GB2552446A

GB2552446A - Improvements in and relating to building materials

Info

Publication number: GB2552446A
Application number: GB1605107.0A
Authority: GB
Inventors: Waring Stephen
Original assignee: Individual
Current assignee: Stephen Waring
Priority date: 2016-03-24
Filing date: 2016-03-24
Publication date: 2018-01-31
Anticipated expiration: 2036-03-24
Also published as: GB201605107D0; GB2552446B

Abstract

A method for manufacturing a coated masonry product comprising a body part coated with a coating material, the method comprises: providing a said body part and a quantity of said coating material in liquid form for coating said body part; providing a mould part presenting a moulding surface; applying to the moulding surface a retardant material adapted to retard the curing of said coating material; placing the coating material and the body part within the mould part such that the coating material is simultaneously in contact with the moulding surface and a surface of the body part; curing those parts of the coating material in contact with the body part; separating the moulding surface from the coating material thereby to expose a surface of the coating material which remains uncured by action of the retardant. The core is preferably polystyrene; the coating preferably a cementitious composition. Also claimed is a moulding apparatus suitable for the above method comprises: a sleeve assembly defining an elongated channel having a substantially uniform cross-sectional moulding profile along its elongate length and comprising a concavity defining said moulding profile for receiving said body to be coated therein with masonry-effect coating material; wherein the sleeve assembly comprises an outer sleeve part and an inner sleeve part removeably insertable into the outer sleeve part for support thereby, wherein the inner sleeve part includes a floor portion bounded at two opposite edges thereof by opposing wall portions which collectively define between them said elongated channel. The walls are preferably made from flexible material to aid removal of the mould.

Description

(54) Title of the Invention: Improvements in and relating to building materials

Abstract Title: Method of forming a coated building element and mould therefor (57) A method for manufacturing a coated masonry product comprising a body part coated with a coating material, the method comprises: providing a said body part and a quantity of said coating material in liquid form for coating said body part; providing a mould part presenting a moulding surface; applying to the moulding surface a retardant material adapted to retard the curing of said coating material; placing the coating material and the body part within the mould part such that the coating material is simultaneously in contact with the moulding surface and a surface of the body part; curing those parts of the coating material in contact with the body part; separating the moulding surface from the coating material thereby to expose a surface of the coating material which remains uncured by action of the retardant. The core is preferably polystyrene; the coating preferably a cementitious composition. Also claimed is a moulding apparatus suitable for the above method comprises: a sleeve assembly defining an elongated channel having a substantially uniform cross-sectional moulding profile along its elongate length and comprising a concavity defining said moulding profile for receiving said body to be coated therein with masonry-effect coating material; wherein the sleeve assembly comprises an outer sleeve part and an inner sleeve part removeably insertable into the outer sleeve part for support thereby, wherein the inner sleeve part includes a floor portion bounded at two opposite edges thereof by opposing wall portions which collectively define between them said elongated channel. The walls are preferably made from flexible material to aid removal of the mould.

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IMPROVEMENTS IN AND RELATING TO BUILDING MATERIALS

FIELD OF THE INVENTION

The present invention relates to building materials such as coated products, e.g. masonry products, and particularly though not exclusively to coated masonry products possessing a coating to produce the visual and/or tactile effect of masonry, stone, brick or other building material or masonry material.

BACKGROUND

Masonry-effect products typically comprise a body part coated with a masonry-effect material designed to present the visual appearance of genuine masonry, such as stone or the like. Examples include cladding applied to the external surfaces of houses or other buildings, and the replacement of degraded masonry within a surface of a stone building as part of a renovation work. Such products are desirable when the use of corresponding genuine masonry on the building is not possible or is undesirable. This may be so if the cost of genuine masonry is prohibitive or if the cost or difficulty of applying it to a building (e.g. as cladding) is prohibitive.

Existing masonry-effect products may be manufactured by providing a body part of suitably strong yet light material (e.g. plastic) having the desired external shape and profile, then manually applying to a surface of the body part a coating of masonry-effect paint, emulsion or fluid mixture which, when hardened, aims to present the appearance of stone or the like. Other methods of manufacture include moulding the masonry-effect coating material around a surface of the body part using a suitably shaped mould.

These methods of manufacture are labour-intensive, slow and usually produce mediocre results in terms of the likeness of the masonry-effect product to the masonry it is supposed to replicate in appearance. In particular, both the manual coating method and the moulding method produce unrealistic surface finishes - e.g. too smooth or too uneven.

