Patent Abstract:
A method of manufacturing a structural member includes preheating a plurality of fibers to a first temperature, moving the preheated fibers along an assembly line, applying a binder to at least one of the preheated fibers, providing a die shaped to receive the preheated fibers, wherein the die moves together with the preheated fibers along at least a portion of the assembly line, maintaining a temperature of the plurality of fibers at a temperature substantially similar to the first temperature, and compressing the plurality of fibers within the die while maintaining a temperature.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 61/855,080 filed on May 7, 2013, the entire content of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a method of manufacturing composite materials, and more particularly to a method of manufacturing fiber reinforced polymer materials. 
     BACKGROUND 
     Fiber reinforced polymers include a fiber material bound by a matrix, typically provided by a binder, such as a resin. Fiber reinforced polymers are conventionally manufactured using a pultrusion process, an example of which is illustrated in  FIG. 1 . 
     In the pultrusion process, incoming fiber  5  is pulled through a production line  10  by a pulling mechanism  15 , such as a pair of driven rollers  20 . The fiber  5  is drawn into a bath  25  containing one of a variety of binders. Once wetted, the fiber  5  is drawn through a static die  30  that may have one or more heating zones to initiate curing of the binder. In the pultrusion process, the die  30  serves several functions. It creates pressure to promote wetting of the fiber  5 , heats the binder and the fiber  5 , controls curing of the binder, and controls the final shape of pultruded product. 
     Binders have curing profiles that are dictated by chemical reactions (curing, crosslinking, drying, etc.). These curing profiles are functions of the chemical reactivity of the binder, process temperature, and dwell time at the process temperature. As production speeds increase, it becomes increasingly difficult to ensure proper curing of the binder. 
     The conventional pultrusion process illustrated in  FIG. 1  has inherent constraints that severely hinder the speed of the process. The length of the die  30  is the primary constraint on the speed of the process, with process temperature, process friction, and process gas removal providing other limiting constraints. The binder bath  25  presents its own drawbacks, including difficulty mixing and maintaining multi-part, reactive binders, undue amounts of waste, and high operating costs due to the typically large volume of binder needed to fill the bath  25 . It has previously not been cost-effective to manufacture fiber reinforced products, especially if one or more fast-curing thermosetting polymers and/or a multi-component thermosetting polymer are utilized as a portion of the binder, for at least the reasons listed above. 
     SUMMARY 
     In some embodiments, the invention provides a method of manufacturing a structural member. The method includes preheating a plurality of fibers to a first temperature, moving the preheated fibers along an assembly line and applying a binder to at least one of the preheated fibers, wherein when the binder is applied, the fibers are spaced apart and extend across a first area. The method further includes providing a die having a first portion with a first diameter positioned to receive the preheated fibers and a second portion with a second diameter positioned downstream of the first portion, wherein the first diameter is greater than the second diameter and wherein the die is tapered between the first portion and the second portion. After applying the binder, the method further includes guiding the plurality of fibers along the die. The method further includes decreasing a distance between the plurality of fibers with the die, wherein after decreasing the distance between the plurality of fibers, the fibers extend across a second area that is smaller than the first area, and after decreasing, maintaining the temperature of the plurality of fibers at a temperature substantially similar to the first temperature. The method further includes while maintaining the temperature, shaping the plurality of fibers with a first shaping station, while maintaining the temperature, shaping the plurality of fibers with a second shaping station, spaced from the first shaping station and while maintaining the temperature, shaping the plurality of fibers with a third shaping station, spaced from the first and second shaping stations. 
     In some embodiments, the invention provides a method of manufacturing a structural member. The method includes preheating a plurality of fibers to a first temperature, moving the preheated fibers along an assembly line and applying a binder to at least one of the preheated fibers, wherein when the binder is applied, the fibers are spaced apart and extend across a first area. Applying the binder includes at least one of the following steps: spraying the binder on the at least one of the plurality of fibers, and extruding the binder from a pressurized chamber and dragging the at least one fiber through the extruded binder. After applying the binder, the method further includes guiding the preheated fibers along a die and decreasing a distance between the plurality of fibers with the die, wherein after decreasing the distance between the plurality of fibers, the fibers extend across a second area that is smaller than the first area. After decreasing, the method further includes maintaining the temperature of the plurality of fibers at a temperature substantially similar to the first temperature. The method further includes shaping the plurality of fibers with a first shaping station while maintaining the temperature, shaping the plurality of fibers with a second shaping station, spaced from the first shaping station while maintaining the temperature, and shaping the plurality of fibers with a third shaping station, spaced from the first and second shaping stations while maintaining the temperature. 
