The present invention relates to a structural element for a body made of mould, and to a making process of said element, of the type specified in the preamble to the first claim. In particular, the present invention relates to a structural element intended mainly, but not exclusively, to be associated with a body defined by a padding for a seat, or for an arm rest or for a headrest, and capable of allowing the attachment of sensory means to the body. As is well known, on bodies, elements or components made in moulds and destined for the realisation of seats, above all in the automotive sector, half sensors are often arranged, from the simplest presence detection sensors used, conveniently, to verify that seat belts have been fastened, to the most complex ones for detecting biological parameters. These sensors are conventionally positioned on the seat padding. The latter is usually made by moulding polyurethane foam into preformed moulds.

Since the padding is generally covered with an anti-adhesive material, which facilitates the removal of the padding from the mould, the sensors embedded in the padding tend to move relative to the body when the seat is in use. The conventional moulding techniques therefore allow bodies to be made with sensor constraining elements that can, when those elements move, be functionally compromised.

For this reason, the detectors are normally connected to flexible supports which are at the same time anchored to the seat by unresolvable constraint means, for example by stitching. Alternatively, the connecting elements between the body and the sensor means may comprise an adhesive support comprising a support layer, e.g. non-woven fabric, on which is arranged a second layer of adhesive material covered by a removable protective strip or film. On the opposite side of the removable film, a layer consisting of iron-poor encapsulating resin is then deposited.

Before the polyurethane foam is inserted into the mould, the adhesive support is introduced into the mould.

The support is then held in the desired position by magnets placed in the mould in such a position as to attract the iron powder and force the support against the surface of the mould.

Following the insertion of the foam, the support material, resin and iron powder are incorporated and retained. In detail, the layer of resin and iron powder remains trapped between the first layer of non-woven fabric and the padded body incorporating the element.

The manufacturing method just described, although very widespread, has some disadvantages.

First of all, inside the mould, since the iron powder and the magnets are spaced out, the retention effect of the magnets is influenced not only by the distance between them but also by the presence of the materials between them, so that the magnets are not always able to keep the adhesive support in the desired position.

In order to increase the force of attraction, the quantity of iron powder present in the resin can be increased, but this results in an inevitable increase in the stiffness of the support material-resin-iron powder assembly which, due to the fact that it is incorporated in the moulded body, locally and unacceptably diminishes the sensation of softness of the seat.

In order to overcome these inconveniences, an element and relative process described in patent application T02005A000870 has been developed.

Essentially, said application describes an adhesive support for attaching parts to a body made of mould, comprising a support and attachment body, a layer of adhesive material disposed over an extended surface of the support and attachment body, and a removable protective portion of the adhesive material layer including a retention material layer and a ferromagnetic material carried by the retention material layer.

The known technique described herein includes some important drawbacks. In particular, the structural element as described in T02005A000870 may be subject to inadvertent separation of the protective layer from the adhesive layer when the magnets are placed in the mould.

Furthermore, the fabrication of the protective layer may not be simple and not economical since specific materials must be used in sufficient quantities to ensure the desired seal.

In this situation, the technical task at the basis of the present invention is to devise a structural element for a body made of mould, and a relative procedure for making said element, capable of substantially obviating at least part of the aforementioned drawbacks. In the context of said technical task, it is an important scope of the invention to obtain a structural element for a body made of mould, and a making process for said element, which is sufficiently robust, but soft and flexible, and which guarantees a correct and efficient adhesion between the protective layer and the adhesive layer in order to avoid, above all, detachments when the magnets are placed in the mould. Another important scope of the invention is to realise a structural element for a body made of mould, and a process for making said element, which is simple to make and economical.

The technical task and the specified purposes are achieved by a structural element for body made of mould, and a making process of said element, as claimed in the annexed claim 1 .

Preferred technical solutions are highlighted in the dependent claims.

The features and advantages of the invention are hereinafter clarified by the detailed description of preferred embodiments of the invention, with reference to the appended drawings, wherein: the Fig. 1 illustrates a side section view of a structural element for body made of mould according to the invention; the Fig. 2 illustrates a side section view of a structural element for body made of mould according to the invention in which the element is in the mould and is trapped in the body; and the Fig. 3 is a side section view of a body including a moulded body structural element according to the invention in which the protective portion has been removed and sensor means are constrained to it.

