Headliner structure for a vehicle and method of manufacturing

Abstract

The present invention provides a headliner structure (10) for a vehicle roof. The headliner structure comprises structural pieces (22-1, 22-2, 22-3, 22-4) that are arranged to define all or a portion of a headliner opening corresponding to a roof panel opening (12) in the vehicle roof and overlap along at least a portion of a circumference of the headliner opening, wherein the structural pieces are bonded by molding, and wherein the structural pieces comprise a fiber-reinforced thermoplastic composite material.

Description

[0001] HEADLINER STRUCTURE FOR A VEHICLE AND METHOD OF MANUFACTURING

[0002] TECHNICAL FIELD

[0003] The present invention relates to a headliner structure for a vehicle and a method of manufacturing the headliner structure.

[0004] BACKGROUND

[0005] The invention provides a headliner structure for a vehicle, and a method for its manufacture, wherein the headliner structure has an opening corresponding to an opening in a vehicle roof, wherein the headliner opening is preferably surrounded and stabilized by a reinforcement frame.

[0006] Prior art headliner structures often had been manufactured from fiber-reinforced thermoplastic composite mats that are cut out to provide the headliner opening. This caused high waste of material, inefficient production and created high material costs.

[0007] SUMMARY OF THE INVENTION

[0008] A first aspect of the invention provides a headliner structure for a vehicle roof, wherein the headliner structure comprises structural pieces that are arranged to define all or a portion of a headliner opening corresponding to a roof panel opening in the vehicle roof and overlap along at least a portion of a circumference of the headliner opening, wherein the structural pieces are bonded by molding, and wherein the structural pieces comprise a fiber-reinforced thermoplastic composite material.

[0009] A further aspect of the invention relates to a method for producing a headliner structure for a vehicle roof, the method comprising providing structural pieces, aligning the structural pieces so that the structural pieces at least partially overlap at one or a plurality of respective ends of each structural piece to surround all or a portion of an opening in the headliner structure (which may, e.g., correspond to a vehicle roof opening), and molding (e.g., compression-molding) the structural pieces in the pressing tool to bond the structural pieces together.

[0010] The headliner structure hence is produced from structural pieces, e.g. preferably in the form of elongated components, that surround all or a portion of an opening in the vehicle roof, rather than from a mat of which the opening is cut out. Material used for manufacturing of the headliner structure hence may be reduced and waste production during the manufacturing process is reduced accordingly, thus, production costs maybe saved compared to headliner structures of the prior art.

[0011] BRIEF DESCRIPTION OF THE DRAWINGS

[0012] To illustrate the technical features of various examples of the invention, the accompanying drawings are provided.

[0013] FIG. i shows an exploded view of a headliner structure in accordance with an example.

[0014] FIG. 2 shows a schematic arrangement of structural pieces for a headliner structure in accordance with an example.

[0015] FIG. 2A shows schematic arrangements of structural pieces for a headliner structure in accordance with another example.

[0016] FIG. 2B shows schematic arrangements of structural pieces for a headliner structure in accordance with yet another example.

[0017] FIG. 3 shows a material composition of a structural piece for a headliner structure in accordance with an example.

[0018] FIG. 4 shows a material composition of a structural piece for a headliner structure in accordance with an example.

[0019] FIG. 5 is a flow chart of a method for manufacturing a headliner structure in accordance with an example.

[0020] FIG. 6 is a flow chart of a method for manufacturing a headliner structure in accordance with an example.

[0021] FIG. 7 shows a plan view of a reinforcement frame for a headliner structure in accordance with an example.

[0022] FIGs. 8A and 8B show details of the reinforcement frame of Fig. 7. FIG. 9 is a flow chart of a method for manufacturing a reinforcement frame in accordance with an example.

[0023] FIG. 10 is a flow chart of a method for manufacturing an automotive headliner in accordance with an example.

[0024] DETAILED DESCRIPTION OF EXAMPLES

[0025] The invention is further illustrated below by way of examples with reference to the figures.

[0026] With reference to FIG. 1, a headliner structure 10 for a vehicle comprising a roof panel opening 12 is shown. The headliner structure may be or form an automotive headliner or a part thereof. When the headliner is installed, it preferably encloses all or a portion of a roof window in a vehicle roof, such as a panoramic window or sliding window. The headliner structure 10 has a frontside 20b that faces the interior of the vehicle and a backside 20a that faces the roof panel of the vehicle. A reinforcement frame 14 is preferably attached to the backside 20a of the headliner structure to enclose and stabilize the roof panel opening 12. As can be further taken from FIG. 1, the headliner structure 10 comprises fastening structures for vehicle interior components 18 (which may also be referred to as assembly parts 18) that may be attached to the headliner structure 10. The vehicle interior components 18 may comprise components to be used from or for the vehicle interior, such as handles, lighting elements, foam padding, roof components, fabric or material covering, or support structures that may be attached to the fastening structures.

