Enhanced adherence uncoupling membrane with integral anchor points

Abstract

Enhanced adherence uncoupling membrane (10), composed of an embossed plastic sheet (101) with recesses facing upwards, bonded on the underside to a base layer (102, 111) made of unwoven fabric, and having integral anchor points (103) exclusively inside the recesses at the bottom, to impart enhanced adhesion compatibility to the plastic sheet. When installing a floor, membrane (10) is interposed between a screed with adhesive mortar and an upper finishing layer, fixed with cementitious adhesive spread on the sheet in order to penetrate the recesses and adhere to the anchor points (103), as a discontinuous bridge that promotes adhesion. The membrane (10) improves adhesion of the adhesive in the recesses, with high picking resistance, and also makes it possible to accommodate expansion and contraction movements in correspondence with the flat portions between bosses, protecting the floor surface or other covering. The system can be manufactured easily and economically using the proposed production procedure.

Description

ENHANCED ADHERENCE UNCOUPLING MEMBRANE WITH INTEGRAL ANCHOR POINTS

[0001] This invention concerns an enhanced adherence uncoupling membrane with integral anchor points, for cementitious adhesive; the invention also describes the production procedure to obtain said membrane.Scope of the invention

[0002] The innovation is destined specifically for the construction industry and especially the sector of semi-finished components for building, such as, without limitation, thin and impermeable membranes designed to separate a sub-base layer from the covering, such as a floor surface, for example. In particular, the proposed solution improves adhesion between the membrane and the cementitious adhesive used to lay ceramic floor or wall coverings, without affecting its uncoupling function, i.e. retaining the ability to accommodate expansion movements on the installation surface in order to prevent cracking of the covering. More generally, the membrane proposed by the invention is suitable for civil or environmental engineering works, also combined with other materials.

[0003] Plastic membranes are widely used in the construction sector today for various purposes; notably, in modern building practice impermeable membranes are widely known and frequently applied by installers of ceramic coverings, marble slabs or anyway coverings of a fragile nature, in order to prevent cracking and detachments. Such problems may be encountered incase of different rates of thermal expansion-contraction between the layers, or due to floor slab movements, micro subsidence of foundations, or for any type of deformation of the bearing plane that is not correctly accommodated by the covering layer. A membrane designed to solve such problems is conventionally called an uncoupling or decoupling membrane, being interposed in the form of a diaphragm between the load bearing structure and said covering in order to prevent direct adhesion, dissipate tensions, accommodate deformations, and also prevent the passage of water or vapour.

[0004] For these aims, embossed type impermeable sheets made of plastic such as polyethylene are generally laid with the recesses facing the covering in order to retain and support the layer of fixing adhesive, such as mortar or a cementitious tile adhesive. In certain applications, for example, to achieve more effective drainage or to increase the uncoupling function, the embossed membrane is also bonded to a permeable base layer in nonwoven polypropylene fabric of the spunbonded or spunlace type, to create a multilayer embossed uncoupling membrane that adheres effectively to the underlying screed; in particular, such a membrane is beneficial when laying ceramic flooring in modern buildings with a reinforced concrete or claycement structure. In said cases it is noted that the aforementioned combination of layers is particularly beneficial because the base layer co-penetrates into the underlying adhesive and adheres effectively to the base structure, while the embossed sheet is impermeable and makes it possible to accommodate stresses, i.e. compensate for differentiated movements between the screed and the overlying floor surface, protecting the latter from cracking and / or lifting.

[0005] Merely by way of example, see the prior art figures (Figs, la-c) in this description showing a conventional uncoupling membrane of the dual layer type, composed of an impermeable sheet having hollow cylindrical bosses positioned in an equally spaced grid pattern, which is also bonded on the lower face to a permeable nonwoven fabric base layer. A detailed description of these membranes is also available in EP3250765B1 (Cais et al.) where it is shown that these generally exert effective uncoupling and protection functions but they also have limited picking resistance due to poor adhesion between plastic sheet and the overlying cementitious adhesive; conversely, adhesion of the base layer to the underlying bedding adhesive layer is solid and effective. Operators in the sector are well aware of the problem of making an impermeable membrane that is also uncoupling, i.e. with effective decoupling between the load bearing structure and a fragile type surface covering, such as ceramic floor tiles, and also that affords good picking resistance and hence adheres effectively to the cementitious adhesive of the covering without impairing the aforementioned ability to accommodate tensions and relative deformations between the layers.

[0006] In principle, there are certain membrane solutions on the market able to improve the aforementioned adhesion by means of facilitated mechanical gripping, using retention or anchoring means incorporated in the recesses or added on top of them. For example, a conventional and known solution is that of a membrane having bosses with the recess equipped with undercut internal protrusions, generally positioned at the edge of the recess as integral anchoring elements designed to retain the cementitious adhesive, which enters in a fluid state during installation but is locked in place once theadhesive has hardened. A conventional and known solution is also bonding of the embossed sheet to a further permeable layer or to a mesh attached on top of the sheet, where the adhesive or mortar co-penetrates during the installation phase and, likewise, prevents extraction after hardening. Merely by way of example, note the membrane marketed under the name Ditra, made by the German company Schluter-Sy stems KG, Iserlohn - www.schlueter.de - or the membrane marketed under the name Platon, made by the Norwegian company Isola AS, Porsgrunn - www.isola.no. Moreover, see the solutions as at US2006201092 (Saathoff et al.), EP2234802 (Becker), US7536835 (Schlueter), US6434901 (Schlueter), US2011232217 (Hartl) or EP2246467 (Sghedoni).