In the present document, the measurements, values, shapes and geometric references (such as perpendicularity and parallelism), when associated with words like “about” or other similar terms such as “approximately” or “substantially”, are to be considered as except for measurement errors or inaccuracies due to production and/or manufacturing errors, and, above all, except for a slight divergence from the value, measurements, shape, or geometric reference with which it is associated. For instance, these terms, if associated with a value, preferably indicate a divergence of not more than 10% of the value. Moreover, when used, terms such as “first”, “second”, “higher”, “lower”, “main” and “secondary” do not necessarily identify an order, a priority of relationship or a relative position, but can simply be used to clearly distinguish between their different components. Unless otherwise specified, as results in the following discussions, terms such as “treatment”, “computing”, “determination”, “calculation”, or similar, refer to the action and/or processes of a computer or similar electronic calculation device that manipulates and/or transforms data represented as physical, such as electronic quantities of registers of a computer system and/or memories in, other data similarly represented as physical quantities within computer systems, registers or other storage, transmission or information displaying devices.

The measurements and data reported in this text are to be considered, unless otherwise indicated, as performed in the International Standard Atmosphere ICAO (ISO 2533:1975). With reference to the Figures, the structural element for body made of mould according to the invention is globally referred to as number 1.

The element 1 is suitable for being housed and trapped on a body 10.

The body 10 is preferably a padded element, for example made of polymer foam, possibly polyurethane foam. The element 1 is, advantageously, suitable for allowing sensor means 11 to be constrained on the body 10 within which it is housed.

The sensor means 11 may include, for example, presence detectors used, as is known, for checking that seat belts have been fastened.

In brief, the element 1 comprises at least a first layer 2, a second layer 3 and a protective layer 4. The first layer 2 is essentially a support layer. It may comprise textile, or plastic or other material.

Preferably, the first layer 2 comprises non-woven fabric. More particularly, the first layer includes non-woven fabric preferably made of polypropylene or polyester or other. The second layer 3 is of an adhesive type. In particular, the second layer 3 is integrally constrained to the first layer 2.

Advantageously, the second layer 3 is bound solidly to the first layer 2 by a calendering process. In general, the second layer 3 is constrained to the first layer 2 by pressing the second layer 3 into contact with the first layer 2. The protective portion 4 is substantially removably constrained to the second layer 3. In detail, the protective portion 4 is constrained to the second layer 3 at a side of the second layer 3 opposite to the first layer 2.

Advantageously, the protective portion 4 comprises a first sheet 40 and an external coating 41. The first sheet 40 is substantially a sheet of anti-adhesive paper, in particular silicone paper or polythene paper or otherwise. Therefore, it comprises an anti-adhesive side 40a. Furthermore, the first sheet 40 also comprises a second side 40b textured or anti adhesive.

The textured side 40b is opposite the anti-adhesive side 40a. Thus, the textured side 40b is the side of the first sheet 40 free from silicone coating or similar.

The first sheet 40, in general, may define a specific weight. Preferably, the first sheet has a grammage between 100 g/m2 and 150 g/m2. More specifically, preferably, the first sheet 40 has a grammage of about 130 g/m2.

Advantageously, the external coating 41 is deposited on the first sheet 40 at the textured side 40b. Then, the external coating 41 is deposited by coating a sticky dispersion containing ferromagnetic material.

The ferromagnetic material may be, for example, iron powder.

Even more suitably, the powder of ferromagnetic material may define a maximum sieve size of 120 mesh. Even more suitably, the ferromagnetic material powder may be less than 100 mesh at the sieve.

Thus, the ferromagnetic material may be contained in the sticky dispersion in a weight percentage of between 2% and 6%. Even more in detail, preferably the ferromagnetic material is included in the sticky dispersion in a weight percentage of about 4%. Advantageously, the second layer 3 is made, before being deposited on the first layer 2, by spreading on the first sheet 40.

