US20060026918A1

US20060026918A1 - Tile for covering roofs

Info

Publication number: US20060026918A1
Application number: US11/198,392
Authority: US
Inventors: Roberta Colombo; Alberto Bruschi; Elena Bruschi; Barbara Bruschi
Original assignee: Drake Corp
Current assignee: Drake Corp
Priority date: 2004-08-06
Filing date: 2005-08-08
Publication date: 2006-02-09
Also published as: ITMI20041624A1

Abstract

Disclosed is a tile for covering roofs, produced in material with a polymer matrix (7) comprising a mineral charge (8) provided in a quantity ranging from 20% and 60% in weight, with respect to the total weight of the tile, the mineral charge being chosen from calcium carbonate, talc, barium sulphate, clay, and the tile having dimensions and thicknesses substantially identical to those of conventional tiles such as, selectively, Portuguese tiles, Marseilles tiles and curved tiles, and preferably being provided joined to similar tiles, in a way suitable to define a multiple tile.

Description

FIELD OF THE INVENTION

The present invention relates to a new tile for covering roofs, of the type in material with a polymer matrix and capable of maintaining substantially unchanged the principal advantages offered by conventional tiles.

DESCRIPTION OF PRIOR ART

As known, the use of tiles is a very widespread system for covering the roofs of houses and of buildings in general.
The function of tiles is to protect the building from atmospheric agents and to insulate it from external temperatures and from the sun's rays.
In particular the preferred and most widely used tiles are those made of clay known as the Portuguese or Spanish tile, the French or Marseilles tile and the curved or barrel tile, also named “coppo”. These tiles are conventional and are always produced with the same dimensions and shapes with the exception of a few small adjustments which might be made by the manufacturers.
One reason for their widespread use lies in the prestigious aesthetic features of these tiles.
Secondly, conventional tiles are widely used due to their standardization, which offers advantages such as easy availability, the chance of replacing any broken tiles perfectly, as the layout and assembly thereof is known to all those operating in the sector.
The clay with which they are produced also offers a high level of thermal insulation and a high thermal capacity, in order to reduce heat dispersions and protect against sudden changes in temperature.
Also known in the sector of roofing tiles are some tiles made of polymer materials, which differ from conventional tiles in shape, structure and technical specifications such as a much lighter weight and greatly increased toughness.
The aforesaid prior art has some important drawbacks.
One of the drawbacks of conventional tiles consists in their fragility. Due to this fragility, tiles must often be discarded due to breakage during processing. In fact, an average 5% of rejects are forecast during processing and other breakages can occur during transport and laying. Due to their fragility, conventional tiles are also liable to breakage during storms, especially hailstorms.
A further drawback of conventional tiles consists in their weight, which limits handling and transport, extending processing times: Marseilles and Portuguese tiles weigh approximately 3 kg each, while curved tiles “coppo” weigh about 2 kg each. This weight also makes it very dangerous for them to be dropped.
The considerable weight of the tiles means that the structure to support them must be stronger than the structure to support any other type of roof covering, such as bitumen or the like.
This means that a structure provided for a bitumen roof or the like in various cases cannot be used to support conventional tiles.
Currently known tiles in polymer materials have disadvantages of a different type.
In fact, they have a different outer appearance to that of conventional tiles and this drawback has always caused builders to prefer the latter.
Another drawback of polymer tiles is their excessive flexibility and low resistance to deformations, which produces an unpleasant feeling of poor solidity to the touch.
A further drawback of polymer tiles is their very light weight, which can cause them to be removed by atmospheric agents.
In practice, owing to their considerable distinguishing characteristics, tiles made of plastic materials have not met with the favor of those who make buildings and other constructions.
In general, one basic drawback of known tiles lies in the lengthy process required to lay them on roofs. For example, 14.5 Portuguese or Marseilles tiles per square meter and 28 curved tiles “coppo” per square meter are required and all the tiles must be reciprocally positioned with care.
As a result, covering a roof requires relatively lengthy working times, with considerable laying costs.