[0007] More generally, it is noted that all known and conventional solutions designed to improve adhesion of the cement mortar by means of gripping means of the mechanical type tend to suffer from problems of initial adhesion and / or delamination and / or scarce effectiveness of the uncoupling function. In particular, tests carried out revealed that said membranes achieve only limited initial adhesion or picking resistance values. It was then observed that membranes having recesses equipped with internal undercut protrusions tend to slow down production and have higher costs due to more numerous rejects and / or bigger investments. Furthermore, it is noted that the same undercut elements, when positioned at the entrance to the boss recess, tend to obstruct the ingress of cementitious adhesive during installation, sometimes resulting in incomplete filling of said recesses. Conversely, it is noted that also a mesh applied in a co-planar manner to the upper face of the embossed sheet, effectively increases picking resistance but tends to limit the accommodationof expansion-contraction movements, reducing the membrane's uncoupling effect and, with increased weight, high product cost, and greater complexity of application, due also to the difficulty of inserting the cementitious adhesive into the recesses which are now partially covered by said mesh.

[0008] In addition, among known solutions with gripping means applied in adherence over the entire surface, note that US2011232217 (Hartl) proposes a layer in nonwoven fabric on the lower face of the sheet and a bonded mesh in adherence on the upper face, in order to increase the adhesive effectiveness of the cementitious mortar due to the effect of the reliefs formed by said mesh on the surface. In contrast, EP2246467 (Sghedoni) requires the upper face of the sheet to be completely coated in adherence with fibres bonded to the surface in the form of flocking; said fibres, between 500 and 1000 micron in length, are sprayed on in a random manner over the entire surface and a predetermined quantity of Teflon® may be applied over them in order to prevent wicking, resulting in rising moisture. In particular, the solutions with applied mesh or fibres adhering to the sheet result in the creation of microanchor points of the type that are uniformly spread over the entire contact surface, also in the recesses; in such cases, however, the uncoupling effect and / or the anti-picking effect are not fully functional, and industrial production is difficult. For example, in order to combine said fibres for flocking, an adhesive must first be applied and then the fibres can be sprayed on and also, in some cases, a protective coat can be applied; this procedure is long and costly, also with high material and environmental costs. In any case, there is a significant increase in the weight and cost of the membrane.

[0009] Having considered all the above, an innovative uncoupling effect plastic membrane solution is required and desirable, such that is capable of improving adhesion to the plastic sheet of a common cementitious adhesive or comparable adhesive mortar, for laying of coverings, in such a way as to achieve elevated picking resistance without impairing the uncoupling capacity, and also such as to allow rapid and economical industrial production, as required today in the sector of plastic membranes for the construction industry.Prior art

[0010] A conventional verification was carried out to establish the state of the art relating to the proposed solution, interrogating public records, resulting in identification of several cases of prior art, including:DI EP3250765 (Cais)D2 WO 13023990 (Supantschitsch)D3 US2018361716 (Ackermann et al.)D4 US2016144397 (Comitale et al.)

[0011] DI proposes an advanced uncoupling membrane solution, designed to improve surface adhesion to the plastic sheet, wherein the recesses are internally equipped with an undercut element, providing an internal choke point that separates the recess into two stacked intercommunicating voids: moreover, in order to further increase adherence, at least one face of the sheet is given a coarse surface by creating superficial micro-recesses, open towards the exterior of the surface in order to allow widespread type grip.

[0012] D2 describes an uncoupling mat composed of a plastic sheet with open recesses on one face, created by thermoforming, for example, with a covering layer applied to the plastic sheet to cover said recesses, which can be filled with rigid and absorbent material such as expanded clay, in order to absorb excess humidity and also to release it thereafter, in dry periods. Furthermore, said filler material can function as a latent heat accumulator, with materials including paraffin and / or salt, for example.

[0013] D3 describes a membrane for waterproofing and covering roofs, with a first barrier layer in a thermoplastic polymer, and a second contact layer in a blend of solid filler and a thermoplastic polymer. D3 also describes a method of producing the aforementioned membrane, a method for waterproofing a substrate, a waterproofed construction, a method for sealing a substrate against water penetration and a construction for sealing a substrate against water penetration.

[0014] D4 proposes an uncoupling membrane with bosses that form a series of recesses on the upper face, and corresponding protuberances on the lower face, where an improved version features spray application, on the upper face, of a continuous layer of polymeric coating designed to increase adhesion to the mortar layer.Drawbacks

[0015] In sum, it is noted that the known solutions described all suffer from drawbacks or at least limitations.

[0016] Primarily, it was observed that the evolved uncoupling membrane solution with integral choke point and roughening, as at the example in DI,increases the afore mentioned picking resistance and facilitates installation, compared to conventional protrusions at the recess neck. However, this solution requires complex production tooling that tends to slow down the industrial production process, being sometimes unsuitable in situations calling for high production volumes and low cost. Furthermore, the operator must use special attention in the process of spreading the cementitious adhesive, in order to insert it correctly into the recesses under the grip element, to create effective column-type supports. Also, it was noted that surface roughening of the plastic sheet tends to increase adhesion in correspondence with the flat portions of the upper surface, between one boss and another; this increase however significantly limits the ability to accommodate stresses and expansion-contraction movements. In this context, it was that in uncoupling membranes these upper portions of the sheet mainly perform the uncoupling function, accommodating stresses and deformations on the installation surface, while the adhesive filled bosses perform mainly the function of support and anchorage, in the form of single support and anchoring columns that are uniformly distributed and anchored on the head by means of the base layer.

[0017] More generally, with regard to the enhanced adhesion of the entire surface, it was noted that limiting the adaptation capacity of these flat portions of plastic sheet between the bosses, or preventing compensation for reciprocal movement of the layers, even of minimum magnitude, tends to lead to the accumulation of stresses and / or the transfer expansion-contraction movements, with the risk of cracks developing in the top covering layer. Conversely, it is also known that an improvement in adhesion obtained bymeans of an additional layer, bonded to the upper face of the sheet, sometimes makes the grip unstable due to delamination, while accommodation of deformations between the layers was found to be anyway limited. In essence, known solutions do not offer high adhesion in combination with high capacity to accommodate tensions, to adequately protect the covering from cracking and / or lifting caused by normal expansion-contraction movements and / or different movements between the layers. In particular, wherever means are applied and / or incorporated and / or fashioned mechanically to facilitate grip in a continuous manner across the entire surface of the sheet, and hence also in the flat portions between the bosses, the aforementioned accommodation capacity is significantly reduced.

