Description:TECHNICAL FIELD
[001] Embodiments disclosed herein relate to vehicle headliners and a method of manufacturing the vehicle headliners having reduced weight with better strength and with reduced volatile organic content emissions.
BACKGROUND
[002] Automotive headliners serve as an integral component of vehicle interiors. Usually, the headliners are installed to the roof area of vehicles above the driver and passenger seats. The headliners offer numerous advantages, such as providing thermal insulation i.e., aiding in maintaining a comfortable temperature within the vehicle interior. Further, the headliner also contributes to acoustical dampening and mitigating noise levels within the vehicle’s passenger compartment. Furthermore, the headliner also adds a decorative finish to the vehicle roof's interior thereby enhancing the overall aesthetic appeal of the interior space. Headliners may also conceal various components such as wiring, structural supports and airbag modules that are housed within the roof area thereby creating a neat and streamlined appearance. Some headliners also include integrated accessories such as overhead consoles, lighting fixtures, air vents, speakers, and handles for passengers to hold onto. In modern vehicles, headliners may incorporate safety features such as side curtain airbags which deploy from the headliner to provide additional protection to occupants during a collision.
[003] The conventional manufacturing process for making the automotive headliners involves the utilization of multiple layers of materials (as shown in FIG. 1). These layers consist of knitted fabric (12), adhesive (14), first non-woven fleece (16), glass fiber (18), first adhesive (20), PU foam (22), second adhesive (24), glass fiber (26), and a second non-woven fleece (28), collectively forming the headliner (10). These layers are further bonded together by using adhesives, which can lead to elevated levels of volatile emissions to the passenger compartment of the vehicle.
[004] Volatile organic compounds (VOCs) are organic chemicals that have a high vapor pressure at ordinary room temperature. This property allows them to easily evaporate and off-gas into the air, potentially leading to air pollution in the vehicle. Conventional headliners, with their constituent materials, may contribute to diminished quality in vehicle interiors, potentially causing discomfort to passengers. Symptoms such as headaches, nausea, and a sensation of vomiting may arise, with prolonged exposure potentially posing risks such as cancer and other serious health concerns if chemical levels exceed permissible limits. Depending on the materials and manufacturing processes used, the specific VOC content can be improved.
[005] Hence, there is a need in the art for headliners that have reduced VOC content thereby improving the interior air quality in vehicles.
OBJECTS
[006] The principal object of embodiments herein is to disclose a vehicle headliner.
[007] Another object of embodiments herein is to disclose the vehicle headliner having reduced volatile organic compounds emission.
[008] Another object of embodiments herein is to disclose the vehicle headliner having reduced weight with better strength.
[009] Another object of embodiments herein is to disclose a method of manufacturing the vehicle headliner.
[0010] Another object of embodiments herein is to attach the layers of the vehicle headliner by thermoforming process (thermal bonding process) thereby eliminating the usage of adhesives.
[0011] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating at least one embodiment and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF FIGURES
[0012] Embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the following illustratory drawings. Embodiments herein are illustrated by way of examples in the accompanying drawings, and in which:
[0013] FIG. 1 is a schematic representation of a conventional vehicle headliner with nine layers, according to existing arts;
[0014] FIG. 2 is a schematic representation of the vehicle headliner (100) with four layers, according to embodiments as disclosed herein;
[0015] FIG. 3 illustrates manufacturing of the vehicle headliner (100), according to embodiments as disclosed herein; and
[0016] FIG. 4 depicts a flowchart indicating steps of a method (200) of manufacturing the vehicle headliner (100), according to embodiments as disclosed herein.
DETAILED DESCRIPTION
[0017] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0018] For the purposes of interpreting this specification, the definitions (as defined herein) will apply and whenever appropriate the terms used in singular will also include the plural and vice versa. It is to be understood that the terminology used herein is for the purposes of describing particular embodiments only and is not intended to be limiting. The terms “comprising”, “having” and “including” are to be construed as open-ended terms unless otherwise noted.
[0019] The words/phrases "exemplary", “example”, “illustration”, “in an instance”, “and the like”, “and so on”, “etc.”, “etcetera”, “e.g.,”, “i.e.,” are merely used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein using the words/phrases "exemplary", “example”, “illustration”, “in an instance”, “and the like”, “and so on”, “etc.”, “etcetera”, “e.g.,”, “i.e.,” are not necessarily to be construed as preferred or advantageous over other embodiments.
