AU671162B2 - Building component - Google Patents

Description

42574 HKS:DP:MH P/00/011 AUSTRALIA Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

i i Name of Applicant: RESIN SANDS PTY LTD Name of inventor: PETER JOHN MADDERN Address for Service: COLLISON CO.,117 King William Street, Adelaide, S.A. 5000 Invention Title: S BUILDING COMPONENT Deta)is of Associated Provisional Applications: PL6175 dated 4th December 1992 The following statement is a full description of this invention, including the best method of performing it known to us: 2 The present invention relates to a building component having sound insulating properties. In particular the present invention relates to a building component useful as a building panel or a ceiling tile.

Whilst the present invention has particular application to ceiling tiles, and indeed reference will be made to these products throughout the specification, it should be understood that the present invention also has application to other building components.

Ceiling tiles are made in large numbers and may be found in most commercial or public buildings. The cost of any ceiling tile is therefore a prime 1 0 consideration in the selection of tiles for a building. Unfortunately, the materials commonly used to form ceiling tiles do not have any significant sound absorption qualities. The result of this is an unpleasantly high level of background noise in a working environment. A more serious consequence is the ready transmission of what may well be confidential discussions. Thus the 1 5 result of the emphasis on less costly tiles has been a compromise in quality.

9 The present invention seeks to resolve the above compromise by providing a tile which may be produced at a competitive price with existing products, but veto.: which additionally has enhanced sound absorbing qualities.

The present invention is predicated on the surprising discovery that a commonly available and inexpensive material, which is presently used for another purpose is also useful as a building component, the components o•co formed from this material having significantly improved sound absorption properties.

The building components of the present invention are also found to be useful in situations where moisture resistance, vermin resistance, thermal insulation and longevity are sought.

The building components of the present invention are formed of a material commonly used in foundries to produce cores and moulds. This material comprises a mineral sand in combination with a curable resin. Typically the mineral sand particles are coated with a resin coating. Under conditions of S temperature the sand is blown into a die cavity which presses the coated sand -r o ~,SLA.I-L-Li3 3 grains against a heated die platten, in which, the resin is melted by heat and, with the addition of a catalyst subsequently cured sand which has not had sufficient heat to cure the resin can be drained from the die cavity leaving a hollow component. Whilst such sand has long been used to form moulded components, the use of core sand in situations requiring sound absorption capacity, and in particular in relation to building components has not heretofore been recognised.

By the term mineral sand it is to be under tood that mineral products such as alumina, and zircon are meant. Alumina-silicates, that is clays, are not S0 suitable for forming the building products of the present invention because of the time required and temperature required to cure, or bake such materials.

Because of its relative abundance and low cost silica is a preferred material for the building components of the present invention.

Thus according to one form of the invention, the present invention comprises a 15 building component having sound insulating properties comprising particles o. of a mineral bound by a thermosetting resin, wherein the mineral is selected o from the minerals silica, alumina or zircon and excluding alumino-silicate clay particles.

Preferably, the mineral sand is core sand and comprises silica particles bound together by a cured resin, typically a phenolic resin. The proportion of resin to sand on a weight for weight basis is preferably 1-5% and more preferably less than The resin can be coated onto the sand in either a warm, hot or cold process. The sand is preferably clean, washed and free of organics, clays or silica flour. The sand particles are also preferably rounded and of similar size.

In one form of the invention the core sand additionally comprises a catalyst to achieve rapid curing of the resin, typically the catalyst would be an amine based compound such as a hexamine catalyst. On a weight for weight basis the amount of catalyst is preferably 5-25% of the resin solids and more preferably the amount catalyst is 15-25% of the resin solids. The presence of a 3 catalyst, in addition to assisting in the curing of the resin, imparts enhanced flexibility to the building component.

i 4 In a further form of the Invention, the core sand is coated with a resin which does not require the presence of a catalyst such a resin may be cured by heat alone, or may be a partially cured resin which requires only a small amount of further curing.

