Abstract:
The present invention provides a laminate material having a polyester film and a layer of polyester fibers cohesively bonded thereto. Generally, a metal layer deposited at least one surface of the laminate. The invention may also include a glass reinforced polymer layer formed on the laminated facer where the polymer of the glass reinforced polymer layer is commingled with the nonwoven of the laminated facer. The laminate may further include a second polymer layer having a thickness joined to the fiber layer and/or a layer of hot melt adhesive applied to the polyester fibers. Also presented is a composite material having a polyester film, a layer of polyester fibers bonded to the second polymer layer; a second polymer layer joined to the polyester film; and a glass reinforced polymer layer formed on the laminated facer, where the polymer of the glass reinforced polymer layer is commingled with the nonwoven of the laminated facer.

Description:
PRIORITY 
       [0001]    This Application is a Continuation-In-Part of U.S. Provisional Application Ser. No. 61/616,863, filed Mar. 28, 20012, entitled, “Laminate Facing for Fiber Reinforced Materials and Composite Materials Formed Therefrom” with Inventor: Thomas Miller. All aspects of Provisional Application Ser. No. 61/616,863 are hereby incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    Polypropylene films are often used as surface materials for laminates and composite materials and are known for use in lining trucks and refrigerated shipping containers. Typically, the polypropylene film is bonded to a nonwoven. The polypropylene face layer is not a suitably durable, temperature resistant or chemically inert surface. The polypropylene facers are generally not suitable for use with a thermoset composite due to adherence issues and temperature resistance. Polypropylene is typically porous and difficult to clean and is therefore generally not suitable for use for a number of applications. The polypropylene laminate is formed with a film of polypropylene, to which a layer of polypropylene is extruded and the extruded polypropylene adheres to the film and the nonwoven material. The three-step process increases material costs, processing expense and material waste. 
       SUMMARY 
       [0003]    In accordance with embodiments, the present invention relates to laminate facings for fiber reinforced or composite materials and materials formed therefrom. The laminate facings are generally formed of a polyester film layer bonded directly to a nonwoven fibrous layer. The facings are cohesively bonded to a nonwoven, typically roll bonded, point bonded or bonded any other suitable method, including coforming of the fiber layer on the film or the film layer on the fibrous layer directly such that the fibers and the polyester film facing are integrally joined without the use of an intermediate layer of adhesive or other polymer. The composite materials may be formed by applying the laminate to a surface and depositing fiber reinforced resin to the laminate or applying the laminate to the surface of a fiber-reinforced resin during manufacture. The laminate provides a rugged outer layer for composite materials and may reduce volatile organic compound emissions by replacing a gel coat layer. The laminate may also include a metalized layer such as aluminum, molybdenum, tantalum, titanium, nickel, and tungsten. The metalized layer improves thermal properties by forming a radiant barrier and also improves opacity of the facing and provides an aesthetically pleasing appearance. 
         [0004]    In accordance with embodiments of the present invention the films may be produced by conventional forming such as casting, blowing, and extrusion or coextrusion processes. The extruded films are created with a single layer made from an extrudable thermoplastic polymer and may include one or more exterior layers. One suitable exterior layer includes a relatively low melting point heat sealable polymer to improve the bonding of the film to the fibrous layer. The bonding material of the film is a heat sealable polymer layer designed to melt bond to the polymer of the fiber layer. In an alternate embodiment of the present invention, a metal layer deposited on one surface or both surfaces of the laminate. 
         [0005]    In accordance with an alternate embodiment of the present invention is presented having a composite material of a laminated facer having a polyester film with a thickness of 0.5-5 mil and a layer of polyester fibers having a density of 17-100 GSM bonded thereto; and a glass reinforced polymer layer formed on the laminated facer where the polymer of the glass reinforced polymer layer is commingled with the nonwoven of the laminated facer. 
         [0006]    In accordance with an alternate embodiment of the present invention is presented having a laminate material having a polyester film having a thickness of 0.5-2 mil, a layer of polyester fibers having a density of 17-70 GSM bonded to the polyester film and a second polymer layer having a thickness of 0.5-5.5 mil joined to the polyester fibers. 
         [0007]    In accordance with an alternate embodiment of the present invention is presented having a composite material having a polyester film having a thickness of 0.5-2 mil, a layer of polyester fibers having a density of 17-70 GSM bonded to the film, a second polymer layer having a thickness of 0.5-5.5 mil joined to the polyester fibers and a glass reinforced polymer layer formed on the laminated facer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    A more complete appreciation of the invention and the many embodiments thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
           [0009]      FIG. 1A  illustrates a plan view of the formation of the laminate material in accordance with one aspect of the present invention; 
           [0010]      FIG. 1B  illustrates a plan view of the formation of the laminate material in accordance with another aspect of the present invention; 
           [0011]      FIG. 2A  illustrates a plan view of the printing of the laminate material in accordance with one aspect of the present invention. 
           [0012]      FIG. 2B  illustrates a plan view of the metallization of the laminate material in accordance with one aspect of the present invention. 
           [0013]      FIG. 3  illustrates a plan view of the composite material of the present invention with a laminate layer and a non-woven included. 
           [0014]      FIG. 4A  is a schematic top view of the laminate of the present invention 
           [0015]      FIG. 4B  is a schematic cross sectional view of the laminate of the present invention. 
           [0016]      FIG. 5  is a schematic cross sectional view of another laminate of the present invention including an adhesive layer or filler layer applied to the nonwoven layer 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    The present invention will now be described with occasional reference to the specific embodiments of the invention. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
         [0018]    Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 
         [0019]    Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth as used in the specification and claims are to be understood as being modified in all instances by the term “about”. Accordingly, unless otherwise indicated, the numerical properties set forth in the specification and claims are approximations that may vary depending on the desired properties sought to be obtained in embodiments of the present invention. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from error found in their respective measurements. 
         [0020]    Fibrous nonwoven webs provide an improved bonding surface between a polymer film layer and a fiber reinforced polymer composite material. Nonwoven webs may be formed from a number of processes including, spunbond, or meltblown. Meltblown fibers are formed by extruding molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into a high velocity gas stream to attenuate the fibers. Spunbond fibers are formed by extruding a molten thermoplastic material from capillaries in a spinneret and being reducing the diameter by mechanical or fluid-drawing. 
