FR2679586A1 - Impermeable (sealing) film for swimming pools (splash-pools, fish-ponds) - Google Patents

Abstract

This film is equipped at its edge with a fastening heel-piece made of plastic, which is constituted by a strip (2), the cross-section of which is compact and which has a plane face (20) via which it is bonded directly to the edge (10) of the film (1), so that, after fitting in the swimming pool, the fastening heel-piece is invisible. Equipment for swimming pools.

Description

POOL SEALING FILM
The present invention relates to a sealing film for swimming pools, and more specifically to a sealing film whose edge is provided with an attached hooking heel, made of plastic.

Some swimming pool models are lined with a sealing film, which is fixed to the wall of the swimming pool by means of a hooking heel welded to the edge of the film. This attachment heel has a bead portion capable of engaging in the slot of an attachment profile fixed to the upper part of the wall of the swimming pool, generally just under the coping.

 Traditionally, this heel is a plastic tape obtained by extrusion and the cross section of which has two very distinct parts, namely a thin part used for welding the heel to the film and a compact part - bulge constituting the bead properly said.

 Figure 1 shows, in section, a heel 7 of known type. Its section has the general shape of a "P". The branch 71 of this "P" forms a strip which is welded to the edge of the film 1. Welding is generally obtained under the combined action of pressure and heat, generated by a high frequency electric field, the materials plastics constituting the film 1 and the heel 7 are of course chosen to be compatible with welding.

 The bulge of the "P", referenced 70, is used for the subsequent mounting of the film in the pool, this bulge being intended to cooperate with the attachment profile of the pool.

 This known technique has a number of drawbacks.

 First, the assembly of the heel to the film, in the workshop, is delicate. In this regard, it should be noted that the extruded ribbons are supplied in rolls, these rollers being progressively unwound during assembly. The shape of the "P" section of the ribbon, which associates a compact part 70 with a thin part 71, has the effect of causing deformations in curling and twisting of the ribbon at the time of its unwinding. This makes assembly difficult, leading to misalignments which cause poor welding in certain places.

 Furthermore, the end-to-end connection of the two ends of the film (after a full turn) is very delicate at the heel, since it requires a certain overlap of the two ends for reasons of good sealing.

 Indeed, the two edges of the film are welded to each other with a certain overlap. At the hooking ribbons, it is necessary to cut the bulged part of one of them so that it can be joined end to end against the bulged part of the other. On the other hand, the fixed part of the ribbon is not cut so that it can be welded with overlap to that of the other.

 We understand that this method is unsatisfactory because it is difficult to implement, unreliable, and gives aesthetic results. The butt welding of the two bulged parts is delicate, so that it is often not carried out, and this results in an interruption of the welding at this level.

 In the known technique, there is also a problem related to the pressure developed by the tools (electrodes) at the time of welding, which generates a weakening of the material located in the transition zone between the tape and the film, zone where one passes. from one to two thicknesses of material. This zone will constitute a line of initiation of rupture likely to appear sometimes at the time of the impoundment of the swimming pool.

 Another problem is related to the fact that the non-welded portion of the strip 71, that is to say the part which protrudes above the edge of the film, as well as the weld line, remain visible after the laying of the film. in the swimming pool.

 There is therefore a solution of continuity which is awkward from an aesthetic point of view, all the more so since it is practically impossible to obtain for the two elements strictly identical colors, since they are obtained by different processes and, correlatively, generally come from different suppliers.

 Another difficulty, also linked to the disparity of colors, is that the manufacturer of the finished sealing films, which assures the heel on the film, is obliged to have a stock of heels of different colors, corresponding to that of movies. This results in additional production costs.

 In general, significant progress has been made in the quality of the plastic materials making up the sealing film. These films are designed to effectively resist the aggression of external agents such as the sun, chlorine, fatty substances, etc., which allows manufacturers to grant a ten-year guarantee. It is not the same for the quality of the (less noble) materials constituting the attachment heel, which is exposed to the same aggressive agents, and constitutes a weak "link" in the sealing film / heel assembly. hanging.

 The invention aims to overcome these various drawbacks.

 To this end, it offers a new type of sealing film, the edge of which is provided with a plastic hooking heel, this film being remarkable for the fact that the hooking heel is a rod whose cross section is compact and has a flat face by which it is welded directly to the edge of the film, so that after mounting in the pool, the hooking heel remains hidden.

 This cross section is for example substantially rectangular. The flat face may have ridges, or other roughness, improving its bond with the film.

 The characteristics and advantages of the invention will appear from the description and the appended drawings which show preferred embodiments thereof.

On these drawings
- Figure 1 shows, as already said above, a device of known type
- Figure 2 is a schematic view in section, intended to illustrate the operation of assembling a heel on a sealing film in accordance with the present invention
- Figure 2A shows (in section) a variant of the heel of Figure 2
- Figure 3 shows the sealing film thus obtained
- Figure 4 shows the film of Figure 3 hung on the wall of a swimming pool
- Figure 5 is a variant of the embodiment of Figure 3.

