AU2002100163A4 - Sheet material with printed information thereon and method of producing the same - Google Patents

Description

SHEET MATERIAL WITH PRINTED INFORMATION THEREON AND METHOD OF PRODUCING THE SAME FIELD OF INVENTION The present invention relates to a rubber sheet material having printed information thereon which comprises a silicone rubber sheet material that is able to releasably cling to glass or a smooth surface having a smoothness similar to glass, particularly common smooth window glass. The invention also relates to a method of producing the rubber material or the silicone rubber material.

BACKGROUND OF INVENTION In the marketplace, there is a need to removably apply or attach printed information to glass windows or other such similar smooth surfaces, in which the printed information is attached temporarily. For instance, in shop windows, there is a need to attach printed advertising information to the glass of the shop window. Typically, it is common to see such information painted directly onto the glass shop windows, which is difficult to remove. Alternatively, paper posters or notices can be adhered to the glass shop windows, usually with adhesive tape, but this can leave some degree of unsightly marking on the glass when the adhesive is removed, particularly when the adhesive has remained on the window for a long period of time. There is therefore a need in the marketplace for an improved printed sheet material which can be easily, conveniently and quickly secured to a smooth glass surface, and which will not leave unsightly markings when the material is removed, and in which the sheet material can be reused multiple times.

Paper posters are not suitable when the printed information sheet is intended to be re-used a multiple number of times. Also, paper can be damaged by rain or moisture. Moreover, paper posters are extremely common and ubiquitous, and hence tend not to stand out. There is therefore a need in the marketplace for a shop window poster that can stand out from the crowd, as it were, so as to attract the attention of potential customers.

Also, most advertising materials require a separate adhesive, such as sticky tape or liquid adhesive or some form of adhesive which is external to the advertising material, in order to adhere the material to the surface. Sometimes, such adhesives will not be available when needed, and so there would be a need for a sheet material that can be adhered to a shop window without requiring a separate adhesive.

Another problem with traditional window signage, such as paper posters and painted details, is that each of these blocks the view through the window, thus putting a practical limit on how much signage can be displayed on the widow without excessively obstructing the view through the window.

Another area in which printed information needs to be temporarily applied to glass surfaces is the application of L-plates and P-plates (or other such driver status information) to the glass windows of cars and vehicles. A know L-plate or P-plate is adapted to be attached to car window glass by suction cups. This manner of attachment performs poorly, particularly when the L or P plates have to adhere to the inside of the front or rear car windscreens which are inclined at an angle. There is a tendency for the suction cups to detach, particularly when exposed to the sun. Without being bound by theory, it is believed that the heat from the sunlight causes the slight amounts of air, caught between the impressed suction cup and the glass, to expand and thus cause the suction cup to detach from the glass.

Another know style of L or P plates consists of a sheet of plastic material, for example, polyester. Such sheets of plastic material, as will be seen in comparison to the present invention, are not inherently sticky or tacky in relation to glass. These prior art plates also are susceptible to readily falling off the window glass, particularly when exposed to sunlight.

Other know L or P plates are made of materials, or make use of adhesive materials, that can leave stains on the glass particularly when allowed to remain in the sun for long periods.

An object of the present invention is to overcome or ameliorate one or more of the above problems in the prior art, or to provide an improved alternative to the above.

SUMMARY OF INVENTION According to the present invention, there is provided a rubber sheet material having an upper surface and an undersurface, at least one of the surfaces having printed information thereon, at least the undersurface being sufficiently smooth to be capable of releasably clinging to a substrate which is smooth glass or which has a smoothness substantially of ordinary window glass, wherein the undersurface is adapted to cling to the flat substrate when pressed thereagainst to enable the printed information to be displayed on the substrate.

In an embodiment of the invention, at least the undersurface of the rubber sheet material has an inherent tacky surface consistency with respect to the substrate which facilitates the undersurface of the sheet material clinging to the substrate.

In an embodiment of the invention, the rubber sheet material is silicone rubber.