[0020] Embodiments herein disclose a vehicle headliner (100). Embodiments herein also disclose a method of manufacturing the vehicle headliner (100). The method, according to embodiments herein eliminates the use of adhesives in the construction of the headliners, thereby reducing emission of volatile organic compounds.
[0021] The headliner (100), according to embodiments herein includes four layers. The combination of these layers provides improved structural integrity, sound insulation, and thermal insulation.
[0022] FIG. 2 is a schematic representation of the vehicle headliner (100) with four layers, according to embodiments herein.
[0023] The headliner (100), according to embodiments herein includes a first thermoplastic layer (102); a fabric layer (104) laid onto a first surface (102B) of the first thermoplastic layer (102); a foam layer (106) laid onto a second surface (102T) of the first thermoplastic layer (102); and a second thermoplastic layer (108) laminated onto the foam layer (106).
[0024] In one embodiment, the first thermoplastic layer (102), is a thermoplastic sheet. Thermoplastic sheets are lightweight, which is advantageous for reducing the overall weight of the vehicle. Furthermore, thermoplastic sheets can be easily molded and shaped to fit the contours of the vehicle's roof, allowing for customization and design flexibility in headliner production This helps improve fuel efficiency and vehicle handling, interior air quality. Non-limiting examples of thermoplastic sheets include Polyethylene (PE), Polypropylene (PP), polystyrene (PS), Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC), Nylon, and combinations thereof. In one embodiment, the thermoplastic sheet is polypropylene based. In one other embodiment, the thermoplastic sheet is nylon based.
[0025] In one embodiment, the thermoplastic sheets are continuous long glass fiber reinforced thermoplastic sheets. Glass fiber reinforced thermoplastic sheets, also known as thermoplastic composites, are composite materials made by combining thermoplastic resins with glass fibers. These materials offer a unique combination of strength, stiffness, and lightweight properties, making them suitable for a wide range of applications across various industries.
[0026] In one embodiment, the first thermoplastic layer (102) is interposed between a fabric layer (104) and a foam layer (106). In one embodiment, the first thermoplastic layer (102) functions to provide stiffness and acts as an adherend for the foam layer (106) and the fabric layer (104).
[0027] In one embodiment, the first thermoplastic layer (102) includes a first surface (102B) and a second surface (102T). In one embodiment, the first surface (102B) of the first thermoplastic layer (102), is bonded directly to the fabric layer (104). In one other embodiment, the second surface (102T) of the first thermoplastic layer (102) is bonded directly to the foam layer (106).
[0028] In one embodiment, the first thermoplastic layer (102) has a weight ranging from 400 g/m2 to 450 g/m2.
[0029] In one embodiment, the first thermoplastic layer (102) has a density ranging from 1.68 g/cc to 1.72 g/cc.
[0030] In one embodiment, the first thermoplastic layer (102) has a thickness ranging from 0.24 mm to 0.30 mm.
[0031] In one embodiment, the headliner (100) includes a fabric layer (104). The fabric layer (104), according to embodiments herein, is laid onto the first surface (102B) of the first thermoplastic layer (102).
[0032] In one embodiment, the fabric layer (104) includes a plurality of knitted fabric or non-woven fabric. Knitted fabrics are textiles made by interlocking yarns in a series of connected loops. These fabrics provide properties such as stretch, resilience, and aesthetic appeal. These fabrics further provide a soft and comfortable surface for occupants to use.
[0033] Non-limiting examples of non-woven fabric includes Polyester, Polypropylene, Polyethylene, Spunbond, Needle-Punched, Acrylic, Rayon, Nylon, bio-based fabric/fiber, and combinations thereof.
[0034] In one embodiment, the fabric layer (104) has a weight ranging from 150 g/m2 to 250 g/m2.
[0035] In one embodiment, the fabric layer (104) has a thickness ranging from 0.3 mm to 0.4 mm.
[0036] In one embodiment, the headliner (100) further includes a foam layer (106). The foam layer (106), according to embodiments herein, is laid onto a second surface (102T) of the first thermoplastic layer (102). Further in an embodiment, the foam layer (106) is bonded directly with the second surface (102T) of the first thermoplastic layer (102). In one embodiment, the foam layer (106) adds thickness and reduces noise and vibration, as well as provides support to the assembly in the headliner (100).
[0037] In one embodiment, the foam layer (106) is at least a polyurethane (PU) foam. Polyurethane is typically formed via an exothermic reaction of an isocyanate - reactive resin composition (including polyols) and an isocyanate in the presence of a blowing agent. The isocyanate - reactive resin composition, the isocyanate, and the blowing agent, are collectively known as a polyurethane system. Suitable polyurethane foams and polyurethane systems may be used to achieve the embodiments herein.