 In Figure 1 is designated by the reference 1 the border area of a sealing film of plastic, for example polyvinyl chloride (PVC). Its thickness is for example 0.8 mm.

 The hooking heel 2 is in the form of a rod of rectangular cross section. As an indication, its thickness e is of the order of 2 to 3 mm, while its width 1 is of the order of 10 mm.

 The rod 2 is made of a semi-rigid plastic material, having good compatibility with the plastic material constituting the film 1. Furthermore, the two materials can be identical.

 The tool used for high-frequency welding of the heel 2 on the film 1 comprises a rigid base 3 in which a rectilinear groove 30 is hollowed out. The shape of the groove corresponds to that of the rectangular heel 2, so that it is possible to place the rod in the groove in order to obtain good precision in the relative positioning of the heel relative to the film 1. The tool also includes a pressing tool 4 and means generating a high-frequency electric field (not shown); for this the base 3 and the tool 4 are designed in the form of two electrodes between which the high frequency current passes and, in a well known manner, are capable of heating the materials inserted between them. The rod 30 having been placed in the groove 30, the operator positions the edge 10 of the sealing film 1 above the upper face 20 of the rod. The tool 4 is then lowered, as symbolized by the arrow F in FIG. 2. As a result of the pressure and the molecular agitation due to the high-frequency field, which generates heat, there is a welding of the shore 10 with face 20.

 This operation, which only concerns a certain length of film (and heel), is repeated step by step over the entire periphery of the sealing film 1.

 It should be noted that the active face 40 of the electrode, which comes to bear against the film 1, has a width 1 'smaller than the width 1 of the heel 2. The difference between these two widths is for example 1 '' order of 2 mm. Thanks to this arrangement, there is no weakening line (starting point) on the edges of the weld zone.

 An assembly is obtained as shown in FIG. 3 in which the heel of compact section 2 is directly fixed by its flat face 20 to the edge of the film 1. The outer edges 21 of the heel 2 and 10 of the film 1 are substantially in coincidence.

 FIG. 4 shows the internal upper part of the wall of a swimming pool equipped with the sealing film of FIG. 3. This wall 5, for example made of concrete, carries on its upper face a fastening device 6 of the film 1. As is well known, the device 6 has a small vertical flange 61 and a horizontal tab 60 which delimit a space intended to receive and trap the latching heel 2. It will also be noted that on the internal face of the wall 5 is arranged a rigid plate 50, perfectly flat, serving as a support for the film 1.

 As can be understood from the simple observation of FIG. 4, once the film 1 has been placed in the pool, the heel 2 is completely hidden, invisible to all. All the problems mentioned above which are due to the disparity of colors between the heel and the film are therefore eliminated. The heel is sheltered from aggressive external agents (sun, chlorine, fatty substances, etc.) and therefore does not compromise the lifespan of the whole.

 The other drawbacks encountered during welding are also eliminated thanks to the invention. Indeed, because the heel 2 has the shape of a rod of compact section, it unwinds regularly without curling or twisting and can be deposited correctly in the receiving groove 30 of the base 3. The end-to-end connection of the two ends of the film do not pose any problems either since at the level of the hooking heels, there is no real sealing problem, the heel being entirely outside the pool, inside the device hanging 6.

 A possible weld defect has no unfortunate consequences in terms of the retention of the film in the pool or, of course, in terms of sealing.

 In the variant of the heel shown in FIG. 2A, the face 20 has surface ridges 200 whose role is to improve the quality of connection by welding with the film 1. For the same purpose, ridges or other surface roughness could be provided on the active face 40 of the electrode 4.

 FIG. 5 shows a variant in which the hooking heel 2 ′ is constituted by a rod of elongated cross section with rounded ends. As in the previous case, this strip has a compact section, that is to say without a thin part, and has a face 20 ′ by which it is welded directly to the edge 10 of the film 1.

 Other shapes can of course be envisaged for the section of the rod, provided that the latter is compact and has a flat face ensuring its attachment to the film 1.

 The connection between the strip and the film does not necessarily take place by actual welding, intermediate agents which can be used such as solvents or glue.

Claims (4)

 1. Sealing film for swimming pools, the edge of which is provided with a plastic hooking heel, characterized in that this hooking heel is a rod (2, 2 ′) whose cross section is compact and which has a flat face (20, 20 ′) by which it is welded directly to the outer face of the edge (10) of the film (1), so that after mounting in the pool, the heel (2, 2 ') remains hidden.  2. Sealing film according to claim 1, characterized in that the cross section of the strip (2) is substantially rectangular.  3. Sealing film according to one of claims 1 or 2, characterized in that said flat face (20) has ridges, or other roughness, improving its connection with the film (1).  4. Sealing film according to one of claims 1 to 3, characterized in that the heel (2, 2 ') is fixed to the film (1) by high-frequency welding.