Abstract:
An interior component for a vehicle may include a nonwoven fabric impregnated with a resin. The nonwoven fabric and resin are consolidated into a solid sheet devoid of pockets. The interior component may exclude metal coated filler particles and lubricants. The method of making the interior component includes the steps of: forming a nonwoven fabric of a staple fiber and a resin, consolidating the nonwoven fabric and the resin into a solid sheet, and forming the solid sheet into the vehicle component. The vehicle may be an airplane, train, subway car, light rail car, bus, or automobile. The resin may be a polymer selected from the group consisting of polyphenylene sulfide, polyetherimide, polyaryletherketone, co-polymers thereof, and combinations thereof.

Description:
FIELD OF THE INVENTION 
       [0001]    An interior panel for a vehicle, such as an airplane, train, subway car, light rail car, bus, or automobile, and its method of manufacture are disclosed. 
       BACKGROUND OF THE INVENTION 
       [0002]    In the commercial passenger transportation industry, reducing vehicle weight can increase fuel efficiency (i.e., reduce fuel consumption). For example, in the airline industry, it is estimated that a reduction of 250 pounds in airplane weight may yield a fuel cost savings of about 1 million dollars per year. 
         [0003]    Vehicle interiors are an important aesthetic aspect of the vehicle for passenger satisfaction. The interior must be pleasing to the eye, but must also be, among other things, safe, easy to maintain, durable, and resistant to the abuse that is normally encountered during the transport of passengers. 
         [0004]    Heretofore, vehicle interior panels have been made of composite materials. Vehicle interior panels may include, for example, window panels, ceiling panels, floor panels, overhead bins and bin doors, lavatory and galley wall structures, class divider and bulkhead panels, and the like. One such composite has a honeycomb center sheet (NOMEX or aluminum) covered on one or both sides with a skin of a woven glass filament fiber sheet impregnated with a phenolic (thermoset) resin. These composite materials range in thickness from 0.125 to 1.5 inches and may be attached directly to the vehicle frame. Woven carbon filament fiber has been used in place of the woven glass filament fiber. Trim pieces, window/door molding, overhead bins, arm rests, and the like, may be made from moldable plastic (typically a thermoplastics) that may be subsequently covered (laminated, skinned) with a decorative plastic film. Materials used in vehicle interiors include: KYDEX from Kydex LLC of Bloomsburg, Pa. (acrylic-PVC), BOLTARON from Boltaron of Newcomerstown, Ohio (PVC-acrylic), ULTEM from Sabic of Pittsfield Mass. (PEI, PEI/glass fiber). 
         [0005]    Additionally, vehicle (aircraft) interiors must be compliant with FAR §25.853. FAR §25.853 is the US regulation (FAA) dealing with the flammability standards for compartment interiors. This standard establishes limits in the broad categories of flame-resistance, smoke density, toxic gas emission, and heat release (referred to in the industry as FSTH). 
         [0006]    There is a need for vehicle interiors, panels, and trim pieces that have improved tensile properties (including impact resistance), lighter weight, more economical than currently used products, and compliant with FAR §25.853, and that are easy and inexpensive to manufacture. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0007]    For the purpose of illustrating the invention, there is shown in the drawings a form that is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown. 
           [0008]      FIG. 1  is an illustration of an exemplary vehicle interior panel. 
           [0009]      FIG. 2  is a flow chart of an embodiment of the method to manufacture the vehicle interior panel. 
       
    
    
