TECHNICAL FIELD OF THE INVENTION

This invention relates to articles such as, without limitation, car mats, seat belt covers, boot liners and the like, and more specifically to such articles which are intended for use in vehicles with a leather or synthetic leather trim.

BACKGROUND

Many vehicles towards the upper end of the price range have real leather seat coverings and internal upholstery. The production of artificial leathers has also evolved to the point where high quality synthetic leather coverings and trims may be used where real leather is unsuitable, or undesirable for ethical reasons. Poromeric or "breathable" imitation leathers may typically have a polyurethane coating applied to a fibrous base layer, typically polyester.

Removable car mats are almost universally used in the foot wells of a vehicle. Although leather mats are available in some countries they are expensive items, and few people would want to spend a lot of money on an item which is very likely to be heavily soiled after a few weeks use. The market has yet to see a vehicle mat or similar accessory which matches the durability and quality of real leather upholstery at an affordable price.

It has been known for several decades to attach an overlay, e.g. a pvc sheet, to a base layer such as fibrous mat using high frequency welding (HFW). In the vast majority of cases the overlay is inset from the peripheral edges of the base mat. Examples of such processes are disclosed in GB 2 344 758-A and US 6 030 490.

In a more recent patent specification, GB 2 533 149-A, it is disclosed that significant manufacturing advantages can be achieved by using a single HFW die to attach a standard size overlay to a variety of different shapes and sizes of base mat. The overlay overhangs at least one edge of the mat during the HFW process and the overhanging portions are then trimmed off before applying an edge binding to the mat.

Again, in most known examples the overlay is attached to the base layer by one or more continuous welding areas. In US 6 030 490 for example, the die has a single continuous welding area, or "relief feature", which is shaped to coincide with the overlay to be applied thereby ensuring firm attachment. However, when part of the overlay overhangs as in GB 2 533 149-A the thermal mass of the overhanging portions is different from the areas which overlie the base mat and there may be a danger of arcing, overheating and wasted energy during the welding process.

SUMMARY OF THE INVENTION

When viewed from one aspect the present invention proposes a method of manufacturing an article for use in a vehicle:

- pre-forming a base layer (2) from a sheet which includes a flexible fibrous material to provide the base layer with a defined peripheral profile;

- placing an overlay (3) of smooth non-porous polymer material onto an HFW die, said HFW die having an upper contact surface which includes active welding areas for contact with the overlay and inset non-active areas which are spaced from the overlay;

- covering the overlay with a hot melt adhesive laminate (40);

- placing the pre-formed base layer onto the hot melt adhesive laminate such that the overlay covers at least part of the pre-formed base layer;

- placing a metal contact plate (42) onto the base layer above the HFW die;

- applying electrical power to the HFW die to cause the hot melt adhesive laminate to melt and bond areas of the overlay in contact with the active welding areas of the die to the corresponding overlying areas of the pre-formed base layer;

- wherein the pre-formed base layer (2) is positioned such that the overlay (3) extends beyond at least one peripheral edge of the base layer;

- wherein the active welding areas of the HFW die comprise lines (25, 26; 37) of discrete active welding areas (30) which are separated by spaces (31).

The configuration of the die ensures that the overlay becomes firmly bonded to the base layer whilst any areas of the die which lie outside the periphery of the base layer are not susceptible to localised electrical effects.

The invention also provides an article for use in a vehicle:

- a base layer (2) which includes a flexible fibrous material, said base layer having a defined peripheral profile;

- an overlay (3) of smooth non-porous polymer material which is bonded by HFW to selected areas of the flexible fibrous material using a hot melt adhesive (40);

- wherein the overlay has lines (25, 26) of discrete welding areas (30) which are separated by spaces (31).

BRIEF DESCRIPTION OF THE DRAWINGS

The following description and the accompanying drawings referred to therein are included by way of non-limiting example in order to illustrate how the invention may be put into practice. In the drawings:

Figure 1 is a plan view of a car mat;

Figure 2 is a top view of a first HFW tool for use in a method of manufacturing the car mat;

Figure 3 is a detailed section III-III through part of the HFW tool of Fig . 2;

Figure 4 is a side view of the section III-III looking from the left in Fig. 3;

Figure 5 is is a top view of a second HFW tool for use in a method of manufacturing the car mat;

Figure 6 is a diagrammatic section through part of the first HFW tool together with the various layers which are used in a method of manufacturing the car mat;

Figure 7 is a section through a third HFW tool for use in a method of manufacturing the car mat; and

Figure 8 is is a diagrammatic section through part of the third HFW tool together with the various layers which are used in a method of manufacturing the car mat.