[0018] Secondly, in membranes that incorporate mechanically anchored gripping means, adhesion compatibility between the plastic sheet and a common cementitious tile adhesive is anyway poor. In contrast, a desirable solution would increase adhesion between materials of different types, of the compatibilising bridge type. Moreover, a combined solution is desirable such that guarantees adhesion compatibility and also accommodation of stresses and expansion-contraction movements, without obstructing penetration of the adhesive into the recesses, thus facilitating installation.

[0019] Thirdly, the known solutions of embossed membranes with an inert material in the boss recesses, such as D2 and D3 for example, have different purposes than those of this invention and they do not improve adhesion between the plastic sheet and the cementitious adhesive. Notably, D2 involves the insertion of a filler material that absorbs and releases humidity and / or heat,such as clay; conversely, D3 has a filler and roof sealing material integrated in the membrane.

[0020] In a fourth case, known solutions of embossed membranes with a continuous layer of a polymeric coating sprayed onto the upper face of the sheet, with constant thickness, in the form of a thin adhesion compatibilising layer, such as for example in D4, have a first drawback in that they uniformly coat both the interior of the recesses and also said flat portions, from one boss to the next, with the aforementioned limitation in terms of accommodation of stresses. Moreover, a spray application solution of this type is impractical and expensive to produce industrially with high production volumes, due to the need for a special industrial plant for spray applications which is generally large in size, extremely costly, and not incorporated in the same membrane forming phase. Conversely, a membrane that can be produced in accordance with modern production logic of the contextual type is desirable, with a continuous cycle and without reworking, wherein the embossed sheet is formed, bonded to the base layer and simultaneously equipped with the aforementioned adhesion facilitating means, to be immediately packaged and ready for storage, shipment, or sale.

[0021] More generally, it is noted that conventional uncoupling membranes offer limited or poor adhesion and have problems of picking resistance such as occurs for example in the case of ceramic tiles laid on screeds subject to vibration or thermal expansion-contraction movements, or applied vertically on bathroom or kitchen walls. Conversely, membranes with upper interface layers designed to promote grip over the entire surface can improve adhesion but tend to limit the uncoupling effect. In particular, it is as noted that acontinuous interface layer acting uniformly over the entire surface of the membrane, inside and outside the recess, tends to transmit stresses and deformations to the surface layers, to the point of causing cracking, because they limit the accommodation capacity on the installation surface. In practice, stratigraphy of this type behaves in the manner of a monobloc solidly conjoined to both the underlying structure and to the top covering layer, which however have different rates of expansion. It is known also that the layers added to the membrane to improve adhesion significantly increase the weight and cost of the finished product.

[0022] In detail, it was noted experimentally that gripping means integrated only inside the recesses allow greater stability and greater picking resistance, compared to gripping means applied to the flat portions between bosses, these being more suitable for accommodating stresses and expansion-contraction movements on the installation surface. Moreover, the means employed to promote said adhesion can be improved with respect to prior art solutions, there being required means that are more effective and / or easily producible and / or applicable in a high production volume industrial plant, for example with greater precision and speed with respect to mechanical roughening of the surface or with respect to undercut choke points in the boss, which increase production costs and can make filling of the recess inconvenient or incomplete,

[0023] This results in the need for companies in the industry to identify solutions that are more effective with respect to past solutions; the purpose of this invention is also that of overcoming the described drawbacks. In particular, there is no known instance of a desirable innovative solution of alightweight and economical enhanced adherence uncoupling membrane, capable of achieving high values of resistance to picking forces perpendicular to the installation surface, and simultaneously able to accommodate expansion and contraction forces parallel to the installation surface, and that can also be produced industrially more easily and rapidly than known solutions.Concise description of the invention

[0024] These and other aims are achieved with this invention in accordance with the characteristics as at the annexed claims, solving the problems described by means of an enhanced adherence uncoupling membrane (10), composed of an embossed plastic sheet (101) with recesses facing upwards, bonded on the underside to a base layer (102, 111) made of nonwoven fabric, and having anchor points (103) incorporated exclusively inside the recess, on the bottom, to allow greater compatibility of adhesion to the plastic sheet. When installing a floor, membrane (10) is interposed between a screed with adhesive mortar and an upper finishing layer, fixed with cementitious adhesive spread on the sheet in order to penetrate the recesses and adhere to the anchor points (103), as a discontinuous bridge that promotes adhesion. The membrane (10) improves adhesion of the adhesive in the recesses, with high picking resistance, and also makes it possible to accommodate expansion and contraction movements in correspondence with the flat portions between bosses, protecting the floor surface or other covering. The system can be manufactured easily and economically using the proposed production procedure.Aims

[0025] In this manner, multiple benefits are achieved by means of a substantial creative contribution whose effect constitutes an immediate technical advance.

[0026] An initial aim consists of creating an uncoupling membrane that includes effective means to increase adhesion compatibility between the plastic material of the embossed sheet and a common cementitious adhesive or analogous adhesive mortar for laying said coverings, acting as a set of bonding bridges between different materials, precisely arranged to form a discontinuous interface.

[0027] A second aim consists of integrating, only in the recess of the bosses, the aforementioned means to increase adhesion compatibility, as compatibilising points integrated in the form of islands arranged discontinuously, at equal spacing, on the upper face of the membrane, without increasing total thickness or the ability to roll up the membrane, and protecting said compatibilising points from any chafing. In essence, internal stitch points are obtained, equidistant one to another in the same manner as the bosses, which overall improve adhesion.

[0028] A third combined aim, consequent to the first two aims, consists of the creation of an embossed uncoupling membrane that simultaneously offers high adhesion on the lower face, for the purpose of increased picking and delamination resistance, and high capacity for absorption of tensions, in order to protect the covering from cracking and / or lifting caused by normal different rates of expansion and / or movements between the layers.

[0029] A fourth aim is to create an enhanced adherence uncoupling membrane that significantly facilitates installation, with respect to conventional solutions with undercut protrusions or overlaid meshes, which tend to obstruct and / or slow application of the cementitious adhesive.