         [0021]    The web may be bonded to improve mechanical properties. Many bonding methods are available including powder bonding using a powdered adhesive added to the web and then typically heated. Another bonding method is point or pattern bonding using heated calender rolls or ultrasonic bonding equipment to bond the fibers together. Point bonding provides for a secure bonding of the nonwoven to the polyester film while leaving unbonded fibers available to commingle with the composite laminate or other coating resin. Roll bonding may be used to bond the web across its entire surface. Bicomponent staple fibers may be used in the process as well. 
         [0022]    As seen in  FIG. 1A , roll  16  of polymer film  18  and roll  12  of nonwoven  14  is laminated by calender rolls  20 ,  22 . The resulting laminate  24  is taken up roll  26 . The polymer film is preferably 0.5-5.0 mil thick. A polyester film such as polyethylene terephthalate sold under the trade names Mylar, Skyrol, Melinex or Hostaphan may be used. Generally, the bonding temperature is 130-180° C. Preferably, a temperature of about 140-170° C. is be used in the bonding process. The fibers and the polyester film facing are cohesively bound, that is, integrally joined without the use of an intermediate layer of adhesive or other polymer. Optionally, a peel ply, such as a 1 mil PET ply may also be included on the polymer film layer to protect the surface. As shown in TABLE 1, a layer of polypropylene or another polymer or a lower grade of polyester may be applied to the nonwoven. The use of lower cost polymers may substantially decrease the overall cost of the material without substantially altering the properties. 
         [0023]    In  FIG. 1B , the polymer film  18  in taken off roll and fed into nonwoven fiber deposition device  10  such that nonwoven  12  is applied to film  18  and the nonwoven  12  and film  18  are laminated by calender rolls  20 ,  22 . The resulting laminate  24  is taken up roll  26 . 
         [0024]      FIG. 2A  shows the printing process in which laminate  24  is unrolled from roll  26  fed through a printing device to form a printed laminate  30  that is rolled onto take-up roll  32 . 
         [0025]      FIG. 2B  shows the vapor deposition of metallic compounds in which laminate  24  is unrolled from roll  26  fed through a deposition device to form a metalized laminate  30  which is rolled onto take-up roll  32 . Various deposition methods may be used including chemical vapor deposition, physical vapor deposition. Metals such as molybdenum, tantalum, titanium, nickel, and tungsten are generally applied by CVD. For the deposition of aluminum, CVD may be used with tri-isobutyl aluminum, tri ethyl/methyl aluminum, or dimethyl aluminum hydride precursors or a physical deposition process may be used. Electrostatic spray assisted vapor deposition, plasma and electron-beam deposition may also be used. The metalized layer may be formed on either the polyester film layer or the non-woven layer. It may also be advantageous to deposit a metallic coating on both sides of the laminate for improved coverage, durability, and aesthetics. 
         [0026]      FIG. 3  shows a composite material  38  including a resin layer  36  including fibers  40  and laminate  24 . Laminate  24  includes polymer film layer  18  bonded to nonwoven  14 . The resin  36  infuses into the fibers of the nonwoven layer to provide an integrated mechanical bond. The mechanical bond formed between the resin  36  and the fibers of nonwoven layer  14  is substantially stronger than the chemical bond formed between the resin and the surface of the polymer layer  18 . Any resin infusion technology, such as liquid molding, resin transfer molding, vacuum assisted resin transfer molding, vacuum infusion processing and composite infusion molding processing as well as vacuum bag molding, open molding, press molding, may be used to form composite member  38 . Other processes such as hot calendering of the laminate onto the resin layer or use of the laminate as a surface film in pulltrusion may be used to form composite member  38 . 
         [0027]      FIG. 4A  and  FIG. 4B  show the point bonded laminate of the present invention including a non-woven layer  14  positioned on poly film  18 . The point bonding sites  14 ′ are formed by rollers  20 ,  22  (as shown in  FIG. 1 ). The point bond sites  14 ′ are substantially compressed such that the polymer of the fibers in the nonwoven  14  is integrally joined with the polymer of the film  18 . One or both of the rollers  20 ,  22  may be heated to melt the fibers of film  14  although it is possible to meld the fibers using pressure alone. 
         [0028]      FIG. 5  shows another embodiment of the laminate  44  including a polymer film  18 , a fibrous layer  24  and a polymer layer  46  applied to the nonwoven layer with bonding sites  14 ′ bonding film  18  to fibers  24 . The laminate may be formed as described above to form a laminate material having a polyester film having a thickness of  0 . 5 -2 mil; a layer of polyester fibers having a density of 17-70 GSM bonded polyester film and a polymer layer of polyester, polyurethane, polypropylene, polyethylene, polyurea and polyvinyl chloride. A second polymer 46 may also be a hot melt adhesive applied to the fibers. The hotmelt adhesives may be any known including Ethylene-vinyl acetate (EVA) copolymers, Ethylene-acrylate copolymers such as ethylene n-butyl acrylate (EnBA), ethylene-acrylic acid (EAA) and ethylene-ethyl acetate (EEA), Polyolefins such as low or high density polyethylene, atactic polypropylene, polybutene-1, and oxidized polyethylene, Polybutene-1 and its copolymers, Amorphous polyolefin polymers, Polyamides and polyesters, Polyurethanes, Thermoplastic polyurethane, reactive urethanes, Styrene block copolymers such as Styrene-butadiene-styrene such as Styrene-isoprene-styrene, Styrene-ethylene/butylene-styrene, and Styrene-ethylene/propylene. Other hotmelt adhesives may include Polycaprolactone Polycarbonates, Fluoropolymers, Silicone rubbers, Thermoplastic elastomers and Polypyrrole may also be used. 
         [0029]    The laminate and composite material of the present invention is suitable for use in any composite structures including truck and trailer liners, refrigerated shipping container liners, ladder rails, tool handles, window lineals, structural materials, wall panels for use in food preparation, health care or sanitary applications, wall panels for recreational vehicles, polls and cross arms, pilings or other infrastructure applications, and signage; or electronic materials such as substrates for electronic boards, laminates for solar panels, integrated circuits, industrial switching, capacitors, and electrical boards; and insulation such as foam facers, glass or mineral wool facers, and radiant heat barriers. 
       EXAMPLES 
       [0030]    Generally, polyester layers are combined with nonwoven layers a wide range of potential laminates is shown in TABLE 1. As shown the face of the polymer film is metalized as shown in trials 5 and 6. The polyester film used in each trial was 20 microns; however, any number of films are suitable. The spunbond nonwoven ranges from 34-65 GSM. The nonwoven is metalized in trials 4 and 6. The metallization of the fibers provides a dull metallic look that is protected from wear in the final composite material. The PP/Glass composite fiber is 50% glass fibers and 50% polypropylene fibers. The polypropylene layer is applied at 108 GSM (˜3.5 mils thick). The use of a second polymer layer improves the strength of the final bond to the composite board, improving the shear strength from 175 PSI to 235 PSI. 
         [0000]    
       