The present invention aims to provide means and methods which may be employed to address these issues.

SUMMARY

At its most general, the invention is to apply a desired external surface profile to a coated product (e.g. masonry-effect) by a pulling or pealing action applied to the coating material when un-cured, during a moulding process. This permits efficient manufacture and the pulling or pealing action has been found, surprisingly, to result in a rough surface texture to the coating material (when cured/hardened) which much better replicates a stone, brick or other masonry surface both visually and in tactile terms. Architectural stone-effect profiles and/or brick slips may be produced accordingly.

The invention may provide a method of manufacture using a mould having an inside (e.g. concave) shaping defining a desired outer surface profile (reciprocal) for a coating material to be applied to a support body, such as a polystyrene body or piece. The mould inner surface may be coated with a “retardant” or “retarder” (for retarding a curing process in the surface of the coating mixture). A retardant/retarder is a chemical agent that slows down a chemical reaction. For example, retarders are used to slow the chemical hardening of cementitious materials. Retarders/retardants may slow the hydration of cementitious materials (e.g. cement, render, or concrete etc.). This may be a liquid chemical retardant substance which may be sprayed or brushed onto the mould inner surface ready for contact with coating material. Fluid coating material may then be inserted into the mould between the retardant-coated mould inner surface and the outer surface of the support body/piece which may be positioned within or adjacent the mould, but spaced from the retardant-coated mould surface by a spacing into which the fluid coating enters. This means that the fluid coating material may contact both the mould and the support body/piece (which may preferably bear no retardant) whilst in the mould. The coating material may thereby coat the support body/piece and adhere to it.

The mould may subsequently be removed after a suitable time sufficient to allow most of the coating to have cured (i.e. set firm or hard), but before those retarded coating parts which touch the retardant have cured. In this way, the coating material is permitted to bond to the support body/piece but not to the inner surface of the mould.

The inventors have been surprised to find that the act of separating the mould from stilluncured coating surface has the benefit of enabling the revealed surface of the coating to acquire a desirable surface texture. This surface texture cannot be achieved if the retarded surface is simply left to cure. In such a case, the surface texture of the coating acquires the texture of the mould. Without being bound by theory, it is postulated that the reason why the retarded (uncured) surface parts of the coating material acquire the desired texture in the way may be the result of one or both of:

(1) The pulling away of the mould surface from the still-wet/sticky un-cured coating surface parts of the coating “pulls-up” the coating surface thereby producing a rougher texture; and/or (2) The release of the coating from the mould removes pressure on the still-wet coating material which “relaxes” and this allows the wet (lubricated) grains of the coating to move slightly to “fluff-up” the surface by making it less compacted and more porous.

In a first of its aspects, the invention may provide a method for manufacturing a coated masonry product comprising a body part coated with a coating material (e.g. masonry-effect), the method comprising: providing a said body part and a quantity of said coating material in liquid form for coating said body part; providing a mould presenting an moulding surface; applying a retardant to the moulding surface adapted to retard the curing of said coating material; placing the coating material and the body part within the mould part such that the coating material is simultaneously in contact with the moulding surface and a surface of the body part; curing those parts of the coating material in contact with the body part; separating the moulding surface from the coating material thereby to expose a surface of the coating material which remains uncured by action of the retardant. In this way, the coating material may coat the body part, and bond to a surface of the body part with which it is in contact, while not bonding to the moulding surface and remaining un-cured at the coating surface which is in contact with the moulding surface enabling that texture of that uncured surface to change/respond to the mechanical action of removal of the moulding surface, as desired in achieving a masonry-effect texture.

The method may include positioning the body part in spaced opposition to the moulding surface thereby to define a void between the moulding surface and an opposing surface of the body part, and filling at least a part of the void with said liquid coating material thereby coating a surface of the body part. Alternatively, the coating material may be placed into the mould in contact with the moulding surface, and subsequently a surface of the body part may be placed (e.g. into the mould) in contact with a surface part of the coating material which is not in contact with the moulding surface, before the coating material is cured. For example, the mould may be in the form of a tray or bed (or the like) comprising a moulding concavity into which coating material is placed to partly fill the concavity, and the body part may then be placed into the remaining volume of the concavity on top of the coating material and in contact with it. Thus, the coating material may be ‘sandwiched’ between the retard a nt-be a ring moulding surface and the body part.

