VEHICLE TRIM ELEMENT

Description

[0001] The present invention relates to a vehicle trim element, in particular for motor vehicles, and a method for manufacturing such a trim element.

[0002] Vehicle trim components made from a blend of polypropylene and glass fibers (also known as Sommold) are already known in the prior art. Such trim components exhibit very good mechanical properties but also present some drawbacks due to the presence of glass fibers. Specifically, the glass fibers can form sharp edges and / or white lines that detract from the trim component's appearance. Furthermore, a blend of polypropylene and glass fibers is typically difficult to recycle. A vehicle trim component using polypropylene fibers is disclosed in document FR 2155798 A1.

[0003] The present invention aims in particular to offer an alternative to Sommold, remedying the aforementioned disadvantages, while presenting satisfactory mechanical characteristics.

[0004] To this end, the invention relates in particular to a vehicle trim element, especially for motor vehicles, comprising: a first structural layer formed from a mixture of first polyethylene terephthalate fibers bonded together by a polyethylene copolymer binder, and a second facing layer entirely formed from second polyethylene terephthalate fibers, characterized in that a portion of the second fibers of the second layer extend into the first layer and are bonded with the first fibers of the first layer by the polyethylene copolymer binder.

[0005] The trim element according to the invention is entirely formed of recyclable polymers, more particularly of polyethylene terephthalate fibers (in both layers), and polyethylene copolymer binder.

[0006] The bond between the two layers is achieved in an original way, surprisingly allowing a bond with satisfactory mechanical strength.

[0007] The trim element according to the invention therefore exhibits good mechanical properties despite the absence of glass fibers, while avoiding any of the drawbacks usually associated with the presence of such glass fibers. In particular, since the trim element is made solely of PET and coPET fibers, it has very good recyclability.

[0008] A trim element according to the invention may further have one or more of the following characteristics, taken alone or in any technically feasible combination: The trim element comprises a reinforcement embedded in the first layer, the reinforcement being selected from: continuous polyethylene terephthalate fibers bonded together with a polyethylene copolymer binder, continuous polyethylene terephthalate fibers bonded together without a binder, and a polyethylene terephthalate film. The trim element comprises a third layer, for example, polyethylene terephthalate foam, bonded to the first layer, for example, by gluing. The trim element forms a rear parcel shelf for a motor vehicle. The second fibers are bonded together by needle punching.

[0009] The invention also relates to a method for manufacturing the trim element as defined above, comprising: the supply of a web intended to form the first layer, the web being formed of a mixture of first polyethylene terephthalate fibers and bonding fibers at least partially of polyethylene copolymer, the supply of the second layer formed of the second pre-needled fibers, the superposition of the web with the second layer, the needle-needling of the web and the second layer together, the needle-needling being carried out through the second layer, from the second layer towards the web, with a needle-needling depth greater than the thickness of the second layer, so that a part of the second fibers penetrates the web, the heating of the web and the second layer to at least the melting temperature of the polyethylene copolymer, the cooling during which the polyethylene copolymer cools and hardens, forming a binder for the first fibers and for the part of the second fibers which have penetrated the web.

[0010] A manufacturing process according to the invention may further have one or more of the following characteristics, taken alone or in any technically feasible combination: The bonding fibers each consist of a polyethylene terephthalate core surrounded by a polyethylene copolymer sheath. The blanket is made of a mixture containing between 30 and 60% bonding fibers by mass and between 40 and 70% primary fibers by mass. Heating is achieved by blowing hot air through the blanket and the second layer. Reinforcement is integrated into the blanket during its delivery.

[0011] The invention also relates to a method of manufacturing the trim element as defined above.

[0012] Various aspects and advantages of the invention will be highlighted in the following description, given solely by way of non-limiting example and with reference to the attached figures, among which: [ Fig 1 ] There figure 1 is a schematic cross-sectional view of a trim element according to a first example of an embodiment of the invention; [ Fig 2 ] There figure 2 is a detail of the figure 1 ; Fig 3 ] There figure 3 is a schematic cross-sectional view of a trim element according to a second embodiment of the invention; [ Fig 4 ] There figure 4 is a schematic cross-sectional view of a trim element according to a fourth embodiment of the invention.

[0013] We have schematically represented, on the figure 1 , a trim element 10, intended to equip a vehicle, in particular a motor vehicle.

[0014] The trim element 10 forms, for example, a rear parcel shelf for a motor vehicle. It should be noted that the invention can be applied equally to any other vehicle trim element.

[0015] The trim element 10 has a first face 12 and a second face 14 opposite the first face 12. For example, the second face 14 is an exterior face, intended to be visible to a user, and the first face 12 is an interior face, generally hidden from the user.