     SUMMARY OF THE INVENTION 
       [0010]    An interior component for a vehicle may include a nonwoven fabric impregnated with a resin. The nonwoven fabric and resin are consolidated into a solid sheet devoid of pockets. The interior component may exclude metal coated filler particles and lubricants. The method of making the interior component includes the steps of: forming a nonwoven fabric of a staple fiber and a resin, consolidating the nonwoven fabric and the resin into a solid sheet, and forming the solid sheet into the vehicle component. The vehicle may be an airplane, train, subway car, light rail car, bus, or automobile. The resin may be a polymer selected from the group consisting of polyphenylene sulfide, polyetherimide, polyaryletherketone, co-polymers thereof, and combinations thereof. 
       DESCRIPTION OF THE INVENTION 
       [0011]    The vehicle interior panel generally comprises a nonwoven fabric impregnated with a resin. The nonwoven and the resin are consolidated into a solid sheet. The sheet is devoid of pockets. Pockets refer to, for example, air pockets or open spaces within the sheet that may weaken the mechanical strength of the consolidated sheet. The sheet does not include thermally conductive metal coated particles (see, for example, U.S. Pat. No. 8,299,159, discussed below) or lubricants used or facilitate extrusion (see, for example, U.S. Pat. No. 8,129,462, discussed below). 
         [0012]    Vehicle interior panels, as used herein, refer to vehicle interiors, panels, and trim pieces. Such interior panels may include: window panels; ceiling panels; floor panels; overhead bins and bin doors; lavatory and galley wall structures; class divider and bulkhead panels; arm rests; seat trim; and the like. In one embodiment, the vehicle interior panel may be used a wall panel. In another embodiment, the vehicle interior panel may be used as a floor panel. An example of a vehicle interior panel is shown in  FIG. 1 . The interior panel  10  is a window trim panel with a cut-out  12  for the window. 
         [0013]    Nonwoven fabric, or nonwoven, refers to randomly oriented staple fiber. In one embodiment, the nonwoven may be made by a wet-laid process, discussed in greater detail below. In this embodiment, the staple may have a length of about 0.125-1.25 inches. In other embodiments, the staple may have lengths in the range of 0.25-0.75 inches, or 0.5-0.75 inches. The staple orientation within the nonwoven may generally yield an anisotropic material with greater physical properties in the machine direction than in the transverse direction, see Table below. 
         [0014]    The staple fibers may be made of any material having good tensile properties (e.g., tensile properties similar to the tensiles of filaments used to make structural/surface components of aircraft). Such materials include glass fiber, carbon fiber, lyotropic/thermotropic liquid crystal polymer fibers (e.g. aramids (KEVLAR, NOMEX, etc), aromatic polyesters (VECTRAN)), polybenzimidazole, and combinations thereof. In one embodiment, the staple fiber may be carbon staple fiber. In another embodiment, the carbon staple is recycled from carbon filament that may have been pre-impregnated with resin (pre-preg carbon filament). Such pre-preg carbon filament may be sourced from, for example, facilities that laid-up carbon filament panels for aircraft components. If recycled from pre-preg carbon filament, it is preferred the resin is thoroughly removed from the filament and the filament cut/chopped to staple length. 
         [0015]    Resin, as used herein, refers to any resin capable of binding the staple fibers of the nonwoven into a solid sheet. In one embodiment, the resin may be a thermoplastic resin. A key feature of the resin is its melt flow index (material must readily flow in the molten state). The resin may be in any form, powder, pellet, fiber, pre-preg resin coating the fibers, or a combination thereof. In one other embodiment, the resin may be in the form of staple fibers. In one embodiment, the resin may be a polyphenylene sulfide (PPS), polyetherimide (PEI), polyaryletherketone (PAEK) or combinations thereof. In another embodiment, the resin may be PPS. In yet another embodiment, the resin may be a PPS staple fiber. PPS may be amorphous, crystalline, or a combination of both. PPS is commercially available, for example, as FORTRON by Ticona, Florence, Ky., and RYTON, Chevron Phillips, The Woodlands, Tex. PEI is commercially available, for example, as ULTEM, Sabic Innovative Plastics, Pittsfield, Mass. PAEK is