The profile of the moulding part is preferably substantially imposed upon the exposed coating material remaining on the body part along its surface.

The method may include subsequently scraping the exposed coating material before it is subsequently cured, thereby to provide a desired surface texture (e.g. roughness, porosity).

The body part may be elongate and preferably the moulding surface extends in a direction along, or parallel to, the elongate axis of the body part. The spacing of the spaced opposition between the body part and the moulding surface may be substantially uniform. This enables a substantially uniform of regular thickness to the coating material in the final coated product. The size of the spacing between the body part and the moulding surface is preferably selected according to the desired thickness of the coating to be applied to the body part.

The coating material may comprise a cementitious composition. An example is a hydraulic lime composition, e.g. a natural hydraulic lime (NHL). Another example is a glass-reinforced cement (GRC). GRC is a known type of architectural/building material comprising a mixture containing a cementitious material and particles of a glass material (e.g. quartz, or other silicate; often referred to as a ‘sand’). The particles of glass material used within a GRC according to preferred embodiments of the invention preferably have a size/diameter not exceeding 2mm (e.g. will pass through a 2mm sieve size), and may comprise particles having a range of sizes/diameters smaller than, but bounded by, this upper size/diameter limit. It has been found that a suitable GRC material permits fast curing times and may enable the aforementioned separating step (as between moulding surface and coating material) to occur at a time of between 3 hours and 4 hours (e.g. about 3.5 hours) after placing the coating and moulding in contact. The coating may comprise a render, plaster, mortar and/or a cement.

Preferably, the coating comprises any one or more of the following materials: Prependuit; Thermocromex (or Monocromex or Monostastier or equivalent material); Axilat; Pentaflow MP. Prependuit and Thermocromex (or Monocromex or Monostastier or equivalent) materials are is natural hydraulic lime powders for use in preparation of renders and plasters and other cementitious materials, and are available for purchase from St. Astier Limes and Mortars, in the United Kingdom. Axilat is a Vinyl Acetate/Versatate powder which is used in mortars and is re-dispersible in water. It has been found to improve adhesion to substrates (e.g. especially polystyrene), hydrophobicity of the coating once cured, mechanical properties and workability of fresh mortar. An example is Axilat HP 8538, available from Momentive Specialty Chemicals Inc., in the USA (address: 180 East Broad Street, Columbus, OH 43215-3799). Pentaflow MP is a fluidifying agent in powder form for ready-mixed concretes and mortars and is available from Pentachem Sri, in Italy (address: Via Galvani 3 - Zona Ind., Casarola - 47832, S. Clemente (RN), Italy). Optionally, materials that can be used in place of Thermocromex include a Brick Render or a Stone Render. These materials are cementitious and may comprise calcined clay mixed with dolomite quartz particles of 0 - 2mm particle size/diameter (suitable for Brick Render, to provide a brick-like surface texture) and optionally also calcium aluminate (for Stone Render, to provide a stone-like surface texture). They may have a bulk density of 550 - 600 kg/m³. These renders are produced by a UK company Jesmonite Limited, having an address at Challenge Court, Bishop’s Castle, Shropshire, SY9 5DW. Brick Render is suitable for the fabrication of e.g. moulded brick slips. Stone Render is suitable for the fabrication of e.g. moulded stone-effect decorative elements etc.

A further optional additive to the coating mixture includes Melment (e.g. Melment® F10) which may be an alternate to Pentaflow. This is a free-flowing spray dried powder of a sulphonated polycondensation product based on melamine. It serves as a superplasticizer for cement and calcium sulphate based materials. It has a density of 500 - 800 kg/m³. This is a BASF product available from BASF Construction Polymers GmbH, having an address at Dr.-Albert-FrankStraBe 32, 83308, Trostberg, Germany. A further optional additive to the coating mixture includes Starvis (e.g. Starvis 3003 F) which may be used to stabilize a low viscosity mixture for pouring into voids in the mould. It helps prevent segregation of particles in the mixture thus enhancing the finished product durability. This is also a BASF product available from BASF Construction Polymers GmbH, having an address at Dr.-Albert-Frank-StraBe 32, 83308, Trostberg, Germany.

The coating may comprise added fibres or particles as a component of the mixture. Fibres or strands/strips of a malleable or pliant material (e.g. plastics) may be used. The fibres, strands or strips may be elongate and, for example, between 2mm and 10mm in length. These have been found to add strength and some flexibility to the coating when set. The particles may comprise particles of a glass material (e.g. quartz, or other silicate glass).