SUMMARY OF THE INVENTION

In this situation, the technical task of the present invention is to create a tile capable of substantially providing a solution to the aforesaid drawbacks while still maintaining said advantages offered by conventional tiles.
Within the scope of said technical task an important object of the invention is to obtain a tile that is quick to assembly.
Another important object of the invention is to produce a tile that is tough and strong.
The technical task and the objects specified are obtained by a tile for covering roofs produced in a material with a polymer matrix comprising a mineral charge provided in a quantity ranging from 20% to 60% in weight, with respect to the total weight of said tile, and having dimensions and thicknesses substantially identical to those of conventional tiles such as, selectively, Portuguese tiles, Marseilles tiles and curved tiles.
Said tile is also preferably provided joined to similar tiles, in a way suitable to form a multiple tile preferably produced by injection molding of a type chosen from “coinjection”, “structural foam” and “gas assisted”.

BRIEF DESCRIPTION OF THE DRAWINGS

Below is the description of a preferred embodiment of a tile according to the invention, shown in the accompanying drawings, wherein:
FIG. 1 a shows an axonometric view of a tile according to the invention with a shape analogous to the Portuguese tile;
FIG. 1 b is similar to FIG. 1 a and shows a tile analogous to the Marseilles tile;
FIG. 1 c is similar to FIG. 1 a and shows a tile analogous to the curved tile or “coppo”;
FIG. 2 a schematically shows a sectional view of a tile according to the invention produced with the “structural foam” process, with reference to the shape in FIG. 1 a;
FIG. 2 b schematically shows a sectional view, again with reference to the shape in FIG. 1 a, of a tile according to the invention produced with a combined “coinjection” and “gas assisted” process;
FIG. 3 a shows an assembly of single tiles pre-assembled, with a shape analogous to the Portuguese tile;
FIG. 3 b is similar to FIG. 3 a and shows tiles analogous to the Marseilles tile;
FIG. 3 c is similar to FIG. 3 a and shows tiles analogous to the curved tile “coppo”;
FIG. 4 a shows the arrangement on the frame of a roof of tiles with a shape analogous to the Portuguese tile;
FIG. 4 b is similar to FIG. 4 a and shows tiles analogous to the Marseilles tile; and
FIG. 4 c is similar to FIG. 4 a and shows tiles analogous to the curved tile “coppo”.

