GB2097837A - Building components - Google Patents

Abstract

The invention relates to building components (10) for example studs for supporting wall boards, comprising a three dimensional non planar body made of a plaster-resin mixture, with a fibrous sheet (13) embedded near the surface. Such components can also be used, for example, as ceiling panels or acoustic tiles, for which purposes they may be of hollow or channel form, and be filled with fibrous or other porous material. Components according to the invention have excellent fire- resistant properties. Such components can be made by, for example, introducing a plaster-resin slurry into a mould lined with fibrous sheets, and allowing the slurry to set, or they may be made continuously by, for example, passing the slurry and sheets through one or more suitably profiled conveyors, vibration being employed to cause the slurry to penetrate through the sheets. <IMAGE>

Description

SPECIFICATION Building components This invention relates to components for use in the building industry. They may be suitable, although not exclusively, as supports for panels or wallboards used in cladding walls, ceilings and like structures.

In our UK Application No. 8017432, published as GB-A-2053779, we have described a building board comprising a core of set cementitious material, such as gypsum, faced on at least one side by a fibrous sheet embedded in the face of the core, and a continuous film of set cementitious material having a higher density and lower porosity than the core extending over the outer face of the sheet. Where the sheet is composed of glass or other mineral fibres, such board has improved performance in fire. When mounted on conventional supports or studs and subjected to fire testing, however, it is found that the structure will eventually deform or collapse owing to deterioration of the supports, while the panels are still intact. Even in the case of steel studs, considerable distortion can occur after a time while the panels themselves remained relatively unharmed.

It is an object of this invention to provide building components having improved fire resistance, which for example, in the form of support members enable the fire resistant capabilities of such building board to be more fully exploited.

In accordance with this invention, a support member or other component for building use comprises a three-dimensional non-planar body composed of a mixture of gypsum and synthetic resin, more especially a thermo-setting or cold hardening resin, together with one or more sheets of inorganic fibres embedded in one or more surfaces of the body.

In the preferred components according to this invention, the inorganic fibre sheet or sheets extend round the entire lateral periphery of the body, immediately beneath the peripheral surfaces of the body. It is preferable for the film of gypsym overlying the fibrous sheet or sheets to be of minimal thickness although continuous, and it should preferably not exceed 2 mm. It is particularly preferred that the sheets of inorganic fibre should be non-woven tissues of glass fibres.

The even spread of fibres across the entire width of a non-woven tissue gives a continuity of reinforcement in the surface which may be lacking if woven or other fabrics having a relatively large mesh size are employed.

The preferred form of component, especially when it is to be employed as a support for building boards, comprises a web portion and at least one flange extending at an angle therefrom, usually at right-angles. Convenient profiles include I, L and C or U sections.

In addition to the use of such components as studs, members of channel or hollow section, such as troughs or trays, may be filled with fibrous or porous material and used, for example, as ceiling panels or acoustic tiles. Suitably mounted sections of the materials may also be used as skirting board, architraving and the like.

One example of a building component to which the present invention can be applied is the socalled cove cornice described in U.K. Patent No.

736,257, in which the paper strip referred to in this patent may be replaced by, for example, a glass fibre tissue. Other uses of components according to the invention include conduits for pipes and wire, and cladding for structural steelwork.

The building components according to the invention may be made by forcing an aqueous slurry comprising gypsum plaster and resin, under pressure, into a mould lined with one or more sheets of inorganic fibre. Preferably, however, the components are made continuously by advancing a first sheet of the fibres into and along a forming channel having a profile corresponding to part of the profile of the desired support member, continuously feeding the aqueous slurry onto the sheet, continuously applying a further sheet over the slurry, enclosing the forming channel as the assembly of sheets and slurry advances with a closure having a profile corresponding to the remainder of the profile of the support member, vibrating the channel and closure to cause the sheets to penetrate beneath the surfaces of the slurry, and releasing the building component continuously from the channel when it has set.