Preferably, the undersurface is provided with clinging means which enhances the capability of the undersurface to cling to the flat substrate when pressure is applied onto the upper surface to physically and resiliently deform the clinging means.

Preferably, the clinging means includes a plurality of discrete indentations in the undersurface that resiliently deform by being flattened when pressure is applied to the sheet material.

Preferably, the plurality of discrete indentations are arranged in an ordered matrix or pattern.

Alternatively, the plurality of discrete indentations may be arranged in a random arrangement.

Preferably, when the undersurface is pressed against the flat substrate, the undersurface clings thereto until released by peeling the sheet material off the substrate.

According to another aspect of the present invention, there is provided a method of producing a silicone rubber sheet material having an upper surface and an undersurface in which at least the undersurface is adapted to releasably cling to a flat substrate having a smoothness similar to ordinary window glass, the method including the steps of: providing a mould having an internal chamber adapted to receive silicone rubber material to mould the sheet material therein, providing at least one internal surface of the moulding chamber with a surface smoothness that causes at least one face of the resulting sheet material, corresponding to the undersurface of the sheet, to have a degree of smoothness such that the undersurface clings to the flat substrate when pressed thereagainst; and filling the mould with the silicone rubber material to produce the silicone rubber sheet material in the mould.

According to a further aspect of the present invention, there is provided a use of a silicone rubber sheet material as an information sheet pressed against a substrate which is smooth glass or which has a smoothness substantially of ordinary window glass, the sheet material having an upper surface and an undersurface, wherein at least the undersurface has a degree of smoothness and an inherent tacky surface consistency which facilitates the undersurface of the sheet material clinging to the substrate, such that the undersurface releasably clings to the substrate when pressed thereagainst to enable printed information on at least one of the surfaces to be displayed on the substrate.

DRAWINGS

In order that the present invention might be more fully understood, embodiments of the invention will be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1A illustrates an embodiment of a silicone rubber sheet material in which the sheet material is shown clinging to a smooth glass surface; Figure 1B illustrates a second embodiment of a silicone rubber sheet material which has an undersurface having an arrangement of indentations which enhance the ability of the sheet material to cling to the glass; Figure 2A illustrates an example of a die mould used in an embodiment of a method used to produce the silicone rubber sheet material of Figure 1A; and Figure 2B is an alternative die mould used in an alternative embodiment of a method used to produce the silicone rubber sheet material of Figure lB.

In the drawings, the actual dimensions of the silicone rubber sheet material and the die mould have been exaggerated merely for the sake of clarity and understanding the drawings and description. Also, in the description, like components have been provided with like numerals, merely for the sake of ease of understanding the description.

DESCRIPTION OF EMBODIMENTS Referring to the drawings, Figure 1A illustrates an embodiment of a sheet material 10A shown clinging to a flat substrate which has a smoothness similar to ordinary window glass. In the embodiment of Figure 1A, the substrate is ordinary unfrosted flat window glass 20, such as found in typical shop windows.

The sheet material 10A has an upper surface 11 and a lower undersurface 12.

In the present embodiment, it is significant that at least the undersurface 12 of the sheet material 10A is adapted to releasably cling to the surface of the substrate 20 when pressed against the substrate. To achieve this, the sheet material 10 is made of a rubber sheet material that has an inherent tacky surface consistency which is felt particularly when the silicone rubber sheet material is pressed against the glass 20. The inherent tackiness of the silicone rubber with respect to the glass substrate or other smooth substrate means that no external adhesives, or external joining means such as suction cups are required.

The upper surface 11 may or may not be smooth, since the upper surface does not participate in clinging to the glass.

In the embodiment, the rubber sheet material is made of silicone rubber sheet material which is tough and durable, and which does not alter its dimensions excessively even when exposed to harsh sunlight.

Preferably, the sheet material 10 is transparent, so that it does not obstruct the view through the glass.