[0030] A fifth aim consists of rapidly and economically producing an uncoupling membrane that incorporates means designed to increase adhesion compatibility, in an industrial plant for high production volumes, with limited investments, but also capable of rapidly modifying versions and / or production batches to meet customer requirements.

[0031] In summary, the invention provides an uncoupling membrane that improves adhesion of the plastic sheet to a common cementitious adhesive for floor or wall coverings, for higher picking resistance, without impairing the ability to accommodate expansion movements on the installation surface. Simultaneously, the proposed membrane is lightweight, because material is added in minimal quantities, applied discontinuously only inside the bosses and not on the upper surface supporting the covering; in addition, it can be produced industrially rapidly, easily, and economically. Furthermore, this solution allows the integration of resins with special effects, for example antifungal or designed to reduce the proliferation of bacteria and moulds, and also making it possible to introduce coloured materials in order to enhance and / or alter the aesthetic effect.

[0032] These and other benefits will become evident from the following detailed description of several preferential construction solutions with the aid of the attached schematic drawings, whose execution parts are provided merely by way of example and without limitation.Contents of drawingsFigures la-c contain a schematic representation of a conventional uncoupling membrane, in accordance with prior art, composed of a plastic sheet with hollow cylindrical protrusions called bosses, arranged at equal spacing with the recesses facing upwards, which is thermally bonded on the boss heads to a bottom layer in nonwoven fabric; in particular, Figure la is an axonometric view of a portion of said membrane with a sectional view in correspondence with the bosses and with a wider base layer to aid comprehension, Figure lb is a plan view of a portion bounded by broken lines, Figure 1c is a sectional view referred to sectional plane XI - XI as shown in Fig. lb.Figure 2 is a schematic plan view of the enhanced adherence uncoupling membrane that is the subject of this invention, being composed of an embossed sheet in plastic material with recesses facing upwards, bonded on the lower face to a base layer (not shown in the figure), and with anchor points integrated inside the recesses, of the droplet type, that increase the adhesion compatibility between the sheet and the cementitious adhesive. By way of example, the anchor points are circular, and they do not entirely cover the base of the recesses.Figure 3a is a vertical sectional view of the proposed membrane referred to sectional plane X2 - X2 as shown in Fig. 2, in a construction configuration denominated first variant wherein the compatibilising material that forms the anchor point is deposited on the bottom of the recesses in such a way as to cover it only partially, assuming a convex shape in the form of a lens.Figure 3b is an alternative sectional view to the previous one, in a construction configuration denominated second variant, wherein the compatibilising material is deposited on the base of the recesses in greater quantities than in the previous variant, in such a way as to cover the bottom over r the entire width and partially fill the recess, with a flat upper face as the adhesion interface.Figure 3c is an alternative sectional view with to the previous one, in a construction configuration denominated third variant, wherein the compatibilising material is deposited in a quantity such as to completely fill the recess, up neck rim and without overspill.Figure 4 is a stratigraphic view of a floor, with the invented uncoupling membrane interposed between a lower supporting structure or screed; on which adhesive mortar is spread to fix the base layer, and an upper finishing layer such as a floor in ceramic tiles fixed by means of a cementitious adhesive spread on the upper face of the sheet in such a way as to penetrate the boss recesses until adhering to the aforementioned anchor points, which function as a compatibilising interface, in a punctiform or discontinuous layout, as bonding bridges. The layers are represented in a graphic diagram to aid comprehension of the installation, being the interfaces between the layers construed as in adhesion, where for example the cementitious adhesive fills the recesses and adheres to the anchor points. The different resistance values offered by the membrane in the vertical and horizontal directions, with respect to the installation surface, is indicated schematically with arrows positioned at right angles to one another.Figures 5 and 6 show another variant of the invention, respectively in a plan view and in a vertical section on sectional plane X3 - X3. The anchor points are small in size with respect to the recess, like a single droplet, of lenticular and elongated shape, of the oval type, in accordance with the feed direction and speed during production.Invention manufacturing practice

[0033] With reference also to the figures (Figs. 2, 3a, 3b, 3c, 4, 5, 6), the subject of the invention concerns a beneficial uncoupling membrane (10, 10a, 10b, 10c, lOd) for building construction and the industrial procedure for its manufacture. In general, note that the membrane structure is of the known and conventional type, originating from an extruded impermeable sheet of plastic material having bosses (101, 104) arranged in a grid and evenly spaced, protruding from the lower face (111) in order to rest on a screed or any other load bearing surface of the building (203, 204); said embossed sheet (101) is bonded on the lower face to a permeable base layer (102) in nonwoven fabric, creating a conventional multi-ply membrane structure of the uncoupling or decoupling type, in accordance with prior art. Moreover, for the purposes of the invention the proposed membrane (10, 10a, 10b, 10c, lOd) includes anchor points (103) made of an adhesion compatibilising material, for the cement mortar, which are incorporated inside the recesses (106) of the bosses in the sheet (101, 104, 110) in which the mortar is applied in droplets at least on the bottom of the recesses (107), as described below.

[0034] Note that the embossed sheet (101) is conventionally made in accordance with known technology through extrusion and forming, forexample performed simultaneously in a continuous cycle by means of rollers, in a plastic material such as polyethylene, polypropylene, or a blend of the two. The base layer (102) is preferably composed of a nonwoven polypropylene fabric, of the spunbonded or spunlace type, and it is, for example, bonded to the boss heads by means of heat sealing or equivalent technology. In general, an uncoupling membrane for floors has a weight of between 350 and 1000 g / sq.m; merely by way of example, the invention is compatible with an extruded sheet of approximately 500 g / sq.m and thickness of around 550 micrometres, with total thickness of the sheet inclusive of bosses of around 3 mm, greater or lesser, as needed.