[0027] The headliner structure as illustrated in FIG. 1 may be constructed from structural pieces that are arranged to preferably surround all or a portion of the roof panel opening 12 and preferably overlap along at least a portion of the circumference of the roof panel opening 12. An example of an arrangement of the structural pieces for the headliner structure 10 is shown in FIG. 2.

[0028] FIG. 2 shows four structural pieces 22-1, 22-2, 22-3 and 22-4 that are arranged to preferably overlap at respective portions (e.g., end portions) of each structural piece 22 (e.g., at corners of the roof panel opening 12) so that they frame the roof panel opening 12. Fig. 2, 2A, and 2B are schematic examples and are not to scale. The width of at least one of the structural pieces 22 may range e.g. between 100 to 600 mm. Examples of the width of the structural pieces are e.g. 100 mm, 200 mm, 300 mm, 400 mm, 500 mm and 600 mm. The length of at least one of the structural pieces 22 may range e.g. between 300 to 3000 mm. Examples of the length of the structural pieces are e.g. 300 mm, 500 mm, 1000 mm, 1500 mm, 2000 mm, 2500 mm and 3000 mm. The width and length eventually shall depend on the targeted headliner geometry. In the example shown in Fig. 2, the structural pieces 22 may be elongated components arranged to enclose the roof panel opening 12 having a square or approximately square shape. However, the roof panel opening 12 may have a geometric shape other than a square shape. The roof panel opening 12 may have a round, oval, rectangular, or a polygonal shape, for example. Depending on the shape of the roof panel opening 12, the shape of the structural pieces that surround the roof panel opening 12 may differ to conform to the different roof panel openings. Therefore, the number of structural pieces 22 may differ from four structural pieces and the shape of the structural pieces 22 may be different from the one shown and does not need to be a rectangular component. For example, two structural pieces each having a crescentshaped cut-out may be arranged to enclose a round roof panel opening.

[0029] Fig. 2 further shows overlap arearegions or portions 24 where preferably, end parts of at least two neighbouring structural pieces 22 overlap. In particular, the structural piece 22-2 overlaps with structural piece 22-1 at one of the overlapping regions 24. Further, the top surface 22-ia of the structural piece 22-1 faces the bottom surface 22-2b of the structural piece 22-2 at the overlapping region 24. The top surface 22-ia and the bottom surface 22-2b of the structural pieces 22-1 and 22-2, respectively, as well as the remaining structural pieces are bonded together at the overlapping regions 24 by molding (e.g., compression-molding) to create a laminated preliminary or intermediate product of the headliner structure. As may therefore be appreciated, one may have at least one overlapping region 24, or a plurality of overlapping regions 24, where it is contemplated that one may have, e.g., in the range of 2-20 overlapping regions 24. With a plurality of overlapping regions 24, it can be appreciated that the geometry of the headliner can be conveniently varied.

[0030] The structural pieces 22 may preferably comprise a fiber-reinforced thermoplastic composite material. In particular, the structural pieces 22 may be cut from a mat or a roll made of (e.g., comprising or consisting of) fiber-reinforced thermoplastic composite material. Further details regarding the structure and composition of the structural pieces 22 are explained with respect to Figs. 3 and 4.

[0031] Fig. 2 shows an example where two neighbouring structural pieces, such as structural pieces 22-1 and 22-2, overlap across their entire width in the overlapping region 24.

[0032] Fig. 2A shows different examples of maximum and minimum overlaps which have been determined based on a compromise between a durable connection of the neighbouring pieces and weight reduction. In other word, the overlap is determined to be as large as necessary to achieve a durable connection and as little as possible in view of weight reduction. Assuming that the width of the structural pieces is between too mm and 600 mm, the overlap may be between 10 mm and too mm, as shown in Fig. 2A.

[0033] The upper left-hand graphic in Fig. 2A shows an example of the headliner structure where at least the upper structural piece 22-1 has a width of too mm and pieces 22-1 and 22-4 overlap by 10 mm. This results in an overlap area 24 of 10 mm x too mm=iooo mm2, which is considered a minimum overlap area advisable to achieve a durable connection. This example is favourable in terms of weight reduction.

[0034] The lower right-hand graphic in Fig. 2A shows an example of the headliner structure where at least the upper structural piece 22-1 has a width of 600 mm and pieces 22-1 and 22-4 overlap by too mm. This results in an overlap area 24 of too mm x 600 mm = 60000 mm2, which is considered a maximum overlap area for achieving a durable connection. This example is less favourable in terms of weight reduction.

[0035] The upper right-hand graphic in Fig. 2A shows an example of the headliner structure where at least the upper structural piece 22-1 has a width of too mm and pieces 22-1 and 22-4 overlap by too mm. This results in an overlap area 24 of too mm x too mm = 10000 mm2, which is considered a medium overlap area for achieving a durable connection. This example is still good in terms of weight reduction.

