WO2001019624A1

WO2001019624A1 - Reflective products

Info

Publication number: WO2001019624A1
Application number: PCT/GB1999/003046
Authority: WO
Inventors: Rahim Banizaman Lari
Original assignee: Powell, Stephen, David
Priority date: 1999-09-14
Filing date: 1999-09-14
Publication date: 2001-03-22
Also published as: AU5874799A

Abstract

A constructional or decorative reflective product (10, 36) comprises a slab (11) of base material with pieces (14) of transparent material embedded therein, the outer surfaces of the pieces (14) being substantially flush with the surrounding slab and the inner surfaces (16) being coated with a reflective substance. The reflective material is preferably a metallic layer applied by means of a vacuum coating process and it may be covered with a protective layer. The product may be a constructional floor or wall tile, or a decorative article such as a vase or jewellery. Alternatively the product may be cast in situ and may be used to provide reflective markings in a path, road or runway.

Description

REFLECTIVE PRODUCTS

The present invention relates to reflective products such as decorative floor tiles, wall panels and other items, and to reflective markings and to methods of manufacturing them.

Various techniques are used at present to produce items with a reflective and/or mosaic effect.

In a first prior art manufacturing technique, glass chips or glass pebbles are used in some construction and decoration items e.g. tiles. Glass mosaic and reconstituted marble products are available, and a quantity of glass, coloured or clear, is used in these products. A glass mosaic is made by placing glass chips on a rubber pad laid in a shaped steel mould and covering them with a mixture of cement, water, marble powder, colour pigments and sand. The above combination is then pressed by a hydraulic press to produce a tile and then the tile is lifted and sent for curing. After curing, the next step is to grind and polish automatically or manually all the exposed portions of the glass chips.

A second prior art manufacturing technique is known as "cast in situ" mosaic. Here a mixture of sand, cement, marble powder, water and marble aggregate is poured on a floor such as concrete and before the mixture hardens, glass chips of different sizes and colours are dropped substantially uniformly onto the surface. The glass chips are then each partly inside and partly outside the smooth surface of the previously poured concrete. After curing, the next step is to grind and polish the surface of the floor.

In a third prior art manufacturing technique, reconstituted marble and glass are made by producing a solid body such as a cube of a mixture of glass chips, marble powder, cement, marble aggregate, colour pigments (admixtures) and water. After the cube has dried and cured, it is cut into slabs or blocks of desired sizes and thicknesses and the next step is to grind and polish a major surface of each block or slab.

All the above techniques employ simple clear or coloured glass chips. A problem is that the appearance of the final product is not perceived as being sufficiently attractive. The mosaic industry has not benefited from any major changes in manufacturing techniques, whereas in the building and other industries there is a demand for more appealing products which, nevertheless, are still cost effective to produce.

The present invention seeks to overcome or reduce the above problems. It seeks to provide an attractive product and/or with improved reflective properties, with little or no modification to existing manufacturing plant and machinery.

According to one aspect of the present invention, there is provided a method of manufacturing a reflective product comprising providing a curable base material, embedding pieces of a transparent material therein, curing the base material and then grinding at least part of the embedded pieces, characterised in that, before the transparent pieces are embedded, they are coated with a reflective substance.

According to a second aspect of the present invention, there is provided a reflective product comprising a slab of material having pieces of a transparent material embedded in a surface thereof, the outer surfaces of the pieces of transparent material being substantially flush with the surrounding slab material, characterised in that the inner surfaces of the pieces of transparent material are coated with a reflective substance.

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, of which: Fig. 1 is a sectional view of a reflective mosaic product in accordance with a first embodiment at an intermediate stage of its manufacture;

Fig. 2 shows the product of Fig. 1 after a grinding/polishing operation;

Fig. 3 shows a block of material having pieces of embedded material therein at an intermediate stage of the manufacture of a product in accordance with a second embodiment; and

Fig. 4 shows a product obtained from the block of Fig. 3.

Referring to the drawings, Fig. 1 shows a reflective product 10 comprises a slab 11 of a base material, which comprises some or all of the components of the base material of the first prior art technique mentioned above. While the base material is still relatively soft glass chips 14 of different sizes and shapes and having different colours are embedded in the top surface 12 of the slab.

The glass chips 14 can be originally produced or of recycled glass, provided that the glass surfaces are clear and without too many scratches. To prepare them before they are pressed into the slab 11, the glass chips are first placed in a container of water inside an ultrasonic cleaning machine. All dust particles are thus removed and the next stage is to dry the glass. The glass pieces are then placed on different trays and put in a dryer (e.g. an electric or gas oven).

After drying they are placed inside a vacuum chamber. The glass chips are then aluminium film coated inside the chamber by using aluminium tungsten wire for melting and vaporising aluminium and by the use of diffusion and vacuum pumps. The glass chips are rotated inside the chamber to coat them completely. After coating, the glass chips are taken out of the vacuum chamber and placed on a special net where they are spray painted all over their surface, Epoxy-based or acrylic-based paint is preferably used. The spray paint serves for the protection of the coated surface which should not be scratched during usage. The spray paint layer also serves to protect the inner layer from chemical attack by the constituents of the base material. During all the-above processes, the human hand should not touch the surface of the glass until the coating is finished, and the environment should be dust free. The coated glass chip is now ready for insertion in the material of slab 11.