[0038] In one embodiment, the foam layer (106) has a weight ranging from 120 g/m2 to 220 g/m2.
[0039] In one embodiment, the foam layer (106) has a thickness ranging from 5 mm to 6 mm.
[0040] In one embodiment, the headliner (100) further includes a second thermoplastic layer (108). The second thermoplastic layer (108), according to embodiments herein is laminated onto the foam layer (106).
[0041] The second thermoplastic layer (108) is a thermoplastic sheet. In one embodiment, the second thermoplastic layer (108), provides stiffness and acts as an adherend for the foam layer (106). Non-limiting examples of thermoplastic sheet include Polyethylene (PE), Polypropylene (PP), polystyrene (PS), Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC), nylon, and combinations thereof. In one embodiment, the thermoplastic sheet is polypropylene based. In one other embodiment, the thermoplastic sheet is nylon based.
[0042] In one embodiment, the second thermoplastic layer (108) has a weight ranging from 400 g/m2 to 450 g/m2.
[0043] In one embodiment, the second thermoplastic layer (108) has a density ranging from 1.68 g/cc to 1.72 g/cc.
[0044] In one embodiment, the second thermoplastic layer (108) has a thickness ranging from 0.24 to 0.3 mm.
[0045] Embodiments herein disclose a method (200) of manufacturing a vehicle headliner (100), said method (200) comprising: subjecting (202) a first thermoplastic layer (102) to a first thermoforming process; laminating (204) the heated first thermoplastic layer (102) with a fabric layer (104) and a foam layer (106) such that the first thermoplastic layer (102) is interposed between the fabric layer (104) and the foam layer (106); subjecting (206) a second thermoplastic layer (108) to a second thermoforming process; laminating (208) the heated second thermoplastic layer (108) with the foam layer (106) thereby facilitating formation of the vehicle headliner (100).
[0046] FIG. 3 is a schematic representation of the method (200) for manufacturing a vehicle headliner (100), according to embodiments as disclosed herein.
[0047] In one embodiment, the method (200) includes subjecting (202) the first thermoplastic layer (102) to a first thermoforming process.
[0048] Thermoforming process is a manufacturing technique used to shape thermoplastic sheets into specific forms and shapes by heating the material to a pliable state and then cooling it to set the desired shape. The thermoplastic sheet is heated to a temperature where it becomes soft and pliable, but not melted. Heating may be achieved using various heating methods, such as infrared heaters, convection ovens, or radiant heaters. The heating process is carefully controlled to ensure uniform heating of the entire sheet. Once heated, the softened thermoplastic sheet is placed over a mold or form with the desired shape. Vacuum pressure, mechanical force, or a combination of both may be used to draw the softened material onto the mold surface and form the final shape. In some cases, pressure may also be applied to assist in forming the material. After the thermoplastic sheet has been formed into the desired shape, it is cooled rapidly to set the shape and ensure dimensional stability. Cooling can be accelerated using air- or water-cooling methods, such as fans, blowers, or water jets. Once cooled, the formed part is removed from the mold, and any excess material is trimmed away to achieve the final shape. Secondary operations, such as drilling, cutting, or assembly, may also be performed as needed to complete the finished product. The thermoforming process offers several advantages, including high production speed, low tooling costs, and the ability to produce complex shapes with tight tolerances.
[0049] In one embodiment, the first thermoforming process includes heating the first thermoplastic layer (102) by passing the first thermoplastic layer (102) through a first hot air oven (302) at a temperature ranging between 210 to 230 degrees Celsius. Further in an embodiment, the first thermoforming process is performed for a time period ranging between 30 to 120 seconds. In one embodiment, the first thermoforming process is carried out for a time period of one minute.
[0050] In one embodiment, the heated first thermoplastic layer (102) is laminated with a fabric layer (104) and a foam layer (106) using steel rollers such that the first thermoplastic layer (102) is interposed between the fabric layer (104) and the foam layer (106).
[0051] In one embodiment, the first thermoplastic layer (108) is laminated with the fabric layer (104) and the foam layer (106) under temperature ranging between 210 to 230 degrees Celsius and pressure ranging from 4 to 6 bar.