[0036] The lower left-hand graphic in Fig. 2A shows an example of the headliner structure where at least the upper structural piece 22-1 has a width of 600 mm and pieces 22-1 and 22-4 overlap by 10 mm. This results in an overlap area 24 of 10 mm x 600 mm = 6000 mm2, which is considered a medium overlap area for achieving a durable connection. This example is still good in terms of weight reduction.

[0037] The feasible overlap correspond to 10% to 100% of the possible overlap.

[0038] Fig. 2B shows different examples of preferred maximum and minimum overlaps which have been determined based on a particularly favourable compromise between a durable connection of the neighbouring pieces and weight reduction. In other word, the overlap is determined to be as large as necessary to achieve a durable connection and as little as possible in view of weight reduction. Assuming that the width of the structural pieces is between too mm and 600 mm, the preferred overlap may be between 20 mm and 50 mm, as shown in Fig. 2B. As further explained below, the preferred minimum overlap area may be 2000 mm2and the preferred maximum overlap area maybe 30000 mm2. The upper left-hand graphic in Fig. 2B shows an example of the headliner structure where at least the upper structural piece 22-1 has a width of 100 mm and pieces 22-1 and 22-4 overlap by 20 mm. This results in an overlap area 24 of 20 mm x 100 mm=2OOO mm2, which is considered a preferred minimum overlap area to achieve a durable connection. This example is favourable in terms of weight reduction.

[0039] The lower right-hand graphic in Fig. 2B shows an example of the headliner structure where at least the upper structural piece 22-1 has a width of 600 mm and pieces 22-1 and 22-4 overlap by 50 mm. This results in an overlap area 24 of 50 mm x 600 mm = 30000 mm2, which is considered a preferred maximum overlap area for achieving a durable connection. This example is good in terms of weight reduction.

[0040] The upper right-hand graphic in Fig. 2BA shows an example of the headliner structure where at least the upper structural piece 22-1 has a width of 100 mm and pieces 22-1 and 22-4 overlap by 50 mm. This results in an overlap area 24 of 50 mm x 100 mm = 5000 mm2, which is considered a medium overlap area for achieving a durable connection. This example is still good in terms of weight reduction.

[0041] The lower left-hand graphic in Fig. 2B shows an example of the headliner structure where at least the upper structural piece 22-1 has a width of 600 mm and pieces 22-1 and 22-4 overlap by 20 mm. This results in an overlap area 24 of 20 mm x 600 mm = 12000 mm2, which is considered a medium overlap area for achieving a durable connection. This example is still good in terms of weight reduction.

[0042] The preferred overlap corresponds to 20% to 50% of the possible overlap, considering the respective widths of the structural pieces. The overlap on respective opposite ends of each one of the structural pieces can be different.

[0043] The structural pieces may have a thickness of between 2 mm and 15 mm, preferably between 3 mm and 6 mm, e.g. a thickness of 4 mm or 5 mm.

[0044] Fig. 3 shows an example of a structure and composition of the fiber-reinforced thermoplastic composite material 30 of which the structural pieces 22 may preferably be made of. The fiber- reinforced thermoplastic composite material 30 may comprise polypropylene as a main component. The amount of polypropylene may, e.g., range between 20 weight percent and 80 weight percent, in one example between 50 weight percent and 80 weight percent, preferably between 30 weight percent (wt%) and 70 weight percent, in some examples between 35 weight percent and 65 weight percent, in one example 45 weight percent. As can be taken from Fig. 3, the fiber-reinforced thermoplastic composite material 30 of this example comprises a porous core layer 34, a porous first layer 32 and a porous second layer 36. The porous core layer 34 is sandwiched between the porous first and second layers 32 and 36. Each layer may comprise or consist of polypropylene and reinforcing fibers.

[0045] The porous layers 32-34 may, e.g., comprise a web or mesh of open cell structures formed by a plurality of reinforcing fibers bonded together with a thermoplastic material. The layers 32-36 may further comprise one or more additives such as for example a lofting agent.

[0046] In another example (not shown), the fiber-reinforced thermoplastic composite material may comprise (e.g., as a main component) one or more of a polyolefin material, a thermoplastic polyolefin blend material, a polyvinyl polymer material, a butadiene polymer material, an acrylic polymer material, a polyamide material, a polyester material, a polycarbonate material, a polyester carbonate material, a polystyrene material, an acrylonitryl-styrene polymer material, an acrylonitrile-butylacrylate-styrene polymer material, a polyether imide material, a polyphenylene ether material, a polyphenylene oxide material, a polyphenylenesulphide material, a polyether material, a polyetherketone material, a polyacetal material, a polyurethane material, a polybenzimidazole material, and copolymers, and mixtures thereof.

[0047] The amount of thermoplastic material present in the thermoplastic composite material and / or in the layers 32-36 may vary and may, for example, range from about 20 weight percent to about 80 weight percent, e.g., 30 to 70 weight percent or 35 to 65 weight percent.

