures 6b to 6e. The polymer panel 14 has at its two outer walls 110 and 120 a closeable opening 135, which can be closed liquid tight by the appropriate means, and a venting hole 170, which also can be closed liquid tight by appropriate means. According to the required specifications, a specified amount of liquid is provided in the hollow volume 130 of the polymer panel 14, and the venting hole and closeable opening, are closed, possibly even sealed. Optionally, the specified amount of liquid is provided in the hollow volume 130 of the polymer panel 14 after the polymer panel being installed at e.g. a building site. This reduces the weight of the polymer panel during transportation.

[0101] During the injection moulding of the half parts 201, rupture sport may be provided in the closed sides 203 by providing locally a less thick injection moulded zone.

[0102] In an alternative, but similar way, another polymer panel 15 is provided as shown in figure 7. In this embodiment, two different half parts 201 and 211 are provided by injection moulding. The two different half parts 201 and 211 are twins, but the positions of inner walls 140, openings 160, closeable openings 135 and venting holes 170 are mirrored according to the plane EE'. In an identical way, the two half parts 201 and 211 are mirror welded one to the other by contacting the two half parts with heated outer edges after one is rotated 180° over the axis E". The resulting polymer panel 15 is shown in figure 8, with a top view and cross sections according to the planes FF', and GG'. In this embodiment, some of the openings 160 in both half parts 201 and 211 are provided from the one inner side of the outer wall 110 to the inner side of the other outer wall 120. As is understood, the openings 160 may also extend to a lesser extent up to the inner sides by injection moulding the openings over a less depth in the half parts 201 and or 211.

[0103] The skilled person understand that in a similar way, also other polymer panels may be provided, by e.g. closing one of the half parts 201 or 211 by a planer polymer sheet.

[0104] Although the present invention has been illustrated by reference to specific embodiments, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied with various changes and modifications without departing from the scope thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. In other words, it is contemplated to cover any and all modifications, variations or equivalents that fall within the scope of the basic underlying principles and whose essential attributes are claimed in this patent application. It will furthermore be understood by the reader of this patent application that the words "comprising" or "comprise" do not exclude other elements or steps, that the words "a" or "an" do not exclude a plurality, and that a single element may fulfil the functions of several means recited in the claims. Any reference signs in the claims shall not be construed as limiting the respective claims concerned. The terms "first", "second", third", "a", "b", "c", and the like, when used in the description or in the claims are introduced to distinguish between similar elements or steps and are not necessarily describing a sequential or chronological order. Similarly, the terms "top", "bottom", "over", "under", and the like are introduced for descriptive purposes and not necessarily to denote relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and embodiments of the invention are capable of operating according to the present invention in other sequences, or in orientations different from the one(s) described or illustrated above.

Claims

1. A polymer panel (10, 11, 12, 13, 14, 15) comprising:

• a first outer wall (110); and

• a second outer wall (120) arranged substantially parallel to said first outer wall, wherein the first outer wall and the second outer wall define a hollow closed volume (130) between them;

• at least one closable opening (135) adapted to provide a liquid in said hollow closed volume from the outside of the panel, wherein the closable opening is liquid tight when closed;

• a plurality of inner walls (140) extending in a substantially perpendicular direction from the first outer wall to the second outer wall, wherein said inner walls divide the hollow volume in a plurality of cells (150, 151, 152); wherein each cell is in fluid connection with at least one adjacent cell via at least one opening (160) for passing liquids.

2. The polymer panel according to previous claim 1, wherein both first and second outer wall have an inner surface oriented towards the hollow closed volume, for at least one cell, the at least one opening of said cell is arranged such that the perimeter of each opening is distant from the inner surface of one of the two outer walls.

3. The polymer panel according to claim 2, wherein the at least one opening of a cell is arranged such that the perimeter of each opening is distant from both inner surfaces of the two outer walls.

4. The polymer panel according to any one of the claims 2 to 3, wherein the at least one opening of a cell intersects with at least one imaginary plane parallel to the first and second outer wall, thereby providing two parts of the at least one opening, said two parts of the at least one opening each define a concave opening, concave towards this at least one imaginary plane.

5. The polymer panel according to claim 4, wherein said imaginary plane parallel to the first and second outer wall is the imaginary plane parallel to and at half the height between the first and second outer wall.

6. The polymer panel according to any one of the claims 4 to 5, wherein said two parts are mirrored one to the other relative to said at least one imaginary plane.

7. The polymer panel according to any one of the previous claims, wherein at least two groups of cells (191, 192, 193, 194, 195, 196, 197) are defined, wherein the walls separating these at least two groups are free of openings.

8. The polymer panel according to previous claim 7, wherein each group of cells further comprises at least one closable opening.

9. The polymer panel according to any one of the previous claims, wherein the panel is made of a thermoplastic polymer material.

10. The polymer panel according to any of the previous claims, wherein at least one of the closable openings is configured as a pressure release valve.

11. The polymer panel according to any one of the previous claims, wherein a liquid is provided in at least one of the cells.

12. The polymer panel according to any one of the previous claims, wherein at least one of the cells is provided with at least one rupture spot (180).

13. A method for using the polymer panel according to any one of the preceding claims, for providing a fire resistant wall floor or ceiling, or for improving the fire resistance of a wall, floor or ceiling, the method comprising the steps of

- mounting one or more polymer panels according to the first aspect of the invention;

- providing liquid in the at least one closable opening (135)

- close the at least one closable opening liquid tight.

14. The use of a polymer wall according to any one of the claims 1 to 12 as a wall, floor and/or ceiling of a building construction.

Drawing