DESCRIPTION OF PREFERRED EMBODIMENTS

With reference to the aforesaid Figures, the new tile according to the invention is indicated as a whole with the numeral 1.
The tile 1 advantageously takes the shape of conventional tiles, such as Portuguese tile, Marseilles tile and curved tile “coppo”.
In particular, in the figures the tile 1 is indicated with 1 a when it takes the shape of the Portuguese tile, with 1 b when it takes the shape of the Marseilles tile and with 1 c when it takes the shape of the curved tile.
The Portuguese tile la, shown in FIG. 1 a, has a substantially rectangular plan, with a length of approximately 41 cm and width of approximately 24 cm.
It has a substantially flat portion in the form of a rectangular trapezoid and a second fraction defined by an angular portion with a truncated cone shaped surface, the axis of which is placed on the virtual extension of the flat portion and is slightly inclined with respect to the direction of the longitudinal axis, so that the external corner of this fraction is parallel to said longitudinal axis.
The Marseilles tile 1 b, shown in FIG. 1 b, also has a substantially rectangular plan, with a length of approximately 41 cm and a width of approximately 25 cm.
This Marseilles tile 1 b extends substantially along a plane in which it has two semi-circular channels extending along the longitudinal axis of said Marseilles tile 1 b.
Finally, the curved tile 1 c, shown in FIG. 1 c, has a plan in the form of an isosceles trapezoid with almost parallel oblique sides, with larger and smaller bases of approximately 18 and 15 cm respectively and a height of 45-50 cm.
This curved tile 1 c is defined by an angular portion with a truncated cone shaped surface, the axis of which is parallel to the longitudinal axis of said tile 1 c.
All the tiles 1 can have specific interlocking elements 2, to promote and reinforce constraint between adjacent tiles.
Preferably, these tiles 1 also have channeling elements 3, suitable to promote the run-off of water or to prevent water from infiltrating through the roof which they form.
According to the invention, tiles are provided 1 shaped as described above, and with the dimensions indicated, which are made of a material with polymer matrix 7, preferably polypropylene, with a mineral charge 8 present in percentages ranging from 20% to 60%, preferably from 20% to 30%.
This mineral charge 8 gives consistency and substance to the polymer matrix.
Moreover, suitable colorants are added to the tile 1 to give it an external appearance identical to conventional tiles.
The mineral charge can, for example, be calcium carbonate, and/or talc and/or barium sulphate. The last is capable of providing the tile with a relatively high density.
Said mineral charge 8 increases the density of the polypropylene, normally of approximately 0.9 kg/dm³, to approximately 1.2 kg/dm³or greater, and the tile can indicatively reach a weight of approximately half or more the weight of the conventional tile.
According to an advantageous embodiment, the mineral charge 8 can be composed of clay.
This mineral charge 8, which has a density of approximately 2.0 Kg/dm³, gives the tile a consistent weight, although still below the weight of conventional tiles. Above all, the clay charge provides an external appearance identical to that of conventional tiles.
This material can be obtained conveniently by grinding conventional tiles that are discarded or broken during processing, assembly or production.
The tiles 1 also preferably have means 4 for fastening to a supporting base 5 suitable to constrain the tiles to said base, often composed of the beams of the roof.
These fastening means 4 are conveniently composed of screws or nails. In this case the tile preferably has a hole or a notch 6, suitable to facilitate insertion of screws or nails.
The tile 1 according to the invention can also be provided at origin joined to a plurality of other tiles 1.
In this case, in practice it produces a multiple tile with the appearance of the tile in FIGS. 3a, 3b and 3c, and between the single tiles provided joined to one another there is no need for interlocking elements 2 or portions of tile produced to constrain single tiles.
Preferably, this multiple tile is defined by tiles all arranged in a single line or row: in particular, five or ten joined tiles can be provided, if these are Portuguese tiles 1 a or Marseilles tiles 1 b, ten or twenty if these are curved tiles 1 c.
This multiple tile preferably also has means 4 for fastening to the supporting base 5 suitable to constrain it to said base 5.
These fastening means 4 are also in the present case conveniently composed of screws or nails and at least one notch or hole 6 is appropriately provided, suitable to facilitate insertion of screws or nails.
The multiple tiles are advantageous also due to the fact that they can be produced in advance to define a contour and/or support for skylights, roof openings, attic windows.
They can also be produced with hooks and projections capable of offering a support and holds for fastening for solar panels and similar elements typically positioned on roofs.
The use of a tile according to the invention, the structure of which is described above, is as follows.
When the tiles 1 are multiple, that is already provided joined to other tiles 1, assembly thereof is much easier: several tiles can be positioned and fastened with a single operation.
In the case of single tiles, the tiles 1 a simulating Portuguese tiles are positioned adjacent on the supporting base 5, composed of the beams of the roof, according to the arrangement in FIG. 4 a.
By means of the specific interlocking elements 2 the tiles la structurally support one another, although it is preferable to constrain them further to the supporting base 5 using the fastening means 4.
The tiles 1 b simulating the Marseilles tiles are arranged adjacent on the supporting base 5, composed of the beams of the roof, according to the layout in FIG. 4 b, wherein several rows of tiles 1 b interlock with one another when the lateral edges of the tiles 1 b of the same row are staggered with respect to the lateral edges of tiles 1 b of a second adjacent row.
By means of the specific interlocking elements 2 the tiles 1 b support one another structurally, but, also in this case, it is preferable to constrain them further to the supporting base 5 using the fastening means 4.
Finally, the tiles 1 c simulating the curved tiles “coppo” are arranged alternately with the concave part facing downward and upward, as shown in FIG. 4 c. For this purpose, two types of curved tile can be provided, according to the direction taken by the concave part, which differ from each other through the presence of suitable interlocking elements 2 and channeling elements 3.
The tiles 1 c are then suitably constrained to the supporting base by specific fastening means 4.
With reference to the use of a mineral charge 8 in clay, the invention also teaches a new use of clay: insertion of said clay as a charge in tiles with a polymer matrix. Moreover, the new use preferably relates to ground clay obtained from broken or discarded tiles.
The clay is provided in granules of small dimension, for example dimensions ranging from one cubic millimeter to one tenth of cubic millimeter.
Another aspect of the invention also relates to the production of said tiles of conventional shape and made of plastic material with said mineral charge.
As known, it is very difficult to produce elements with a polymer matrix using normal injection molding when these elements have considerable dimensions, as in the case in hand, when wishing to reproduce the thickness of traditional tiles.