     In some embodiments, the invention includes a method of manufacturing a continuous structural member. The method includes preheating a plurality of fibers to a first temperature, moving the preheated fibers along an assembly line, applying a binder to at least one of the preheated fibers, providing a die shaped to receive the preheated fibers, wherein the die moves together with the preheated fibers along at least a portion of the assembly line, maintaining a temperature of the plurality of fibers at a temperature substantially similar to the first temperature, and compressing the plurality of fibers within the die while maintaining a temperature. 
     Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic representation of a typical pultrusion process. 
         FIG. 2  is a schematic representation of an assembly line according to some embodiments of the invention. 
         FIG. 3  is a perspective view of a portion of the assembly line of  FIG. 2 . 
         FIG. 4  is a perspective view of a portion of the assembly line of  FIG. 2 . 
         FIG. 5  illustrates a binder application assembly according to one embodiment for use in the assembly line of  FIG. 2 . 
         FIGS. 6 and 7  illustrate a binder application assembly according to some embodiments for use in the assembly line of  FIG. 2 . 
         FIG. 8  is a perspective view of another portion of the assembly line of  FIG. 2 , illustrating a die being curled around a length of wetted fibers. 
         FIG. 9  is a perspective representation of the die being curled around the length of wetted fibers. 
         FIG. 10  is an end view of a shaping station of the assembly line of  FIG. 2 . 
         FIG. 11  is a schematic representation of a shaping station according to some embodiments. 
         FIG. 12  is a schematic representation of a shaping station according to some embodiments. 
         FIG. 13  is a schematic representation of a shaping station according to some embodiments. 
         FIG. 14  is a schematic representation of a shaping station according to some embodiments. 
         FIG. 15  is a schematic representation of a shaping station according to some embodiments. 
         FIG. 16  is a schematic representation of a shaping station according to some embodiments. 
     
    
    
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
     DETAILED DESCRIPTION 
       FIGS. 2 and 3  illustrate an assembly line  100  for manufacturing fiber-reinforced polymer (FRP) structural composites (i.e. matrix composites). The structural composites may form a wide variety of structural members, such as rebar, I-beams, C-channels, tubes, structural laminates, and the like. The illustrated assembly line  100  includes a roving station  105 , a binder application station  110 , and a plurality of shaping stations  115 . In some embodiments, additional or alternative stations may be included in the assembly line  100 . The assembly line  100  is generally linear and defines a central axis  120  along which the structural composite is produced ( FIG. 3 ). As described in greater detail herein, the assembly line  100  enables FRP structural composites to be continuously manufactured at high speed. 
     The roving station  105  includes a plurality of spools or bobbins  125  that support and dispense strands or rovings of fiber  130  to be included in the structural composite. In the illustrated embodiment, the fiber  130  includes basalt; however, the fiber  130  may include glass, aramid, carbon, or any other desired fiber material. The bobbins  125  may be coupled to a power drive system that controls the fiber feed rate. In such embodiments, dancers or other automatic tensioning devices (not shown) may be provided to maintain a consistent tension on the fibers  130 . 
     After being dispensed from the bobbins  125 , the fibers  130  pass through a guide assembly  135  that arranges the fibers  130  for wetting at the binder application station  110  ( FIGS. 3 and 4 ). In some embodiments, the guide assembly  135  may arrange the fibers  130  in a plane to provide a relatively large, rectangular surface area for wetting. Alternatively, the guide assembly  135  may arrange the fibers  130  into other patterns, such as cylindrical, tubular, or spiral patterns. 
     In some embodiments, the roving station  105  includes one or more heating elements (not shown) to preheat the fibers  130  to a desired temperature before they are dispensed to the binder application station  110 . The heating elements may be located internally within the bobbins  125 , or may be external to the bobbins  125 . For example, heated air may be directed over the fibers  130  as they leave the roving station  105 . Preheating the fibers  130  may reduce the energy input required at the binder application station  110  and may help stabilize the binder curing process, described in greater detail below. 
     Due to the relatively small diameter of the fibers (when compared to the diameter of the grouped fibers in the die and shaping stations), less time and/or energy is required to preheat the individual fibers than would be required to heat the grouped fibers in one or more of the shaping stations. The shaping stations are operable to maintain the elevated temperature of the preheated fibers. In some embodiments, the binder is heated prior to being applied to the fibers  130 . 