As in the first prior art technique, the base 11 is then hardened by curing and at least the protruding region of the glass chips 14 are ground off to produce the product as shown in the Fig. 2 which is then polished.

In use of the product, a particularly advantageous "jewel" effect occurs in that natural or artificial light passes through each glass chip 14, is strongly reflected at the back surface 16, which acts as a mirror and the light then passes back through the chip to the eyes of an observer.

Advantages of the product and its method of manufacture are that it can employ existing machinery, and thus there are no costs of additional plant. Also, recycled glass may be used for the chips 14 so that the materials used are relatively inexpensive.

Various modifications can be made to the above-described arrangement. For example, any suitable cement or other material may be used for the base material of slab 11. Also, the chips 14 can comprise any suitable transparent material. For example, they may comprise marble instead of glass. The pieces of transparent material used may be rough and jagged, or they may be geometrically-shaped or they may have a curved surface. Best results are obtained when the transparent material in the final product is as smooth and clear as possible but the back surface can have any shape. The glass pieces 14 may be of any combination of size and/ or colour.

The glass pieces can be coated by other materials. For example, with one type of vacuum coating machine, one can coat the glass or other transparent material with copper, -brass or gold. Particles of the metal may be incorporated in a paint or other carrier material, which produces a different reflective effect. Further suitable metallic materials are silver, bronze, nickel or rainbow powder, but aluminium has proved to be the least expensive.

The glass pieces can be coated by other processes. For example, in one modification, Ag (NH)₂ is used and the glass surface can be cleaned by caustic soda, but this process is time consuming and more expensive.

The outer paint layer may be applied by any suitable process. Since it serves as a protection, polyurethane or varnish may be used instead. If the inner, reflective layer is strong enough and resistant enough, the additional outer layer may be omitted.

The glass pieces are preferably ground substantially flush with the surrounding material of the slab. However, the glass pieces may still protrude providing enough of the coating is removed to allow a reflective effect.

The product may be manufactured in accordance with the second prior art technique mentioned in the introduction, i.e. the "cast in situ" method.

The product may alternatively manufactured in accordance with the third prior art technique mentioned in the introduction as shown in Fig. 3. A block 30 of base material is cast with glass pieces 34 mixed throughout its volume and the block is then allowed to harden. Slices of any desired thickness are then cast from the block along generally parallel lines 35 to produce individual products 36, Fig. 4. The top or front major surfaces 37 of the slices are then ground as necessary and polished; the bottom or rear major surfaces 38 may be similarly treated if desired.

The product may be of mosaic or terrazzo type and may be used in the construction industry, e.g. as a wall or floor tile or may be decorative e.g. a vase or jewellery.

The product could be incorporated as permanent markings, e.g. traffic markings, in pavements, curb stones, roads or airport runways. For such applications toughened glass is preferably used to provide a durable surface. Also, for such applications, glass pieces of a uniform geometrical shape have the advantage of providing reflections with a substantially uniform range of directions and intensity. Of course, the product may be brought to the construction site as slabs, or it can be made in situ; this gives a wide range of flexibility.

The glass pieces may have concave or convex shape like a lens glass and can be used to produce a heating effect at a surface by projection of sunlight.

Fibre optic means can be connected to each reflective glass chip to enable clear sign making and special effect flooring and road markings.

Claims

1. A method of manufacturing a reflective product (10, 36) comprising providing a curable base material (11), embedding pieces (14) of a transparent material therein, curing the base material and then grinding at least part of the embedded pieces, characterised in that, before the transparent pieces (14) are embedded, they are coated with a reflective substance.

2. A method according to claim 1, wherein the reflective substance is wholly or partly metallic.

3. A method according to claim 1 or 2, wherein the reflective surface (16) is coated with a second protecting layer before the pieces are embedded.

4. A method according to any preceding claim wherein, before being coated, the pieces (14) of transparent material are cleaned and dried.

5. A method according to any preceding claim wherein the reflective surface is applied using a vacuum coating process.

6. A method according to any preceding claim wherein the product is made in situ.

7. A method of producing markings for a path, road or runway employing a method according to claim 6.

8. A method according to any of claims 1 to 5, wherein the material is transported after manufacture.

9. A method of manufacturing a constructional tile employing a method according to claim 8.

10. A reflective product (10, 36) comprising a slab (11) of material having pieces (14) of a transparent material embedded in a surface thereof, the outer surfaces of the pieces of transparent material being substantially flush with the surrounding slab material, characterised in that the inner surfaces (16) of the pieces of transparent material are coated with a reflective substance.

11. A product according to claim 10, wherein the pieces (14) of transparent material in the slab (11) are coated with different reflective substances.

12. A product according to claims 8 or 9 wherein the pieces (14) of transparent material have a geometrical shape.