Method for manufacturing rock-polymer conglomerate building boards and building board

Abstract

Solid input raw materials with the following composition: chalk 60.0-75.0 wt.%, polystyrene 5.0-25.0 wt.%, high styrene rubber 5.0- 20.0 wt.%, and additives 1÷5 wt.% are provided. The particle size of the input raw materials supplied to a dispenser (1) does not exceed 75 μm, and the temperature of the plastic mass pumped under pressure to a slotted head (4) is within the limits 178-210˚C and the discharge pressure is within 4÷5 MPa. In addition, the temperature of the plastic mass pumped under pressure into the slotted head (4) is chosen so that its dynamic viscosity is in the range of 0.97x103 to 1.03x103 Pa*s.

Description

[0001] METHOD FOR MANUFACTURING ROCK-POLYMER CONGLOMERATE BUILDING BOARDS AND BUILDING BOARD

[0002] The subject of the invention is a method for manufacturing rock- polymer conglomerate building boards and a building board produced by this method. The invention particularly relates to the manufacture of building boards used as support layers for floor or wall panels. Such support layers have coupling elements shaped close to the connecting edges, allowing building boards to be joined together to form a floor or wall covering.

[0003] State of the art

[0004] Boards made from rock-polymer conglomerates (SPC) tend to have varying surface energies that hinder bonding of their top layer. Another significant complication is the high brittleness of these boards, especially in the areas of thin coupling elements near their edges .

[0005] EP3245249B1 discloses a method for manufacturing building boards for use as floor boards, wall boards or ceiling boards, comprising at least a top layer and a support layer which is made of synthetic material, such as polystyrene, in an amount of 15 to 75% by weight and filler material such as chalk. This well-known building board can contain rubber in its composition, in which case carbon black is used as a filler material. The well-known method comprises the following steps:

[0006] - mixing synthetic material and filler material, thus producing a mixture ; - extrusion of this mixture, thus producing a building board as a substrate to be bonded to the top layer;

[0007] - optionally, laminating this substrate with the top layer to produce a two-layer building board and annealing the board manufactured in this way.

[0008] Also known from EP3132945B1 is a method for manufacturing building, wall or floor boards in which a comminuted material, in particular in the form of granules, is provided in predetermined proportions, the provided material is placed between conveyor belts, the support material is formed at elevated temperature to form an endless strip, this support strip is passed through a set of rollers at a predetermined pressure and temperature, after which the strip of predetermined thickness is cooled and optionally further layers are applied to it.

[0009] The aim of the invention is to develop a method for manufacturing building boards with increased surface adhesion, containing neither PVC nor any other substances containing chlorine compounds in their composition, and at the same time characterised by increased homogeneity of the extruded mass, giving homogeneity of elastic and strength properties throughout the board cross-section.

[0010] Summary of the invention

[0011] The method for manufacturing building boards of rock-polymer conglomerate according to the invention comprises the following steps : - providing input raw materials in a solid state, in the form of shredded chalk, shredded rubber, shredded polystyrene and auxiliary materials, in fixed proportions to a mixer,

[0012] - mixing the supplied input raw materials in the mixer until a homogeneous mixture is obtained,

[0013] - providing the homogeneous mixture of the input raw materials to a dispenser,

[0014] - providing the homogeneous mixture of the input raw materials to an extruder,

[0015] - heating the homogeneous mixture of the input raw materials in the extruder to a plastic state,

[0016] - mixing the mass in the plastic state in the extruder,

[0017] - providing the pressurised mass in the plastic state to a slotted head, where this plastic mass is forced through the slot to produce an endless strip in the plastic state,

[0018] - providing the strip in the plastic to a calender assembly comprising a heated pressing and smoothing roller unit and a cooled roller unit to achieve uniform thickness and flatness of the pressed strip, moving the flat strip through the transport system while it continues to cool, cutting the cooled strip into building boards of specified dimensions .

[0019] The solution according to the invention is characterised by the fact that the following input raw materials are used in amounts expressed as weight percentages:

[0020] - chalk 60-75.0, - polystyrene 5.0-25.0,

[0021] - high-styrene rubber 5.0-20.0,

[0022] - stearic acid 0-3.7,

[0023] - calcium stearate 0-3.5, additives le5, preferably in the form of compatibilizers, lubrication modifiers or plasticisers.