     With reference to  FIGS. 2 and 3 , the binder application station  110  is located downstream of the roving station  105  such that fibers  130  exiting the guide assembly  135  are drawn into the binder application station  110  to be wetted with a binder, such as a resin. In the illustrated embodiment, the binder is a thermosetting polymer such as a phenolic resin or an epoxy resin. In other embodiments, the binder may include polyester, vinyl ester, Portland cement, or any other suitable binder. 
     The binder application station  110  is operable to apply a desired amount of binder to the fibers in a precisely metered manner. Specifically, depending upon the desired ratio of binder to fibers, the appropriate amount of binder can be applied directly to the fibers. This is in direct contrast to the binder bath shown in  FIG. 1  which does not control the amount of binder that is applied to the fibers. The excess binder must be removed and thus, more waste is created. Also, the entire binder bath must be maintained at the appropriate temperature which is a waste of energy to heat the extra binder, especially when some of the heated binder is removed from the fibers. Also, the product produced with the binder bath can be inconsistent because the ratio of fibers to binder is not controlled. In the present invention, the quantity of binder applied to the fibers can be controlled to assure the desired quality and consistency of the product produced. 
       FIGS. 3-5  illustrate one embodiment of the binder application station  110 . In the illustrated embodiment, the binder application station  110  includes a pressurized well  140 . The pressurized well  140  receives the binder from a binder source  145 , such as a hopper or storage vessel ( FIG. 2 ). The well  140  includes an end plate  150  having an inlet opening  155  through which the binder may be injected ( FIG. 5 ). The binder is then extruded under pressure through a plurality of channels  160  extending radially-outwardly from the inlet opening  155 . The channels  160  communicate with wetting regions  165  located at an outer periphery of the end plate  150 . 
     During operation, the binder is continuously extruded through the channels  160  and into the wetting regions  165 . The fibers  130  pass through the wetting regions  165  to be wetted with the binder, beginning the formation of the matrix composite. In the illustrated embodiment, the end plate  150  includes two wetting regions  165  offset from each other by about 180 degrees. Thus, the fibers  130  may be arranged along two paths that are wet simultaneously. The fibers  130  are spaced apart while traveling through the wetting regions  165  to promote thorough coating of the fibers  130  with the binder. In other embodiments, the end plate  150  may include any number of wetting regions. The operating pressure of the well  140  and the number and size of the channels  160  may be variable to provide a desired wetting rate. 
       FIGS. 6 and 7  illustrate portions of a binder application station  110   a  according to another embodiment. The binder application station  110   a  can be utilized with any of the embodiments described herein. In some embodiments, the binder application station  110   a  is utilized in addition to the binder application station illustrated and described in other embodiments, whereas in other embodiments, the binder application station  110   a  is utilized in the place of the binder application station illustrated and described in other embodiments. In the illustrated embodiment, the binder application station  110   a  includes a die  170  that guides the incoming fibers  130  into a generally tapered or conical arrangement. The die  170  can be capable of moving in a longitudinal direction (i.e. along the central axis  120 ). This movement may facilitate formation of the incoming fibers  130  into a generally continuous wall or sheet. The binder application station  110   a  includes a spray nozzle  175  that receives binder from the binder source  145  ( FIG. 2 ) and is operable to spray a stream of binder against the incoming fibers  130 . The position of the nozzle  175  may be modified in the longitudinal direction to adjust the binder spray characteristics. 
     In yet another alternative embodiment, the binder application station may include a binder bath. After passing through the bath, the fibers  130  may be routed through a series of parallel rollers to mechanically agitate and physically force the binder into the passing fibers. The binder content of the impregnated fibers may be controlled using wipers and/or rollers. In addition, the binder content may be controlled by directing some of the fibers  130  to bypass the binder bath. 
     In this alternative embodiment, the assembly line  100  may further include an oven buncher station between the binder application station and the one or more shaping stations  115  to heat the binder impregnated fiber  130 , finish the wetting process, begin the curing process, and roughly form the wetted fibers. In addition, the oven buncher station may include one or more drive rollers to pull the fibers from the roving station  105  and through the binder application station. 