Using the quantities of resin and catalyst noted above the core sand may be cured in the temperature range of 100-3000C, more preferably in the range 100-280oC. The resultant tile typically having a cold tensile strength in the region 400-800 psi at room temperatures and a hot tensile strength of 200- 600 psi depending on the composition formulation used.

The core sand may advantageously further comprise a lubricant material such as a salt of a fatty acid, typically calcium stearate.

The core sand formulations of the present invention are normally expressed in terms of weight ratios in the following manner; where X represents the weight for weight percentage of catalyst in the rosin; Y represents the weight for weight percentage of resin to sand; and ~Z represents the weight for weight percentage of lubricant to resin I solids.

Thus a core sand formulation of 15/3/3 would have 15%w/w catalyst in the resin, 3%w/w resin in sand and 3%w/w lubricant in resin solids.

The core sand would typically be formed by heating the sand to 80-1650C, adding the hexamine catalyst in a slurry followed by the lubricant eg calcium stearate, and when these two materials are evenly mixed adding the resin to the sand in the form of a slurry in methanol, followed by mixing in a mill.

Gradually, the liquids evaporate prod.icing a viscous dough comprised of sand particles coated with resin when the liquids are evaporated. The sand and resin mixture is broken down and put onto a vibrating screen to ensure that the core sand product is free flowing. It is important to ensure that all the methanol is evaporated from the sand to prevent caking of the sand.

C- In one embodiment of the invention, a ceiling tile is formed of a composition of the present invention, the tile being formed in two halves and brought together In a manner that a!lows a substantially hollow space to be formed between the two halves. The tile formed in this manner has the advantage of being considerably lighter than a solid tile, whilst maintaining the necessary qualities of sound absorption. To provide structural strength, a tile formed with a hollow centre as described may have a plurality of support posts of the tile composition extending between the two halves. Moreover, the tile may be filled with material such as wool slag, polystyrene or other suitable material.

Advantageously the support posts may be integrally formed with one half of the tile.

In a further form of the invention, a building component may be integrally manufactured so as to produce two faces having a plurality of support posts extending through the space therebetween. The component being i 1 5 manufactured with one edge of the component being open to allow uncured sand to drain out of the centre of the component during a manufacturing process. In a still further form of the invention the component is formed as a solid component, which may have a decorative surface thereon formed by contacting the sand which a decorative surface of a mould.

20 The invention also provides a process for the manufacture of a building component comprising the steps using core sand, heating a mould to a temperature sufficient to cure a resin coated on the sand, filling the mould with o0 00 sdnd, the sand in contact with the mould being cured by the heat of the mould and heat being transferred through the sand thereby curing the sand, 2 5 removing the excess, uncured sand from the mould and removing the formed component from the mould.

Advantageously the sand is removed from the mould by inverting the mould and allowing the sand to drain from a hole in the mould into a dump box.

Alternatively, the mould is formed in two halves, which in turn form two halves of a component. Clearly the period during which the sand is in contact with the hot mould surface is dependent on the thickness of the component being manufactured. The heat from the hot mould is conducted through the sand and the sand gradually fuses as it achieves the necessary temperature. In a typical ceiling tile of 25 mm thickness the time required to cure a sufficient 1 1 j 6 thickness of sand may be less than one minute, depending on the mould temperature and the resin type. For any given application of the method of the present invention, a skilled addressee would readily be able to determine by trial and error the optimum conditions for producing the component.

In an alternative embodiment the sand is introduced into the mould a core blowing step. As indicated by the name, this step involves actively blowing the uncured sand into the mould, as a mixture of air and sand. The uncured sand can be drained from the mould after the component is formed.

In a still further embodiment the excess sand is introduced into the mould in a core shooting step. In a core shooting step, the uncured sand is delivered into the mould and removed therefrom by a vacuum process.