[0016] The trim element 10 comprises a first layer 16 and a second layer 18. The first layer 16 extends in thickness between the first face 12 and an interface 20 with the second layer. The second layer extends in thickness between the interface 20 and the second face 14.

[0017] The first layer 16 is a structural layer formed from a mixture of first 22 polyethylene terephthalate (PET) fibers bonded together by a binder 24 in polyethylene copolymer (coPET).

[0018] The second layer 18 is a facing layer made entirely of second polyethylene terephthalate (PET) fibers 26. These second fibers 26 are, for example, bonded together by needle punching. The term "facing layer" refers to this second layer 18, which is primarily intended to be visible to the user.

[0019] According to the invention, part of the second fibers 26 of the second layer 18 extend into the first layer 16 and are linked with the first fibers 22 of the first layer 16 by the coPET binder 24.

[0020] It should be noted that, in accordance with a second embodiment shown on the figure 3 , the first layer 16 includes a reinforcement 28.

[0021] For example, reinforcement 28 is integrated into the first layer using a process similar to that described in FR3 051 711.

[0022] This reinforcement 28, for example, is made of continuous PET fibers, notably with a length greater than 20 cm. These continuous fibers are, for example, bonded by a coPET binder.

[0023] Alternatively, reinforcement 28 is formed by a PET film.

[0024] According to another variant, reinforcement 28 is formed by a powder.

[0025] The reinforcement 28 adheres to the first layer 16 by means of the binder 24.

[0026] The presence of such a reinforcement 28 makes it possible to significantly improve the mechanical properties of the lining element 10, at the cost of a slight increase in mass.

[0027] In accordance with a third embodiment, shown in the figure 4, the trim element 10 has at least a third layer 30 assembled to the first layer 16.

[0028] The third layer 30, for example, is formed by a PET foam.

[0029] This third layer 30 is for example attached to the first face 12 by gluing, using a layer of glue 32.

[0030] Optionally, the third layer 30 forms a spacer between the first layer 16 and a fourth layer 34, also glued to the third layer 30 by a layer of glue 32.

[0031] A manufacturing process for the trim element 10 will now be described.

[0032] The manufacturing process includes a first step of preparing the first layer 16, in the form of a sheet.

[0033] For this purpose, a mixture of the first 22 polyethylene terephthalate (PET) fibers is made with bonding fibers, at least partially in polyethylene copolymer (coPET).

[0034] Advantageously, the bonding fibers are of the "bi-component" type, consisting of a PET core surrounded by a coPET sheath. Alternatively, the bonding fibers are made entirely of coPET.

[0035] Preferably, the linking fibers have a lower title than the first fibers 22. For example, the linking fibers have a title of about 4 dTex, and the first fibers a title of about 11 dTex.

[0036] Preferably, the mixture comprises between 30 and 60% by mass of linking fibers and between 40 and 70% by mass of first fibers 22. For example, the mixture comprises 50% linking fibers and 50% first fibers 22.

[0037] The mixed fibers are then layered and carded in the conventional way to obtain the aforementioned layer.

[0038] The manufacturing process also includes a second step of preparing the second layer 18.

[0039] This second layer 18 is formed from the second pre-needled fibers 26. These second needled fibers 26 are thus intertwined in a conventional manner, to give structural coherence to the second layer 18.

[0040] The manufacturing process then includes a third step of superimposing the layer with the second layer 18.

[0041] Following this layering step, the manufacturing process includes a fourth step of needle punching the web and the second layer 18 together. Needle punching is carried out through the second layer 18, from the second layer 18 towards the web, with a needle punching depth greater than the thickness of the second layer 18.

[0042] Thus, a portion of the second fibers 26 of the second layer 18 is drawn into the web and becomes entangled with the first fibers 22 and the connecting fibers. The web and the second layer 18 are thus joined together.

[0043] The manufacturing process then includes a fifth step of heating the assembly to at least the melting temperature of the coPET in the bonding fibers. It should be noted that the melting point of coPET (approximately 110 to 120°C) is lower than the melting point of PET (approximately 250°C), so the coPET can melt without damaging the PET fibers, particularly the first fibers 22, the second fibers 26, and the cores of the bonding fibers.

[0044] If good creep resistance at high temperatures is required (especially above 90°C), a high-temperature coPET should be chosen, with a melting point, for example, between 175 and 185°C. This melting point, however, remains lower than that of PET. This is the case, for example, when the trim component is intended to be subjected to high temperatures, such as a rear parcel shelf in a motor vehicle.