[0024] According to the invention, the particle size of the used input raw materials provided to the dispenser does not exceed 75 pm. In addition, the temperature of the pressurised plastic mass pumped into a slotted head is in the range of 180-210 °C and the pumping pressure is in the range of 4e5 MPa, with the temperature of the pressurised plastic mass pumped into the slotted head selected to achieve its dynamic viscosity in the range of 0.97xl03to 1.03xl03Pa*s.

[0025] Preferably, more than 50% of the input raw material particles provided to the dispenser are larger than 15 pm and do not exceed 30 pm.

[0026] Preferably, the input raw materials are provided to the mixer via pneumatic conveying ducts with preset air flow velocities in the range of 12 to 14 m / s.

[0027] Preferably, the input raw materials are used in quantities expressed as weight percentages:

[0028] - chalk 67.5-71.0,

[0029] - polystyrene 12.0-14.0,

[0030] - high-styrene rubber 11.0-13.0,

[0031] - calcium stearate 0-3.5%, stearic acid 0-3.7% - additives 4.6-5.0, and the temperature of the plastic mass pumped under pressure into the slotted head is in the range of 190-210 °C, and the pumping pressure is in the range of 4e5 MPa, with dynamic viscosity in the range of 0.99xl03to l.OlxlO3Pa*s.

[0032] Preferably, the input raw materials are used in quantities expressed as weight percentages:

[0033] - chalk 71.0-73.0,

[0034] - polystyrene 5.0-9.0,

[0035] - high-styrene rubber 16.0-17.0,

[0036] - additives 4.7-5.0, and the temperature of the plastic mass pumped under pressure into the slotted head is in the range of 182-191 °C, and the pumping pressure is in the range of 4.3-4.5 MPa, with dynamic viscosity in the range of 0.98xl03to l.OOxlO3Pa*s.

[0037] Preferably, a twin-screw extruder is used as the extruder.

[0038] The building board of rock-polymer conglomerate according to the invention is characterised by the fact that it is manufactured by the method according to the invention.

[0039] Preferably, the building board has resilient coupling elements shaped on at least two edges.

[0040] By supplying the dispenser with the input raw materials of the indicated chemical composition and with the particle size of no more than 75 pm , while simultaneously selecting such a temperature of the plastic mass pumped under pressure into the slotted head that ensures a dynamic viscosity in the range of 0.97xl03to 1.03xl03Pa*s, building boards with increased elasticity and bending strength were obtained, which allowed to eliminate the unfavourable phenomenon of cracking of parts of the building boards in the areas of thin coupling elements shaped near the edges of these boards. In addition, the homogeneity of the structure of the external surface of the building board was improved, thereby also improving the uniformity of the surface energy. This resulted in improved bonding ability of the building board produced in this way with the decorative top layer.

[0041] Building boards obtained by the method according to the invention also have increased sound absorption and reduced tendency to self-fold. In the raw material structure, the PVC polyvinyl chloride, commonly used in conglomerate board manufacturing processes, was eliminated.

[0042] Description of drawings

[0043] The subject of the invention is presented in embodiments in the schematic drawing, in which:

[0044] Fig. 1 presents a production line implementing the method for manufacturing building boards from rock-polymer conglomerate;

[0045] Fig. 2 presents a part of the production line showing a strip of the rock-polymer conglomerate moving through a calender assembly;

[0046] Fig. 3 presents a building board produced by the method according to the invention;

[0047] Fig. 4 presents examples of embossing patterns on one plane of the board;

[0048] Fig. 5 presents the widths and heights of the embossing; Fig. 6 presents a specimen of a plate test shape for measuring the mechanical properties of different materials;

[0049] Fig. 7 presents a graph of Young's modulus of elasticity [MPa] according to ISO 178 for selected tested materials for building boards ;

[0050] Fig. 8 presents the tensile strength graph [MPa] according to ISO 527 of selected tested materials for building boards;

[0051] Fig. 9 presents a graph of the elongation according to ISO 527 [%] of selected tested materials for building boards;

[0052] Fig. 10 presents the tensile strength — Young's modulus relationship .

[0053] The method for manufacturing building boards la from rock- polymer conglomerate is carried out on the production line shown in Fig. 1. In the initial stage, raw material streams from dispensers 1 are fed in strictly according to set proportions. The following raw materials are used as the input: chalk in the amount in the range of 65.0-75.0 wt.%, polystyrene in the amount in the range of 5.0- 25.0 wt.%, high styrene rubber in the amount in the range of 5.0- 20.0 wt.%, calcium stearate 0-3.5 wt.%, stearic acid 0-3.7 wt.% and additives in the amount of la5 wt.%, with the particle size of used input raw materials provided to the dispenser 1 not exceeding 75 pm. All stages of the manufacturing method are carried out in the production hall, under microclimatic conditions typical for industrial production halls (10-35°C) and relative humidity of 35e45% .