The coating may comprise a fluid mixture comprising the following ingredients: 1.0 to 1.2 litres water per 5kg of Thermocromex. The higher proportion of water (up to 1.2 litres) may be preferred if/when the coating mixture also contains a water-absorbent dye material, as may be included in some applications requiring specific colouring of the final product. The mixture may be produced by mixing the ingredients for about six minutes. Of these six minutes, preferably the first four minutes of mixing is performed in a bladed mixer, such as a 4-bladed horizontal mixer such as would be known to the skilled person. Preferably the remaining two minutes of mixing is done using a higher speed of mixer/mixing, e.g. using a high-speed hand mixer. This has been found to produce desirable mixture properties in terms of viscosity, texture and response to the pulling or pealing action. Similar mixtures of water with Monocromex or Monostastier may be made.

Axilat may be added at between about 2% and about 3% (e.g. in the range 2.2 - 2.8%) of the overall coating mixture weight. This has been found to achieve a particularly efficient performance. Pentaflow or Melment may be added at between about 0.1% and about 2% of the overall mixture weight. In many applications, Pentaflow or Melment may be added at about 0.16% in typical use, but this can be increased to up to 2% depending on the desired viscosity of the coating mixture. Lowering the viscosity by adding more than this could undesirably allow sediment components of the mixture to separate from the liquids within the mixture when left to settle. This is separation could be emphasised if/when the moulds are optionally vibrated to ensure the coating mixture flows thoroughly into the cavity or void of the mould. This separation can cause a weakness when the product is exposed to weather, and is avoided by the suitable design of the coating mixture as described above.

The body part may comprise polystyrene. The polystyrene may be Expanded Polystyrene (EPS), or Extruded Polystyrene (XPS) which is a rigid foam insulation formed with polystyrene polymer. Alternatively, the body part may comprise a phenolic material, such as a phenolic foam or insulation material, or equivalent. An example is Celotex available from Celotex Insulation Limited, in the United Kingdom (Celotex Insulation Limited, Lady Lane Industrial Estate, Hadleigh, Ipswich, Suffolk, IP7 6BA). The body part is most preferably flame retardant.

The coating may be applied directly to a surface of the body part. The retardant may be a fluid substance applied directly the surface of moulding surface by spraying or brushing, of by dipping the moulding surface into a bath of the retardant. Preferably the retardant is applied to the moulding surface substantially uniformly across that surface. Preferably, about 1 litre of retardant fluid per 6m² of surface area. Preferably, the coating material has a density of between 100g/m² and 300g/m², such as about 200g/m². Preferably, the separating of the moulding surface form the coating material takes place when the depth of uncured coating material extends into the coating material from the exposed surface of the coating material, to a depth not exceeding about 1.0mm. Preferably, the depth of the uncured coating material is between about 0.1mm and about 0.5mm, and more preferably between about 0.1mm and about 0.3mm. The retardant may be an acidic substance, and may have a pH value not exceeding about pH 4.0, e.g. about pH 3.5. Higher acidity retardants have been found to be particularly suited to the implementation of retardant according to the invention. The retardant may be a water-based (e.g. aqueous) solution. This is advantageous when the material of the moulding apparatus is a polystyrene as it does not damage the structure of the polystyrene in the way a solvent-based retardant would. The retardant may be a release agent. Preferably, no retardant is comprised within the coating material immediately prior to the step of filling the void within the mould with the coating material. This allows the coating material to cure in an un-retarded manner at all parts except those in contact with the retardant-coated moulding surface.

Retardants are used to slow the rate of setting of cementitious mixtures. By slowing the initial setting time, the cementitious mixture can stay in a non-hardened state longer before it attains its hardened form. Retardants can be formed by organic and inorganic material. Typical suitable organic material includes any of: lignosulfonic acids (e.g. calcium lignosulfonate or sodium lignosulfonate), hydroxycarboxylic acids, and carbohydrates. Typical suitable inorganic material includes any of: oxides of Pb and Zn, phosphates, magnesium salts, fluorates, and borates (e.g. borax (Na₂B₄O₇«10H₂) and other borates such as boric acid (H₃BO₃)). Commonly used retarders comprise any of: lignosulfonates acids, hydroxylated carboxylic (HC) acids. A retardant may comprise a polyol. Typical polyol retarders comprise any of: sugar, sucrose, sodium gluconate, glucoheptonate, gluconic acid, citric acid, and tartaric acid. Two common synthetic retarders are maleic anhydride, and 2-Acrylamido-2-methylpropanesulfonic acid (AMPS) copolymers.