commercially available, for example, from Victrex, Lancashire, UK, and Solvay Plastics, Houston, Tex. In other embodiments, the resins may include, in additions to those mentioned above, polyamides (PA), polyamide-imides (PAI), polyarylates (PAR), PAEKs (PEK, PEEK, PEKK, PEEKK), polyarylsulfones (PAS), polycarbonates (PC), polybutylene terephthalates (PBT), polyether sulfones (PES, PESV), high density polyethylenes (HDPE), ultra high molecular weight polyethylenes (UHMWPE), polyethylene terephthalates (PET), thermoplastic polyimides (TPI), liquid crystal polymers (LCP), polyphenylene ether blends (PPE, PPO), polysulfones (PSU), thermoplastic polyurethanes (TPUR), their copolymers, and combinations thereof. 
         [0016]    The solid (or consolidated) sheet refers to the consolidated nonwoven fabric of staple fibers and resin. This sheet, in one embodiment, may be free of pockets, as discussed above. This sheet may have any thickness. In one embodiment, the sheet may have a thickness of about 0.0625-0.75 inches. In another embodiment, the thickness may range from about 0.0625-0.5 inches. In yet another embodiment, the thickness may range from about 0.125-0.25 inches. In still another embodiment, the thickness may be, as little as, for example, 6 mils (0.006 inches). This sheet may be formed into, for example, 4 by 8 foot sheets, or any other convenient size. 
         [0017]    In one embodiment, the specific gravity may range from about 1.10-1.40. In another embodiment, the specific gravity may range from about 1.15-1.35. In yet another embodiment, the specific gravity may range from about 1.20-1.33. 
         [0018]    In one embodiment, the sheet may have a tensile strength (ASTM 938) of at least about 250 Kpsi/inch (1 Kpsi=1000 psi). In another embodiment, the sheet may have a tensile strength of at least 275 Kpsi/inch. In yet another embodiment, the sheet may have a tensile strength of at least 300 Kpsi/inch. In still another embodiment, the sheet may have a tensile strength in the range of about 250-650 Kpsi/inch (including all subsets therein). 
         [0019]    In one embodiment, the sheet may have a flexural strength (ASTM D790) of at least about 350 Kpsi/inch. In another embodiment, the sheet may have a flexural strength of at least 400 Kpsi/inch. In yet another embodiment, the sheet may have a flexural strength of at least 500 Kpsi/inch. In still another embodiment, the sheet may have a flexural strength in the range of about 350-950 Kpsi/inch (including all subsets therein). 
         [0020]    In one embodiment, the sheet may have a flex modulus (ASTM D790) of at least about 12,000 Kpsi/inch. In another embodiment, the sheet may have a flex modulus of at least 15,000 Kpsi/inch. In yet another embodiment, the sheet may have a flex modulus of at least 20,000 Kpsi/inch. In still another embodiment, the sheet may have a flex modulus in the range of about 12,000-30,000 Kpsi/inch (including all subsets therein). 
         [0021]    In one embodiment, the sheet may have an impact resistance (Notched IZOD, ASTM D256) of at least about 100,000 Joule/meter 2 /inch (J/m 2 /in). In another embodiment, the sheet may have an impact resistance of at least 150,000 J/m 2 /in. In yet another embodiment, the sheet may have an impact resistance of at least 200,000 J/m 2 /in. In still another embodiment, the sheet may have an impact resistance in the range of about 100,000-600,000 J/m 2 /in (including all subsets therein). Impact resistance is a key parameter for vehicle interior panels. 
         [0022]    The weight ratio of staple fiber to resin in the sheet may range from about 1-2:1-2. In one embodiment, the weight ratio may be in the range of about 1.0-1.5:1.0-1.5. In another embodiment, the weight range may be about 1.0:1.0-1.8. In yet another embodiment, the weight ratio may be about 1.0:1.2-1.7. In still another embodiment, the weight ratio may be about 1.0:1.3-1.6. 
         [0023]    The vehicle interior panels may be formed from the solid sheet or a composite of the solid sheet and a core material. Additionally, the vehicle interior panel may be skinned with a protective film (e.g., a thermoplastic film which may have a decorative aspect as well) as is customary in the art. The consolidated sheet, when at the desired thickness, may replace the composites previously used in the vehicle interior panels (mentioned in the Background section above). The composite may be formed where the consolidated sheet forms the skin, on at least one side, of a core structure. The core structure may be any structure that may provide increased structural to the composite. One example of a core structure is a honeycomb material, as is known in the art. Such honeycomb materials may include NOMEX and aluminum. The consolidated sheet may form a skin on both sides of the core structure. In one embodiment, the consolidated sheet is affixed to the core material without a binder. In another embodiment, the consolidated sheet is affixed to the core material with a binder. The binder may be, for example, an epoxy or a heat activated epoxy, but other binders may be used. These vehicle interior panels may be compliant with FAR §25.853. 