[0052] Lamination typically involves bonding together several layers of materials to create a finished headliner assembly. The lamination process typically involves assembling the various layers of the headliner assembly and then subjecting them to heat and pressure to activate the adhesive and bond the layers together. This process may be performed using specialized lamination equipment, such as heated steel rollers or vacuum presses, to ensure uniform bonding and proper adhesion between the layers
[0053] In one embodiment, the method (200) further includes subjecting (206) a second thermoplastic layer (108) to a second thermoforming process.
[0054] In one embodiment, the second thermoforming process includes heating the second thermoplastic layer (108) by passing the second thermoplastic layer (108) through a second hot air oven (304) at a temperature ranging between 210 to 230 degrees Celsius for a time period ranging between 30 to 120 seconds. In one embodiment, the second thermoforming process is carried out for a time period of one minute.
[0055] In one embodiment, the heated second thermoplastic layer (108) is laminated with the foam layer (106) using steel rollers at a temperature ranging between 210 to 230 degrees Celsius and pressure ranging from 4 to 6 bar.
[0056] In one embodiment, the first hot air oven (302) and second hot air oven (304) facilitate in softening the first thermoplastic layer (102) and the second thermoplastic layer (108).
[0057] In one embodiment, the vehicle headliner (100) has a weight in the range of 1.0 kg to 1.2 kg. In one other embodiment, the vehicle headliner (100) has a thickness ranging from 7 mm to 8 mm.
[0058] In one embodiment, the vehicle headliner (100) has a peel strength ranging from 5N/25 mm to 10N/25mm.
[0059] Conventionally during headliner construction, adhesive layers are used to bond the various layers of the headliner assembly together. Specialized adhesives are applied between each layer to ensure strong and durable bonding. The present invention provides a method of headliner manufacturing process that eliminates usage of adhesives. Instead, the layers disclosed in the headliner are molecularly bonded. Molecular bonding occurs between the layer of thermoplastic glass reinforced sheet with foam and fabric layers after passing through hot air oven under defined temperature and pressure conditions, this process is also referred as lamination bonding and eliminates the usage of adhesive in headliner manufacturing process.
[0060] The combination of the four layers in the headliner assembly provides synergistic benefits, including enhanced structural integrity, improved acoustic performance, and thermal insulation. Additionally, the modular design of the headliner assembly facilitates ease of manufacturing, customization, and integration into various automotive models. The proposed headliner (100) construction involves only 4 layers of material as compared to multiple layers of materials disclosed in the prior arts. Further, the non-usage of adhesive in headliner construction provides an advantage in controlling the volatile organic compounds emissions, improving the vehicle interior air quality, passenger comfort etc.
[0061] It is understood that various such modifications in the headliner construction would be apparent to a person skilled in the art in light of the disclosures made herein and are included within the scope of the embodiments herein.
[0062] Embodiments are further described herein by reference to the following example by way of illustration only and should not be construed to limit the scope of the claims provided herewith.
Experimental study
[0063] Density of each layer was measured following the ASTM D792 test method procedure. GSM was measured by dividing the weight with unit area of test specimen. Peel strength was found to be minimum 5N/25mm.
S.No. Parameter Unit Results
GSM
1 PU Foam g/m2 170 ± 50
2 Non – Woven / Knitted Fabric g/m2 200 ± 50
3 Thermoplastic sheet g/m2 425 ± 25
Density
1 Thermoplastic sheet g/cc 1.7 ± 0.02

[0064] The results obtained were found to be comparable with the conventional automotive headliners in terms of peel strength. However, the vehicle headliner (100) disclosed in the present invention is superior to conventional headliners in terms of having reduced weight. The method (200) of manufacturing the vehicle headliner (100) is also simple and cost-effective. In one embodiment, the method (200) achieves a vehicle headliner (100) having a weight reduction of at least 0.5 kg as compared to the conventional headliners.
[0065] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of embodiments and examples, those skilled in the art will recognize that the embodiments and examples disclosed herein can be practiced with modification within the scope of the embodiments as described herein.
, Claims:We claim,
1. A vehicle headliner (100) comprising:
a first thermoplastic layer (102);
a fabric layer (104) laid onto a first surface (102B) of the first thermoplastic layer (102);
a foam layer (106) laid onto a second surface (102T) of the first thermoplastic layer (102); and
a second thermoplastic layer (108) laminated onto the foam layer (106).
2. The vehicle headliner (100) as claimed in claim 1, wherein the fabric layer (104) and the foam layer (106) are bonded directly with the first surface (102B) and the second surface (102T) of the first thermoplastic layer (102) respectively by a first thermoforming process (thermal bonding process) such that the first thermoplastic layer (102) is interposed between the fabric layer (104) and the foam layer (106).