Preferably, the retardant is a water-activated retardant substance and the coating material is a water-based (e.g. aqueous) fluid. Preferably, the retardant and is permitted to dry upon the moulding surface it is applied to before insertion of the coating material into the mould. The water within the water-based coating material may then activate the water-based retardant substance by direct contact therewith at the moulding surface. Preferably, the retardant comprises any one or more of the following materials: Rheoface 480 Green; Rheoface 480 Blue; Rheoface 480 Pink; Rheoface 480 Grey. Preferably, the retardant comprises one of: Rheoface 480 Green; Rheoface 480 Blue. These Rheoface 480 retardants are available from BASF pic, Construction Chemicals, P.O. Box 4, Earl Road, Cheadle, Cheshire, SK8 6QG, UK.

The coating material may be caused to acquire different levels of texture by using different retardant strengths, as desired. For example, Rheoface 480 Blue is suitably effective for many of the coating materials. Stronger retardants have been found to provide a deeper retardancy (i.e. penetrating further into the coating surface) rather than slowing-down the curing process more, and this deeper retardancy may be used to influence surface texture produced by the aforementioned separating step (as between moulding surface and coating material).

In a third of its aspects, the invention may provide a coated masonry product comprising a body part coated with a masonry-effect coating according to the method of the invention described above. The body part of the product may be polystyrene.

In a fourth aspect, the invention may provide a moulding apparatus adapted for use in applying a coating of masonry-effect coating material to the surface of a body of a masonry product. The moulding apparatus may comprise an elongate channel having a substantially uniform cross-sectional moulding profile along its elongate length. The moulding apparatus may comprise a sleeve part which defines a floor or base portion bounded at two opposite sides/edges by generally upright (or inclined) opposing wall portions which collectively define between them a concavity defining a desired moulding profile for receiving a body to be coated with masonry-effect coating material.

The moulding profile may extend along the elongate length of the moulding apparatus, and may also be substantially uniform along that elongate length. The moulding apparatus may comprise an outer sleeve part and an inner sleeve part removeably insertable into the outer sleeve part. Each of the inner sleeve part and the outer sleeve part may comprise a respective floor or base portion bounded at two opposite sides/edges by a respective two opposing and wall portions. The base and wall portions of the inner sleeve part are preferably shaped and dimensioned to match (e.g. reciprocate) and extend over the inner surfaces of the corresponding floor or base portion and opposing sidewalls of the outer sleeve part. The base and sidewalls of the inner sleeve part may be relatively thin in comparison to, respectively, to the base and sidewalls of the outer sleeve part. The base and sidewalls of the inner sleeve part may be sufficiently malleable and/or frangible to permit them to be peeled or pulled to deform the inner sleeve part to separate it from a coating of a coated masonry product when contained therein in use. The material of the inner sleeve part may be a polystyrene, or may be a malleable rubber, plastic or other suitably malleable synthetic material. The inner sleeve part is preferably made of polystyrene, permitting it to be manually broken or torn away from the surface of a moulded masonry product, is use, when the inner sleeve part is fully separated from the outer sleeve part, with a moulded masonry product contained within it. Optionally the outer sleeve part may also be made of polystyrene, but may be made of another material.

The base and side walls of the outer sleeve parts may be relatively thicker and more robust than the floor and sidewalls of the inner sleeve part, in order to provide structural support to the inner sleeve part in use, when the inner sleeve part is inserted within the outer sleeve part in use. Both the inner sleeve part on the outer sleeve part may be elongate and of uniform transverse cross-section which extends along the elongate length of the respective sleeve parts. The sleeve parts may be dimensioned and arranged such that outer, convex surface of the inner sleeve part, when inserted into the outer sleeve part, may be in closely-spaced opposition to the concave, inner surface of the outer sleeve part, such that the former proposes the latter across a narrow spacing. This narrow spacing may permit the inner sleeve part to slide axially relative to the outer sleeve part enabling the former to be inserted into, and separated from, the latter.