[0054] Description of embodiments Example 1

[0055] In the first embodiment, input raw materials of the following composition were used: chalk 70.0 wt.%, polystyrene 15.0 wt.%, high styrene rubber 10.5 wt.% and additives of 4.5 wt.%. The following were used as additives: 1% SCONA modifier TSKD 9103 (styrene- ethylene / butylene-s tyrene block copolymer (SEES) functionalized with maleic anhydride) at 1.1 wt.% and wax substitute BYK-MAX P 4102 (hydroxy functional carboxylic acid ester with affine pigment groups) in the amount of 1.4 wt.% and stearin (a mixture of stearic, palmitic and unsaturated acids) in the amount of 1.0 wt.%.

[0056] The input raw materials used are in the solid phase and their particle size is predominantly larger than 15 pm and does not exceed 75 pm. The input raw materials are provided to the mixer 2 via pneumatic conveying ducts with preset air flow velocities in the range of 12 to 14 m / s. In the mixer 2, the dosed raw materials are mixed into a compositionally uniform working mixture, which is fed successively, in cyclic and uniform portions, into a heated extruder 3. In the embodiment, a twin-screw extruder with counter-rotating screw direction was used as the extruder 3. The interior of the extruder 3 is heated to a temperature in the range of 178 to 210 °C, preferably the temperature of 195 °C was used, obtaining a dynamic viscosity of the plastic mass pumped under pressure into a slotted head 4 equal to l.OlxlO3Pa*s and therefore contained within predetermined limits in the range of 0.97xl03to 1.03xl03Pa*s, at a pressing pressure of 4.5 MPa, also contained within predetermined limits of 4e5 MPa. The pressing pressure depends on the temperature and viscosity of the plastic mass being pumped.

[0057] The plasticised mass, under the pressure caused by rotating screws of the extruder 3, moves towards the slotted head 4. As a result of the pressure exerted, the plasticised mass is forced through the slotted head 4 aperture, taking the shape of a horizontal plate, extruded as an endless strip 5.

[0058] The endless strip 5 such extruded is introduced into a calender assembly 6, in order to give it a uniform thickness and flatness, after which this strip 5 is drawn through a pre-cooling chamber 7 and a primary cooling chamber 8, using a pulling machine 9 which moves the strip 5 at a constant linear speed. In order to maintain a constant linear velocity of the displaced strip 5 with a thickness of 6 mm and a width of 200 mm, the force exerted by the pulling machine 9 of 195 N allows a constant linear velocity of 0.3 m / s.

[0059] In the first pre-cooling chamber 7, air previously cooled to a temperature of 3-8 °C blows over the surface of the strip 5. Once a section of the strip 5 has passed through the pre-cooling chamber 7, it is cooled to a temperature of 55-50 °C, and the heated air involved in the cooling process is removed to the atmosphere. In the primary cooling chamber 8, the air previously cooled to 8-10 °C blows over the surface of the strip cooling it to 32-35 °C, and the heated air involved in the cooling process is also removed to the atmosphere. Further cooling of the flat strip 5 is carried out as it moves through a linear transport system 10. The strip 5 cooled to ambient temperature is cut with a guillotine 11 into building boards la with predetermined length dimensions. The cut-off building board la is transported by a receiving conveyor 12, the level of which is lowered between 30 and 60 mm relative to the level of the linear transport system 10. This difference in levels precludes blocking of the strip 5 with cut building boards la awaiting collection. By means of the receiving conveyor 12, the cut-off building board la is moved to the operating area of a pick-up and drop-off manipulator 13, which receives each cut-off building board la and stacks it in a packet on a pallet 14.