3. The vehicle headliner (100) as claimed in claim 1, wherein a weight of the first thermoplastic layer (102) is in the range of 400 g/m2 to 450 g/m2;
a density of the first thermoplastic layer (102) is in the range of 1.68 g/cc to 1.72 g/cc;
a thickness of the first thermoplastic layer (102) is in the range of 0.24 mm to 0.30mm; and
the first thermoplastic layer (102) is selected from a group consisting of Polyethylene (PE), Polypropylene (PP), Polystyrene (PS), Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC), nylon, and combinations thereof.
4. The vehicle headliner (100) as claimed in claim 1, wherein the foam layer (106) is at least a polyurethane (PU) foam;
a weight of the foam layer (106) is in the range of 120 g/m2 to 220 g/m2; and
a thickness of the foam layer (106) is in the range of 5mm to 6mm.
5. The vehicle headliner (100) as claimed in claim 1, wherein a weight of the second thermoplastic layer (108) is in the range of 400 g/m2 to 450 g/m2;
a density of the second thermoplastic layer (108) is in the range of 1.68 g/cc to 1.72 g/cc;
a thickness of the second thermoplastic layer (108) is in the range of 0.24 mm to 0.3 mm; and
the second thermoplastic layer (108) is selected from a group consisting of Polyethylene (PE), Polypropylene (PP), Polystyrene (PS), Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC), nylon, and combinations thereof.
6. The vehicle headliner (100) as claimed in claim 1, wherein a weight of the fabric layer (104) is in the range of 150 g/m2 to 250 g/m2;
a thickness of the fabric layer (104) is in the range of 0.3 mm to 0.4 mm;
the fabric layer (104) is one of a knitted fabric or a non-woven fabric, wherein the non-woven fabric is selected from a group consisting of Polyester, Polypropylene, Polyethylene, Spunbond, Needle-Punched, Acrylic, Rayon, Nylon, bio-based fabric/fiber, and combinations thereof.
7. The vehicle headliner (100) as claimed in claim 2, wherein the second thermoplastic layer (108) is directly bonded onto the foam layer (106) through a second thermoforming process (thermal bonding process);
a weight of the vehicle headliner (100) is in the range of 1.0 kg to 1.2 kg;
a thickness of the vehicle headliner (100) is in the range of 7 mm to 8 mm;
a peel strength of the vehicle headliner (100) is in the range of 5N/25 mm to 10N/25mm;
the first surface (102B) of the first thermoplastic layer (102) is a bottom surface of the first thermoplastic layer (102); and
the second surface (102T) of the first thermoplastic layer (102) is a top surface of the first thermoplastic layer (102).
8. A method (200) of manufacturing a vehicle headliner (100), said method (200) comprising:
subjecting (202) a first thermoplastic layer (102) to a first thermoforming process;
laminating (204) the heated first thermoplastic layer (102) with a fabric layer (104) and a foam layer (106) such that the first thermoplastic layer (102) is interposed between the fabric layer (104) and the foam layer (106);
subjecting (206) a second thermoplastic layer (108) to a second thermoforming process;
laminating (208) the heated second thermoplastic layer (108) with the foam layer (106) thereby facilitating formation of the vehicle headliner (100); and
wherein the first thermoplastic layer (102) and second thermoplastic layer (108) are glass fiber reinforced thermoplastic sheet.
9. The method (200) as claimed in claim 8, wherein said subjecting (202) the first thermoplastic layer (102) to the first thermoforming process includes heating the first thermoplastic layer (102) by passing the first thermoplastic layer (102) through a first hot air oven (302) at a temperature ranging between 210 to 230 degrees Celsius for a period ranging between 30 to 120 seconds,
wherein
the first thermoplastic layer (108) is laminated with a fabric layer (104) and a foam layer (106) under above temperature and pressure in the range of 4 to 6 bar.
10. The method (200) as claimed in claim 8, wherein said subjecting (206) the second thermoplastic layer (108) to the second thermoforming process includes heating the second thermoplastic layer (108) by passing the second thermoplastic layer (108) through a second hot air oven (304) at a temperature ranging between 210 to 230 degrees Celsius for a period ranging between 30 to 120 seconds,
wherein
the second thermoplastic layer (108) is laminated with the foam layer (106) under above temperature and pressure in the range of 4 to 6 bar.