A floor slab for prefabricated modular bathroom pods

Abstract

The invention relates to a floor slab for a prefabricated modular bathroom pod comprising: a) 25 – 85 wt.-%, preferably 30 – 80 wt.-%, of at least one polymer P and b) 5 – 65 wt.-%, preferably 10 – 60 wt.-%, of at least one solid filler F, all proportions being based on the total weight of the slab, wherein the floor slab is obtained by using an additive manufacturing process.

Description

[0001] A FLOOR SLAB FOR PREFABRICATED MODULAR BATHROOM PODS

[0002] Technical field

[0003] The invention relates to floor slabs supporting a draining surface for use in prefabricated modular bathroom pods. The invention also relates to methods for producing such floor slabs and to transportable bases supporting a wall structure and a floor slab.

[0004] Background art

[0005] Modular building techniques offer significantly increased efficiency when it comes to construction of high rise buildings, large passenger vessels, and the like. Particularly, prefabricated bathroom units, also known as bathroom pods, can be produced off site, transported to the construction site, and connected to the required infrastructure (electricity, water, sewer), which significantly shortens the overall construction time. Generally, efficiency of a construction process can be improved by conducting most of the construction work off-site, since time and cost inefficiencies associated with, for example, downtime due to weather and access difficulties, can be avoided in an off-site factory premises.

[0006] A typical prefabricated bathroom pod comprises a base supporting a wall structure and a floor slab having a drain opening and a draining surface finished to form a floor finishing, such as tiles. A waterproofing layer, such as a polymeric membrane, is usually installed on the draining surface of the floor slab before finishing of the draining surface, for example, with floor tiles. The waterproofing layer is applied to ensure that the floor slab is protected from any moisture that penetrates through the draining floor, for example by seeping through the grout between the floor tiles and into the tile bed.

[0007] Waterproofing of the floor slab typically also requires a further step of applying a second waterproofing layer to prevent lateral migration of the through the wall of the drain hole into the space between the first waterproofing membrane and the draining surface. Especially the installation of the second waterproofing layer requires a lot of manual work since the size of the dimensions of the membrane must handcrafted to fit with the dimensions of the drain hole.

[0008] There is thus a need for a new type of floor slab for use in a modular bathroom pod that does not necessarily require installation of waterproofing layer(s) between the floor slab and the floor finishing. Furthermore, although most bases of modular bathroom pods are standardized, it would also be desirable to be able to produce floor slab having an arbitrary shape to be able to provide bathroom modules with individual geometries.

[0009] Brief description of figures

[0010] Fig. 1 shows a photographic presentation of a 3D printed floor slab (12) having a drain hole extending though the slab and situated approximately in the middle of the floor slab.

[0011] Fig. 2 shows a schematic representation of a 3D printing process whereby an exemplary floor slab (12) is printed with a 3D printer (7) based on the digital model (10) of the floor slab.

[0012] In the figures, the same components are given the same reference symbols.

[0013] Disclosure of the invention

[0014] It is an object of the present invention to provide a floor slab for a prefabricated modular bathroom pod that enables savings in installation time and costs.

[0015] Particularly, the floor slab should have a draining surface that is operative to bond with fresh cementitious compositions. Due to the unique properties of the draining surface, a floor finishing, such as tiles, can be directly bonded to the draining surface using an adhesive, such as tile adhesive, to form a continuous waterproofed structure without use of additional waterproofing layers, particularly waterproofing membranes, between the draining surface and the floor finishing.

[0016] Surprisingly, it has been found out that the object can be achieved by the features of claim 1.

[0017] Especially, it has been found out that floor slabs produced by an additive manufacturing process, particularly 3D printing, from a filled polymeric composition have a draining surface that is operative to bond with cementitious compositions, such as tile adhesives. Use of the additive manufacturing process also allows producing customized floor slabs at very low costs. Specifically, the costs per part are essentially independent on the lot size.

[0018] Specifically, according to the invention, a floor slab for a prefabricated modular bathroom pod is proposed, the floor slab comprising: a) 25 - 85 wt.-%, preferably 30 - 80 wt.-%, of at least one polymer P and b) 5 - 65 wt.-%, preferably 10 - 60 wt.-%, of at least one solid filler F, all proportions being based on the total weight of the floor slab, wherein the floor slab is obtained by using an additive manufacturing process.

[0019] As it turned out, the inventive floor slab has a draining surface that is operative to bond with fresh cementitious compositions, such as cementitious tile adhesives. The expression “operative to bond” is understood to mean in this context that that the draining surface of the floor slab forms a permanent bond to a fresh cementitious composition casted against it after hardening. The use of the floor slab enables significant savings in installation time and costs since presence of an additional waterproofing layer between the draining surface and the floor finishing, such as tiles, is not necessarily required for waterproofing of the floor slab. Additional aspects of the present invention are defined in further independent claims. Particularly preferred embodiments are outlined throughout the description and the dependent claims.