BRIEF DESCRIPTION OF DRAWINGS

A non-limiting example of a preferred embodiment of the invention shall now be described with reference to the accompanying drawings in which:

Figure 1 illustrates a cross-sectional view of a moulding apparatus according to an embodiment of the invention;

Figure 2 illustrates a cross-sectional view of the moulding apparatus of Figure 1 in which a moulding surface has a curing retardant applied;

Figure 3 illustrates a cross-sectional view of the aspect illustrated in Figure 2 in which a coating material is contained within the moulding apparatus;

Figure 4 illustrates a cross-sectional view of a coated masonry profile extracted from the moulding apparatus of figure 3, in part;

Figure 5, in which a moulding surface is being peeled away from the coating material coating the masonry profile;

Figure 6 illustrates a perspective view of a coated masonry product comprising the coated masonry profile as illustrated in figures 1 to 5;

Figure 7 schematically illustrates a cross-sectional view of a mould containing coating material and a part of a masonry product (e.g. a moulded brick slip) being coated by the coating material.

In the drawings, like items are assigned like reference symbols.

DESCRIPTION OF EMBODIMENTS

While a few exemplary embodiments of the invention have been described both, it is to be understood that modifications, variants and equivalents thereto, such as would be readily apparent to the skilled person are encompassed within the scope of this invention, such as is defined by the claims.

Figure 1 schematically illustrates a cross-sectional view of a moulding apparatus (1) adapted for use in applying a coating of masonry-effect coating material to the surface of a support body (5) of a coated masonry product (see Figure 6). The moulding apparatus is elongate in the dimensional transverse to the cross-section illustrated in Figure 1 and has a substantially uniform cross-sectional profile along its elongate length. The moulding apparatus comprises a sleeve part (2, 4) which possesses a substantially square or rectangular outer peripheral profile and defines a floor or base portion bounded at either side by generally upright (or inclined) wall portions which collectively define between them a concavity defining a desired moulding profile for receiving the support body (5) to be coated with masonry-effect coating material.

The moulding profile is substantially uniform in the dimensional transverse to the cross-section illustrated in Figure 1, and extends along the elongate length of the moulding apparatus. The sleeve part (2, 4) comprises an outer sleeve part (2) and an inner sleeve part (3). The inner sleeve part comprises a relatively thin floor or base portion bounded at either side by a pair of opposing and relatively thin wall portions shaped and dimensioned to match and extend over the inner surfaces of the corresponding floor or base portion and opposing sidewalls of the outer sleeve part (2). The floor and sidewalls of the outer sleeve part are thicker and more robust than the floor and sidewalls of the inner sleeve part. Both the inner sleeve part on the outer sleeve part are elongate and of uniform transverse cross-section which extends along the elongate length of the respective sleeve parts. The outer, convex surface of the inner sleeve part are in closely-spaced opposition to the concave, inner surface of the outer sleeve part, such that the former proposes the latter across a narrow spacing (4) which permits the inner sleeve part to slide axially relative to the outer sleeve part enabling the former to be separated from the latter, as will be discussed below in detail.

The inner sleeve part is preferably made of polystyrene, permitting it to be manually broken or torn away from the surface of a moulded masonry product, as discussed in detail below, when the inner sleeve part is fully separated from the outer sleeve part, with the moulded masonry product contained within it. Optionally the outer sleeve part may also be made of polystyrene, but may be made of another material.

Figure 1 illustrates the moulding apparatus as containing within its concavity, the polystyrene support body (5) of a masonry product to be coated with a coating material. An elongated rectangular seat member (6) is also placed within the concavity of the moulding apparatus on the floor or base thereof, adjacent one of the two outstanding sidewalls of the moulding apparatus. The seat member is of uniform cross-sectional profile and extends along substantially the entire elongate length of the moulding apparatus within the concavity. The seat member is dimensioned to permit the support body (5) to sit upon its upper surface to position the support body in a “floating” position within the concavity whereby external surfaces of the support body are positioned in spaced opposition to facing concavity surfaces of the side walls and base of the inner sleeve part of the moulding apparatus (3). The external profile of the support body reciprocates the profile of the concavity of the moulding apparatus, as defined by the inner sleeve part (3). A substantially uniform spacing (7) is thereby provided between the profile of the concavity of the moulding apparatus, and the reciprocating convex profile of the support body (5). This spacing extends uniformly along the axial length of the moulding apparatus and the support body located within it.