In components made in this way, the reinforcing fibres are to be found immediately below the surface of the gypsum and resin body, where they exercise the maximum reinforcing effect, while the film of gypsum confers a smooth or desirably textured surface on the body.

In making the building components according to the invention, it is necessary that both the plaster, usually calcium sulphate hemihydrate, and the thermo-setting or cold curing resin should harden. The composition of the slurry should therefore be adjusted to ensure that both these reactions occur at the desired rate. In the case of urea-formaldehyde or other aminoplast resins, curing takes place under acid catalysts.

By-product gypsum can be used for the purposes of the present invention, and where this is derived from phosphoric acid manufacture, residues in such gypsum may serve to catalyse the resin, while a conventional acidic setting accelerator, such as aluminium sulphate, can be added to ensure rapid set of the gypsum. Mineral gypsum, however, may contain a certain amount of carbonate, which tends to neutralise any acid which may be added, so that although plaster made from such gypsum may set, an aminoplast resin precondensate present in the slurry may not.

In these circumstances, additional additives may be employed to ensure setting of both components, for example, a combination of aluminium chloride or sulphate will accelerate the plaster set, and an organic acid such as citric acid will help to control the resin set.

The preferred gypsum and resin composition for use in components according to the invention comprises from 100 parts to 300 parts hemihydrate plaster and 70 parts to 120 parts thermosetting resin, by weight. Such a composition may additionally contain up to 5 parts chopped glass fibres or additional reinforcement, and fillers such as exfoliated vermiculite or expanded perlite.

In manufacturing the components, the aqueous slurry preferably contains from 100 parts to 300 parts hemihydrate plaster, from 40 parts to i5 parts (solids) thermo-setting resin precondensate, by weight, together with customary percentages of setting accelerators or other additives.

The resin used may be, for example, an epoxy or a phenolic resin, or it may be an aminoplast resin such as urea-formaldehyde. Epoxy and phenolic resins render the finished building component impervious to water, and are therefore most suited for use in components which are required to be load-bearing.

The invention will further be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of one example of a building component embodying the invention; Fig. 2 is a diagrammatic illustration of one example of plant for manufacturing components according to this invention; and Fig. 3 is a perspective view of another example of a component embodying the invention.

A support member or stud 10 for waliboards is shown in Fig. 1 and comprises a web portion 11 and two opposed flange portions 12 extending at right-angles from the longitudinal edges of the web portion. Such members can be manufactured continuously by the method described below, and cut into suitable lengths for use.

The stud is preferably composed of about 80% by weight gypsum and about 20% ureaformaldehyde resin, with glass fibre tissues 13 extending beneath the surface of the composition on at least the external faces of the stud.

Preferably only a thin film of the composition extends over the tissue, providing a smooth surface to the stud. Preferred tissues for this purpose are resin-bonded non-woven tissues of glass fibre having a weight per unit area of from 60 gm-2 to 120 gum~2 and composed of glass fibres of diameter 10 um to 20 um.

Continuous manufacture of components of this invention may be achieved by, for example, the following method, using apparatus shown diagrammatically in Fig. 2.

A sheet of inorganic fibres 1 5, supplied by a reel 16, advances along a lower belt conveyor 17, the edges of which at 1 8 are turned upward to form a trough having a profile corresponding to the lower part of the profile of the member being produced. Onto this sheet is poured a plaster and resin slurry from a continuous mixer 1 9. The slurry is evenly distributed on the sheet by a reciprocating spreader bar 24. A second sheet of inorganic fibres 20, again supplied by a reel 21, is drawn by a continuous belt 22 onto the surface of the slurry. Belt 22 has a profile corresponding to the remaining profile of the produced member. As the assembly of sheets and slurry passes along the trough region 1 8 beneath the belt 22 it hardens to a condition in which it can safely be handled.The member 23 is then released continuously from the conveyors and cut into convenient lengths.