     With reference to  FIGS. 2, 4, 8, and 9 , the assembly line  100  further includes a continuously-conformable translating die  180  that is wrapped around the wetted fibers  130  as they exit the binder application station  110 . The illustrated die  180  is a strip of paper fed from a roll  185  ( FIG. 4 ). The paper die  180  travels along the central axis  120  adjacent the wetted fibers  130 , and a series of Teflon guide plates  190  gradually curls the die  180  around the wetted fibers  130  until the die completely surrounds and encases the wetted fibers  130  ( FIGS. 8 and 9 ). As the wetted fibers  130  enter a first portion or entrance  195  of the die  180 , the fibers  130  are compressed from the relatively large, rectangular area into a smaller generally circular area corresponding with the diameter of the die at the entrance  195 . 
     The die  180  travels with the wetted fibers  130  through the remainder of the assembly line  100 . As described in greater detail below, the die  180  facilitates travel of the wetted fibers  130  through the shaping stations  115  by inhibiting the wetted fibers  130  from sticking to the shaping stations  115 . In addition, the die  180  constrains the wetted fibers  130  during curing, facilitates mixing of the binder and the fibers  130  to ensure thorough wetting, and helps to maintain a consistent curing pressure and temperature. 
     The process speed or product output rate of the assembly line  100  and any other continuous FRP manufacturing process is governed by the following equation:
 
Process Speed=Die Length/Resin Curing Time
 
     Because the continuously-conformable translating die  180  moves with the wetted fibers  130 , it can be many times longer than the static die  30  employed in the typical pultrusion process ( FIG. 1 ). Accordingly, the assembly line  100  may operate at a process speed many times greater than that of the typical pultrusion process. For example, if the translating die has a length of 2,000 feet, and the binder requires 2 minutes to cure, the assembly line  100  will have a potential process speed of 1,000 feet per minute. In some embodiments, the assembly line  100  is configured to have a process speed greater than about 20 feet per minute. In other embodiments, the assembly line  100  is configured to have a process speed between about 20 feet per minute and about 40 feet per minute. In other embodiments, the assembly line  100  is configured to have a process speed between about 40 feet per minute and about 60 feet per minute. In other embodiments, the assembly line  100  is configured to have a process speed between about 60 feet per minute and about 80 feet per minute. In other embodiments, the assembly line  100  is configured to have a process speed between about 80 feet per minute and about 100 feet per minute. In other embodiments, the assembly line  100  is configured to have a process speed between about 50 feet per minute and about 100 feet per minute. In other embodiments, the assembly line  100  is configured to have a process speed between about 20 feet per minute and about 100 feet per minute. In other embodiments, the assembly line  100  is configured to have a process speed between about 20 feet per minute and about 1,000 feet per minute. In other embodiments, the assembly line  100  is configured to have a process speed between about 100 feet per minute and about 1,000 feet per minute. 
     The paper die  180  may be coated with a release agent, such as silicone, to facilitate removal of the die  180  from the finished structural composite. In addition, the paper die  180  may be relatively porous to permit gas and vapor to be released through the die  180 . Alternatively, the die  180  may be substantially air tight. 
     The die  180  may include other substrate materials or combinations of materials applied to the wetted fibers  130  in various ways. For example, in some embodiments the die  180  may include a powder or a liquid (e.g., molten wax) that is applied to the wetted fibers  130  and subsequently hardened or cured using UV light, temperature, a chemical reactant, or other suitable means. In other embodiments, the die  180  may include a vapor releasing micro-porous membrane such as GORE-TEX. In other embodiments, the die  180  may include a macro-porous material such as a woven fabric or fiber mat. In yet other embodiments, the die  180  may include one or more metal films, such as non-sacrificial stainless steel, carbon steel cover, or copper etc. 
     In some embodiments the die  180  may be wetted by the binder to bind the die  180  to the matrix composite, thereby creating an integrated construction that includes all or a portion of the die  180 . Thus, the die material may be chosen to provide the produced structural composite with additional desired properties. For example, the die  180  may include an electrically-conductive material to provide electrical conductivity to an otherwise non-conducting composite. The die material may have an affinity to an external binding compound (e.g., Portland cement) to facilitate integration of the structural composite (e.g., rebar) into its particular application (e.g., reinforced concrete). 
     Now referring to  FIGS. 2-4 , the shaping stations  115  are located downstream of the binder application station  110 . In the illustrated embodiment, the assembly line  100  includes first, second, and third shaping stations  115  that are spaced from one another along the central axis  120  ( FIG. 2 ). In other embodiments, the assembly line  100  may include any number of shaping stations  115 . 