It is to be understood that both the support body (5) and the seat member (6) are freely movable into and from the concavity of the moulding apparatus via an open end of the elongate moulding apparatus, allowing sliding insertion along the elongate length of the moulding concavity. A top opening of the moulding apparatus is formed between the terminal top ends of opposing the sidewalls of the moulding apparatus, and this top opening extends axially along the full elongate length of the moulding apparatus. The top opening reveals the inner surfaces of the base and walls of the inner sleeve of the moulding apparatus and permits direct access to the concavity thereof, as necessary for applying retardant substance and subsequently applying coating material during the moulding process. A process of applying a masonry-effect coating material to the support body (5) of the masonry product will now be described with reference to figures 2 to 6.

A first step of the moulding process is to apply to the inner surfaces of the concavity of the moulding apparatus, upon the walls of the inner sleeve part (3), a chemical retardant substance (8) arranged for the purposes of retarding the curing of a coating material to be subsequently inserted into the concavity of the moulding apparatus, as discussed in more detail below. Application of the retardant substance (8) is performed by spraying or brushing the substance onto the inner walls of the inner sleeve part when the support body (5) and seat member (6) are absent from the concavity. Subsequently, after the inner walls of the inner sleeve part have been suitably covered with retardant substance (8), the seat member (6) is first inserted into the concavity of the moulding apparatus, as is shown in Figure 2, and subsequently the support body (5) of the masonry product (to be coated) is seated on top of the seat member within the concavity of the moulding apparatus, so as to achieve the uniform spacing (7) between the outer surface of the support body and the retardant-coated in a surface of the inner sleeve part of the moulding apparatus. Insertion may be by sliding the seat member and support body axially along the elongate length of the moulding concavity from an open end of the moulding apparatus permitting full access to the concavity

In a subsequent step, illustrated in Figure 3, a masonry-effect coating material (9) is injected or poured into the concavity of the moulding apparatus so as to substantially fill the entirety of the spacing between the support body (5) and the opposing retardant-coated inner surface of the inner sleeve member defining the moulding concavity. This coating material is injected in liquid form and is allowed to bond or adhere to the surface of the support body (5) of the masonry product by normal action of the coating material acting upon the polystyrene surface of the support body to form a suitable bond therewith. This arrangement is allowed to sit for a minimum period of time appropriate to allow the coating material to cure/set/harden at all parts of the coating material for which curing is not retarded by action of the retardant substance (8). The result is that the coating material is allowed to firmly bond to the surface of the support body (5) thereby forming a durable coating across it, whereas the same coating material is prevented from forming a significant bond with the retardant-coated surface of the inner sleeve part with which it also forms a direct contact. This permits the inner sleeve part to be removed from the coated masonry product with relative ease when the coating is firmly bonded to the support body (5).

To permit this removal the inner sleeve (3), containing the coated support body (5) and seat member in situ, is extracted from the outer sleeve part by axially sliding the inner sleeve part out from within the outer sleeve part, to expose the outer sleeve part as shown in Figure 4. The polystyrene walls and base or floor of the inner sleeve part are then peeled, torn or pulled away from the coating material with which they are in contact as shown in Figure 5. This action reveals and exposes an external surface of the coating material which presents a refund or porous texture (10) generated or enhanced by the peeling/pulling action. The coated masonry product is separated from the seat member and allowed sit for a further period of time appropriate to allow the outermost surface of the coating material to cure/set/harden as appropriate to the effects of the retardant substance (8). Additionally, or alternatively, the exposed but un-cured outermost surface of the coating material may be mechanically processed or treated in order to enhance or manipulate the surface texture thereof, as appropriate to achieve a desired masonry-effect texture. The relative malleability of the retarded and un-cured outermost surface of the coating material facilitates this.

The final product is an elongate a masonry-effect item, such as the lintel illustrated in figure 6, comprising a lightweight polystyrene support body coated by a masonry-effect coating having a desired outermost texture and finish simulating masonry, such as stone or brick or other similar building material. While the example described herein is substantially rectangular and elongate, it is to be understood that other shapes of product may be made according to the invention simply by a suitable choice of mould shape and body-part shape.