It is appreciated that not just any sheet material has the same capacity to inherently cling to the surface of an ordinary pane of window glass as effectively as does silicone rubber sheet material. Also, significantly, it has been found that not all silicone rubber sheet material clings to glass. It has been found that the silicone rubber sheet material cannot cling to the glass surface when its undersurface lacks a certain degree of smoothness that is required to cling to the glass. For instance, if the undersurface 12 of the sheet is too rough, or otherwise not sufficiently smooth, the silicone rubber sheet will not have the ability to cling sufficiently to the glass substrate or other such smooth surface. Also, if the undersurface 12 has the required degree of smoothness, but is dirty with dust or grit, the sheet material will also not adequately cling to the glass for an extended period. Hence, the undersurface should preferably be cleaned before pressing the sheet material against the glass.

The degree of smoothness and tackiness with respect to the glass is sufficient to allow the sheet material to cling to the glass for long periods, even when exposed to harsh sunlight, and even when the silicone material is clinging to the underside of an inclined sheet of glass, such as the inside of a car windscreen.

A parameter which influences the cling of the silicone sheet material to the glass or glass-like surface is the surface roughness. On one hand, an example of a silicone sheet, which is able to cling to glass, has a roughness Ra parameter of 0.65 micron. On the other hand, an example of a silicone sheet, which cannot cling to glass, has a roughness Ra parameter of 4.85 micron. The Ra roughness parameter may be tested in accordance with ISO 4287, DIN 4762 or DIN 4768 which measure an arithmetic mean of surface roughness. However, these two roughness values are given as examples, and experimentation may be required to find the appropriate degree of surface smoothness to ensure clinging to the anticipated type of glass or glass-like surface.

The cross-sectional thickness of the sheet material 10 also influences the ability of the sheet material to cling to the glass 20. A thicker cross-section is associated with a heavier mass of sheet material 10. For a given flat surface area of the sheet material 10, experiments would have to be conducted to ascertain how thick the sheet can be made, beyond which the sheet becomes too heavy for the silicone rubber material to effectively cling to the glass.

As an example, for a sheet material 10 which is 90 mm in diameter, the sheet thickness might be around 0.8 mm, and may even be as thick as 2.5 to 3 mm thick. In this example, when the thickness exceeds, say, around 3 mm, the weight of the sheet material would tend to overcome any attraction between the smooth silicone rubber sheet material and the glass, and thus the silicone rubber sheet material would not be effective in clinging to the glass surface. These figures are specific examples given to illustrate the broad principle of the need to take into account the size of the sheet, as a factor that influences the size of material that can adhere to the glass.

In a second embodiment in Figure 2A, the undersurface 12 of the silicone rubber sheet 10B is provided with clinging means. (References to a sheet without the suffix A or B, can refer to either 10A or 10B). As an example, in the embodiment of Figure 2A, the clinging means is in the form of a plurality of discrete indentations 15 in the undersurface 12. The function of the clinging means is to enhance the capability of the undersurface 12 to cling to the flat substrate 20 when pressure is applied onto the upper surface 11 of the sheet.

This pressure causes the clinging means to physically and resiliently deform. For instance, when the upper surface 11 of the sheet material is pressed, for example, by applying finger pressure to the surface, the indentations 15 are deformed by being flattened when the pressure is applied to the sheet material.

Without being bound by theory, it is believed that when the resilient silicone rubber sheet material is pressed against the glass surface, the downwards deformation of the indentations 15 causes any air or gas contained therein to be forced out of the indentation. Thereafter, it is believed that the resiliency of the silicone rubber sheet material causes the indentations to expand back towards their original configuration, thus forming a micro vacuum suction effect, similar to a rubber suction cup used by plumbers. This suction effect would be most effective when the user takes care to apply the silicone rubber sheet material onto the glass in a sequential, sweeping manner, in other words, first applying one side of the sheet 10, and then progressively pressing portions of the sheet onto the glass from one side of the sheet to the other in a sweeping motion, all the time ensuring that no gas bubbles are entrapped. This allows the air in the indentations to have access to escape when the indentations 15 are being pressed against the glass surface.

In the embodiment of Figure 2A, the indentations 15 are arranged in an ordered matrix or pattern, similar to a grid pattern (not shown). However, in other alternative embodiments, the arrangement of the indentations can be random.