[0035] In particular, note that the term cementitious adhesive (202) in this description is generally referred to a cement based adhesive or mortar for the installation of rigid floor and wall coverings. In greater detail, reference is made to common cementitious adhesives, also including polymers, which are widely used in the building trade for installing ceramic tiles; said cementitious adhesives, being of low cost and easily sourced, unlike wide spectrum adhesives for special uses, exclusively polymer based, which are extremely costly and difficult to source. Moreover, the term compatibilising material refers to a material that makes the foregoing cementitious adhesive (202) compatible with adhesion on the embossed plastic sheet (101), in such a way as to improve reciprocal adherence and promote grip. It is known that said cementitious adhesive and the plastic sheet are, intrinsically, poorly compatible with adhesion and tend to become detached. The compatibilising material, once deposited and hardened, therefore forms a bonding bridge.

[0036] In detail, a beneficial solution of an uncoupling membrane (10, 10a, 10b, 10c, lOd) is described, wherein a compatibilising material is inserted in spots exclusively into the bosses, in the upward opened recesses (106), creating integral anchor points (103), of the droplet type, as a discontinuous bonding bridge that is overall composed of said anchor points positioned in series, in correspondence with the single bosses. Moreover, note that the above definition of a droplet anchor point is intended to identify the result obtained by the spot deposition of the aforementioned compatibilising material, once hardened, being deposited in droplets on the bottom of the recess. It follows that the definition droplet anchor point is intended to identify the technical solution adopted but it does not refer to the actual size and hardened shape, it being possible to create diversified anchor points, also in accordance with the quantity of material deposited, its consistency or density at the time of application, the depth and / or size of the bosses.

[0037] In greater construction detail, there are multiple variants (10a, 10b, 10c, lOd) differentiated in accordance with the quantity of compatibilising material effectively deposited on the bottom of the recess (107), and on the shape and / or width and / or height ofthe anchor point (103a, 103b, 103c, 103d) with respect to the recess (106). In a first variant (10a, 103a) (Figs. 2, 3a), the compatibilising material is deposited in limited quantity with respect to the bottom (107) to cover it partially or incompletely, with a width (La) that is less than the total width (Lt) of the bottom, and assuming therefore a configuration (113) in the form of a lens or dome, where the height at the centre (Ha) is greater than at the edges due to the surface tension of the material, which is applied in liquid or semi-liquid form and then solidifies. Inthis case (10a), the recess side walls (108) are entirely exposed, as is also part of the bottom (107), obtaining effective grip of the adhesive thanks to the lens shaped surface, which constitutes the grip interface (113), and also obtaining high stability in relation to lateral movements, i.e. movements parallel to the installation surface (206), thanks to the maximum adhesive depth with an ample direct surface for adhesion to the sheet. It was noted, in fact, that the bosses constitute the spot supporting elements of the floor, guaranteeing support and stability in relation to movements, in which case they act as load bearing columns (Fig. 4, 205, 206).

[0038] In a second variant (10b, 103b) (Fig. 3b) the compatibilising material is deposited on the bottom of the recess in greater quantity, in order to cover the bottom for its entire width and fill the recess partially. In this case (10b), the anchor point (103b) has a flat adhesion interface, with respect to the adhesive, and therefore replicates the portion of filled recess, with width (Lt) equal to the total width (Lt) and height (Hb) lower than total height (Ht); the side walls are therefore partially exposed, in order to maintain partial direct adhesion to the sheet for the purposes of stability.

[0039] In a third variant (10c, 103c) (Fig. 3c), the compatibilising material is deposited in an even greater quantity in such a way as to fill the recess entirely, up to the rim of the neck, without any overspill and hence without overlapping the adjacent flat portions (109) of sheet, between one boss and the next, which have a different function with respect to the recesses. Said flat portions (109, 206) are in fact accommodating for the purpose of layer to layer uncoupling. In this variant (10c), the anchor point (103c) has a flat adhesion interface, with respect to the adhesive, and fully replicates the filled recess,with width (Lt) equal to the total width (Lt) and height (Hb) equal to the total height (Ht); the side walls are therefore partially covered and there is no direct adhesion of the adhesive to the sheet, inside the recess. In this case therefore, said stability is assured only by the anchor point.

[0040] Note that the foregoing variants (10a, 10b, 10c) are intended merely by way of example, without limitation, there being possible intermediate configurations and / or combined configurations, even if not shown in the figures; in fact, the anchor points of the proposed membrane can be altered time by time in accordance with the materials employed and / or production plant and / or process parameters. For example, there are additional variants of the lens type, analogous to the aforementioned first variant (10a), where the deposited material is of minimum quantity, being a small droplet of compatibilising material deposited in the centre of the recess, on the bottom (107). The anchor point made in this manner can be circular or, more likely, it can be deformed in accordance with the deposition method. In this latter case, denominated fourth variant (lOd, 103d)), shown schematically in the figures (Figs. 5 and 6), the deposited material is dragged, during the release phase, by the feed movement and / or the surface tension and / or the density and / or the friction, assuming an elongated configuration with respect to the first contact on the bottom, and thus obtaining a anchor point (103d) having width (LI) in the feed direction (112) that is greater than width (L2) in the orthogonal direction. In detail, it was also noted that the deposited droplet tends to have a wider portion corresponding to the initial deposit zone, which tends to narrow progressively, assuming a shape that is more elongated in thefeed direction, in a manner that is also asymmetrical as in the case of an oval or restrained droplet.

[0041] It is therefore possible to create said integral anchor points in multiple configurations or construction variants, equivalent in their function and in the purposes, being optimised time by time to match the application requirements. Again, merely by way of example, a combined variant between the first (10a) and second (10b) variant described above, not shown in the figures, wherein the anchor point, once the material has hardened, covers the bottom over the entire width and partially fills the recess, with the adhesion interface towards the adhesive being of a lens shaped type. In practice, it was noted that said material tends to assume a convex interface shape (113), in the form of a lens or dome, due to the surface tensions of the material in the application phase; to reduce this phenomenon and obtain a flat interface, as in the examples shown (10b, 10c) (Figs. 3b, 3c), it is beneficial to reduce the tension and / or use compatibilising materials in liquid form and / or extend the cycle time and / or include an additional flattening operation, e.g. by means of downward compression.