[0048] In one example, the fiber-reinforced thermoplastic composite material comprises polyolefin, e.g., as a main component. The amount of polyolefin in the fiber- reinforced thermoplastic composite material may for example be between 20 weight percent and 80 weight percent, e.g., 30 to 70 weight percent or 35 to 65 weight percent, preferably 45 weight percent.

[0049] In an example, the reinforcing fibers maybe glass fibers. In different examples, the reinforcing fiber may additionally or alternatively comprise one or more of carbon fibers, graphite fibers, synthetic organic fibers, inorganic fibers, natural fibers, mineral fibers, metal fibers, metalized inorganic fibers, metalized synthetic fibers, ceramic fibers, and combinations thereof.

[0050] The reinforcing fiber content in the thermoplastic composite material and / or in some or all of the layers 32-36 may each independently be from about 20 to about 90 weight percent, more particularly from about 30 to about 80 weight percent of the layer, in some examples between 40 weight percent and 70 weight percent, preferably between 50 weight percent and 60 weight percent, e.g., 55 weight percent. Typically, the reinforcing fiber content of a multi-layer assembly comprising the layers 32-36 may vary between about 20 to about 90 weight percent, more particularly about 30 to about 80 weight percent.

[0051] In one preferable example, the reinforcing fibers are or comprise glass fibers and the glass fiber content in the thermoplastic composite material is between 40 weight percent and 70 weight percent, preferably between 50 weight percent and 60 weight percent, e.g., 55 weight percent.

[0052] In another example, the glass fiber content in the thermoplastic composite material is between 10 weight percent and 40 weight percent, in some examples between 20 weight percent and 30 weight percent, e.g. 25 weight percent.

[0053] As described earlier, the thermoplastic material and the plurality of reinforcing fibers may form a web or mesh of open cell structures. For example, the thermoplastic composite material and / or some or all of the layers 32-36 may each comprise open cell structures such that voids or pores maybe present in the thermoplastic composite material and / or in the layers 32-36.

[0054] For example, the thermoplastic composite material and / or some or all of the layers 32-36 may each independently comprise a void content or porosity of 0-30%, 10-40%, 20-50%, 30-60%, 40-70%, 50-80%, 60-90%, 0-40%, 0-50%, 0-60%, 0-70%, 0-80%, 0-90%, 10-50%, 10-60%, 10- 70%, 10-80%, 10-90%, 10-95%, 20-60%, 20-70%, 20-80%, 20-90%, 20-95%, 30-70%, 30- 80%, 30-90%, 30-95%, 40-80%, 40-90%, 40-95%, 50-90%, 50-95%, 60-95% 70-80%, 70- 90%, 70-95%, 80-90%, 80-95% or any value within these exemplary ranges.

[0055] The high porosity present in the thermoplastic composite material and / or in the layers 32-36 may reduce the overall weight of the layers and may allow the inclusion of additives or agents, such as flame retardants, colorants, smoke suppressants and other materials, in the voids of the layers 32-36.

[0056] The weight per unit of the fiber-reinforced thermoplastic composite material maybe 500 g / m2to 3 000 g / m2. The weight per unit of the porous core layer may be 500 g / m2to 1600 g / m2.

[0057] As can be taken from Fig. 4, the fiber- reinforced thermoplastic composite material may further comprise a scrim material 42 and 46 on one or both sides of the fiber- reinfo reed thermoplastic composite material.

[0058] The scrim material may comprise or consist of a woven material, a knitted material and / or a non-woven material. The scrim material may comprise or consist of a synthetic fiber such as polyester, polyolefin, and / or polyamide (e.g., nylon), which may be woven or knitted together, e.g., to create a stable and flexible fabric. The woven or knitted structure of the scrim material may allow it to be easily adhered to other materials during the headliner manufacturing process. Additionally, or alternatively, the scrim material may comprise or consist of one or more of metal, wood fibre, and any other type of mesh material.

[0059] However, as the structural pieces are to be bonded at the overlapping regions 24 through molding (e.g., compression molding), the scrim material on the structural pieces may optionally be removed at the overlapping regions 24 on the respective sides facing each other, because the scrim material may block fusion of the material of the contacting structural pieces and thus bonding of the structural pieces. Therefore, in areas or regions, e.g., at the corners of the roof panel opening, where the structural pieces overlap, the scrim material is preferably removed from the structural pieces on the respective sides facing each other. In particular, with reference to Fig. 2, the respective sides 22-ia and 22-2b of the structural pieces facing each other do not comprise scrim material.

[0060] The headliner structure may further comprise a cover stock layer (e.g., made of polypropylene) that is arranged on a frontside of the fiber- reinfo reed thermoplastic composite material (which is to face the interior of the vehicle). The cover stock layer may be an innermost layer of the headliner structure that faces the interior of the vehicle.

[0061] The material used for the cover stock layer may be a polypropylene spacer fabric, a polypropylene knitware, a polypropylene circular knitware, a polypropylene woven material, or a polypropylene non-woven material.