DETAILED DESCRIPTION OF THE DRAWINGS

It should firstly be noted that the sectional drawings included herewith are diagrammatic and are not necessarily in proportion. Referring firstly to Fig.1, the drawing illustrates a typical car floor mat 1 having a base layer 2 of flexible fibrous carpet material which, in one embodiment, may comprise polyester fibres bonded to a rubberised backing sheet. The base layer is pre-cut to a defined peripheral profile to fit in the foot well of a vehicle, but the required profile may vary considerably from one vehicle to another. The mat could also be configured to fit in the boot, or a moulded boot liner, of the vehicle. In this embodiment the upper surface of the base layer 2 is partially covered by an overlay 3 to provide an additional durable covering in areas which are most likely to suffer wear and soiling. These areas will also vary from one vehicle to another, but in the illustrated embodiment there is a peripheral area 4 which lies underneath the foot pedals of the vehicle and an inset area 5 which lies at the bottom of the foot well. In the area 4 the overlay 3 extends right up to one continuous peripheral edge portion of the base layer 2, but in other embodiments the overlay could extend between two or more separate edge portions of the base layer. The inset area 5 may comprise one or more discrete areas arranged in a pattern to match or compliment the trim pattern of the vehicle. None of the discrete areas within the inset area 5 adjoin the peripheral edge of the base layer 2. The peripheral edges of the mat are covered with an edge binding 6 which extends around the entire periphery of the base layer 2. The binding may be attached by sewing or other appropriate means, providing a neat finish to the mat and neatly covering the rough cut edges at the periphery of the mat.

To manufacture the mat 1 the base layer 2 is first pre-cut to the required peripheral profile using a suitable die or template. The overlay 3 from which the areas 4 and 5 are formed may comprise one or more sheets of hard-wearing non-porous waterproof polymer sheet, preferably a vinyl material, particularly polyvinyl chloride (pvc), and vinyl co-polymers. The overlay 3 may have at least one surface which is textured to mimic the creases and pits found in real leather. The piece or pieces of overlay 3 are bonded to the base layer 2 using a hot melt adhesive and high frequency welding (FIFW). The processes involved in attachment of the peripheral area 4 and inset area 5 are somewhat different, and each will now be described in detail.

PERIPHERAL AREAS:

The peripheral areas 4 are produced using a first purpose-made HFW tool, an embodiment of which is shown in Fig. 2. The HFW tool 20 is of a suitable size and shape to cover the peripheral area 4, extending beyond the peripheral areas of the base layer 2. A single tool which is larger than the peripheral area 4 of the largest mat to be produced can be used with any smaller mat. The tool shown in Fig. 2 has three straight edges 21-23 and a fourth edge 24 which is shaped to form a curved edge 4A which extends across the base layer, as seen in Fig. 1. In this embodiment part of the curved edge 24 which extends between the points X and Y forms the curved edge 4A but it will be appreciated that this can be varied depending on the desired shape of the peripheral area 4. It will be noted that the upper contact surface of the tool 20 also incorporates an intersecting pattern of two sets of parallel lines 25 and 26, Fig. 2, with circles 27 formed at each of the points of intersection. When viewed in greater detail as in the sectional views of Fig.s 3 and 4, it can be seen that the lines 25, 26 each comprise two parallel rows 28 and 29 of flat-headed castellations 30. The castellations all end on a common plane A together with the circles 27. The castellations 30 and circles 27 form active welding areas which are separated by inset non-active areas or lands 31. These rows of castellations 30 help to secure the overlay to the base layer and closely mimic the intersecting rows of stitching which are often found on real and simulated leather vehicle trims.

Although the die having a pattern shown in Fig.s 2-4 is preferred other patterns can be used. For example, Fig. 5 shows a second die 36 which has raised hexagonal areas crating a peripheral area 4 with a 3-dimensional honeycomb pattern. Again, the lines 37 which create the hexagonal pattern may be formed by raised active welding areas with rows of castellations and intervening non-active lands 38.

Fig. 6 shows how the HFW die of Fig.s 2-4 is used in forming a peripheral area 4. The various layers are shown separated for clarity but they are of course in contact during the welding process. A suitably sized piece of the overlay 3 is laid onto an appropriate area of the FIFW die 20. Where the overlay has a surface which is textured to mimic real leather this is placed face down in contact with the FIFW die. A hot melt adhesive laminate sheet 40 is placed on top of the piece of overlay 3.