[0020] Detailed description

[0021] A first aspect of the present invention is directed to a floor slab for a prefabricated modular bathroom pod comprising: a) 25 - 85 wt.-%, preferably 30 - 80 wt.-%, of at least one polymer P and b) 5 - 65 wt.-%, preferably 10 - 60 wt.-%, of at least one solid filler F, all proportions being based on the total weight of the floor slab, wherein the floor slab is obtained by using an additive manufacturing process.

[0022] Generally, the “amount or content of at least one component X” in a composition, for example “the amount of the at least one polymer P” refers to the sum of the individual amounts of all polymers P contained in the composition. Furthermore, in case the composition comprises 20 wt.-% of at least one polymer P, the sum of the amounts of all polymers P contained in the composition equals 20 wt.-%.

[0023] According to ISO 52900-2015 standard, the term “additive manufacturing (AM)” refers to technologies that use successive layers of material to create a 3D objects. In an AM process, the material is deposited, applied, or solidified under computer control based on a digital model of the 3D object to be produced, to create the 3D article. The abbreviation 3D is used throughout the present disclosure for the term “three-dimensional.

[0024] Additive manufacturing processes are also referred to using terms such as "generative manufacturing methods" or "3D printing". The term “3D printing” was originally used for an ink jet printing based AM process created by Massachusetts Institute of Technology (MIT) during the 1990s. Compared to conventional technologies, which are based on object creation through either molding / casting or subtracting / machining material from a raw object, additive manufacturing technologies follow a fundamentally different approach for manufacturing. Particularly, it is possible to change the design for each object, without increasing the manufacturing costs, offering tailor made solutions for a broad range of products.

[0025] Generally, in an AM process a 3D article is manufactured using a shapeless material (e.g. liquids, powders, granules, pastes, etc.) and / or a shape-neutral material (e.g. bands, wires, filaments) that in particular is subjected to chemical and / or physical processes (e.g. melting, polymerization, sintering, curing or hardening). The main categories of AM technologies include VAT photopolymerization, material extrusion, material jetting, binder jetting, powder bed fusion, direct energy deposition, and sheet lamination techniques.

[0026] The floor slab is preferably a monolithic part. With monolithic parts, there is no risk of leakage caused by weld lines or the like. Thus, a monolithic part is much more reliable than a part consisting of several interconnected sections.

[0027] According to one or more preferred embodiments, the additive manufacturing process is effected by 3D printing, preferably by fused filament fabrication (FFF) or fused particle fabrication (FPF).

[0028] In a fused filament fabrication, also known as fused deposition modeling (FDM), a 3D article is produced based on a digital model of the 3D article using a polymer material in form of a filament. A "digital model" refers to a digital representation of a real world object, for example of a waterproofing detail part, that exactly replicates the shape of the object. A digital model can be created, for example, by using a CAD software or a 3D object scanner. Typically, the digital model is stored in a computer readable data storage, especially in a data file. The data file format can, for example, be a computer-aided design (CAD) file format or a G-code (also called RS-274) file format. In a fused filament fabrication process, a polymer filament is fed into a moving printer extrusion head, heated past its glass transition, or melting temperature, and then deposited through a heated nozzle of the printer extrusion head as series of layers in a continuous manner. After the deposition, the layer of polymer material solidifies and fuses with the already deposited layers.

[0029] The printer extrusion head is moved under computer control to define the printed shape based on control data calculated from the digital model of the 3D article. Typically, the digital model of the 3D article is first converted to a STL file to tessellate the 3D shape and slice it into digital layers. The STL file is then transferred to the 3D printer using custom machine software. A control system, such as a computer-aided manufacturing (CAM) software package, is used to transform the STL file into control data, which is used for controlling the printing process. Usually, the printer extrusion head moves in two dimensions to deposit one horizontal plane, or layer, at a time. The formed object and / or the printer extrusion head is then moved vertically by a small amount to start deposition of a new layer.

[0030] A fused particle fabrication, also known as fused granular fabrication (FGF), differs from a fused filament fabrication only in that the polymer material is provided in form of particles, such as granules or pellets, instead of a filament.

[0031] According to one or more embodiments, the floor slab comprises: a) 35 - 75 wt.-%, preferably 40 - 70 wt.-%, of the at least one polymer P and b) 15 - 55 wt.-%, preferably 20 - 50 wt.-%, of the at least one solid filler F, all proportions being based on the total weight of the floor slab.

[0032] Suitable polymers for use in the floor slab include, for example, ethylene vinyl acetate copolymers, polyolefins, halogenated polyolefins, polyvinylchloride, thermoplastic polyolefin elastomers (TPE-O), and ketone ethyl esters. Term "polyolefin" refers in the present disclosure to homopolymers and copolymers obtained by polymerization of olefin monomers. “Thermoplastic polyolefin elastomer (TPE-O)” refers to a class of polyolefin based copolymers or physical mixture of polyolefin-based polymers, typically plastic and rubber, that exhibit both thermoplastic and elastomeric properties.

[0033] According to one or more preferred embodiments, the at least one polymer P is selected from ethylene vinyl acetate copolymers, polyethylene, ethylene copolymers, polypropylene, propylene copolymers, and polyvinylchloride, more preferably from ethylene vinyl acetate copolymers, polyethylene, ethylene copolymers, polypropylene, and propylene copolymers.