[0060] Example 2

[0061] In the second embodiment, input raw materials of the following composition were used: 68.0 wt . % chalk, 14.0 wt . % polystyrene, 13.0 wt . % high styrene rubber and 5.0 wt . % additives, wherein SCONA TSKD 9103 compatibilizer of 3.0 wt . % and BYK-MAX P 4102 wax replacement of 2.0 wt . % were used as additives. The input raw materials used are in the solid phase and their particle size ranges from 15 pm to 75 pm. The input raw materials are provided to the mixer 2 via pneumatic conveying ducts with preset air flow velocities in the range of 12-14 m / s. In the mixer 2, the dispensed raw materials are mixed in a compositionally homogeneous working mixture, which is fed successively, in cyclic and homogeneous portions, into the extruder 3 heated to a temperature in the range of 178 to 210 °C, preferably 185 °C, obtaining a dynamic viscosity of the plastic mass pumped under pressure into the slotted head 4 equal to l.OOxlO3Pa*s, at a pressing pressure of 4e4.5 MPa. Further steps in the manufacture of building boards la were carried out as in the embodiment 1. As an option, it is possible to emboss the concave patterns shown in Fig. 4, on one of the planes of the extruded strip 5 during the pressing operation in the calender assembly 6.

[0062] Example 3

[0063] In the third embodiment, input raw materials of the following composition were used: chalk 60.0 wt.%, GPPS M-170 general-purpose polystyrene in an amount of 24.0 wt.%, 1904 high-styrene rubber in an amount of 14.0 wt.%, and additives in an amount of 2.0 wt.%, wherein SCONA BYC compatibilizer at 1.0 wt.% and stearin at 1.0 wt.% were used as additives. The input raw materials used are in the solid phase and their particle size ranges from 15 pm to 75 pm. The input raw materials are provided to the mixer 2 via pneumatic conveying ducts with preset air flow velocities in the range of 12-14 m / s. In the mixer 2, the dispensed raw materials are mixed in a compositionally homogeneous working mixture, which is fed successively, in cyclic and homogeneous portions, into the extruder 3 heated to a temperature in the range from 178 to 210 °C, preferably 195 °C, obtaining a dynamic viscosity of the plastic mass pumped under pressure into the slotted head 4 equal to l.OOxlO3Pa*s, at a pressing pressure of 4e4.5 MPa. Further steps in the manufacture of building boards la were carried out as in the embodiment number 1.

[0064] Example 4

[0065] In the fourth embodiment, input raw materials of the following composition were used: chalk 73.0 wt.%, polystyrene 7.5 wt.%, high styrene rubber 14.5 wt.% and additives of 5.0 wt.%. Only SCONA TSKD 9103 compatibilizer was used as an additive. The input raw materials used are in the solid phase and their particle size ranges from 15 pm to 75 pm. The input raw materials are provided to the mixer 2 via pneumatic conveying ducts with preset air flow velocities in the range of 12 to 14 m / s. In the mixer 2, the dispensed raw materials are mixed in a compositionally homogeneous working mixture, which is fed successively, in cyclic and homogeneous portions, into the extruder 3 heated to a temperature in the range from 178 to 210 °C, preferably 190 °C, obtaining a dynamic viscosity of the plastic mass pumped under pressure into the slotted head 4 equal to 0.98xl03Pa*s, at a pressing pressure of 4.25 MPa. Further steps in the manufacture of building boards la were carried out as in the embodiment 1.

[0066] Optionally, the cut-off building boards la, obtained in embodiments 1 to 3, are subjected to further machining to shape the resilient coupling elements at their edges .

[0067] As shown in Fig. 2 the calender assembly 6 used in the embodiments has an assembly of heated pressing and smoothing rollers 15, 16, 17 and an assembly of cooled rollers 18, 19, enabling uniform thickness and flatness to be imparted to the pressed strip 5. The extruded endless strip 5 extruded from the slotted head 4 is moved to the calender assembly 6, where it is given a uniform thickness and flatness. In the first calendering zone, the lower adjustable pressing and smoothing roller 15 is heated to a temperature in the range of 190e210°C. The middle pressing and smoothing roller 16 is heated by heat transfer from the calendered endless strip 5 wrapping it. A gap size of 0.3 mm more than the desired final thickness of the building board is set between the pressing and smoothing rollers 15 and 16. In the second calendering zone, the upper adjustable pressing and smoothing roller 17 is heated to a temperature of 176^185 °C and the gap size between the pressing and smoothing rollers 16, 17 is 0.05 mm larger than the desired final thickness of the building board.

[0068] The endless strip 5, after being made thick in the area of the pressing and smoothing rollers 16, 17, is transferred to the cooling zone of the calender assembly 6. The endless strip 5 travels from the roller 17 to the cooled rollers 18 and 19 wrapping the surfaces of both rollers over at least half (^) of the circumferential surface. The surface temperature of the cooled rolls is adjusted and adapted to the material composition of the strip 5. The temperature of the cooled rollers 18 and 19 for the strip material used is about 140 °C. The endless strip 5 is cooled in the calender assembly 6 to a temperature of approximately 150 °C and, via a guiding roller 20, it is conveyed to the linear transport system 10, which moves it through successive operating zones to the end point of the building board production line la.