[0042] Additionally, said anchor points can be created with circular and / or elongated base, with partial and / or total recess filling, and with the adhesion interface towards the adhesive being flat and / or lens shaped. Furthermore, the same shape of the anchor points can be implemented over the entire membrane, or differentiated configurations can be simultaneously created on the same membrane, in such a way as to offer optimal performance in accordance with positioning or any special uses. In practice, the proposed membrane solution is extremely versatile, and it makes it possible to adaptthe configuration of the anchor points to match particular requirements for use or for industrial production.

[0043] The invention is well served by various materials with a compatibilising function, suitable for creating said integral drip type anchor points; these materials are time by time adopted in accordance the sheet polymer and / or according to the degree of elasticity and / or rigidity and / or grip that is to be obtained, in combination also with the adopted deposition technology. In principle, said compatibilising material is a polymeric resin or a polymeric aqueous dispersion capable of adhering securely to the plastic sheet and, simultaneously, of increasing adhesion to said cementitious adhesive commonly used for laying ceramic tiles; said resin or dispersion, being used as-is or with powdered aggregate additives, or with powdered binder additives, or with combinations thereof. In detail, by way of example and without limitation, among the resins or aqueous dispersions suitable in relation to the invention, elastomeric adhesives of the hot-melt type, or styrene-butadiene based, or acrylic based polymeric blends, or combinations of said polymers are particularly beneficial. Equally beneficial are polyurethane resins or polyurethane aqueous dispersions (PUD), or resins containing polyester polyether based polymers, or blends between said resins or aqueous polyurethane dispersions and said polyester polyether based polymers. Among the powdered portions of aggregates particularly indicated for the invention are: calcium carbonate, basalt, sand, aluminosilicates and / or colouring oxides such as titanium dioxide, or also combinations thereof. Furthermore, beneficially employed powdered binder portions include: cement or hydraulic lime.

[0044] Consequently the cementitious mortars are included in a compound wherein the binder is a cement, such as the cementitious mortars commonly used for grouting, or dual component cementitious mortars composed of water, soft polymers, and cementitious binders, or also cementitious resins for floors in a compound based on cement and a polymeric resin. For example, when a highly elastic blend is required, the more suitable adhesive is a dual component mortar based on cementitious binders, including selected fine grit or powdered aggregates, specific synthetic additives and polymers; merely by way of example, note the dual component mortar marketed under the trade name Mapelastic by the Italian company Mapei - https: / / www.mapei.com. Conversely, for a stiffer mix a compound of cement should be used mixed with a polymeric resin, such as grout for ceramic wall coverings, marketed under the trade name Fugabella by the Italian company Keracoll - https: / / products.kerakoll.com. It was experimentally observed that cementitious mortar for grouting is particularly suitable for the invention, being analogous and compatible with cementitious adhesives; said mortars however must be integrated with polymers designed to increase adhesion to the plastic sheet, obtaining an interface material that is adequately compatibilising with both layers, functioning as a gripping bonding bridge.

[0045] With reference also to the example stratigraphic diagram (Figs. 3a, 4), concerning a floor laid on the membrane proposed by the invention (10, 200), the cementitious adhesive (202) is spread in adherence and uniformly on said membrane (10, 101) fixed beforehand with adhesive mortar (203) to a load bearing structure or screed (204); the adhesive penetrates easily into the recesses (106), which are open at the top and without choke points, untiladhering to the integral fixing points (103, 113), allowing rapid and effective installation of the floor (201) or other surface covering, such as ceramic wall tiles. This means the tiles and the adhesive (201, 202) remain securely attached to said anchor points (103, 113) integrated on the bottom of the recesses (106, 107) and also to the internal walls (108), thus forming, inside the recesses, rigid floor support columns that increase picking resistance in a perpendicular direction with respect to the installation surface (205). Simultaneously, areas of reduced adhesion of the cementitious adhesive (202) to the plastic membrane (101) are produced in the flat portion (109) between the bosses, in a direction parallel to the installation surface (206), and especially in areas lacking the compatibilising material, in such a way as to allow adequate accommodation of stresses and expansion-contraction movements between the floor and the underlying layers. In essence, the combined effect is achieved of increasing fixing of the covering layer (201, 202) to the plastic sheet of the membrane (10, 101) without impairing uncoupling capacity, as stated in the invention aims.

[0046] In practice, it was experimentally observed that said integral anchor points (103) function overall as discontinuous bonding bridges, as in spot stitching where said points are positioned in an even manner over the entire membrane, in the bosses, while said flat portions (109) between the bosses function as free accommodation zones; these are beneficially interposed between the aforementioned points for uniform compensation of the differentiated stresses and / or deformations that occur between the layers above (201, 202) and below (203, 204) the membrane (10).

[0047] This invention requires an innovative production method for the above described membrane (10, 10a, 10b, 10c, lOd), wherein it is particularly original and beneficial to apply said adhesion compatibilising material inside the recesses (106), in order to incorporate the aforementioned anchor points (103) in an embossed plastic sheet. Therefore, it must be primarily clarified that said application of the compatibilising material, as required by the invention, takes place on an embossed sheet specifically manufactured in accordance with known technical methodology. Merely by way of example, it is beneficial to produce a conventional uncoupling membrane, wherein an embossed membrane is bonded to a base layer, with the following operational phases: extrude the raw material in such a way as to make a thin sheet, said raw material being composed of at least one thermoplastic polymer or a blend of polymers; then form the sheet around an embossed forming roller, with protrusions arranged in an equidistant grid pattern; on completion of the forming process, use a heat sealing process to bond a base layer of nonwoven fabric of the spunbonded type to the underside of the membrane, i.e. on the heads of the bosses.

[0048] Moreover, note that the proposed production method is original and the beneficial drip application of the compatibilising material in spots, exclusively inside the bosses by means of two different automated application solutions, used alternatively or in combination, in accordance with the membrane dimensions and / or the type of material applied, and / or the combination of materials applied.