[0034] The term “copolymer” refers in the present disclosure to a polymer derived from more than one species of monomer (“structural unit”). The polymerization of monomers into copolymers is called copolymerization. Copolymers obtained by copolymerization of two monomer species are known as bipolymers and those obtained from three and four monomer species are called terpolymers and quaterpolymers, respectively.

[0035] Suitable ethylene vinyl acetate copolymers for use as the at least one polymer P include ethylene vinyl acetate bipolymers and terpolymers, such as ethylene vinyl acetate carbon monoxide terpolymers.

[0036] Suitable ethylene vinyl acetate bipolymers and terpolymers are commercially available, for example, under the trade name of Escorene® (from Exxon Mobil), under the trade name of Primeva® (from Repsol Quimica S.A.), under the trade name of Evatane® (from Arkema Functional Polyolefins), under the trade name of Greenflex® (from Eni versalis S.p.A.), under the trade name of Levapren® (from Arlanxeo GmbH), and under the trade name of Elvaloy® (from Dupont).

[0037] Suitable polyethylenes for use as the at least one polymer P include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE), preferably having a melting temperature (Tm) determined by differential scanning calorimetry (DSC) according to ISO 11357-3:2018 standard using a heating rate of 2 °C / min of at or above 85 °C, preferably at or above 95 °C, more preferably at or above 105 °C.

[0038] Suitable ethylene copolymers for use as the at least one polymer P include random and block copolymers of ethylene and one or more C3-C20 a-olefin monomers, in particular one or more of propylene, 1 -butene, 1 -pentene, 1 -hexene, 1 -heptene, 1 -octene, 1 -decene, 1 -dodecene, and 1 -hexadodecene, preferably comprising at least 60 wt.-%, more preferably at least 65 wt.-% of ethylene-derived units, based on the weight of the copolymer.

[0039] Suitable ethylene random copolymers include, for example, ethylene-based plastomers, which are commercially available, for example, under the trade name of Affinity®, such as Affinity® EG 8100G, Affinity® EG 8200G, Affinity® SL 8110G, Affinity® KC 8852G, Affinity® VP 8770G, and Affinity® PF 1 OG (all from Dow Chemical Company); under the trade name of Exact®, such as Exact® 3024, Exact® 3027, Exact® 3128, Exact® 3131 , Exact® 4049, Exact® 4053, Exact® 5371 , and Exact® 8203 (all from Exxon Mobil); and under the trade name of Queo® (from Borealis AG) as well as ethylene-based polyolefin elastomers (POE), which are commercially available, for example, under the trade name of Engage®, such as Engage® 7256, Engage® 7467, Engage® 7447, Engage® 8003, Engage® 8100, Engage® 8480, Engage® 8540, Engage® 8440, Engage® 8450, Engage® 8452, Engage® 8200, and Engage® 8414 (all from Dow Chemical Company).

[0040] Suitable ethylene-a-olefin block copolymers include ethylene-based olefin block copolymers (OBC), which are commercially available, for example, under the trade name of Infuse®, such as Infuse® 9100, Infuse® 9107, Infuse® 9500, Infuse® 9507, and Infuse® 9530 (all from Dow Chemical Company).

[0041] Suitable polypropylenes for use as the at least one polymer P include, for example, isotactic polypropylene (iPP), syndiotactic polypropylene (sPP), and homopolymer polypropylene (hPP), preferably having a melting temperature (Tm) determined by differential scanning calorimetry (DSC) according to ISO 11357- 3:2018 standard using a heating rate of 2 °C / min of at or above 100 °C, preferably at or above 105 °C, more preferably at or above 110 °C.

[0042] Suitable propylene copolymers for use as the at least one polymer P include propylene-ethylene random and block copolymers and random and block copolymers of propylene and one or more C4-C20 a-olefin monomers, in particular one or more of 1 -butene, 1 -pentene, 1 -hexene, 1 -heptene, 1 -octene, 1 -decene, 1- dodecene, and 1 -hexadodecene, preferably comprising at least 60 wt.-%, more preferably at least 65 wt.-% of propylene-derived units, based on the weight of the copolymer.

[0043] Suitable propylene random and block copolymers are commercially available, for example, under the trade names of Intune®, and Versify (from Dow Chemical Company) and under the trade name of Vistamaxx® (from Exxon Mobil).

[0044] According to one or more preferred embodiments, the at least one polymer P comprises at least one ethylene vinyl acetate copolymer P1 , preferably having a content of structural unit derived from vinyl acetate of at least 5 wt.-%, more preferably at least 10 wt.-%, based on the weight of the ethylene vinyl acetate copolymer.

[0045] Generally, the expression “the at least one compound X comprises at least one compound XN”, such as “the at least one polymer P comprises at least one ethylene vinyl acetate copolymer P1” is understood to mean in the context of the present disclosure that the material comprises one or more ethylene vinyl acetate copolymers P1 as representative(s) of the at least one polymer P.