         [0024]    The following references are not directed to vehicle interiors, panels, and trim pieces, as discussed above, but, disclose materials consisting of resins and fibers. 
         [0025]    In U.S. Pat. No. 7,387,828, the web comprises an intimate mixture of long reinforcing fibers (e.g., carbon fiber staple, 2-4 inches in length) and resin (e.g., PPS). The reinforcing fibers are mutually parallel; therefore the reinforcing fibers are not a nonwoven. 
         [0026]    In U.S. Pat. No. 8,129,462, the extrudable resin comprises a high temperature engineering thermoplastic (e.g., PPS), reinforcement components (e.g., glass fiber), filler (e.g., TiO 2 ), and lubricant (e.g., PTFE). This resin is used to make pipes, liners, or similar shapes. 
         [0027]    In U.S. Pat. No. 8,299,159, the thermally-conductive moldable thermoplastic composition comprises a matrix polymer (e.g., PPS), metal-coated filler particles, and secondary filler (e.g., carbon fiber). This composition is used in heat dissipation applications. 
         [0028]      FIG. 2  illustrates the flow chart for an embodiment of the manufacturing process  100 . The vehicle interior panel may be manufactured, in general, by: forming a nonwoven fabric of a staple fiber and a resin  102 , consolidating the nonwoven and resin into a solid sheet  104 , and forming the solid sheet into the vehicle interior panel  106 . 
         [0029]    The nonwoven may be made by any process for forming nonwovens. In one embodiment, the nonwoven is formed by a wet-laid process. In this process, the staple fiber and resin, for example in the form of staple fiber, are mixed together, with a suitable liquid, to form a furnish. The consistency of the furnish (weight of fiber/weight of liquid×100) may range from about 0.25-1.0% (or about 0.3-0.7% or about 0.5%). Dispersants, defoamers, and viscosity modifiers may be added to the furnish in conventional amounts. The furnish is de-liquefied (e.g., by passing it over an inclined wire machine). 
         [0030]    The de-liquefied sheet is dried. 
         [0031]    This dried sheet is then consolidated with heat and pressure. The amount of heat and pressure will be dependent upon the choice of resin. In one embodiment, when PPS is used as the resin, the temperature may be about 590° F. (range may be 545-645° F., or 580-610° F., &amp; all subsets thereof), and the pressure may be about 100 psi (range may be 50-350 psi, or 50-250 psi, &amp; all subsets thereof). Consolidation may be accomplished, for example, in a heated platen press or double belt press, or by bringing the material to temperature and calendering. To obtain the desired basis weight, it may be necessary to laid up several (2+) of the de-liquefied sheets and consolidate the laid-up sheets together. Alternatively, the de-liquefied sheet may have the desired basis weight and no lay-up is necessary. 
         [0032]    The consolidated sheet is then formed into the vehicle interior panel. The consolidated sheet may also be formed by any suitable process. Such processes include, for example, molding (match or stamp), vacuum forming, autoclaving, or a combination thereof. The parameters of these processes will be governed by choice of resin, thickness and weight of the consolidated sheet, to name a few, as will be understood by those of ordinary skill. 
         [0033]    Before, after, or during the formation of the vehicle interior panel, the panel may be laminated with a film (e.g., a thermoplastic film that adds protection and/or a decorative aspect to the panel). 
         [0034]    The invention may be further understood by reference to the following examples of the invention and their comparison to existing products used as vehicle interiors, panels, and trim pieces. 
       EXAMPLES 
       [0035]    In the following Table, the present invention is compared to materials currently being used as vehicle interior panels. 
         [0000]    
       