[0062] Due to the material composition, as shown in Figures 3 and 4, and the material used for the cover stock layer, the headliner structure may preferably be entirely recyclable, for example as a result of the use of a thermoplastic material. The material used for the cover stock layer, the headliner structure may for example be mechanically, physically and / or chemically recyclable. In some examples, only a single polymer (such as polypropylene) may be used (comprised) in the thermoplastic composite material, the structural pieces and / or the entire headliner structure. The material composition may, e.g., be chosen so as to allow a circular recycling process resulting in the continual reuse and remanufacturing of the polymer-based material composition. The material composition of a discarded headliner structure may be reintroduced to the manufacturing process. The material composition of the discarded headliner structure may be broken down or depolymerized into their basic components. The basic components may be repolymerized or reprocessed into new polymer chains that may be used to make a new headliner structure. The recyclability of the material composition may reduce waste accumulation and environmental pollution, increasing material lifespan, and reducing production costs. Fig. 5 shows a preferred method for manufacturing a headliner structure for a vehicle roof.

[0063] As outlined in step 501, structural pieces are provided. Preferably, a fiber-reinforced thermoplastic composite material may be provided in the form of structural pieces which may be elongated, for example. The structural pieces may be cut from a larger mat or may be produced as such, for example.

[0064] The structural pieces are aligned in step 502, so that the structural pieces at least partially overlap at one or a plurality of respective ends of each structural piece to surround all or part of an opening. The structural pieces may be aligned in a pressing tool or pre-aligned in a fixture. The structural pieces may for example overlap along at least a portion of a circumference of the opening. In the final headliner structure, the opening maybe aligned with a corresponding opening in the vehicle roof.

[0065] Optionally, the structural pieces may be heated after being aligned, e.g., as in step 604 described below with reference to Fig. 6. The structural pieces may be heated in the pressing tool or pre-heated in a separate heating tool and then transferred to the pressing tool.

[0066] The structural pieces in the pressing tool are preferably molded to bond the structural pieces together, as outlined in step 503, for example so that the material of the overlapping portions of the structural pieces fuse to create a laminated part of / for the headliner structure. The bonded structural pieces (laminated part) of the headliner structure may be a preliminary or an intermediate product, which maybe processed further to yield the final headliner structure in some examples, e.g. as detailed below with reference to Fig. 6. However, in the broad context of the present invention, the molding may include any form of hybrid molding that allows for overmolding and the option to include other components to the finally formed headliner. Preferably, the molding may include or be performed by compression-molding or press-molding.

[0067] A more in-depth example of a preferred method for manufacturing a headliner structure for a vehicle roof is described with reference to Fig. 6.

[0068] The steps 601 and 603 may correspond to the two steps 501 and 502 of the method illustrated in Fig. 5. A fiber-reinforced thermoplastic composite material is provided in the form of structural pieces. The structural pieces are aligned so that the structural pieces surround all or a portion of an opening in the headliner structure and at least partially overlap at one or a plurality of respective ends of each structural piece, preferably at the corners of the opening. The structural pieces may overlap along at least a portion of a circumference of the opening. In a region or area where the structural pieces overlap, scrim material on the respective sides facing each other may have been preferably removed, as outlined in step 602. Step 602 maybe implemented prior to aligning the structural pieces.

[0069] As provided by step 604, the structural pieces further may have been heated before introduction into the pressing tool or may be heated in the pressing tool if the tool is provided with a heating mechanism. In one example, the structural pieces may be heated to a temperature of 110- 29O°C, preferably I6O-22O°C, or no-i6o°C in some examples.

[0070] Additionally, as provided by step 605, a cover stock layer may be placed on the structural pieces, in particular on a side of the structural pieces which will become a frontside of the headliner structure, wherein the frontside of the headliner structure is configured to face an interior of the vehicle. Preferably, the cover stock layer is provided (e.g., added or attached to the structural pieces) after the heating provided by step 604. The cover stock thus may provide the visible side of the headliner structure. The cover stock layer may comprise or consist of polypropylene. It may be a spacer fabric, a knitware, a circular knitware, a woven material, or a nonwoven material, for example.

[0071] Next, the structural pieces in the pressing tool may be molded (e.g., compression-molded) to bond the structural piece together, thereby creating a laminated part of the headliner structure, see step 606. The laminated part of the headliner structure maybe a preliminary or an intermediate product.

[0072] Further, the molded structural pieces may be cut along the outer and / or inner edges to provide a finished shape, see step 607. Additionally, cut-outs for vehicle interior components (assembly parts) may be made in the molded structural pieces and the vehicle interior components may be attached to the molded structural pieces, see step 608. Further, see step 609, the molded structural pieces may be edge-folded, for example.

[0073] Additionally, a reinforcement frame may preferably be fastened to the headliner structure, see step 610. The reinforcement frame may be inserted in the pressing tool together with the structural pieces and may be attached to the structural pieces by molding, in particular compression-molding, as described further below.