[0046] Preferably, the at least one ethylene vinyl acetate copolymer P1 has a content of a structural unit derived from vinyl acetate of 10 - 90 wt.-%, preferably 15 - 80 wt.- %, based on the weight of the copolymer. The polymer P can be composed of the ethylene vinyl acetate copolymer P1 , or it may comprise further polymers, for example, to improve some properties of the polymer P1. For example, if especially soft ethylene vinyl acetate copolymers are used, addition of other types of polymers having a higher softening point than P1 may be used, for example, to reduce the tackiness of the polymer component.

[0047] According to one or more embodiments, the at least one polymer P further comprises at least one polymer P2 different from the at least one ethylene vinyl acetate copolymer P1 .

[0048] According to one or more embodiments, the at least one polymer P2 is compatible with the at least one ethylene vinyl acetate copolymer P1.

[0049] By the polymers components being “compatible” is meant in the present disclosure that the properties of a blend composed of the polymer P1 and P2 are not inferior to those of the individual polymer components.

[0050] It may also be preferable that the polymer P1 and P2 are partially miscible but not necessarily entirely miscible with each other. By the polymer components being “miscible” is meant in the present disclosure that a polymer blend composed of the polymer P1 and P2 has a negative Gibbs free energy and heat of mixing. The polymer blends composed of entirely miscible polymer components tend to have one single glass transition point, which can be measured using dynamic mechanical thermal analysis (DMTA).

[0051] Especially suitable polymers for use as the polymer P2 include, for example, polyolefins, halogenated polyolefins, thermoplastic elastomers, and polyvinylchloride.

[0052] According to one or more embodiments, the at least one polymer P2 is polyolefin, preferably polyethylene, wherein the weight ratio of the amount of the at least one ethyne vinyl acetate copolymer P1 to the amount of the at least one polymer P2 is preferably from 3:1 to 1 :3, preferably from 2:1 to 1 :2. The floor slab further comprises at least one solid filler F.

[0053] According to one or more embodiments, the at least one solid filler F has a median particle size dso of not more than 150 pm, preferably not more than 100 pm, more preferably not more than 50 pm, even more preferably not more than 35 pm.

[0054] The term “particle size” refers in the present disclosure to the area-equivalent spherical diameter of a particle (Xarea). The term “median particle size dso“ refers in the present disclosure to a particle size below which 50% of all particles by volume are smaller than the dso value. The particle size distribution can be determined by sieve analysis according to the method as described in ASTM C136 / C136M -2014 standard (“Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates).

[0055] According to one or more embodiments, the at least one solid filler F has a median particle size dso in the range of 0.1 - 50 pm, preferably 0.25 - 35 pm, more preferably 0.5 - 25 pm, even more preferably 1 - 15 pm.

[0056] Suitable compounds for use as the at least one solid filler F include, for example, inorganic fillers, such as sand, granite, calcium carbonate, clay, expanded clay, diatomaceous earth, pumice, mica, kaolin, talc, dolomite, xonotlite, perlite, vermiculite, Wollastonite, barite, magnesium carbonate, calcium hydroxide, calcium aluminates, silica, fumed silica, fused silica, aerogels, glass beads, hollow glass spheres, ceramic spheres, bauxite, comminuted concrete, and zeolites.

[0057] Further suitable compounds for use as the at least one solid filler F include mineral binders, such as hydraulic binders, non-hydraulic binders, latent hydraulic binders, and pozzolanic binders.

[0058] Generally, the term “mineral binder” refers to mineral materials, which undergo a hydration reaction in the presence of water. Particularly, the term “mineral binder” refers to non-hyd rated mineral binders, i.e., to unreacted mineral binders that have not yet reacted in a hydration reaction.

[0059] Hydraulic binders react with water in a hydration reaction hydration reaction under formation of solid mineral hydrates or hydrate phases, which are not soluble in water or have a low water-solubility. Therefore, hydraulic binders, such as Portland cement, can harden and retain their strength even when exposed to water, for example underwater or under high humidity conditions. In contrast, non-hydraulic binders harden by reaction with carbon dioxide and, therefore, do not harden in wet conditions or under water.

[0060] Examples of suitable hydraulic binders to be used as the at least one hydraulic binder include hydraulic cements and hydraulic lime. The term “hydraulic cement” refers here to mixtures of silicates and oxides including alite, belite, tricalcium aluminate, and brownmillerite.

[0061] Commercially available hydraulic cements can be divided in five main cement types according to DIN EN 197-1 , namely, Portland cement (CEM I), Portland composite cements (CEM II), blast-furnace cement (CEM III), pozzolan cement (CEM IV) and composite cement (CEM V). These five main types of hydraulic cement are further subdivided into an additional 27 cement types, which are known to the person skilled in the art and listed in DIN EN 197-1. Naturally, all other hydraulic cements that are produced according to another standard, for example, according to ASTM standard or Indian standard are also suitable for use as the at least one mineral binder.