Preferably, the second layer 3 is made by coating an aqueous dispersion containing a permanent self-adhesive material at the anti-adhesive side 40a.

In particular, the second layer 3 does not cover the entire surface of the anti-adhesive side 40a but leaves a portion, for example about 1 cm, uncovered, preferably from one edge only, so that the operator, when he has to remove the protection of the adhesive in order to then affix the sensor, is facilitated in the operation avoiding the breaking of part of the pieces, detaching, in the attempt to remove the protection, the TNT embedded in the foam, from the foam itself.

The invention comprises a new making process of a structural element 1 .

In the process, it is contemplated to procure a first sheet 40, as previously described. Furthermore, the procedure comprises at least a first coating step, a transfer step and a second coating step.

In the first coating step, a second layer 3 of aqueous dispersion containing a permanent self-adhesive material is coated at the anti-adhesive side 40a.

Preferably, the second layer 3 is coated on the first sheet 40 with a strip squeegee. Furthermore, the first sheet 40 and the second layer 3 are baked following the coating. For example, they may be baked at a temperature of about 140°C, passing through oven at a speed of about 2 m/min.

Then, in the transfer step, the first sheet 40, provided with said second layer 3 following the first coating step, is transferred or arranged on the second layer 2 by pressing the second layer 3 into contact with the first layer 2.

Of course, the pressure can be exerted by any machine known in the state of the art. Preferably, in the transfer step, the first sheet 40 is transferred by calendering onto the first layer 2. Essentially, therefore, the first sheet 40 is calendered on the first layer 2 in such a way that the second layer 3 remains trapped between the first sheet 40 and the first layer 2.

In conclusion, in the second coating step, the external coating 41 of sticky dispersion containing ferromagnetic material is coated on the first sheet 40 in correspondence with the textured side 40b so that the first sheet 40 and the coating 41 realize, altogether, the protective layer 4.

The latter is, of course, removable with respect to the second layer 3.

The second coating step can, therefore, be carried out with a continuous doctor blade. Thus, the layers 2, 3 and the protective portion 4 may also be passed through the oven following the coating. Preferably, the complete element 1 is passed through the oven at temperatures of about 40°C.

The element 1 , as already mentioned, is generally encapsulated in a body 10.

Thus, the invention allows to realize a moulded body 10 comprising the structural element 1 .

In order to realise the body 10, substantially a moulding process already known in the present state of the art can be used. The process may, therefore, provide that the element 1 is inserted inside a mould 100. The mould 100 may be any moulding mould, for example shaped in such a way as to enable a body 10 to be made for the seat.

The element 1 is, therefore, suitable to be made or assembled, prior to being disposed in the mould 100.

Once placed in the mould 100, the element 1 is held in the desired position by one or more magnets 101.

The magnets 101 are, therefore, preferably arranged along a perimeter edge of the element 1 , in particular in correspondence with the cladding 41 so as to efficiently cooperate with the ferromagnetic material, attracting it. Once the positioning is completed, the material defining the shaped body 10 is introduced into the mould 100. Then, the element 1 is progressively embedded in the material of the body 10 itself. When the moulding is completed, the body 10 and the element 1 are removed from the mould, and the protective portion 4 removed leaving the second layer 3 of adhesive material uncovered. In conclusion, the sensor means 11 are connected to the element 1 , and thus to the body 10, by applying a surface of the sensor means 11 to the free surface of the second layer 3.

The moulded structural body element 1 , and a process for making said element, according to the invention achieve important advantages. In fact, the structural element for body made of mould, and relative realization procedure, allow to obtain an element sufficiently strong, but soft and flexible, which guarantees, therefore, a correct and efficient adhesion between the protective portion 4 and the second adhesive layer 3.

Thus, the element 1 makes it possible to avoid, above all, detachments when the magnets 101 are arranged in the mould 100. In addition, the structural element per body made in the mould, and the making process thereof, allow an element to be obtained in a simple and economical manner.

The invention is susceptible to variations within the scope of the inventive concept defined by the claims. Within this scope, all details are substitutable by equivalent elements and the materials, shapes and dimensions can be any.