In one example of the production of studding as described, the sheets employed are of resinbonded non-woven glass tissue as described above. The slurry employed is composed of: Hemi-hydrate plaster 200 parts by weight Urea-formaldehyde resin 100 parts by weight Aluminium sulphate 5 parts by weight Water 34 parts by weight A further example of an application of the invention is in a ceiling panel as shown in Fig. 3. A channelled or hollow sectioned member 25, having glass fibre tissue 26 embedded just below the surface contains fibrous or other porous material 27 in the channel. The fibrous material serves as thermal insulation, and in a suitable structure may confer acoustic absorbency properties.

In the structure shown, the glass tissue extends round the entire peripheral surfaces of the channel member with only a thin film of gypsum and resin extending continuously over the tissue. The channel member can be made by the method described with reference to Fig. 2, employing for example the slurry formulation set out above.

Claims (23)

1. A building component comprising a threedimensional non-planar body composed of a mixture of gypsum and resin and one or more sheets of inorganic fibres embedded immediately below one or more surfaces of the body.

2. A building component according to claim 1 in which the inorganic fibre sheet or sheets extends around the entire lateral periphery of the body.

3. A building components according to either of claims 1 or 2 in which the sheet of inorganic fibres is a non-woven tissue of glass fibre.

4. A building component according to any of claims 1 to 3 for use as a stud for supporting building panels or boards comprising an elongate web having a flange extending from each longitudinal edge thereof substantially perpendicular to the plane of the web.

5. A building component for use as a ceiling panel according to any of claims 1 to 3 having a web of rectangular shape, with two or more flanges extending along respective edges of the web in the same direction substantially perpendicular to the plane of the web.

6. A building component according to claim 5 in which the volume defined by the web and flanges contains fibrous or other porous material.

7. A building component according to any of claims 1 to 3 having a section making it suitable for use as a skirting member.

8. A building component according to any preceding claim, in which the resin is a thermosetting or cold curing resin.

9. A building component according to claim 8, in which the resin used is urea-formaldehyde.

1 0. A building component according to claim 8, in which the resin used is phenol-formaldehyde.

11. A building component according to claim 8, in which the resin used is a water dispersed epoxy resin.

12. A building component according to any preceding claim, in which the mixture contains chopped glass fibres.

13. A building component according to any preceding claim, in which the mixture contains an aggregate.

14. A building component according to claim 13, in which the aggregate is exfoliated vermiculite or expanded perlite, or both.

1 5. A method of making a building component according to claim 1, in which an aqueous slurry comprising gypsum plaster and resin or resin precursor is forced under pressure into a mould lined with one or more sheets of inorganic fibres.

1 6. A method of making a building component according to claim 1, comprising the steps of continuously advancing a first sheet of inorganic fibres into and along a forming channel having a profile corresponding to part of the profile of the desired support member, continuously feeding an aqueous slurry comprising hydraulic cementitious material, gypsum plaster and a resin or resin precursor onto the sheet, continuously applying a further sheet of inorganic fibres over the slurry, enclosing the forming channel as the assembly of sheets and slurry advances with a closure having a profile corresponding to the remainder of the profile of the support member, vibrating the channel and closure to cause the sheets to penetrate beneath the surfaces of the slurry and releasing the building component continuously from the channel when it has set.

17. A method according to claim 1 5 or 16, in which the slurry contains hemi-hydrate plaster.

18. A method according to claim 1 5 or 16, in which the slurry contains a thermo-setting or cold curing resin precondensate.

19. A method according to claim 15 or 16, wherein the slurry contains an aminoplast resin precondensate.

20. A method according to claim 19, in which the slurry contains aluminium chloride.

21. A method according to claim 19, in which the slurry contains aluminium sulphate.

22. A method according to any of claims 19 to 21, in which the pH of the slurry is controlled by the addition of acid.

23. A method according to claim 22, in which the acid is citric acid.