It has been found that silicone rubber sheet material is able to cling to the glass substrate almost indefinitely, until it is released by the user peeling the silicone rubber sheet material off the glass substrate (assuming clean surfaces).

Care must be taken, however, to ensure that before the silicone rubber sheet material is pressed against the glass, that the undersurface 12 of the sheet material is clean. Otherwise, if there are any dirt particles on the undersurface 12, this can cause the sheet material 10 to prematurely fall off the glass surface on its own accord.

Figure 2A illustrates an injection die mould 100 which can be used in relation to an embodiment of a method of producing the silicone rubber sheet material 10A shown in Figure 1A. The mould 100 has an internal die chamber 200 which is adapted to receive the raw silicone rubber material within the chamber, so that the silicone rubber material can be moulded into the form of the sheet material. At least one internal surface 110OA of the moulding chamber is provided with a surface smoothness that is sufficient to produce the required degree of surface smoothness of the undersurface 12 of the sheet material After the particular internal surface 110 A has been provided with the necessary degree of smoothness, the mould 100 is filled with silicone rubber material to produce the silicone rubber sheet Figure 2B illustrates a modification of the mould of Figure 2A, in that the smoothened surface 110B is provided with a plurality of protrusions 150B. These plurality of discrete protrusions correspond to the indentations 15 found on the undersurface 12B of the second embodiment of the sheet material Thus, when the die mould 100B of Figure 2B is used to produce the silicone rubber sheet material, the protrusions 110 OB cause the undersurface 12B of the sheet material to be provided with the arrangement of indentations Silicone rubber sheet material, produced according to the above embodiments, can be used to provide temporary signage on glass shop windows.

For instance, letters of the alphabet, produced from the silicone sheet material, can be sold as sets so that window dressers can cause the silicone letters to cling to the glass to produce temporary wording on the window surfaces.

The silicone rubber sheet material 10 can be transparent with printed information thereon, so that when it is used in shop window signage, the transparency of the base material means that the sheet does not block the view through the window. This can be used for temporary signage on shop windows, for example.

Alternatively, information can be printed directly onto the surface of the silicone rubber sheet material, so that the sheet acts as a poster material that can cling to shop windows.

The transparent silicone sheet material of the present embodiment can be placed on car windows, such as when L-plates or P-plates must be releasably adhered to the glass surfaces of car windows. An advantage of the silicone rubber material is that it can be made transparent, so that the L and P plates can be transparent, without blocking the vision of the driver. Moreover, use of the silicone rubber sheet material for such purposes has an advantage of avoiding unsightly markings when the sheet material is removed from the glass surface.

Another use of the silicone rubber sheet material of the present invention is in applying information to the surface of refrigerators in homes. Unlike magnets, which are commonly used to cling to refrigerators, the silicone rubber sheet will not scratch the surface.

Without being bound by theory, it is believed that once the silicone rubber sheet material exceeds 3.5mm in thickness, the embodiment in Figure 1B, having the indentations 15, will be required. However, some degree of experimentation would be required since sheet materials with a larger surface area may tend to have greater clinging attraction to the glass surface by virtue of its large surface area, compared to, say, sheet materials of smaller surface areas.

An advantage of silicone rubber sheet material is that it is tough and has a high degree of wear resistance.

Other applications for the silicone rubber sheet material of the present invention is the use as an anti-slip material that can be applied to the undersurface of bathroom surfaces.

Another use for the silicone sheet material is in the form of soles for shoes, since the sheet material provides a good anti-slip friction grip with very smooth polished floor surfaces, and moreover does not leave unsightly markings that would be associated with ordinary rubber shoe soles. Unlike some ordinary adhesives, which tend to leave markings when left for a long period of time, the silicone rubber sheet material will not leave markings, no matter how long it has adhered to the glass.

The silicone rubber sheet material has a high temperature resistance, and can be used typically withstand up to 2600 in temperature.