[0049] Entering into the technical characteristics, a first controlled deposition system of the compatibilising material occurs with a robotic applicator, of thetype generally used in the industrial production and packaging sector to apply spots or beads of adhesive or resin, involving a mobil e head equipped with at least one nozzle, and with sensor and control devices capable of detecting the presence of a boss and releasing a predetermined quantity of said material into the bosses by gravity, on the bottom of each recess. Said applicators have the benefit of being composed of a small number of moving parts, guaranteeing high precision and long life with minimal maintenance requirements. Merely by way of example, note the industrial hot-melt adhesive of the US company Nordson, 28601 Clemens Road Westlake, Ohio - http: / / www.nordson.com.

[0050] A second controlled compatibilising material deposition system involves gravity application by means of hollow rollers to deposit droplets, of the type generally used in the food production industry for rapid deposition of chocolate drops or chips in series, where drum rollers are arranged horizontally, with an internal chamber continuously supplied with chocolate or a mixture containing chocolate, or any mixture of similar consistency, controlling rotation, flow, and temperature. The rollers have circular openings on the outer surface, and they rotate in synchrony with the forward movement of an underlying substrate in order to deposit the material in a continuous cycle, in a regular and controlled manner. An application line with rollers for droplet deposition may include a vibrating table to obtain different shapes of the deposited material. Immediately down-line from the deposition stage, the substrate and droplets are transferred into a cooling tunnel. Merely by way of example, note the systems denominated Rotary Chocolate Chips Depositing Line made by the Chinese company NJ Food Machinery Technology Co. LTD - Taizhou, Jiangsu - China, 225300 - www.njmachinery.com.

[0051] In the case of this invention, for industrial implementation of compatibilising material application on a membrane with the aforementioned second system, this involves the use of hollow rollers to deposit droplets, beneficially containing said material, being a resin, a mortar, or a polymer, all of which having a consistency comparable to that of molten chocolate during the application phase. The underlying substrate is therefore the embossed sheet (101), positioned horizontally with the recess (106) of the bosses facing upwards, and advancing in synchrony with the roller in such a way that said drip deposition of resin is equal to the progressive forward movement of the recesses, centring the recesses and accurately depositing the material inside them, on the bottom (107), without overspill from the recesses. Notably, it was observed that such gravity application systems using hollow rollers to deposit droplets, once perfect synchrony has been achieved between forward motion of the substrate and action of the roller, or falling of the droplets, guarantee high precision and repeatability of deposition, and they are also easy to use and easy to clean, offering high production capacity and limited costs, being therefore particularly suitable for the building construction membrane proposed by this invention.

[0052] In a combined variant, both the aforementioned application systems are present simultaneously in such a way as to deposit different materials in the same recess, to increase adhesion of all or some of the anchor points or to make multiple adhesive types compatible, or such as to apply the same material on diversified areas of the sheet, in order to facilitate production of large size membranes or obtain specific grip effects, being diversified time by time in accordance with the intended use of the membrane. An additionalbenefit is that of making available a combined and highly versatile production method, capable of diversifying the grip effect and also the aesthetic effect, for example simultaneously applying two different colour materials; furthermore, this combined variant makes it possible to adapt to production requirements, time by time.Key(10) enhanced adherence uncoupling membrane, according to this invention;(101) impermeable embossed plastic sheet;(102) layer of permeable nonwoven fabric;(103) integral anchor point, droplet type, in compatibilising or binding material, which acts as a bonding bridge between the plastic sheet and cementitious adhesive; the combination of anchor points constitutes a discontinuous or punctiform interface that promotes adhesion to the upper face of the sheet. Four construction variants are described by way of example: a first variant (103a) in which the anchor point is lens shaped, with the compatibilising material deposited on the bottom without entirely covering it, i.e. without reaching the side walls of the recess; a second variant (103b) in which the anchor point entirely covers the bottom, partially filling the recess; a third variant (103c) in which the anchor point fills the entire recess; a fourth variant (103d) in which the anchor point is of small size, lens shaped and elongated.(104) boss, hollow protrusion of the sheet;(105) boss head;(106) boss recess, open upwards;(107) recess bottom;(108) boss side wall;(109) flat portion of sheet, between bosses;(110) membrane upper side, with boss recesses facing upwards;(111) membrane lower side, with boss heads facing downwards;(112) sheet feed direction in production;(113) adhesion interface for the adhesive, of a single anchor point;(200) installed floor;(201) floor surface finish, e.g. ceramic tiles, on a horizontal installation surface;(202) cementitious adhesive, for fixing the covering to the membrane;(203) bedding mortar, for fixing the membrane to the subfloor screed;(204) subfloor, load bearing structure;(205) strength in direction perpendicular to the installation surface;(206) strength in direction parallel to the installation surface;(Ha) anchor point height in first variant, lens type;(Hb) anchor point height in second variant, less than total recess height;(He) anchor point height in third variant, equivalent to total recess height;(Ht) total recess height, maximum depth;(LI) major width of elongated anchor point;(L2) minor width of elongated anchor point;(La) anchor point width in first variant, less than total recess width;(Lb, Lc) anchor point width in second and third variants, equivalent to total recess width;(Lt) total recess width, on bottom.

Claims

CLAIMS1. An enhanced adherence plastic separating membrane (10, 10a, 10b, 10c, lOd), composed of an embossed type extruded film (101), with the lowermost face (111) bonded to a base layer (102) in nonwoven fabric; said film (101), featuring a regular embossed surface in which the bosses are equidistant and protrude downwards (104, 111) and have their cavities open upwards (106, 110) to allow penetration of a cementitious adhesive for the installation of floor or wall coverings; said membrane, equipped with compatibilizing material to maximize adhesion of the adhesive to the film, contact bonded on the upper face (110); said separating membrane (10, 10a, 10b, 10c, lOd) characterised by the fact that said compatibilizing material as a discontinuous adhesion bridge is inserted exclusively in said cavities (106), in contact at least with the bottom of the cavities (107), whereby it creates integrated droplet type anchorage points (103, 103a, 103b, 103c, 103d).

2. An enhanced adherence separating membrane (10, 10a, 10b, 10c, lOd), according to the previous claim, characterised by the fact that said adhesion compatibilizing material is, alternatively: a polymer resin or an aqueous polymeric dispersion.