         
               
               
               
             
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                   
                   
                 Trial Number 
               
             
          
           
               
                 Layer 
                 unit 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
               
               
                   
               
               
                 Metalized 
                   
                   
                   
                   
                   
                 Y 
                 Y 
                   
               
               
                 Film 
                 Microns 
                 20 
                 20 
                  20 
                 20 
                 20 
                 20 
                  20 
               
               
                 Spunbond 
                 GSM 
                 65 
                 34 
                  34 
                 34 
                 34 
                 34 
                  34 
               
               
                 Metalized 
                   
                   
                   
                   
                 Y 
                   
                 Y 
                   
               
               
                 PP Coating  
                 GSM 
                   
                   
                 108 
                   
                   
                   
                   
               
               
                 Composite 
                 PP/Glass % 
                 50/50 
                 50/50  
                 50/50  
                 50/50 
                 50/50 
                 50/50 
                 50/50 
               
               
                 Shear 
                 PSI 
                   
                   
                 235 
                   
                   
                   
                 175 
               
               
                 Strength 
               
               
                   
               
             
          
         
       
     
         [0031]    The present invention should not be considered limited to the specific examples described herein, but rather should be understood to cover all aspects of the invention. Various modifications, equivalent processes, as well as numerous structures and devices to which the present invention may be applicable will be readily apparent to those of skill in the art. Those skilled in the art will understand that various changes may be made without departing from the scope of the invention, which is not to be considered limited to what is described in the specification.