         
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
           
               
                   
               
               
                   
                 KYDEX 
                 KYDEX 
                 KYDEX 
                 BOLTARON 
                 ULTEM 
                 ULTEM 
                 INVENTION 
                 INVENTION 
               
               
                   
                 0.125″ 
                 0.125″ 
                 0.125″ 
                 0.125″ 
                 0.126″ 
                 0.126″ 
                 0.054″ 
                 0.062″ 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Product 
                 FSTH 
                 6565 
                 6200 
                 9915FST 
                 0% glass 
                 30% glass 
                 40% C/60% 
                 40% C/60% 
               
               
                 Designation 
                   
                   
                   
                   
                   
                   
                 PPS 
                 PPS 
               
               
                 Full Compliance 
                 YES 
                 NO 
                 NO 
                 YES 
                 YES 
                 YES 
                 YES 
                 YES 
               
               
                 with FAR 25.853 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Chemical 
                 Acrylic/ 
                 Acrylic/ 
                 Acrylic/ 
                 Acrylic/ 
                 PEI 
                 PEI/Glass 
                 Carbon fiber/ 
                 Carbon fiber/ 
               
               
                 Components 
                 PVC/ 
                 PVC 
                 PVC 
                 PVC/ 
                   
                   
                 PPS 
                 PPS 
               
               
                   
                 LEXAN 
                   
                   
                 LEXAN 
                   
                   
                   
                   
               
               
                 Thickness range 
                 0.060-0.187 
                 0.028+ 
                 0.028+ 
                 0.040-0.187 
                 0.003-4.0 
                 0.003-4.0 
                 0.006+ 
                 0.006+ 
               
               
                 offered (inch) 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Specific Gravity 
                 1.34 
                 1.46-1.49 
                 1.38 
                 1.34 
                 1.27 
                 1.51 
                 1.22 
                 1.31 
               
               
                 Weight 4′ × 8′ 
                 27.87 
                 30.37/ 
                 28.7 
                 27.87 
                 26.62 
                 31.65 
                 10.96 
                 13.51 
               
               
                 sheet (pounds) 
                   
                 30.99 
                   
                   
                   
                   
                 [0.125″-27.1] 
                 [0.125″-27.1] 
               
               
                 Tensile Strength 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 ASTM 938 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 (PSI) 
                 10,400 
                 6,500 
                 6,000 
                 10,600 
                 16,000 
                 24,500 
                 32,778/21,175 
                 19,290/19,580 
               
               
                 (MPa) 
                 74 
                 45 
                 41 
                 73 
                 110.38 
                 169 
                 226/146 
                 133/135 
               
               
                   
                   
                   
                   
                   
                   
                   
                 [MD/TD] 
                 [MD/TD] 
               
               
                 Flexural Strength 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 ASTM D-790 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 (PSI) 
                 16,600 
                 10,000 
                 9,200 
                 16,700 
                 23,900 
                 33,000 
                 37,410/41,615 
                 23,780/44,865 
               
               
                 (MPa) 
                 107 
                 70 
                 63 
                 115 
                 151.7 
                 227 
                 258/287 
                 164/309 
               
               
                 Flex Modulus 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 ASTM D-790 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 (PSI) 
                 362,000 
                 420,000 
                   
                 363,000 
                 509,000 
                 1,300,000 
                 1,122,591/ 
                 461,220/ 
               
               
                 (MPa) 
                 2,320 
                 2,896 
                   
                 2,502 
                 3,510 
                 8,960 
                 1,372,056 
                 735,341 
               
               
                   
                   
                   
                   
                   
                   
                   
                 7,740/9,460 
                 3,180/5,070 
               
               
                 Impact 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Resistance 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Notched IZOD 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 ASTM D256 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 (J/m2) 
                 194 
                   
                 187 
                 265 
                 1326 
                 488 
                 22,000/15,800 
                 13,674/13,356 
               
               
                 (Ft-pounds/inch2) 
                 3.63 
                   
                 3.5 
                 5 
                 25.01 
                 9.2 
                 411/295 
                 258/252 
               
               
                 Rockwell 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Hardness ASTM 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 D 785 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 (R Scale) 
                 125 
                 98 
                   
                 107 
                 109 
                 114 
                   
                   
               
               
                 Molding Temp 
                 330-400 
                 325-390 
                   
                 360-400 
                   
                   
                 580-620 
                 580-620 
               
               
                 (° F.) 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
               
             
          
         
       
     
         [0036]    The present invention may be embodied in other forms without departing from the spirit and the essential attributes thereof, and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention.