WO2008149164A2

WO2008149164A2 - Laminated mat fabrication system

Info

Publication number: WO2008149164A2
Application number: PCT/GB2008/050424
Authority: WO
Inventors: Norman Arthur Allen; Elizabeth Irene Allen
Original assignee: At Promotions Limited
Priority date: 2007-06-07
Filing date: 2008-06-09
Publication date: 2008-12-11
Also published as: WO2008149164A3; WO2008149164A4; GB0710873D0

Abstract

A method of making a laminated mat, in particular a computer mouse mat, of which the two top layers comprise respectively a substratum and a plastics film bonded to one another and characterised by the features that the substrate is pre-printed before being bonded to the film and then the film and substrate are then subject to the simultaneous actions of pressure and heat in a process in which the film, as well as being heated and pressed against the substrate, is also embossed.

Description

LAMINATED MAT FABRICATION SYSTEM

Field of the Invention

The invention relates to laminated mat fabrication systems and in particular to systems for manufacturing "computer mouse" mats.

Review of Art Known to the Applicant

The closest art known to the applicant are various systems for fabricating computer mouse mats. One of the most popular mouse mat systems is the "Hard Top" derivative, which comprises a base layer of foam, typically EVA (Ethylene-Vinyl Acetate), rubber sponge or EPDM (Ethylene Propylene Diene Monomer). The base layer is fixed with a layer of adhesive to a plastic sheet, which incorporates a print on its underside surface. The plastic sheet is a mark-resistant, embossed plastic, which is typically PVC (polyvinyl-chloride) or polypropylene. The plastic sheet is typically 300 to 400 microns thick. The plastic sheet used in this method is expensive and requires specialist printing techniques. The mouse mat produced by this system is very durable and will last for an extended period of time without degrading.

An alternative method of fabricating computer mouse mats incorporates the use of laminated paper. This derivative is cheaper to produce than the Hard Top derivative previously mentioned. The laminated paper method offers print which can be seen clearer and brighter due to a thinner layer of plastic. A typical laminated paper mat has a design printed onto paper, typically 180 to 200 gsm (grammes per square meter). Then an embossed lamination film is applied on top of the printed paper, typically around 100 microns in thickness. The lamination film will typically be embossed with a "sand-grain" effect. However, this form of mouse mat tends to delaminate at the edges and corners with normal or excessive use. This method of mouse mat does not give a perceived value which is as high as the Hard Top variant previously mentioned. Paper laminated mats of this kind use a film which is expensive, the manufacturing techniques also require more processes.

Another alternative method of fabricating computer mouse mats incorporates the use of a thick layer of PVC which is fixed to a paper print to form a "Hard Top" mouse mat.

Another alternative method of fabricating computer mouse mats is the Supreme mat "Q- Mat". This method of fabrication incorporates paper which has been embossed, typically before printing, but could be done after printing. A thin unembossed matt or gloss OPP (Oriented Polypropylene) film is then applied to the paper, typically 27 to 30 microns thick. The embossing on the paper, results in a slightly roughened surface, which assists in the performance of the tracking of the mouse. This method offers the use of lamination film which is cheap. If the paper is embossed in bulk the operation is inexpensive.

Then there are two disadvantages of this approach. Firstly the embossing process, which is normally carried out by a pair of rollers, through which materials pass under considerable pressure, degrades the rigidity of the mouse mat fabricated from embossed materials such as paper or board. This reduces the perceived value of the mouse mat; the preferred perceived value of the product is a stiff and sturdy mouse mat which is indicative of quality and endurable product. A floppy mouse mat gives the impression of a weak and flimsy product which is not durable. Even if heavy board (300gsm) is used the mat still ends up floppy and reduces the perceived value of the product.

Secondly, it is difficult to apply an OPP film laminate to the embossed surface without trapping tiny amounts of air. This trapped air beneath the laminates creates an effect known as "silvering" and it is unsightly, particularly when the printed design comprises areas of solid dark colours. These two qualities, lack of rigidity and silvering are, characteristic of paper laminated mats made this way and they reduce the perceived value of the product. A stiffer and sturdier construction without silvering is indicative of a quality and endurable product. Another big disadvantage of this technique is that the embossing process degrades that rigidity of the paper and the mat then becomes floppy. This reduces the perceived value of the mouse mat; the preferred perceived value of the product is a stiff and sturdy mouse mat which is indicative of quality and endurable product. A floppy mouse mat gives the impression of a weak and flimsy product which is not durable. Even if heavy board (300gsm) is used the mat still ends up floppy and reduces the perceived value of the product.

Summary of the Invention

The invention is embodied in laminated mats, apparatus for laminating such mats, and methods of operating such apparatus. It is particularly applicable with advantage to so- called mouse mats whose top (operating) in-use surface is designed to be traversed by a mouse (a hand held button activated computer input control). It will be described with specific reference to such mouse mats in the text and drawings which follow this summary.

In its broadest independent aspect, the invention is embodied in a laminated mat of which the two top layers comprise respectively a substratum and a plastics film bonded to one another and characterised by the features that the substrate is pre-printed before being bonded to the film and then the film and substrate are then subject to the simultaneous actions of pressure and heat in a process in which the film, as well as being heated and pressed against the substrate, is also embossed.

This enables a relatively low cost unembossed gloss or matt plastics film to be used but resulting nevertheless in a relatively rigid bonded-to-substrate structure to which (optionally) a relatively conventional base layer of foam can be bonded by known means; and resulting laminated sheet can then be cut into individual mats.

If the heating temperature, the embossing pressure, and the film thickness are appropriately chosen then the embossing affects the film without doing damage to the inherent rigidity of the substrate. The heating has the further advantage in that it makes the adhesive which is bonded to the film, and by which the film presses and adheres against the substrate flow; so that a nominally thick film - nominally because the thickness in this context includes the thickness of the adhesive and not just the plastics film alone - can nevertheless be used in certain circumstances.

Another advantage is that the plastics film layer itself will also automatically be softened by the heat and this results in maximum embossing effect at minimum embossing pressure.

In the specific case of a mouse mat, where the substrate is typically paper or cardboard (above 200 gsm, paper is usually called board or card). The rigidity of the mat is an important feature of the product in an intensely competitive sales industry. This "feel" of a relatively rigid mat is achieved by carrying out the invention in its processed form using pre-printed substrate, initially unembossed film, and the essential features of simultaneous pressure, heating, and embossing to laminate the film to the substrate before the resulting bonded structure is subsequently itself adhered to the base foam layer to complete the mat or the sheet from which individual mats are subsequently cut.

Preferably the film is bonded to the substrate by feeding it around an embossing roller which is heated and pressed simultaneously onto the film. Conventionally the film and pre-printed substrate may be fed between the nip of two rollers, one or both of which may be heated, and one of which performs the embossing. Relatively light embossing pressures and readily achievable heating temperatures can be combined to produce a bonded film- to-substrate structure which has the necessary rigidity, but yet another advantage of the process is that the embossing of the film is not impaired by any cushioning effect of the adhesive layer because the simultaneous application of heat and pressure whilst embossing the film surface largely overcomes any such tendency.

The invention may be applied with advantage to the production of mouse mats using conventional OPP film (in which the necessary adhesive layer is already coated over the film underside) and substrate paper or card (onto which the desired pattern to be displayed by the mat surface may be viewed subsequently through the plastics film) can be printed before the bonding and embossing process takes place. The invention contrasts wholly with previous laminated mat manufacture where either the pattern was expensively printed onto the film itself and/or inexpensively but unsatisfactorily printed onto the substrate and then an embossed laminated plastics film was applied and/or heavy embossing degraded the rigidity of the paper or the film or both even when relatively heavy substrate or board were used.

A process embodying the invention makes it easy to avoid the "silvering" effect discussed above.

The invention includes within its scope a method of making laminated mats, an apparatus adapted to operate such a method, and a mat produced by virtue of such a method or as a result of the operation of such an apparatus, all substantially as described herein with reference to and as illustrated in any appropriate combination of the accompanying text and drawings.

One such specific illustration will now be described by way of example only with reference to the drawings.

Brief Description of the Drawings

Figure 1 shows a mechanical schematic diagram of a portable pad fabrication process.

Figure 2A shows a cross-sectional view of a film membrane, incorporating an adhesive layer.

Figure 2B shows a cross-sectional view of a film membrane, incorporating an alternative adhesive layer.

Figure 3A shows a cross-sectional view of a board substrate.

Figure 3B shows a cross-sectional view of a board substrate incorporating an alternative width.

Figure 4A shows a side view of a hand held portable pad with perceived high quality value. Figure 4B shows a side view of an alternative hand held portable pad which has a perceived low quality value.

Detailed Description of the Drawings

Figure 1 shows a process for fabricating laminated mats 1 characterised in the form of mouse mats. The process incorporates a film membrane role 2 and a substrate role 3. The film membrane 4 incorporates an adhesive layer 15 on its bottom surface. The substrate 5 incorporates a print upon its upper surface (not shown). The process applies a continuous length of film membrane 4 originating from film membrane roll 2 and a continuous length of substrate 5 originating from substrate roll 3, simultaneously 6 to the vertical roller configuration 7. The vertical roller configuration 7 incorporates upper roller 8 and a lower roller 1 1. The upper roller 8 incorporates an embedded heater (not shown) and a raised pattern across its outer cylindrical surface 9. Therefore, enabling the upper roller 8 to function as a cylindrical die. The upper roller 8 rotates in the direction shown by arrow 10 and applies a downward pressure onto the film membrane 4. The Upper roller 8 squeezes the film membrane 4 onto the substrate 5 by applying pressure onto the lower roller 1 1, which rotates in the direction indicated by arrow 12.