The pre-shaped base layer 2 is placed onto the hot melt adhesive laminate sheet 40 with its fibrous surface downwards, and the position of the mat is carefully adjusted so that the required peripheral area 4 covers the appropriate portion of the HFW die 20 with the overlay 3 and adhesive laminate 40 interposed.

A metal contact plate 42 is placed onto the article above the HFW die 20 to direct energy through the die and prevent arcing during the welding process. High frequency electrical current is then passed through the HFW die to melt the hot melt adhesive laminate 40 and bond the overlay 3 to the corresponding overlying areas of the base layer. During this process the raised active areas 30 of the die press the overlay 3 into the fibrous surface of the base layer 2 and areas of the overlay which overlie the non-active areas 31 of the die maintain a greater separation from the backing material of the base layer.

When the bonding process is complete the edges of the overlay 3 which overhang the shaped peripheral edge of the base layer are trimmed off.

It will be appreciated that the overlay 3 could extend up to the entire periphery of the base layer 2, covering the entire upper surface of the base layer, for example, where a particular application requires the entire top surface of the mat to be water-repellent.

INSET AREAS :

The inset area 5 is produced using a different HFW tool, and embodiment of which is shown in the cross-sectional view of Fig. 7. In this case the HFW tool 50 is of a suitable size and shape to cover an inset area 5 lying entirely within, and inset from, the peripheral areas of the base layer 2. A single tool which is smaller than the periphery of the smallest mat to be produced can be used with any larger mat. The tool shown in Fig. 7 has a continuous relatively sharp edge 51 which is shaped to bite into the sheet of overlay 3 during the HFW welding process. Although one edge 51 is shown in the drawing it will be appreciated that the tool may have a number of such edges to define several discrete sections of the inset area 5. Within the continuous edge 51 there is a recessed non-active area or land 52. In some embodiments the lands 52 may incorporate flat-topped active welding areas 53 which are raised above the lands 52 ending on a common plane A. These active welding areas do not project above the continuous cutting edge 51, but they form patterns within the individual sections of the inset area 5, such as the circles seen in Fig. 1, and help to secure the overlay to the base layer.

Fig. 8 shows how the HFW die 50 is used in forming the inset area 5. A suitably sized piece of the overlay 3 is laid onto an appropriate area of the HFW die 50. Where the overlay has a surface which is textured to mimic real leather this is placed face down in contact with the HFW die. A hot melt adhesive laminate sheet 40 is placed on top of the piece of overlay 3. The pre-shaped base layer 2 is placed onto the hot melt adhesive laminate sheet 40 with its fibrous surface downwards, and the position of the mat is carefully adjusted so that the required inset area 5 covers the appropriate portion of the HFW die 20 with the overlay 3 and adhesive laminate 40 interposed. A metal contact plate 42 is placed onto the article above the HFW die 50 to direct energy through the die and prevent arcing during the welding process. Electrical current is then passed through the HFW die to melt the hot melt adhesive laminate 40 and bond the overlay 3 to the corresponding overlying areas of the base layer. During this process raised active areas 53 of the die press the overlay 3 into the fibrous covering of the base layer, and areas of the overlay which overlie the non-active areas 52 of the die maintain a greater separation from the backing material of the base Iayer2.

In the course of the welding process the cutting edge 51 bites into the overlay 3 producing a line of weakness which defines the individual sections of the inset area 5. When the bonding process is complete the portion of the overlay 3 lying outside the individual sections of the inset area 5 can be torn away leaving just the required inset areas themselves which are firmly bonded to the base layer.

To finish the mat the edge binding 6 is attached around the periphery of the mat using sowing or other means of attachment. Apart from enhancing the appearance of the mat in a manner which can closely mimic or complement real leather, the overlay provides a tough, waterproof wearing surface which enables the most used areas of the mat to be kept clean and dirt-free, being easily wiped clean with a damp cloth. The manufacturing process also enables the overlay to be applied to a multitude of shapes and configurations of mat using just one or two HFW tools, without requiring a different set of tools to be produced for each mat. The design of the mat may be enhanced by using an overlay of a different colour from the base layer. For example, the base layer may be red and the overlay black. The invention also enables printed matter to be applied to the overlay if desired, using suitable vinyl printing techniques.

The configuration of the die described in relation to Fig.s 2-4 ensures that an effective bond is achieved between the overlay and the base mat whilst ensuring that portions of the die which lie outside the periphery of the base mat are not subject to any risk of arcing, overheating or wasted energy during the welding process.

Whilst the above description places emphasis on the areas which are believed to be new and addresses specific problems which have been identified, it is intended that the features disclosed herein may be used in any combination which is capable of providing a new and useful advance in the art.