[0074] With reference to Fig. 7, a top view of the reinforcement frame 14 for the headliner structure 10 according to an example is shown. As can be taken from Fig. 7, the reinforcement frame 14 may comprise two side frame portions 72a and 72b, a front frame portion 74 and a rear frame portion 76. Some or all of the frame portions may for example be elongated components such as ledges. The frame portions may for example be connected by latch connectors. The reinforcement frame 14 may be assembled by latching neighbouring frame portions via latch connectors that form a latch connector system 77. The latch connectors may be provided at or next to respective corners of a rectangular or trapezoidal frame. Having the connectors at or near the corners allows using straight or largely straight frame portions. The reinforcement frame is to reinforce a cut-out 12 in the headliner structure 10. The frame portions may surround the cut-out 12 completely or partially.

[0075] For example, the reinforcement frame may comprise three frame portions. Thus, the three frame portions may surround the cut-out partially, allowing a partial reinforcement of the cutout.

[0076] The reinforcement frame 14 (e.g., some or all of the frame portions) may have an L-shaped, S- shaped, or U-shaped cross-section. The frame portions may be particularly adapted to be attached or secured to an opening in the headliner of a vehicle and / or to a sunroof module in a roof opening of the vehicle. Additionally or alternatively, the frame portions may be particularly adapted to be attached or secured (e.g., to the opening in the headliner or to the sunroof module) so as to provide a waterproof seal with the roof of the vehicle and / or provide a visually acceptable edging and reinforcement to the opening.

[0077] The reinforcement frame (e.g., some or all of the frame portions) also may have one or more additional reinforcement structures, such as reinforcement ribs.

[0078] The reinforcement frame 14 (e.g., some or all of the frame portions) may comprise or consist of carbon fiber reinforced polypropylene. The frame portions may include carbon fiber reinforced polypropylene as a main component.

[0079] The frame portions may for example include at least 50 weight percent, in some examples at least 70 weight percent, preferably at least 80 weight percent, more preferably at least 90 weight percent, most preferably at least 95 weight percent of carbon fiber reinforced polypropylene. The frame portions may for example include between 40 weight percent and 90 weight percent, preferably between 50 weight percent and 80 weight percent of polypropylene and / or between 10 weight percent and 40 weight percent, preferably between 20 weight percent and 30 weight percent of carbon fibers (e.g., 25 weight percent carbon fibers). In some examples, some or all of the frame portions may further include one or more additives. The amount of additives comprised in these frame portions may for example range up to 20 weight percent, preferably up to 10 weight percent, most preferably up to 5 weight percent. Additives may comprise one or more of a UV and / or anti-aging stabilizer (e.g., an anti-oxidant), a flame retardant and pigments or colorants, for example.

[0080] In an example, the carbon fiber reinforced polypropylene may comprise between to and 40 weight percent or between 10 and 30 weight percent carbon fiber. In another example, the carbon fiber reinforced polypropylene may comprise between 15 and 25 weight percent carbon fiber, e.g., about 20 weight percent carbon fiber.

[0081] In an example, the carbon fiber reinforced polypropylene may comprise or consist of recycled material. For example, at least 80 weight percent, preferably at least 90 weight percent, in some examples too weight percent of the polypropylene in the carbon fiber reinforced polypropylene may be recycled polypropylene. For example, the source for the recycled polypropylene may be any discarded material, preferably discarded automotive parts such as interior trim parts, headliner structures and / or battery casings, comprising or consisting of polypropylene.

[0082] Additionally or alternatively, at least 80 weight percent, preferably at least 90 weight percent, in some examples too weight percent of the carbon fiber in the carbon fiber reinforced polypropylene may be recycled carbon fiber. The source for recycled carbon fiber may for example be discarded remains or scraps of carbon mat productions.

[0083] The recycled material maybe a blend of recycled carbon fibers and matrix polypropylene staple fibers.

[0084] The length and diameter of the carbon fibers (e.g., the recycled carbon fibers) may vary, for example depending on the recycling process and the intended use. For example, the length of the carbon fibers may range between 5 mm and 50 mm, in some examples between 10 mm and 30 mm, in one example between 15 and 20 mm. For example, the diameter of the carbon fibers may range between 2 pm and 20 pm, in some examples between 5 pm and 10 pm. Preferably, the diameter of the carbon fibers is between 6 pm and 8 pm, e.g., 7 pm.

[0085] Due to the carbon fiber present in the polypropylene material, the weight of the reinforcement frame may be reduced relative to conventional frames made from metal, for example, the weight of the reinforcement frame may be reduced by 30% or from about 1000 g to 700 g or from about 600 g to 400 g.

[0086] An area weight and / or a wall thickness of the reinforcement frame may vary depending on the vehicle type for which the reinforcement frame is intended for. In an example, the reinforcement frame may have an area weight of between 1500 g / m2and 3000 g / m2, preferably between 2000 g / m2and 2500 g / m2, e.g., 2240 g / m2. Additionally or alternatively, the reinforcement frame may have a wall thickness of between 2 mm and 6 mm, in some examples between 4 mm and 5 mm, e.g., 3 mm.

