This invention is related to a sheet and specifically it is related to a sheet used for instance in furniture, floor covering or counter tops.

It is known that the currently used hardboard, plywood, chipboard, MDF (medium density fiberboard), or laminated boards are not durable and resistant against humidity and water. Despite of the protective precautions, these materials are affected by water somehow. When said materials are used as floor covering or in kitchens and baths as counter tops or furniture, problems like swelling, cracking and fractures are very likely to happen. Another problem that is likely to happen is the bacteria propagation caused as a result of humidity and water.

On the other hand, cracking may happen while screwing with screws bigger than a certain diameter. During the connection of the sheets made of these materials fractures may happen in the sheet. Or due to the deformation caused by the unscrewed screw, it is impossible to screw the material at the same spot.

Flammability of the said materials is fairly low and it brings risks along.

It has been possible to eliminate all the above mentioned shortcomings by means of the sheet provided according to this invention. The sheet according to this invention has also the advantage of not being harmful for environment and human health.

Said sheet comprises thermic power plant slag, fly ash, polymer binder, chloroparaffin and optionally pigments. Fly ash is a fine residue obtained and transmitted along with the flue

gas as a result of burning of ground or powder coal. Fly ash is a waste product of coal- fired electric power plants.

Fly ash is successfully used in various building materials especially in road paving, pavement blocks.

The sheet according to this invention is specifically development in order to substitute the medium density fiberboard (MDF), hardboard, plywood, chipboard or other materials used in kitchen and bathrooms.

DETAILED EXPLANATION OF THE INVENTION

In the process for manufacturing the sheet according to his invention, thermic power plant slag and fly ash are sieved and mixed with other ingredients until a desired consistency is obtained. This consistent mixture is poured and pressed into the molded presses or moulds with lids. After being cured, one or all surfaces of the sheet are covered or coated with desired material and get ready for sale. Besides the main element that is slag and fly ash, binder, water absorbency retardants and pigments can be used. Although several materials can be used as binders, polymer binders are successfully preferred in this invention.

In order to eliminate water absorbency, preferably chloroparaffin is used. Pigments may also be added in order to add attractiveness to the end product.

The properties of the sheet according to this invention such as flammability, resistance against humidity and water, screwing were compared with MDF, hardboard, chipboard called green chipboard.

The results are shown in the following table.

In the resistance against humidity and water test, all four sheets were immersed into water for seven days and examined at the end of the seventh day. At the end of the seventh day, chipboard and MDF have become swollen and discolored. Green hardboard has softened and leaked out the green dye and the top coating has ripped out. The sheet according to this invention did not show any change.

In the inflammability test, MDF, chipboard and green hardboard have flamed. The sheet according to this invention has not flamed but tarnished.

In the tests for screwing feature, there were fractures when a 3 mm screw was applied to a 18 mm MDF crosswise and the screw could not be applied at the same point. When a 7 mm screw was applied to a 18 mm chipboard crosswise, fractures have happened and a screw could not be applied at the same point. Green hardboard has the same disadvantages. Swelling has occurred when screws were applied to the coating and not two screws can be applied too close due to the tendency to fracture. In the sheet according to this invention when a 7 mm crews was applied to the 18 mm sheet crosswise, swelling and fractures have not happened and the same screw could have been rescrewed. There was no problem with the screwing when 7 mm screws were applied to points 5 mm apart.

The sheet according to this invention has the same properties with the other materials as far as the mechanical applications ( strip saw, planing machine, lathe) are concerned during the handling of the sheet.

No difference has been observed as far as the hardness and usage when compared with the other materials.

On the other hand, it is well known that formaldehyde used as binder in MDF, chipboard and green hardboard is hazardous against environment and human health. Especially

MDF has been forbidden in children furniture in many countries. In the sheet according to this invention polymer is used as binder which is not hazardous.

Other ingredients (fly ash and slag) are known to be not hazardous against the environment

(USA EPA)