     The shaping stations  115  each include at least one guide that contacts and shapes the fibers  130 . In some embodiments, the guide can include one or more rollers with one or more slots sized to receive and shape the fibers  130 . In some embodiments, the guide can include one or more stationary or rotating dies that have one or more openings sized to receive and shape the fibers  130 . The slots in the rollers and the openings in the stationary dies can each have different shapes and sizes to mold the fibers  130  into different shapes and sizes. 
     Each of the illustrated shaping stations  115  includes a plurality of rollers  200 . The rollers  200  are arranged in pairs, and each includes a groove  205  through which the die-wrapped fibers  130  are rolled and shaped ( FIG. 10 ). In some embodiments, pairs of rollers  200  may be positioned in different orientations. For example, pairs of rollers  200  may alternate between horizontal and vertical orientations. Some or all of the rollers  200  may be driven using variable speed drive motors to draw the die  180  and fibers  130  through the assembly line  100 . 
     Referring again to  FIGS. 2 and 3 , each shaping station  115  can further include thermal transfer panels (not shown) to allow precise control of the process temperature. For example, each shaping station  115  may be controlled to maintain the wetted fibers  130  at a stable, controlled temperature that cures the binder at a rate of speed that corresponds to the process speed. The specific temperature is dependent upon the type of binder used and the process speed of the assembly line. In some embodiments, a phenolic resin is used as the binder and the fibers are maintained at a temperature of about 160 degrees Celsius. In some embodiments, an epoxy resin is used as the binder and the fibers are maintained at a temperature of between about 50 and about 90 degrees Celsius. Accordingly, the binder curing process may be completed while the shaped, wetted fibers  130  are traveling through the shaping stations  115 . 
     Process temperature can be controlled in multiple zones along the length of each shaping station  115  to promote or reduce the speed of curing along the length of the die  180 . The rollers  200  exert pressure on the die  180  to provide the required curing pressure. As the die  180  and fibers  130  pass between adjacent shaping stations  115 , the product may be cooled if desired (either by exposure to the ambient environment between the adjacent shaping stations  115  or through controlled cooling zones), and gas or vapor byproducts may be vented through the die  180 . This is not possible in a typical pultrusion process, as the static dies  30  ( FIG. 1 ) are typically impermeable. In some embodiments, one or more of the shaping stations  115  cool the die  180  and the fibers  130  to a temperature below the glass transition temperature of the binder. Therefore, the die  180  and fibers  130  dispensed from the shaping stations  115  can maintain its shape. In other embodiments, the die  180  and fibers  130  are not cooled below the glass transition temperature until after the die  180  and fibers  130  have exited the shaping stations  115  to permit final manipulation of the die  180  and fibers  130  into the desired final shape and/or formation of any surface configurations (such as, for example, ribs, protrusions, recesses and/or other suitable surface configurations). 
     In a typical process, gaps between any stations must be minimized so that proper support is offered to the fibers along an entire length of the assembly line. In contrast, the illustrated shaping stations  115  are spaced apart a distance in the die flow direction, because the die  180  provides sufficient supports to the fibers  130  between the shaping stations  115 . The space between the shaping stations  115  permits air and water to vent from the die  180  and fibers  130 . Further, the spaced apart shaping stations  115  extend across a longer distance than if the shaping stations  115  were directly adjacent. The increase in the overall distance of the shaping stations  115  permits the die  180  to move through the shaping stations  115  at a faster speed while still partially or fully curing in the shaping stations  115 . Therefore, by using more shaping stations  115  and spaced apart shaping stations  115 , the process speed can be increased, thereby increasing productivity and profitability. The distance between the shaping stations  115  also decreases the capital cost of building and installing the assembly, when compared to an arrangement in which shaping stations are adjacent for an entire length of the shaping assembly. The shaping stations  115  can be modular, such that one or more shaping stations  115  can be added, removed or repaired without a substantial loss of production. Instead of shutting down production of the entire assembly line (as would be required for units that utilized a single, stationary die), the production would be shut down for a brief period to permit addition, removal or replacement of one or more of the shaping stations  115 . The removed shaping station  115  can be repaired or stored while the assembly line is in operation. 
     With reference to  FIGS. 11-16 , one or more of the shaping stations  115  may also dynamically manipulate the die  180  and the fibers  130  to promote thorough wetting and homogeneous curing. Wetting is improved through shear viscosity changes that are induced by dynamically modifying the cross-sectional area of the matrix composite. Further shear mixing of the matrix composite can be induced by selectively increasing and decreasing the mechanical pressure applied by the shaping station  115 . In some embodiments, the shaping station  115  can be configured to have incomplete wet-out of the fibers  130  to improve the flexibility of the fibers  130  upon curing. 