[0062] Examples of suitable non-hydraulic binders to be used as the at least one solid filler F include air-slaked lime (non-hydraulic lime) and gypsum. The term "gypsum" refers in the present disclosure to any known form of gypsum, in particular calcium sulfate dehydrate, calcium sulfate a-hemihydrate, calcium sulfate R>-hemihydrate, or calcium sulfate anhydrite or mixtures thereof. The term "latent hydraulic binder” refers in the present disclosure to type II concrete additives with a “latent hydraulic character” as defined in DIN EN 206- 1 :2000 standard. These types of mineral binders are calcium aluminosilicates that are not able to harden directly or harden too slowly when mixed with water. The hardening process is accelerated in the presence of alkaline activators, which break the chemical bonds in the binder’s amorphous (or glassy) phase and promote the dissolution of ionic species and the formation of calcium aluminosilicate hydrate phases.

[0063] Examples of suitable latent hydraulic binders to be used as the at least one solid filler F include ground granulated blast furnace slag. Ground granulated blast furnace slag is typically obtained from quenching of molten iron slag from a blast furnace in water or steam to form a glassy granular product and followed by drying and grinding the glassy into a fine powder.

[0064] The term “pozzolanic binder” refers in the present disclosure to type II concrete additives with a “pozzolanic character” as defined in DIN EN 206-1 :2000 standard. These types of mineral binders are siliceous or aluminosilicate compounds that react with water and calcium hydroxide to form calcium silicate hydrate or calcium aluminosilicate hydrate phases.

[0065] Examples of suitable pozzolanic binders to be used as the at least one solid filler F include natural pozzolans, such as trass, and artificial pozzolans, such as fly ash and silica fume. The term "fly ash” refers in the present disclosure to the finely divided ash residue produced by the combustion of pulverized coal, which is carried off with the gasses exhausted from the furnace in which the coal is burned. The term “silica fume” refers in the present disclosure to fine particulate silicon in an amorphous form. Silica fume is typically obtained as a by-product of the processing of silica ores such as the smelting of quartz in a silica smelter which results in the formation of silicon monoxide gas and which on exposure to air oxidizes further to produce small particles of amorphous silica.

[0066] According to one or more embodiments, the at least one solid filler F comprises: - at least one inorganic filler F1 , preferably selected from sand, granite, calcium carbonate, clay, expanded clay, diatomaceous earth, pumice, mica, kaolin, talc, dolomite, xonotlite, perlite, vermiculite, Wollastonite, barite, magnesium carbonate, calcium hydroxide, calcium aluminates, silica, fumed silica, fused silica, aerogels, glass beads, hollow glass spheres, ceramic spheres, bauxite, comminuted concrete, and zeolites, more preferably from calcium carbonate, clay, expanded clay, diatomaceous earth, pumice, mica, kaolin, talc, dolomite, xonotlite, perlite, vermiculite, Wollastonite, barite, and magnesium carbonate and / or

[0067] - at least one mineral binder F2, preferably selected from hydraulic binders, non- hydraulic binders, latent hydraulic binders, and pozzolanic binders, more preferably hydraulic binders, particularly Portland cement.

[0068] According to one or more embodiments, the at least one solid filler F comprises:

[0069] - calcium carbonate, wherein the amount of the calcium carbonate preferably constitutes at least at least 15 wt.-%, preferably at least 35 wt.-%, more preferably at least 50 wt.-%, even more preferably at least 75 wt.-%, still more preferably at least 85 wt.-%, of the total weight of the at least one solid filler F, or

[0070] - a hydraulic binder, preferably Portland cement, wherein the amount of the hydraulic binder preferably constitutes at least at least 15 wt.-%, preferably at least 35 wt.-%, more preferably at least 50 wt.-%, even more preferably at least 75 wt.- %, still more preferably at least 85 wt.-%, of the total weight of the at least one solid filler F.

[0071] The floor slab preferably has a drain hole extending through the floor slab, wherein the drain hole particularly has a drain opening leading to the drain hole. The drain hole is required to connect the bathroom pod containing the floor slab to plumbing services of the building. Particularly, the floor slab may comprise a plumbing flange comprising a pipe and a flanged edge, which plumbing flange is connected to drainage pipes during installation of the bathroom pod. Figure 1 shows a photographic presentation of a 3D printed floor slab (12) having a drain hole extending though the slab and situated approximately in the middle of the floor slab.

[0072] In one or more embodiments, the floor slab has a substantially rectangular structure. However, other shapes than rectangular are also possible, although floor slabs having a substantially rectangular shape are most commonly used. The draining surface of the floor slab may further contain a flat portion and an angled portion to ensure efficient removal of water from the surface of the floor finishing though the drain hole. The floor slab may also include a hob extending peripherally along the periphery of the floor slab.

[0073] The preferences given above for the at least one polymer P and at least one solid filler F apply equally to other subjects of the present invention unless specified otherwise.