The present invention will now be further described, by way of example only, with reference to the accompanying drawings in which: FIG 1 illustrates schematical;y a building component in the form of a a 1 5 ceiling tile in accordance with one aspect of the present invention; FIG 2 illustrates the building component together with the closing portion of FIG 1 in cross section; and "FIG 3 illustrates a second form of a building component in accordance with the present invention.

a. a 0 :0 20 Shown in FIGS 1 and 2 is a ceiling tile 10 comprising a base 12 and closing portion 14. The ceiling tile 10 is formed of cured core sand of a composition as :a outlined above and manufactured in a mould as described above.

The base 12 is in the form of a trough having raised side walls 16 and a depressed interior surface 18. Arranged at spaced intervals on the interior 18 2 5 of the base 12 are a number of upstanding pins 20. As can be seen especially well in FIG 2 the pins 20 have a hollow interior 22.

The base 12 is formed as described above using a mould containing an array of pins around which the pins 20 form.

5 7 The closing portion 14 is a planar core sand sheet is similar outer dimensions to the base 12. The closing portion 14 is formed separately to the base 12 and is attachable thereto by any known suitable connection means such as silastic. The upper surface 24 of the closing portion 14 is the only surface visible in use and the surface 24 can readily be formed in a pattern of other desirable contoured surface. If desired the surface 24 can also be painted.

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0,1 0 *0 (40 The under surface of the closing portion 14 is adapted to fit within the Side walls 16.

FIG 3 illustrates a further ceiling tile 30 in accordance with the present 1 0 invention. The ceiling tile 30 comprises a pair of spaced faces 32, 34 which are closed at one open end 36 by a cap 38. The tile 30 is formed in the manner described above as a single unit, core sand being used in contact with a hot mouild to produce the component 30. During the formation of the tile the open end 36 is used to allow any uncured sand to drain from the tile.

1 5 As with the ceiling tile 10, the tile 30 has a series of throughgoing support posts 40 disposed in an array between the faces 32 and 34.

Modifications and variations of the present invention, such as would be apparent to a skilled addressee, are deemed to be within the scope of the present invention.

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Claims (12)

1. A building component having sound insulating pioperties comprising particles of a mineral bound by a thermosetting resin, wherein the mineral is selected 'Irom the minerals silica, alumina or zircon and excluding alumino-silicate clay particles.

2. A building component according to claim 1, in which the matrix comprises up to 5% by weight of the thermosetting resin.

3. A building component according to claim 1 or claim 2, which additionally comprises a catalyst. ~~10 4. A building component according to claim 3, in which the catalyst 0 comprises up to 25% by weight of the thermosetting resin. A building component according to any one of the preceding claims, 0 000' in which the thermosetting resin is a phenolic resin.

6. A building component according to claim 3 or 4, in which the catalyst S 1 5 is a hexamine catalyst.

7. A building component according to any one of the preceding claims, in which the matrix additionally comprises a lubricant.

8. A building component according to claim 7, in which the proportion of lubricant is up to 5% by weight of the thermosetting resin content. 2 0 9. A building component according to claims 7 or 8, in which the lubricant is a salt of a fatty acid. A building component according to claim 9, in which the lubricant is calcium stearate.

11. A building component according to any one of the preceding claims, in which the component is a ceiling tile. -I1 st

12. A building component according to claim 11, which the tile comprises upper and lower faces defining a substantially hollow space therebetween.

13. A building component according to claim 12, wherein there are provided a plurality of spaced posts extending between the upper and lower faces.

14. A building component according to claim 13 wherein the posts are integrally formed with one face of the file. A building component according to claim 14 which the component is 1 0 formed in two halves.

16. A building component substantially as hereinbefore described with reference to the accompanying drawings. 1 5 Dated this 7th day of March 1996 1 1 r 1 I 4 9 9 9 99 99 9« 9 99* o ft 9 9 6 9r ro a e o a *a d fr *d RESIN SANDS PTY LTD By their Patent Attorneys, COLLISON CO. L li ABSTRACT The invention relates to a building component, and in particular to a building component useful as a ceiling tile. By making a component from a composite of mineral particles bound together by a thermosetting, preferably phenolic, resin, the building component may be formed with substantial acoustic absorption properties. A process for manufacturing the building components using a moulding technique is disclosed. r r 84

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