[0087] The reinforcement frame 14 including the latch connector system 77 may be formed by molding, preferably injection molding, in particular the frame portions 72a, 72b, 74 and 76 may be formed by injection molding.

[0088] The fiber-reinforced thermoplastic composite material of the headliner structure 10 and the frame 14 maybe bonded by molding, e.g., compression molding.

[0089] Figures 8A and 8B show the reinforcement frame in further detail, in particular, a detailed view of the latch connector system 77. Fig. 8A shows a connected state of two frame portions (e.g., ledges) with two latch connectors being interlocked, while Fig. 8B shows a released state of two frame portions with separated latch connectors. As further shown in Fig. 8B, the latch connector system 77 comprises a first latch connector 77a and a second latch connector 77b formed on an opposite side of neighboring frame portions. The first latch connector 77a may comprise a male connector portion 82a and a female receptacle portion 84a located side-by- side. On the opposite side, the latch connector 77b may comprise a male connector portion 82b configured to be inserted into the corresponding female receptacle portion 84a of the latch connector 77a and a female receptacle portion 84b configured to receive the male connector portion 82a of the latch connector 77a. Together, the latch connector 77a and the latch connector 77b form the latch connector system 77 that is configured to securely connect the frame portions. As mentioned earlier, each frame portion may comprise a latch connector at one or more ends of the frame portion, in particular, each frame portion may comprise a first latch connector 77a at one end and a second latch connector 77b at another end. The latch connectors may be configured to be movable within a certain tolerance of a few millimeters relative to each other when the frame portions are connected. A movement tolerance of the connected latch connectors may be in the range of 0.5 to 2 mm, for example. This allows accommodating a certain relative movement of the structural pieces forming the headliner. The movement tolerance will depend on the absolute dimensions of the headliner opening and reinforcement frame wherein the width of the reinforcement frame may range from 300 mm to 1200 mm, for example, and the length of the reinforcement frame may range from 200 mm to 3000 mm, for example.

[0090] The latch connectors may be formed from (e.g., comprise or consist of) the carbon fiber reinforced polypropylene. Hence, the latch connectors may be formed from the same material in the same molding process as the side frame portions of the reinforcement frame. In particular, the latch connectors may be integrally formed in the same injection molding process as inherent parts of the side frame portions.

[0091] Fig. 9 shows a method for forming the reinforcement frame 14.

[0092] As outlined in step 901, at least one mold for forming frame portions (e.g., ledges) such as frame portions 72a, 72b, 74 and 76, are provided. For example, the side frame portions 72a and 72b may be formed from the same mold (e.g., a first mold) and the front and rear frame portions 74 and 76 may be formed from the same mold (e.g., a second mold different from the first mold).

[0093] The frame portions 72a, 72b, 74 and 76 including the latch connectors 77a, 77b maybe injection molded from carbon fiber reinforced polypropylene using the one or more molds, see step 902.

[0094] The frame portions 72a, 72b, 74 and 76 may then be connected to form the frame, as outlined in step 903. For this, the latch connectors 77a, 77b maybe engaged. In one example, the latch connectors 77a, 77b are dimensioned such that they do not fit firmly but there is a loose fit having a movement tolerance of a few millimeters.

[0095] Fig. 10 shows a method for forming an automotive headliner having an opening or a cut-out 12 for a roof window. As outlined in step 1001, a reinforcement frame 14 formed from carbon fiber reinforced polypropylene is provided (e.g., by forming the reinforcement frame, for example as described above, or by providing a pre-formed reinforcement frame). The reinforcement frame 14 may be rectangular formed from two side frame portions 72a and 72b, a front frame portion 74 and a rear frame portion 76, the frame portions being connected by latch connectors 77 at or near respective corners, e.g., as described above with reference to Figs. 7 and 8A / B.

[0096] As outlined in step 1002, the frame 14 is positioned in a mold.

[0097] In a step 1003, a fiber-reinforced thermoplastic material is inserted into the mold. The fiber- reinforced thermoplastic material may for example have a material composition as described above for the headliner structure 10. In some examples, the fiber- reinforced thermoplastic material maybe the headliner structure 10.

[0098] As further outlined in step 1004, the mold is closed. Additionally, heat maybe applied, and the headliner is formed by bonding the fiber-reinforced thermoplastic material and the frame 14 together, see steps 1005 and 1006. The bonding may, e.g., be achieved by compression- molding. The bonding may comprise press-forming one or both of the fiber-reinforced thermoplastic material and the frame 14.

[0099] In an example, the step of closing the mold may further comprise applying pressure to the fiber-reinforced thermoplastic material and the frame.

[0100] In an example, the step of applying heat may relate to heating inner surfaces of the mold to a temperature of no-2io°C, preferably I6O-2OO°C, or no-i6o°C in some examples.