An advantage of the silicone rubber sheet material, having the required degree of smoothness, is that when the sheets are placed on top of each other in storage, each sheet will lightly cling to adjoining sheets, but can be readily separated.

Another use of the present embodiments is for placing name identification signs on office glass doors. The name signs would be easier to replace when personnel change rooms, compared to normal means of placing signs on doors.

The silicone sheet material of the present embodiment is suited for advertising purposes as an alternative to painting or using adhesives to adhere information onto the glass surface. In the present embodiment, the silicone sheet clings to the glass, and is easily removed by simply peeling the sheet from the glass surface.

In this specification, the word "cling", rather than the word "adhere", is used to describe and define the manner of joining the silicone rubber sheet to the substrate, since there is no need for a separate adhesive, such as tape, glue or lumps of adhesive.

The invention is not limited to a particular shape of the indentations, so long as the indentations can provide the function described above. The indentations might be circular, oval-shaped, irregular-shaped, or otherwise.

Embodiments of the sheet material can be used for Christmas and festive decorations that have to be attached to the glass panes of windows.

The expression "printed information" applies generally to all manner of imprinting or applying visual information onto a surface, such as painting or screen printing. Thus, the information might be painted onto the surface of the silicone rubber.

In addition to glass, it has been found that embodiments of silicone rubber sheet material are able to cling to other smooth surfaces that have a similar smoothness to glass, including: smooth plastic surfaces such as found in light switches, smooth polished wood, smooth metal surfaces such as found on refrigerator doors, whiteboards, smooth oil-painted glossy walls, to name a few examples. Thus, the invention is clearly not limited to sheet materials that cling to glass, but also covers surfaces that have a degree of smoothness similar to glass. It is appreciated that, at a microscopic level, the examples of surfaces named in this paragraph will vary considerably in respect of smoothness.

However, the similarity to the smoothness of glass is used in this specification as a reference point which the skilled addressee of this specification will understand in broad terms. It will, also, require some experimentation to ascertain if the silicone rubber sheets will adhere to other smooth surfaces. Thus, the reference to the substrate having a smoothness substantially of ordinary window glass is intended to at least cover the foregoing examples mentioned in this paragraph. It is found that the inherent tackiness of the silicone rubber sheet also exists with respect to the non-glass examples mentioned in this paragraph.

The expression "displayed on a substrate" includes a case where the substrate is transparent, such as window glass, and where the information is viewed through the substrate. For instance, an L or P plate, made form the silicone rubber of the present embodiment is viewed through the windscreen glass. In this case, the information is still said to be displayed on the substrate.

The embodiments have been advanced by way of example only, and modifications are possible within the scope of the present invention as defined by the appended claims.

Claims (4)

1. A rubber sheet material having an upper surface and an undersurface, at least one of the surfaces having printed information thereon, at least the undersurface being sufficiently smooth to be capable of releasably clinging to a substrate which is smooth glass or which has a smoothness substantially of ordinary window glass, wherein the undersurface is adapted to cling to the flat substrate when pressed thereagainst to enable the printed information to be displayed on the substrate.

2. A sheet material of claim 1 wherein at least the undersurface of the rubber sheet material has an inherent tacky surface consistency with respect to the substrate which facilitates the undersurface of the sheet material clinging to the substrate.

3. A sheet material of any one of the preceding claims wherein the rubber sheet material is silicone rubber.

4. A sheet material of any one of the preceding claims wherein the undersurface is provided with clinging means which enhances the capability of the undersurface to cling to the flat substrate when pressure is applied onto the upper surface to physically and resiliently deform the clinging means. Use of a silicone rubber sheet material as an information sheet pressed against a substrate which is smooth glass or which has a smoothness substantially of ordinary window glass, the sheet material having an upper surface and an undersurface, wherein at least the undersurface has a degree of smoothness and an inherent tacky surface consistency which facilitates the undersurface of the sheet material clinging to the substrate, such that the undersurface releasably clings to the substrate when pressed thereagainst to enable printed information on at least one of the surfaces to be displayed on the substrate. DATED this 4 th day of March 2002 BY JAMES Z. SHEN