[0074] A further aspect of the present invention is related to a method for producing a floor slab for a prefabricated modular bathroom pod, the method comprising steps of: i. Providing and / or obtaining a digital model of the slab and ii. Based on the digital model, producing the slab by additive manufacturing, wherein the floor slab is produced from a material comprising: a) 25 - 85 wt.-%, preferably 30 - 80 wt.-%, of at least one polymer P and b) 5 - 65 wt.-%, preferably 10 - 60 wt.-%, of at least one solid filler F, all proportions being based on the total weight of the material.

[0075] The expression “produced from a material” is understood to mean that the floor slab is produced by additive manufacturing using the material, for example, by feeding the material into a 3D printer. According to one or more preferred embodiments, the additive manufacturing is effected by 3D printing, preferably by fused filament fabrication (FFF) or fused particle fabrication (FPF).

[0076] In one or more embodiments, step ii. of the method comprises steps of:

[0077] - Feeding the material into a 3D printer,

[0078] - Heating the material to provide a melted material,

[0079] - Depositing the melted material by using a printer extrusion head of the 3D printer in a selected pattern in accordance with the digital model to form the floor slab.

[0080] In the heating step, the material is preferably heated to a temperature, which is above the melting temperature of the at least one polymer P to obtain the melted material. Should the material comprise multiple different polymers, the material is preferably heated to a temperature, which is above the melting temperature of the polymer P having the highest melting temperature.

[0081] The movements of the printer extrusion head in the deposition step are controlled according to control data calculated from the digital model of the floor slab. The digital model is preferably first converted to a STL file to tessellate the 3D shape of the part and to slice it into digital layers. The STL file is transferred to the 3D printer using custom machine software. A control system, such as a computer- aided manufacturing (CAM) software package, can be used to generate the control data based on the STL file. The control system can be part of the 3D printer, or it can be part of a separate data processing unit, for example a computer system.

[0082] Fig. 2 shows a schematic representation of an additive manufacturing process whereby a floor slab (12) is printed with a 3D printer (7) based on the digital model (10) of the floor slab (12). In the exemplary additive manufacturing process, a digital model (10) of the floor slab stored in a data file (9) is provided to the 3D printer (7). The control unit (8) of the 3D printer (7) converts the digital model (10) of the floor slab (12) into slices, which are then used to generate the control data for the printer extrusion head (11) of the 3D printer (7) to produce the floor slab (12). As seen on the right side of Fig. 2, the floor slab (12) is a monolithic substantially rectangular element comprising a drain hole.

[0083] The preferred embodiments of the at least one polymer P and the at least one filler F have already been discussed in the context of the floor slab of the present invention.

[0084] According to one or more embodiments, the material comprises: a) 35 - 75 wt.-%, preferably 40 - 70 wt.-%, of the at least one polymer P and b) 15 - 55 wt.-%, preferably 20 - 50 wt.-%, of the at least one solid filler F, all proportions being based on the total weight of the material.

[0085] In one or more embodiments, the material further comprises: c) At least one chemical blowing agent CBA.

[0086] Chemical blowing agents, also known as chemical foaming agents, are typically solids that liberate gas(es) by means of a chemical reaction, such as decomposition, when exposed to elevated temperatures. Inorganic, organic, exothermic, and endothermic chemical blowing agents are all equally suitable.

[0087] Endothermic blowing agents may be preferred over exothermic blowing agents, since the latter have been found to have potential to trigger respiratory sensitivity, are generally not safe from a toxicological point of view or have a risk of explosion. Furthermore, by-products such as ammonia, formamide, formaldehyde or nitrosamines are released during decomposition of exothermic blowing agents and these substances have been classified as hazardous substances. A chemical blowing agent is added to the material, from which the floor slab is produced, to provide a molten material containing a blowing gas, which is released, mainly after deposition with a printer extrusion head, from the molten material. The blowing may be added to the molten material to enable providing the floor slab with a specific surface structure / roughness that may improve the ability of the draining surface to form a bond with a fresh cementitious composition after hardening.

[0088] The at least one blowing agent CBA, if used, is preferably present in the material in an amount of not more than 5 wt.-%, preferably not more than 3 wt.-%, more preferably not more than 2 wt.-%, even more preferably not more than 1 .5 wt.-%, based on the total weight of the material.

[0089] The material for the floor slab may further comprise one of more additives, particularly selected from reinforcing fibers, flame retardants, and color pigments.

[0090] In one of more embodiment, the material further comprises at least one reinforcing fiber material, preferably selected from milled glass fibers, aramid fibers, wollastonite fibers, and carbon fibers.

[0091] Suitable reinforcing fibers have an average fiber length in the range of 100 - 500 pm, preferably 150 - 350 pm and / or an average fiber diameter in the range of 5 - 50 pm, preferably 10 - 35 pm. The term “average fiber length / diameter” refers to the arithmetic average of the individual lengths / diameters of the fibers within a sample or collection or a statistically significant and representative random sample drawn from such a sample or collection. The term “fiber diameter” refers in the present disclosure to the equivalent diameter of the fiber determined according to EN 14889-2:2006 standard.