[0045] The use of PET-core bonding fibers is particularly advantageous because, after the coPET is melted, these PET cores remain intertwined with the first fibers 22 and the second fibers 26 that were inserted into the first layer by needle punching. Furthermore, these PET cores remain perfectly embedded in the coPET, since the latter surrounded these cores before melting. The mechanical strength of the resulting element is therefore better than in the case where the bonding fibers are entirely made of coPET.

[0046] This heating stage is preferably carried out by passing hot air through the layer and the second layer. Alternatively, this heating stage is carried out by contact with hot plates, the heat in this case being transferred by conduction.

[0047] The assembly can then be placed in a heated mold to thermoform the element. Preferably, the heated mold is regulated at a low temperature.

[0048] The manufacturing process then includes a sixth cooling step, during which the coPET cools and therefore hardens. The coPET thus forms a binder for the first fibers 22, the PET cores (which will hereafter be considered as part of the first fibers), and, according to the invention, for the second fibers 26 which have been inserted into the first layer by needle punching.

[0049] The bonding between the first and second layers is therefore ensured by these second fibers 26 linked to the first fibers 22 by the binder 24.

[0050] It thus appears that, according to the invention, the bonding between the first and second layers is achieved simultaneously with the formation of the structure created by the first layer. Furthermore, this bonding does not require the addition of glue or any other binding agent.

[0051] It should be noted that, since the second layer does not contain a binder, it has a better appearance and feel after cooling than the first layer. The second layer remains abrasion-resistant, however, due to its needle punching during the fourth punching stage.

[0052] It should be noted that, in the case of the second embodiment, the reinforcement 28 is integrated into the first layer 16 during the production of the sheet intended to form this first layer.

[0053] Furthermore, in the third embodiment, the third layer 30 is bonded to the first surface 12 after the cooling step. Another layer of PET fibers bonded with a coPET binder can then also be bonded to this third layer 30.

[0054] It appears that a trim element 10 according to the invention has sufficient mechanical properties for usual applications.

Claims

1. A trim element (10) for a vehicle; in particular an automotive vehicle, comprising: - a first structural layer (16) formed of a mixture of first polyethylene terephthalate fibres (22) bound together by a binder (24) in polyethylene copolymer, and - a second facing layer (18) entirely formed of second polyethylene terephthalate fibres (26), - a portion of the second fibres (26) of the second layer (18) extending into the first layer (16) and being bound with the first fibres of the first layer by the binder in polyethylene copolymer.

2. The trim element (10) according to claim 1, comprising a reinforcement (28) embedded in the first layer (16), the reinforcement being chosen from among: - continuous fibres of polyethylene terephthalate bound together by a binder (24) in polyethylene copolymer, - continuous fibres of polyethylene terephthalate bound together without binder, - a film of polyethylene terephthalate.

3. The trim element (10) according to claim 1 or 2, comprising a third layer (30), for example a polyethylene terephthalate foam secured onto the first layer (12) for example by bonding.

4. The trim element (10) according to any of the preceding claims, forming a rear window shelf of an automotive vehicle.

5. The trim element (10) according to any of the preceding claims, wherein the second fibres (26) are bound together by needle punching.

6. A method for manufacturing the trim element (10) according to any of the preceding claims, comprising: - providing a web intended to form the first layer, the web being formed of a mixture of first polyethylene terephthalate fibres (22) and binding fibres at least partially in polyethylene copolymer, - providing the second layer (18) formed of the second pre-needle punched fibres (26), - superimposing the second layer (18) over the web, - needle punching the web and second layer (18) together, needle punching being performed through the second layer (18), from the second layer (18) towards the web, with a needle-punching depth greater than the thickness of the second layer (18) so that a portion of the second fibres penetrates the web, - heating the web and second layer (18) at least up until the melt temperature of the polyethylene copolymer. - cooling, whereby the polyethylene copolymer cools and hardens forming a binder for the first fibres (22) and for the portion of second fibres (26) having penetrated the web.

7. The manufacturing method according to claim 6, wherein the binding fibres are each formed of a core in polyethylene terephthalate surrounded by a sheath of polyethylene copolymer.

8. The manufacturing method according to claim 6 or 7, wherein the web is formed of a mixture comprising between 30 and 60 % by weight of binding fibres and between 40 and 70 % by weight of first fibres (22).

9. The manufacturing method according to any of claims 6 to 8, wherein heating is performed by blowing hot air through the web and the second layer (18).

10. The manufacturing method according to any of claims 6 to 9, wherein a reinforcement (28) is integrated in the web when providing said web.