[0069] As shown in Fig. 3, the building board la obtained by the method according to the invention has a rectangular shape and may include coupling elements 21, 22 shaped at the edges 23, 24. The coupling elements 21, 22 are shaped by milling and have a significantly smaller thickness in their thinnest section than the thickness of the building board la. These coupling elements 21, 22 have a uniform structure throughout their cross-section, which reduces their susceptibility to mechanical damage during manufacture and assembly. Furthermore, the building board la obtained by the method according to the invention has an increased adhesion capacity, which facilitates the adhesion of other materials to the top and bottom side of the building board la.

[0070] Optionally, in each of the embodiments, it is possible to emboss concave patterns on one of the planes of the strip 5 during the pressing operation in the calender assembly 6. Fig. 4 and Fig. 5 present the embossing patterns on the plane 25 of the building board la already formed at the extrusion stage of the strip 5. Examples of the patterns are as follows: inclined groove embossing 26 of width S and height h, parallel groove embossing 27 of width S and height h; cross groove embossing 28 of width S and height h; and hexagonal groove extrusions 29 of width S and height h.

[0071] Investigative process experiments were carried out to confirm the achievement of selected assumed properties of building board la for further refinement processes.

[0072] In eleven additional process experiments carried out on the research process plant, selected properties of boards with different raw material compositions according to recipes 1-11 were measured.

[0073] From the building board la, obtained according to each of the eleven recipes tested, the pattern shown in Fig. 6 which was characterised by the following dimensions was cut:

[0074] LI length of the narrow section 80 mm;

[0075] L2 total length 150 mm;

[0076] L0 gauge length 50 mm;

[0077] L grip to grip separation 115 mm; R radius 60 mm;

[0078] Bl specimen width in gauge area 10 mm;

[0079] B2 specimen width in shoulder area 20 mm;

[0080] G specimen thickness 5 mm.

[0081] The particle size of the input raw materials used, supplied to the dispenser 1 did not exceed 75 pm, the temperature of the pressurised plastic mass pumped into the slotted head 4 was in the range of 178-210 °C and the pumping pressure was in the range of 4e5 MPa, with the temperature of the pressurised plastic mass pumped into the slotted head 4 selected so that its dynamic viscosity was in the range of 0.97xl03to 1.03xl03Pa*s.

[0082] Table 1 shows mass percentages of the raw material components (recipes) for each tested material and the results obtained for the mechanical properties of the tested boards.

[0083] Table 1. Raw material composition of the tested panels and their mechanical properties.

[0084]

[0085] In the experiment with recipe number 2 from Table 1

[0086] (comparative example) , a thermoplastic elastomer TPE in the amount of 8% was used instead of the high styrene rubber, in order to implement a comparative example that is incompatible with the method according to the invention.

[0087] The measured mechanical properties of the building board template include tensile strength, elongation and Young's modulus, which is a measure of the stiffness of materials and determines the tensile resistance of the material. A higher value of this parameter indicates a lower deformation of the material, which is a desirable feature for floor panels. The results of the measurements of the mechanical properties of the tested materials produced according to recipes number 1 to number 11 in the Table 1 are illustrated in Fig. 7, Fig. 8 and Fig. 9.

[0088] In the comparative experiment (recipe number 2 in Table 1) , favourable strength parameters, especially the corresponding elasticity of building board la, were not obtained. The Young's modulus of the material resulting from this recipe was 467 MPa, which was more than five times worse than the worst result of 2650 MPa, obtained by the method according to the present invention, for recipe number 5 in Table 1, when 8.5% high styrene rubber was used.

[0089] The participation of high styrene rubber in the manufacturing method according to the invention allowed to produce homogeneous building boards la with acceptable strength parameters and homogeneous elastic properties.