     In some embodiments, the guides may be configured to progressively increase the applied mechanical pressure over the length of the die  180 . In some embodiments, the increase in pressure is created by moving the fibers  130  through a tapered stationary die that has an opening with a decreasing diameter along the length. In other embodiments, the increase in mechanical pressure can be created by moving the fibers  130  through a series of stationary dies, each of which has progressively smaller openings. In some embodiments, the holes in the stationary dies can have different shapes and sizes of openings to dynamically alter the cross-sectional shape of the die  180  and the fibers  130 . 
     In the embodiment illustrated in  FIG. 11 , the rollers  200  are configured to progressively increase the applied mechanical pressure over the length of the die  180 . As such, the cross-sectional area of the die  180  may decrease through each successive pair of rollers  200 . This promotes thorough wetting and compacting of the fibers  130 . In other embodiments, the rollers  200  may be configured to dynamically alter the cross-sectional shape of the die  180  and the fibers  130  ( FIGS. 12-15 ). For example the die  180  may be rolled into an oval shape that assumes different orientations at alternating roller pairs  200  to promote further shear mixing ( FIG. 12 ). Alternatively, die  180  may be rolled into a variety of other shapes, such as oval, circle, rectangle, square, triangle, etc. (see, for example,  FIG. 13 ). In other embodiments, one or more of the shaping stations  115  may twist the die  180  and the fibers  130  about the central axis  120  ( FIG. 14 ). In yet other embodiments, one or more of the shaping stations  115  may alternatingly increase and decrease the cross-sectional area of the die  180  ( FIG. 15 ). In still other embodiments, the rollers  200  may be offset to create undulations in the die  180  and the fibers  130  ( FIG. 16 ). Each of the shaping stations  115  can have different arrangements and configurations of rollers  200  and/or stationary dies. 
     In some embodiments, the assembly line  100  may further include a burn-off station  210  to thermally abrade the cured surface of the composite structure ( FIG. 2 ). The burn-off station  210  may be employed to remove the die, to expose portions of the fiber, and/or to provide a carbonaceous char that may have an affinity for an external binding compound like Portland cement. 
     In some embodiments, the assembly line  100  may further include a post-cure station  215 . The post-cure station  215  may include one or more heating elements to provide any necessary secondary curing time and temperature controls. In addition, the post-cure station  215  may include one or more machining devices operable to shape the structural composite into a desired final shape. For example, the structural composite may be bent or cut and folded into a C-channel shape, a spiral shape or other desirable shape. 
     In some embodiments, the assembly line  100  may further include a packaging station  220 . The packaging station  220  may include one or more cutting devices operable to cut the structural composite into a desired length for sale and shipping. The structural composite may be marked with product information, branding information, or other indicia, and then packaged for shipping. 
     In operation, a plurality of fibers  130  is dispensed from the roving station  105  and moved along the assembly line  100  to the binder application station  110 . The fibers  130  are generally spaced apart as they enter the binder application station  110  such that the fibers  130  extend across a first, relatively large surface area. After being wetted with binder, the wetted fibers  130  are guided into the first portion  195  of the die  180  proximate the binder application station  110 , and the die  180  is curved to wrap around the wetted fibers  130 . As the die  180  is wrapped around the wetted fibers  130 , the fibers  130  are compressed together. The wetted fibers  130 , encased by the die  180 , are then fed into the shaping stations  115 . 
     In the shaping stations  115 , the die  180  and the wetted fibers  130  are compressed between the guides, such as the sets of rollers  200  or the stationary dies to mix the binder and the fibers  130 , to form the product shape. The die  180  separates the wetted fibers  130  from the rollers  200  and/or the stationary dies in order to prevent the binder from sticking to the rollers  200  and/or the stationary dies. Heat is applied throughout the shaping stations  115  to promote curing of the binder. As the die  180  travels between adjacent shaping stations, the matrix may cool and/or expel gas and vapor byproducts. 
     In some embodiments, sand may be applied to the die  180  and/or the fibers  130  before or after curing has been completed. The sand may be chosen to improve physical bond characteristics between the final composite of the fibers  130  and the binder and the material the final composite will be connected to, such as, for example, concrete. 
     Various features of the invention are set forth in the following claims.

Technology Classification (CPC): 1