[0092] The fiber length and diameter may be determined by using dynamic image analysis method conducted according to ISO 13322-2:2006 standard, for example, with a dry dispersion method, where the particles are dispersed in air, preferably by using air pressure dispersion method. The measurements can be conducted using any type of dynamic image analysis apparatus, such as a Camsizer XT device (trademark of Retsch Technology GmbH).

[0093] The at least one reinforcing fiber material, if used, is preferably present in the material in an amount of not more than 20 wt.-%, preferably not more than 15 wt.- %, more preferably not more than 10 wt.-%, based on the total weight of the material.

[0094] According to one or more embodiments, the material further comprises at least one flame retardant, preferably selected from the group consisting of magnesium hydroxide, aluminum trihydroxide, antimony trioxide, ammonium polyphosphate, and melamine-, melamine resin-, melamine derivative-, melamine-formaldehyde-, silane-, siloxane-, and polystyrene-coated ammonium polyphosphates.

[0095] Further suitable flame retardants for use as the at least one flame retardant include, for example, 1 ,3,5-triazine compounds, such as melamine, melam, melem, melon, ammeline, ammelide, 2-ureidomelamine, acetoguanamine, benzoguanamine, diaminophenyltriazine, melamine salts and adducts, melamine cyanurate, melamine borate, melamine orthophosphate, melamine pyrophosphate, dimelamine pyrophosphate and melamine polyphosphate, oligomeric and polymeric 1 ,3,5-triazine compounds and polyphosphates of 1 ,3,5-triazine compounds, guanine, piperazine phosphate, piperazine polyphosphate, ethylene diamine phosphate, pentaerythritol, borophosphate, 1 ,3,5- trihydroxyethylisocyanaurate, 1 ,3,5-triglycidylisocyanaurate, triallylisocyanurate and derivatives of the aforementioned compounds.

[0096] Suitable flame retardants are commercially available, for example, under the trade names of Martinal® and Magnifin® (both from Albemarle) and under the trade names of Exolit® (from Clariant), Phos-Check® (from Phos-Check) and FR CROS® (from Budenheim). According to one or more embodiments, the material further comprises at least one color pigment, preferably selected from the group consisting of titanium dioxide, zinc oxide, zinc sulfide, barium sulphate, iron oxide, mixed metal iron oxide, aluminium powder, and graphite.

[0097] Preferably, the at least one color pigment has a has a median particle size dso of not more than 1000 nm, more preferably not more than 750 nm, even more preferably not more than 500 nm. According to one or more embodiments, the at least one color pigment has a has a median particle size dso in the range of 50 - 1000 nm, preferably 75 - 750 nm, more preferably 100 - 650 nm, even more preferably 125 - 500 pm, still more preferably 150 - 350 nm, most preferably 200 - 300 nm.

[0098] The material for the waterproofing detail part may further comprise various auxiliary compounds, such as thermal stabilizers, antioxidants, plasticizers, dyes, matting agents, antistatic agents, impact modifiers, biocides, and processing aids such as lubricants, slip agents, antiblock agents, and denest aids. The total amount of these types of further additives is preferably not more than 5 wt.-%, more preferably not more than 2.5 wt.-%, based on the total weight of the material.

[0099] A further aspect of the present invention is related to a transportable base comprising a floor slab of the present invention.

[0100] The floor slab preferably has a drain hole extending through the floor slab, wherein the drain hole particularly has a drain opening leading to the drain hole.

[0101] The transportable base may further comprise a plumbing flange installed at the drain hole. The plumbing flange can comprise a pipe and a flanged edge. The pipe is preferably positioned such that the flanged edge extends radially outwardly from the pipe. However, it is also possible that the plumbing flange is installed after the transportable base, or a modular bathroom pod containing the transportable base, has been transported to the construction site.

[0102] In one of more embodiments, the floor slab has a draining surface and a floor finishing covering at least a portion of the area of the draining surface. Particularly, the floor finishing defines the draining floor of the transportable base. The draining floor typically finishes up to and adjacent the drain opening of the floor slab.

[0103] The floor finishing may comprise or be essentially composed of tiles, particularly flooring tiles. However, any other suitable flooring material suitable for a wet area that could provide a draining floor may also be used, such as a liquid applied flooring material.

[0104] In one or more embodiments, the floor finishing, particularly a layer of floor tiles, is directly adhered to the draining surface of the floor slab via a layer of adhesive. The expression “directly adhered” is understood mean in this context that no further layer than the adhesive layer is present between the draining surface and the opposing lower surface of the floor finishing. Generally, it is not required to pretreat the draining surface prior to application of the adhesive since the surface of the floor slab exhibits good bonding to commonly used adhesives, particularly to cementitious adhesives, such as tile adhesives. However, it may be advantageous to de-grease, clean, or brush the draining surface before application of the adhesive.

[0105] Any suitable adhesive can be used for adhering the floor finishing to the drain surface of the floor slab. According to one or more embodiments, the adhesive is a cementitious adhesive.