Figures 7 shows an alternative mould arrangement comprising in which the coating material (9) is be placed into the mould (3B) into contact with the retardant-bearing (8) moulding surface, and subsequently a surface of the body part (5B) is placed (into the mould) into contact with the upper exposed surface part of the coating material (9) which is not in contact with the moulding surface. This is done before the coating material is cured. The mould (3B), in this example, is in the form of a tray comprising a moulding concavity into which coating material is placed to partly fill the concavity, and the body part is then placed into the remaining volume of the concavity on top of the coating material and in contact with it. Thus, the coating material is ‘sandwiched’ between the retardant-bearing moulding surface and the body part. The mould is preferably a manually malleable rubber material easily removed from the coated masonry product by a pealing action as indicated in Fig.7. The action of separation of the moulding surface from the un-cured surface layer of the otherwise cured coating material serves to produce the desired texture in that surface, as explained above. This technique is particularly suitable for the fabrication of e.g. moulded “brick slips”, wherein the textured coating has the texture and appearance of a brick surface. Brick slips, a.k.a 'Brick Tiles', 'Thin Brick', or 'Veneer Bricks' comprise slither or thin (relative to a complete brick) piece of material providing a brick-like face typically designed to be mounted upon a surface (e.g. wall) as a covering. When so mounted, the exposed brick slip surface gives the outward impression of a complete brick being in place.

It is to be understood that the examples and embodiments described above are provided to aid an understanding of the invention and are not intended to be limiting of the scope of the invention. Accordingly, modifications, variations and equivalents of elements of the embodiments described herein, such as would be readily apparent to the skilled person, are encompassed within the scope of the invention, such as is defined by the claims, for example.

Claims

CLAIMS:

1. A method for manufacturing a coated masonry product comprising a body part coated with a coating material, the method comprising:

providing a said body part and a quantity of said coating material in liquid form for coating said body part;

providing a mould part presenting a moulding surface;

applying to the moulding surface a retardant material adapted to retard the curing of said coating material;

placing the coating material and the body part within the mould part such that the coating material is simultaneously in contact with the moulding surface and a surface of the body part;

curing those parts of the coating material in contact with the body part;

separating the moulding surface from the coating material thereby to expose a surface of the coating material which remains uncured by action of the retardant.

2. A method according to any preceding claim including:

positioning the body part in spaced opposition to the moulding surface thereby to define a void between the moulding surface and an opposing surface of the body part;

filling at least a part of the void with said liquid coating material thereby coating a surface of the body part.

3. A method according to any preceding claim including:

placing the coating material into the mould part in contact with the moulding surface; and, subsequently placing a surface of the body part in contact with a surface part of the coating material which is not in contact with the moulding surface, before the coating material is cured.

4. A method according to any preceding claim in which the cross-sectional profile of the mould part is substantially imposed upon the exposed coating material upon the body part along the exposed surface of the coating material.

5. A method according to any preceding claim including subsequently curing at least the exposed surface of the coating material.

6. A method according to any preceding claim including scraping the exposed surface of the coating material and subsequently curing at least the exposed surface of the coating material, thereby to provide a desired surface texture.

7. A method according to any preceding claim in which the body part is elongated and the moulding surface extends in a direction substantially parallel to the elongate axis of the body part.

8. A method according to any preceding claim in which said spaced opposition comprises a spacing between the body part and the moulding surface substantially uniform in at least one direction (e.g. along said void), thereby providing a substantially uniform or regular thickness to the coating material upon the coated masonry product.

9. A coated masonry product comprising a body part coated with a masonry-effect coating material according to the method of any preceding claim.

10. A coated masonry product according to claim 9 in which the body part is polystyrene.

11. A brick slip comprising a coated masonry product according to any preceding claim.

12. An architectural profile item comprising a coated masonry product according to any of preceding claims 1 to 10.

13. A moulding apparatus adapted for use in applying a coating of masonry-effect coating material to the surface of a body of a masonry product, the moulding apparatus comprising:

a sleeve assembly defining an elongated channel having a substantially uniform crosssectional moulding profile along its elongate length and comprising a concavity defining said moulding profile for receiving said body to be coated therein with masonry-effect coating material;

wherein the sleeve assembly comprises an outer sleeve part and an inner sleeve part removeably insertable into the outer sleeve part for support thereby, wherein the inner sleeve part includes a floor portion bounded at two opposite edges thereof by opposing wall portions which collectively define between them said elongated channel.

14. A method substantially as disclosed hereinbefore with reference to the description and/or accompanying drawings.

15. A coated masonry product substantially as disclosed hereinbefore with reference to the

10 description and/or accompanying drawings.

Intellectual

Property

Office

Application No: GB1605107.0 Examiner: Mr Jason Scott