Stock material or miscellaneous articles – Composite – Of epoxy ether
Reexamination Certificate
2001-08-02
2003-12-09
Dawson, Robert (Department: 1712)
Stock material or miscellaneous articles
Composite
Of epoxy ether
C428S688000, C428S703000, C156S061000, C156S263000, C156S285000, C156S330000, C125S012000
Reexamination Certificate
active
06660384
ABSTRACT:
OBJECT OF THE INVENTION
The present invention consists of a compound tile with a natural stone visible face, preferably marble, of the type comprising a plate of natural stone of reduced thickness and firmly fixed by adhesive means to a rigidification and strengthening supporting sheet, said support having a particular composition which is adapted to the physical characteristics of the natural stone plate.
The present invention also consists of a process for manufacturing the above-mentioned tiles, in which the union between the natural stone plate and the supporting plate is made by stacking and curing the adhesive between plate and sheet in an oven.
The compound tile with natural stone visible face of the present invention has a special application in all sectors which commonly use natural stone, mainly for decoration.
DESCRIPTION OF THE STATE OF THE ART
In the state of the art the use of sheets of different materials is known, which are joined to plates of natural stone, for example marble, to obtain a lighter more rigid and cheaper compound tile by replacing part of the stone by other materials which prevent the mineral from breaking due to its fragility. But the industrial manufacturing process has not been technically developed or solved effectively. In order to obtain thin plates of natural stone, which involve a good use of the material and a lower cost, a combination of natural stone and supporting sheet are subjected to cutting processes.
In U.S. Pat. No. 3,723,233, filed by P. T. Bourke et al., a process is disclosed which consists of sticking a 2-5 mm sheet of natural stone, specifically marble, to a metal sheet, preferably having a honeycomb panel structure, and a thickness of between 1 and 2 cm. Since the metal material is light in weight but resistant to compression, it is strengthened with thin layers of fibreglass, which increase its resistance to tension and which are situated at both ends of the metal plate. For sticking the different components together, an epoxy resin or polyurethane resin is used. In this process, the use of material having a honeycomb panel structure does not offer the guarantees necessary for its later use as a support since it is difficult to attach it to floors and especially to walls. Moreover, the manufacture of honeycomb panel structures requires the use of especially light materials which increase the cost of the finished product, not only due to the material but also to the greater volume, which affects material transport costs. In the described process, the compatibility between the physical and chemical features of the minerals and the supporting materials is not analysed in relation to different physical effects which would influence the features of the final product, making its use and assembly complicated and unreliable.
Another method for obtaining strengthened tiles of natural stone may be seen in U.S. Pat. No. 3,950,202 filed by W. Hodges, in which a block of mineral material for decoration (marble, onyx, granite, etc.) is cut using a machine with parallel cutting blades, obtaining plates of approximately 20 mm in thickness. Once cut, supporting honeycomb panel sheets are stuck to the two larger sides of said plates and another cut is later made, this time through the middle of the previous mineral sheet, reaching a thickness of 5 mm, supported by an adhering honeycomb panel sheet. The use of other minerals is mentioned, and in the event that these are translucent, colouring is used on the supporting plate to camouflage this, thus unifying the appearance of the tile. In addition to the supporting materials mentioned, fibre wood, cellular structures of fibreglass and asbestos and even derivatives of Portland cement may be used. In this process, with the natural stone sheets in vertical position, that is, supported on their side of least thickness, the applicant is able to separate them after cutting without falling and then to introduce a strengthening sheet between each sheet, preferably also made of light material and with a honeycomb panel structure, which carries with it the drawbacks mentioned above. Adhesion of these supporting sheets to the natural stone sheets is carried out in this position, although it is not clear how application of the adhesive is carried out since if it is done in a vertical position an even application of said adhesive will not be obtained, which will affect the characteristics of the final product.
The feasibility of the manufacturing process and the strength of the compound tiles with a natural stone visible face stems mainly from the correct composition of the strengthening support material whose physical and chemical features must conform as far as possible to those of the natural stone so that they react in a similar way to the same physical or chemical reactions so that the compound tile is as stable as possible. Several materials may be used as a support for the natural stone plate, and different patent applications disclose the use of fibre materials, EP0252434, Leis, or polyurethane, EP255795, Rigas.
With respect to what has been described in the foregoing, an object of the present application is to obtain a supporting sheet for the natural stone plate with particular composition and materials which provide said sheet with similar characteristics to those of the natural stone plate so that their behaviour will be as similar as possible and the resulting stone product will have greater strength and said supporting sheet will have less thickness, particularly using fibre cement. To achieve this, it is necessary to prevent the distortions which occur in the fibre cement sheets mentioned in the state of the art when they absorb and release humidity, and which cause the natural stone plate to curve, becoming functionally unacceptable as a result and even breaking. To increase the stability of the resulting tile, it is necessary to increase the stability of the supporting sheet, which mainly consists of reducing the movement of humidification. The supporting sheets which use fibre cement described in the state of the art as a support for natural stone plates absorb humidity and release it, causing size increases. Because the fibre cement sheet is stuck to the natural stone plate, said size increases affect the tile resulting from said adhesion, making the tile curve and even break or crack.
Another object of the present invention is to provide improvements in the manufacturing processes used up to the present time for obtaining compound tiles with a natural stone visible face by means of introducing new materials and conditions into the industrial process.
DESCRIPTION
The objects mentioned above are, in accordance with the present invention, achieved by using a supporting sheet made up of a light sheet of reduced thickness to configure the tile with natural stone visible face, the purpose of said sheet being to strengthen the natural stone plate. The problem described above has been resolved in accordance with the invention by proposing and testing different materials and means to achieve on the one hand a reduction in the movement of humidification and on the other a reduction in resistance to the usual bending of fibre cement, pressed and cured in an autoclave, which has been chosen to make up said supporting sheet.
The movement of humidification is proportional, among other variables, to the cement content, to the inverse of the particle size and to the inverse of the density, variables which it has been necessary to modify by means of many test runs to achieve a greater stability of size. To increase stability and therefore reduce the movement of humidification it has been found that the cement content should be decreased, the sand content should be increased and the average size of the particles of the mixture should also be increased and, at the same time, the fibre percentage should be reduced in order to increase density. The products subjected to treatment in autoclave undergo an increase in their movement of humidification as they age. To prevent this, stabilising elements have
Ceara Apraiz Kepa
Martinez Tejera Jose Maria
Segura Juan J. Pastor
Costellia Jeffrey L.
Dawson Robert
Keehan Christopher M
Nixon & Peabody LLP
Uralita de Productos Y Servicios, S.A.
LandOfFree
Compound tile having a natural stone visible face and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Compound tile having a natural stone visible face and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Compound tile having a natural stone visible face and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3176306