The embedded heater (not shown) within the upper roller 8, heats the upper roller 8 to a set temperature, which is required to melt the film membrane's adhesive layer 15. The heating process enhances the lamination of the film membrane 4 to the substrate 5. By reducing the amount of pressure applied to them both when they are passed through the vertical roller configuration 7 for bonding. The typical pressures applied onto the film membrane 4 and substrate 5, between the heated upper roller 8 and supporting roller 1 1 is a maximum of approximately 0.5 tonnes. The film membrane 4 is laminated onto substrate 5 in the direction indicated by arrow 13.

The heating of the upper roller 8 also enables the upper roller 8 to emboss the pattern incorporated within its outer cylindrical surface 9 onto the film membrane 4. The embossing process functions simultaneously with the bonding process. The heated upper roller 8 may incorporate a number of patterns such as sand grain, linen, which are applicable to matt or gloss film membranes. This gives a low cost solution and a high quality appearance to items such as laminated covers and company reports etc, which are price competitive. The textured surface on the film membrane increases the friction on the mouse mat's laminated surface, to improve the action of the ball within a computer mouse device, therefore enabling improved tracking of the mouse pointer on the computer screen. The unevenness of the textured surface also enables any movement to be detected by optical sensors incorporated within an optical mouse.

Figure 2A shows a cross-sectional view of the film membrane 4 (shown in figure 1) which incorporates an adhesive layer 15 along its bottom surface. The figure shows the thickness of the film membrane is constant, with a typical value of 12 microns. The figure also shows the thickness of the adhesive layer 15 is also constant, with a typical thickness of 13 microns.

Figure 2B shows an alternative cross-sectional view of the film membrane 4 which incorporates an adhesive layer 15 which has a thicker adhesive layer, typically 30 microns. The varying thickness of the adhesive layer does not impact on the quality of the embossed, textured finish on to the film membrane 4, by the heated upper roller. The varying thickness of the adhesive layer is required to bond the film membrane onto various substrates, which have various bonding characteristics. The adhesive layer does not act as a cushion during the embossing process.

Figure 3A shows a substrate 5 (as shown in figure 1) which has a typical thickness of 300 microns (30). If the substrate is a board of 300 gsm (31) and has a thickness of 300 microns, then it has a weight to thickness ratio of 1:1.

Figure 3B shows a substrate 5 having a typical thickness of 500 microns (32). This provides a higher thickness to weight ratio, which results in an improved performance in rigidity. The typical weight of substrate is 250gsm to 350 gsm.

The hand held mouse mat 20 shown in figure 4a was manufactured using the process shown in figure 1 and has been subjected to less than 0.5 tonnes when the film membrane and substrate were laminated together. Therefore, this process maintained the rigidity of the substrate, without any degradation, when being squeezed through the vertical roller configuration 7. The rigidity shown by the mouse mat 20 is considered to indicative of a product which has a perceived high value and improved quality.

The hand held mouse mat shown in figure 4b was manufactured by one of the more conventional processes. In which the film membrane was sequentially located on to the mat, then subsequently glued to the mat and then subsequently embossed at pressures typically of 5 to 6 tonnes. This high pressure weakens the rigidity of the substrate material ant therefore has the undesired effect of making the finished product looking limp and floppy. Therefore, indicative of a product which has a perceived low value and poor quality.

Claims

1. A method of making a laminated mat, in particular a computer mouse mat, of which the two top layers comprise respectively a substratum and a plastics film bonded to one another and characterised by the features that the substrate is preprinted before being bonded to the film and then the film and substrate are then subject to the simultaneous actions of pressure and heat in a process in which the film, as well as being heated and pressed against the substrate, is also embossed.

2. The method of claim 1 in which the film is bonded to the substrate by feeding it around an embossing roller which is heated and pressed simultaneously onto the film.

3. The method of claim 1 or claim 2 in which the ratio of the thickness of the film to the thickness of the adhesive bonding layer is typically 12:13, i.e. approximately

1 :1.

4. The method of claim 3 but in which the thickness of the adhesive bonding layer is approximately 3 times that of the film.

5. The method of claim 3 in which the substrate has a weight of thickness ratio of 1 :1.

6. The method of claim 5 but in which the substrate has a weight to thickness ratio in the range 2:1 to 10:7.

7. The method of any preceding claim and in which the mat is subjected to no more than 0.5 tonnes pressure when the film and substrate are laminated together.

8. A method of making a laminated mat, in particular a computer mouse mat substantially as described herein with reference to and as illustrated in any appropriate combination of the accompanying text and drawings.

9. A laminated mat, in particular a computer mouse mat, made by a method according to any preceding claim.