This is even more difficult when wishing to produce multiple tiles, which have vast dimensions in a direction parallel to the surface to be covered. In fact, due to the high level of volumetric shrinkage of the plastic material during cooling, very evident and unacceptable defects and lack of homogeneity occur.
An embodiment based on an injection molding process selectively chosen from “structural foam”, “coinjection” and “gas assisted” overcomes said drawbacks.
In particular, during “structural foam” molding, semi-expanded polymer material, which is not liable to volumetric shrinkage during cooling, is injected into a mold.
In fact, as known, during this injection molding process the polymer material is injected into the mold together with an expanding agent.
During the injection process the polymer material is at high pressures and, therefore, due to external pressure, the expanding agent does not exert its action.
However, once inserted into the mold cavity the polymer material is not subjected to high pressures and consequently the expanding agent exerts its action to dilate the polymer material. This dilation opposes the volumetric shrinkage of the polymer material.
The tiles 1 produced with this technology have a rough, often aesthetically pleasing, surface.
In “coinjection” molding, two different polymer materials are instead injected in succession through the same nozzle. The second injected polymer material is therefore introduced inside the first injected polymer material. Said first injected polymer material thus forms the skin of the molded article, while said second injected polymer material forms the inside of the article.
In the present case said first injected material is preferably composed of a compact polymer material and said second injected polymer material is preferably composed of a semi-expanded polymer material.
The compact material therefore forms the outer surface of the article being produced, which will have the best properties of dimensional precision, roughness, hardness and the like.
Instead, the semi-expanded material remains inside the article being produced and opposes the volumetric shrinkage of the compact material on the surface, due to the expansion process of the expanding agents described above.
The tiles 1 produced with this technology have the best surface and therefore the best appearance.
Finally, in “gas assisted” molding compact polymer material and gas are injected in succession into the mold through the same injection nozzle. The gas therefore exerts, inside the polymer material, a pressure that opposes shrinkage of said material during solidification.
The tiles 1 thus produced are therefore substantially hollow inside. They therefore have an excellent surface finish, due to the use of compact polymer materials, a relatively low weight, and high thermal and acoustic insulation properties.
The process can also include combination of said molding processes with one another to obtain structures which although of considerable thickness are well finished off, without volumetric shrinkage and relatively light in weight.
For example, “coinjection” molding can originally be combined with “gas assisted” molding.
In this case, the tile produced substantially has three layers: an outer layer in compact material, a semi-expanded intermediate layer and a hollow inner layer determined by the gas injected centrally.
The tile 1 thus produced, combining “coinjection” and “gas assisted” molding, is shown schematically in FIG. 2 b.
Among other things, this tile also has the advantage of noteworthy thermal and acoustic insulation.
FIG. 2 a instead shows a sectional view of a tile produced using “structural foam” molding, in which the mineral charge 8 is also shown schematically.
The invention allows important advantages.
In fact, the tiles 1 according to the invention cannot be distinguished from conventional tiles with regard to color, consistency and shape and therefore maintain the advantages of aesthetics and standardization of said tiles, being perfectly interchangeable with them.
If the tile 1 is also provided already joined to other tiles, to form a multiple tile, this offers a great advantage in terms of installation times.
For example, if five tiles are joined to one another, in the case of Portuguese tiles 1 a or Marseilles tiles 1 b, less than three installations of tiles are required per square meter, compared with the previous 14.5 installations per square meter.
Moreover, these tiles provided joined to other tiles also maintain unchanged their external appearance, assembly system, interchangeability with other single tiles or with conventional tiles, namely they maintain all the advantages of the latter.
Multiple tiles can then define, as mentioned, the edges or supports of skylights, attic windows, through openings, holds for solar panels, etc.
Moreover, the tiles 1 according to the invention have the extreme toughness and strength of polymer materials.
Therefore, during assembly it is unnecessary to provide for percentages of rejects, as the tiles 1 cannot be broken even if dropped from a height of several meters.
Moreover, storms, hailstorms and other accidental events do not cause breakage of the tiles.
A further advantage is provided by the weight of the tiles 1 according to the invention.
This weight is in fact lower than the weight of conventional tiles, although relatively consistent, i.e. 1.2 kg with regard to Portuguese tiles 1 a and Marseilles tiles 1 b and 0.6 kg with regard to curved tiles.
Thanks to this the tiles 1 are easier to transport and handle. At the same time the weight of the tiles 1 according to the invention is sufficiently high to guarantee stability and strength, as well as a feeling of consistency and strength to the touch.
A further advantage is offered by the presence of the fastening means 4 of the tiles 1. These fastening means 4 guarantee quick connection of the tiles 1 to the supporting base 5.
In the case in which the supporting means 5 are composed of screws or nails inserted in the tile 1, the impermeability of the tile 1 is not changed, as after coupling the screws and nails are constrained firmly by friction to the tile 1 and do not allow water to pass through.
Yet another advantage is offered by the fact that the tiles 1 according to the invention insulate the dwelling from external temperatures better than conventional tiles.
In fact the heat transmission coefficient of the materials of which the tile 1 according to the invention is composed—which is inversely proportional to the thermal insulation offered by the material—is approximately one order of magnitude smaller than the heat transmission coefficient of conventional tiles.
Insulation is even better using tiles produced in two or more layers, for example in the case of said tiles in three layers produced combining “coinjection” molding with “gas assisted” molding.
Together with thermal insulation, the tiles 1 according to the invention also improve the acoustic insulation of the building on which they are laid.
Yet another advantage is obtained during laying at the change of pitch or edge of the roof, or in all those points in which the profile of the edges must be varied.
In these cases, in fact, the tiles must be cut and shaped and it is considerably advantageous that they can be sectioned using, for example, normal tools for wood and obtaining clean, precise and well-finished cuts.
The openings in the roofs can therefore be easily produced after the tiles have been laid.