[0106] Suitable cementitious adhesives are commercially available, for example, under the trade name of Sika Ceram® (from Sika AG), Schdnox Q® series (from Sika Deutschland GmbH), and Ke raf I ex® (from Mapei). Still another aspect of the present invention is related to a method for producing transportable base for a prefabricated modular bathroom pod, the method comprising steps of:

[0107] I. Providing a floor slab of the present invention having a draining surface and

[0108] II. Applying a floor finishing to at least a portion of the draining surface of the floor slab.

[0109] The floor finishing may comprise or be essentially composed of tiles, particularly flooring tiles. However, any other suitable flooring material suitable for a wet area that could provide a draining floor may also be used, such as a liquid applied flooring material.

[0110] In one or more preferred embodiments, step II. of the method comprises using an adhesive to adhere the floor finishing to the draining surface of the floor slab, preferable a cementitious adhesive.

[0111] The method for producing transportable base may comprise a further step of installing a plumbing flange at the drain hole of the floor slab. The plumbing flange can comprise a pipe and a flanged edge. The pipe is preferably positioned such that the flanged edge extends radially outwardly from the pipe.

[0112] Still another aspect of the present invention is related to a prefabricated modular bathroom pod comprising a base supporting a wall structure, wherein the base comprises a floor slab according to the present invention.

[0113] In one or more preferred embodiments, the base supporting a wall structure is a transportable base according to the present invention.

[0114] Particularly, the modular bathroom pod is prefabricated in a factory and then transported to the work site where it is installed into the structure of the building. The modular bathroom pod may further comprise internal fittings, plumbing, electrical wiring that are needed to connect the pod to the plumbing and wiring services of the building. In the installation process, the pod is placed in position and secured to the floor structure using appropriate fasteners. Particularly, the modular bathroom pod comprises a plumbing flange comprising a pipe and a flanged edge, which plumbing flange is connected to drainage pipes under the floor slab and to the plumbing system of the building.

Claims

Claims1 . A floor slab for a prefabricated modular bathroom pod comprising: a) 25 - 85 wt.-%, preferably 30 - 80 wt.-%, of at least one polymer P and b) 5 - 65 wt.-%, preferably 10 - 60 wt.-%, of at least one solid filler F, all proportions being based on the total weight of the slab, wherein the floor slab is obtained by using an additive manufacturing process.

2. The floor slab according to claim 1 , wherein the additive manufacturing process is effected by 3D printing, preferably by fused filament fabrication (FFF) or fused particle fabrication (FPF).

3. The floor slab according to claim 1 or 2, wherein the at least one polymer P comprises at least one ethylene vinyl acetate copolymer P1.

4. The floor slab according to any one of previous claims, wherein the at least one solid filler F comprises:- at least one inorganic filler F1 , preferably selected from calcium carbonate, clay, expanded clay, diatomaceous earth, pumice, mica, kaolin, talc, dolomite, xonotlite, perlite, vermiculite, Wollastonite, barite, and magnesium carbonate and / or- at least one mineral binder F2, preferably selected from hydraulic binders, non- hydraulic binders, latent hydraulic binders, and pozzolanic binders, more preferably hydraulic binders.

5. The floor slab according to any one of previous claims having a drain hole extending through the slab.

6. A method for producing a floor slab for a prefabricated modular bathroom pod, the method comprising steps of:i. Providing and / or obtaining a digital model of the slab and ii. Based on the digital model, producing the slab by additive manufacturing wherein the floor slab is produced from a material comprising: a) 25 - 85 wt.-%, preferably 30 - 80 wt.-%, of at least one polymer P and b) 5 - 65 wt.-%, preferably 10 - 60 wt.-%, of at least one solid filler F, all proportions being based on the total weight of the material.

7. The method according to claim 6, wherein the additive manufacturing is effected by 3D printing, preferably by fused filament fabrication (FFF) or fused particle fabrication (FPF).

8. The method according to claim 6 or 7, wherein the at least one polymer P comprises at least one ethylene vinyl acetate copolymer P1.

9. The method according to any one of claims 6-8, wherein the material further comprises at least one chemical blowing agent CBA.

10. The method according to claim 9, wherein the at least one blowing agent CBA is present in the material in an amount of not more than 2 wt.-%, preferably not more than 1 .5 wt.-%, based on the total weight of the material.11 . A transportable base comprising a floor slab according to any one of claims 1 - 5.

12. The transportable base according to claim 11 , wherein the floor slab has a draining surface and a floor finishing covering at least a portion of the area of the draining surface.

13. The transportable base according to claim 11 or 12, wherein the floor finishing is directly adhered to the draining surface via a layer of adhesive, preferably a cementitious adhesive.

14. A prefabricated modular bathroom pod comprising a base supporting a wall structure, wherein the base comprises a floor slab as defined in any one of claims 1 -5 or a transportable base as defined in any one of claims 11-13.

15. A method for producing transportable base for a prefabricated modular bathroom pod, the method comprising steps of:I. Providing a floor slab as defined in any one of claims 1-5 having a draining surface andII. Applying a floor finishing to at least a portion of the draining surface of the floor slab.

16. The method according to claim 15, wherein step II. of the method comprises using an adhesive, preferably a cementitious adhesive, to adhere the floor finishing to the draining surface of the floor slab.

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