3. An enhanced adherence separating membrane (10, 10a, 10b, 10c, lOd), according to the previous claim, characterised by the fact that said adhesion compatibilizing material is, alternatively:a hot-melt type elastomeric resin; or a styrene - butadiene-based resin or aqueous dispersion; or an acrylic-based resin or aqueous dispersion; or a resin or aqueous dispersion based on a combination between at least an acrylic polymer and styrene - butadiene; or a polyurethane resin; or a PUD type aqueous polyurethane dispersion; or a resin containing at least one polyether based polymer; or a mixture of any of the aforementioned resins and at least a base polymer; polyester polyether; or a mixture of said polyurethane dispersion and at least a base polymer; polyester polyether.

4. An enhanced adherence separating membrane (10, 10a, 10b, 10c, lOd), according to claim 2 or 3, characterised by the fact that said adhesion compatibilizing material is charged with at least one of the following powder aggregates: calcium carbonate and / or basalt and / or sand and / or aluminium silicates and / or colouring oxides such as titanium dioxide, for example.

5. An enhanced adherence separating membrane (10, 10a, 10b, 10c, lOd), according to claim 2 or 3, characterised by the fact that said adhesion compatibilizing material is charged with one of the following powder binders: cement or hydraulic lime.

6. An enhanced adherence separating membrane (10, 10a, 10b, 10c, lOd), according to claims 4 and 5, characterised by the fact thatsaid compatibilizing material is charged with at least one of said powder aggregates and one of said powder binders.

7. An enhanced adherence separating membrane (10, 10a, 10b, 10c, lOd), according to at least one of the previous claims, characterised by the fact that it has said integrated anchorage points (103, 103 a, 103b, 103c, 103d) with the following construction configuration: said points (103a) cover bottom (107) of cavity (106) only partially, with width (La) that is less than total width (Lt) of the cavity; and / or said points (103b) fill cavity (106) partially, with height (Hb) that is less than total height of the cavity (106, Ht); and / or said points (103c) fill cavity (106) entirely, with height (He) that is equal to the total height of the cavity (106, Ht); and / or said points (103d) cover bottom (107) of the cavities only partially and are extended in one direction, having width (LI) greater than width (L2) orthogonal to said direction.

8. An enhanced adherence separating membrane (10, 10a, 10b, 10c, lOd), according to the previous claim, characterised by the fact that it has said integrated anchorage points (103, 103a, 103b, 103c, 103d) having the face oriented upwards, functioning as an adhesion interface, with the following construction configuration: convex after the fashion of a lens (103a, 103d);and / or flat (103b, 103c).

9. A method of production of an enhanced adherence separating membrane (10, 10a, 10b, 10c, lOd), fashioned pursuant to the previous claims, said method including: a) extrusion and forming of the plastic film with bosses (101, 104), b) union by thermofusion of the base layer (102) in nonwoven fabric on the lower side (111) of said film in adherence with the heads of the bosses (105); c) application of the compatibilizing material on the upper side (110) of the film; said production method, characterised by the fact that said application of the compatibilizing material occurs through spot deposition in droplet form exclusively inside bosses (104), directly on the bottom (107) of the cavities (106), creating said integrated anchorage points (103, 103a, 103b, 103c, 103d); said compatibilizing material being applied in liquid or semi-liquid form to then solidify to create said integrated anchorage points; said spot deposition on the embossed film (101) which has the cavities of the bosses (106, 110) facing upwards and advances horizontally functioning as a mobile support; said spot deposition being implemented by means of: a hollow roller for deposition of droplets, of the drum type with an internal chamber supplied with the compatibilizing materials, and with surface openings of circular shape from which saidmaterial is issued in the form of droplets, and wherein said roller is arranged with horizontal rotation axis above the embossed film (101) and rotates in synchrony with its feed movement, depositing droplets of said material by gravity into the cavities (106), on the bottom (107), in a continuous cycle; and / or a robotic applicator with mobile head, equipped with at least one nozzle responsible for depositing the compatibilizing material in droplets, which operates above the embossed film (101) in combination with sensor devices and control devices designed to detect the presence of the bosses and release said compatibilizing material in correspondence with said cavities (106), on the bottom (107).

10. A method of producing an enhanced adherence separating membrane (10, 10a), according to the previous claim, characterised by the fact that said spot deposition, in a first application variant (10a) covers said bottom (107) only partially, creating anchorage points (103a) of width (La) less than total width (Lt) of the cavity.

11. A method of producing an enhanced adherence separating membrane (10, 10b), according to claim 9, characterised by the fact that said spot deposition, in a second application variant (10b) fills the cavity of bosses (106) only partially, creating anchorage points (103b) of width (Lb) equal to the total width (Lt) of the cavity, and of height (Hb) that is less than the total height (Ht) of said cavity.

12. A method of producing an enhanced adherence separating membrane (10, 10c), according to claim 9, characterised by the fact that said spot deposition, in a third application variant (10c) fills the cavity of the bosses (106) entirely, creating anchorage points (103c) of width (Lc) and height (Hb) equal to total width (Lt) and total height (Ht) of said cavity.

13. A method of producing an enhanced adherence separating membrane (10, lOd), according to claim 9, characterised by the fact that said spot deposition, in a fourth application variant (lOd) covers the cavity bottom (107) only partially, creating anchorage points (103d) extended in the film feed direction (112), having length (LI) that is greater than width (L2) orthogonal to said direction.

14. An enhanced adherence separating membrane (10, 10a, 10b, 10c, lOd), according to claim 9 or 10 or 11 or 12 or 13, characterised by the fact that said spot deposition of the compatibilizing material creates said integrated anchorage points (103, 103a, 103b, 103c, 103d) having the face oriented upwards, functioning as an adhesion interface, that: is made convex in the manner of a lens, due to the surface tension of said material applied in liquid or semi-liquid form; and / or is made flat and horizontal with means designed to reduce said surface tension; and / oris made flat and horizontal with means of top-down compression.

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