Claims

1. Tile for covering roofs, produced in material with a polymer matrix, comprising a mineral charge provided in a quantity ranging from 20% and 60% in weight, with respect to the total weight of said tile, and having dimensions and thicknesses substantially identical to those of conventional tiles such as, selectively, Portuguese tiles, Marseilles tiles and curved tiles.

2. Tile according to claim 1, provided joined to similar tiles, in a way suitable to form a multiple tile.

3. Tile according to claim 2, wherein said multiple tile is in one piece.

4. Tile according to claim 2, wherein said multiple tile is defined by tiles aligned with one another in a way suitable to define a row.

5. Tile according to claim 1, wherein said mineral charge is at least prevalently chosen from calcium carbonate, talc, barium sulphate.

6. Tile according to claim 1, wherein said mineral charge is at least in prevalence clay.

7. Tile according to claim 1, wherein said mineral charge tile is at least in prevalence ground clay obtained from conventional tiles.

8. Tile according to claim 1, wherein means are provided for fastening to a supporting base.

9. Tile according to claim 8, comprising a notch suitable to facilitate insertion of said fastening means.

10. Tile according to claim 1, produced with injection molding of the type chosen from “coinjection”, “structural foam”, “gas assisted”.

11. Tile according to claim 1, having three layers: an outer layer in compact material, an intermediate layer in semi-expanded material and a hollow inner layer determined by gas injected centrally, said tile being produced with injection molding of a type combining “coinjection” and “gas assisted”.

12. Tile for covering roofs, produced in material with a polymer matrix, having dimensions and thicknesses substantially identical to those of conventional tiles such as, selectively, Portuguese tiles, Marseilles tiles and curved tiles, provided joined to a plurality of similar tiles, in a way suitable to define a multiple tile.

13. Tile according to claim 12, wherein said multiple tile is in a single piece.

14. Tile according to claim 12, wherein said multiple tile is defined by tiles aligned with one another in a way suitable to define a row.

15. Tile according to claim 12, produced with injection molding of the type chosen from “coinjection”, “structural foam”, “gas assisted”.

16. Tile according to claim 12, having three layers: an outer layer in compact material, an intermediate layer in semi-expanded material and a hollow inner layer determined by gas injected centrally, said tile being produced with injection molding of “coinjection” and “gas assisted” type.