[0090] Reference numbers:

[0091] 1 dispenser la building board

[0092] 2 mixer

[0093] 3 twin-screw extruder

[0094] 4 slotted head

[0095] 5 extruded strip

[0096] 6 calender assembly

[0097] 7 pre-cooling chamber

[0098] 8 primary cooling chamber

[0099] 9 pulling machine

[0100] 10 linear transport system 11 guillotine

[0101] 12 receiving conveyor for building boards

[0102] 13 pick-up and drop-off manipulator

[0103] 14 pallet

[0104] 15 pressing and smoothing roller

[0105] 16 pressing and smoothing roller

[0106] 17 pressing and smoothing roller

[0107] 18 cooled roller

[0108] 19 cooled roller

[0109] 20 guiding roller

[0110] 21, 22 coupling element

[0111] 23, 24 edge

[0112] 25 plate plane

[0113] 26 inclined groove embossing

[0114] 27 parallel groove embossing

[0115] 28 cross groove embossing

[0116] 29 hexagonal groove extrusions h groove, recess height

[0117] S groove, recess width

[0118] LI length of the narrow section

[0119] L2 total length

[0120] L0 gauge length

[0121] L grip to grip separation

[0122] R radius

[0123] Bl specimen width in gauge area

[0124] B2 specimen width in shoulder area

[0125] G specimen thickness

Claims

Claims1. A method for manufacturing building boards (la) from rock-polymer conglomerate comprising the following steps:- providing input raw materials in a solid state, in the form of shredded chalk, shredded rubber, shredded polystyrene and auxiliary materials in fixed proportions to a mixer (2) ,- mixing the supplied input raw materials in the mixer (2) until a homogeneous mixture is obtained,- providing the homogeneous mixture of the input raw materials to a dispenser ( 1 ) ,- providing the homogeneous mixture of the input raw materials to an extruder ( 3 ) ,- heating the homogeneous mixture of the input raw materials in the extruder (3) to a plastic state,- mixing the mass in the plastic state in the extruder (3) ,- providing the pressurised mass in the plastic state to a slotted head (4) , where this plastic mass is forced through the slot to produce an endless strip (5) in the plastic state,- providing the strip (5) in the plastic state to a calender assembly(6) comprising a heated pressing and smoothing roller unit (15, 16, 17) and a cooled roller (18, 19) unit to achieve uniform thickness and flatness of the pressed strip (5) ,- moving the flat strip (5) through the transport system while cooling it further,- cutting the cooled strip (5) into building boards (la) of specified dimensions ,characterised in that the input raw materials are used in quantities expressed as a percentage by weight:- chalk 60.0-75.0,- polystyrene 5.0-25.0,- high-styrene rubber 5.0-20.0,- stearic acid 0-3.7,- calcium stearate 0-3.5, additives 1.0-5.0, preferably compatibilizers, lubrication modifiers or plasticisers, wherein- the particle size of the input raw materials used, supplied to the dispenser (1) does not exceed 75 pm,- the temperature of the plastic mass pumped under pressure into the slotted head (4) is in the range of 178-210 °C and the pumping pressure is in the range of 4e5 MPa, wherein the temperature of the plastic mass pumped under pressure into the slotted head (4) is chosen so that its dynamic viscosity is in the range from 0, 97xl03to l,03xl03Pa*s.

2. The method according to claim 1, characterised in that more than 50% of the input raw material particles delivered to the dispenser (1) are larger than 15 pm and do not exceed 30 pm in dimension.

3. The method according to claim 1 or 2, characterised in that the input raw materials are provided to the mixer (2) via pneumaticconveying ducts with preset air flow velocities in the range of 12 to 14 m / s.

4. The method according to claim 1 or 2 or 3, characterised in that the input raw materials are used in amounts expressed as a percentage by weight:- chalk 67.5-71.0,- polystyrene 12.0-14.0,- high-styrene rubber 11.0-13.0,- additives 4.6-5.0, wherein the temperature of the plastic mass pumped under pressure into the slotted head (4) is in the range of 190-210°C and the pumping pressure is in the range of 4e5 MPa, with a dynamic viscosity in the range of 0.99xl03to l.OlxlO3Pa*s.

5. The method according to claim 1 or 2 or 3, characterised in that the input raw materials are used in amounts expressed as a percentage by weight:- chalk 71.0-73.0,- polystyrene 5.0-9.0,- high-styrene rubber 16.0-17.0,- additives 4.7-5.0, where the temperature of the plastic mass pumped under pressure into the slotted head (4) being in the range of 182-191 °C and the pumping pressure in the range of 4.3e4.5 MPa, with a dynamic viscosity in the range of 0.98xl03to l.OOxlO3Pa*s.

6. The method according to claim 1, characterised by using a twin- screw extruder as the extruder (3) .

7. A building board (la) of rock-polymer conglomerate manufactured by the method according to any of claims 1 to 6.

8. The building board (la) according to claim 7, characterised in that it has resilient coupling elements (21, 22) shaped on at least two edges (23, 24) .

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