Claims

Claims1. A headliner structure for a vehicle roof, wherein the headliner structure comprises structural pieces that are arranged to define all or a portion of a headliner opening corresponding to a roof panel opening in the vehicle roof and overlap along at least a portion of a circumference of the headliner opening, wherein the structural pieces are bonded by molding, and wherein the structural pieces comprise a fiber-reinforced thermoplastic composite material.

2. The headliner structure for a vehicle according to claim 1, further comprising a reinforcement frame attached to the structural pieces to stabilize the headliner opening.

3. The headliner structure for a vehicle according to claim 1 or 2, wherein the fiber-rein- forced thermoplastic composite material comprises polypropylene as a main component.

4. The headliner structure for a vehicle according to one of the preceding claims, wherein the fiber-reinforced thermoplastic composite material comprises a porous core layer, a porous first layer and a porous second layer, the core layer sandwiched between the porous first and second layers, wherein each layer comprises polypropylene and reinforcing fibers.

5. The headliner structure for a vehicle according to claim 4, wherein the reinforcing fibers are glass fibers.

6. The headliner structure for a vehicle according to one of the preceding claims, wherein the fiber-reinforced thermoplastic composite material comprises one or more of a polyolefin material, a thermoplastic polyolefin blend material, a polyvinyl polymer material, a butadiene polymer material, an aciylic polymer material, a polyamide material, a polyester material, a polycarbonate material, a polyester carbonate material, a polystyrene material, an acrylonitryl- styrene polymer material, an acrylonitrile-butylacrylate-styrene polymer material, a polyether imide material, a polyphenylene ether material, a polyphenylene oxide material, a polyphenylenesulphide material, a polyether material, a polyetherketone material, a polyacetal material, a polyurethane material, a polybenzimidazole material, and copolymers, and mixtures thereof.

7. The headliner structure for a vehicle according to one of the preceding claims, wherein the reinforcing fibers comprise one or more of glass fibers, carbon fibers, graphite fibers, synthetic organic fibers, inorganic fibers, natural fibers, mineral fibers, metal fibers, metalized inorganic fibers, metalized synthetic fibers, ceramic fibers, and combinations thereof.

8. The headliner structure for a vehicle according to one of the preceding claims, wherein the fiber-reinforced thermoplastic composite material further comprises a scrim material on one or both sides of the fiber- reinforced thermoplastic composite material.

9. The headliner structure for a vehicle according to claim 8, wherein in areas where the structural pieces overlap, the structural pieces do not comprise the scrim material on respective sides facing each other.

10. The headliner structure for a vehicle according to one of the preceding claims, wherein the weight per unit of the fiber- reinforced thermoplastic composite material is 500 g / m2 to 3000 g / m2.

11. The headliner structure for a vehicle according to one of the preceding claims and claim 4, wherein the weight per unit of the porous core layer is 500 g / m2 to 1600 g / m2.

12. The headliner structure for a vehicle according to one of the preceding claims, wherein the headliner further comprises a cover stock layer made of polypropylene that is arranged on a frontside of the fiber-reinforced thermoplastic composite material, wherein the frontside is configured to face an interior of the vehicle.

13. The headliner structure according to claim 12, wherein the cover stock layer is an innermost layer of the headliner structure facing an interior of the vehicle.14- The headliner structure for a vehicle according to one of the preceding claims, wherein one or more vehicle interior components are fastened to the headliner structure.

15. The headliner structure for a vehicle according to one of the preceding claims, wherein the structural pieces have a width between too mm and 600 mm and respectively overlap in an area of between 1000 mm2and 60000 mm2, preferably between 2000 mm2and 30000 mm2.

16. A method for producing a headliner structure for a vehicle roof according to one of the preceding claims, comprising: providing structural pieces, aligning the structural pieces so that the structural pieces at least partially overlap at one or a plurality of respective ends of each structural piece to surround all or a portion of an opening in the headliner structure, molding the structural pieces in a pressing tool to bond the structural pieces together.

17. The method of claim 16, wherein the pieces are aligned in the pressing tool or are prealigned in a fixture.

18. The method according to claim 16 or 17, wherein the structural pieces are heated before the molding.

19. The method according to claim 18 further comprising, prior to heating the structural pieces and after aligning the structural pieces: in areas where the structural pieces overlap, removing scrim material on the respective sides facing each other.

20. The method according to one of claims 17 to 19 further comprising, prior to and / or after heating the structural pieces: attaching a cover stock layer comprising polypropylene on a frontside of the headliner structure, wherein the frontside of the headliner structure is configured to face an interior of the vehicle.

21. The method according to one of claims 16 to 20 further comprising, after molding the structural pieces together: cutting the molded structural pieces into a desired shape, and / or creating one or more cut-outs for vehicle interior components in the molded structural pieces, and / or edge-folding of the molded structural pieces.

22. The method according to one of claims 16 to 21 further comprising: fastening a rein- forcement frame to the headliner structure.

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