Abstract:
A fiber includes a base having a surface to be impacted by a fluid wave for propelling the fiber forward and a body having a trailing end connected to the base, a leading free end, and a spiral shape causing the fluid wave to rotate the fiber. A locking system causes the fiber to engage and hold at least one other fiber being propelled and rotated by the fluid wave.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This is a divisional application of application Ser. No. 11/636,740, filed Dec. 11, 2006; the prior application is herewith incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to a fiber for producing three-dimensional, self-interlacing composites. 
         [0004]    2. Description of the Related Art 
         [0005]    The reinforcing elements of most lightweight composites are high tensile strength fibers of compounds or polymers, such as fiberglass or carbon fiber or other suitable reinforcing fibers used in composites. Woven or unwoven, those layers of fibers are limited to two-dimensional interlacements. The fiber “becomes the strength” of the finished composite, and are layered into pre-made forms or molds and hardened into desired shapes by hardening binders. Different fiber patterns, fiber “tape” or even sprayed, non-interlacing short fibers fail to improve the fiber integrity. Two-dimensional orientations of the fibers give superb strength in the single plane of the XY (east-west and north-south) axis, due to crisscrossing, interlacing, or interlocking of fibers, which create “in effect” a continuous and locked fiber. Since no effective fibers run between the layers, to complete a true “vertical” interlocking in the third dimension, those materials have a much reduced strength in this Z (front to back) axis. It is only in flat or gently curving forms like boats or tubes, where the material can be formed with good overlap, minimal distortion or cutting of the fibers and where stresses can be restricted to the two dimensions or “in plane” with the directions of interlacements, that the strength of the composite is preserved. The fibers&#39; own rigidity restricts stretching and makes layering in irregular or hyper-contoured molds very difficult. To fold, distort or cut the remaining interlinking or to use chopped fibers which have zero interlinking is so destructive to strength integrity as to make the techniques unwise. 
         [0006]    A contoured composite object, formed with destroyed XY axis strength (no interlinking) and no Z axis strength (no interlinking) has little tensile strength in any direction, and failures or delaminations occur because there are no remaining effective strength elements, just a “weak glued-together mixture”. The integrity of the fiber continuity is everything in composites because the hardening binders carry no significant portion of the stress loads. 
       SUMMARY OF THE INVENTION 
       [0007]    It is accordingly an object of the invention to provide a fiber and a process for producing three-dimensional, self-interlacing composites by mechanical polymerization with ultrasonic manipulation, which overcome the hereinafore-mentioned disadvantages of the heretofore-known fibers and processes of this general type and which provide improved strength in three axial directions. 
         [0008]    According to the invention, the “lack of cross-linking” failure is overcome by creating an effective mechanical method for cross-linking of the fibers in a true three dimensional, three (XYZ) axis array for an enhanced quality, and high tensile strength in complex composite shapes. 
         [0009]    With the foregoing and other objects in view there is provided, in accordance with the invention, a fiber. The fiber comprises a base having a surface to be impacted by a fluid wave for propelling the fiber forward and a body having a trailing end connected to the base, a leading free end, and a spiral shape causing the fluid wave to rotate the fiber. A locking system causes the fiber to engage and hold at least one other fiber being propelled and rotated by the fluid wave. The fibers are locked together in random positions in three dimensions, providing increased strength and integrity of a composite formed of the fibers in the X, Y and Z directions. 
         [0010]    In accordance with another feature of the invention, the surface of the base is concave, hemispherical, frustoconical, substantially unobstructed or provided by two webs describing an acute angle therebetween. In each of these embodiments, a surface is provided to be impacted by the waves for propagation in substantially one general direction. The webs may include one flat and one structured web together imparting turbulence to the fiber. 
         [0011]    In accordance with a further feature of the invention, the body has at least one gap formed therein, such as between nodes of intertwined arms and/or the base has a hole formed therein and/or the body has protrusions or teeth disposed thereon and/or the body is a single arm bent in a spiral. The leading free end has a tip with a blunt, rounded, pointed or flat shape. The locking system includes the at least one gap, hole, protrusions, teeth or spiral arm and the leading free end engaging and holding the same in at least one other fiber. Thus, a reliable interlinking occurs, due to the locking system, in three dimensions. 
         [0012]    In accordance with an added feature of the invention, the entire fiber is formed of carbon or fiberglass or most any high tensile strength material used in composites. 
         [0013]    With the objects of the invention in view, there is also provided a process for producing three-dimensional, self-interlacing composites by mechanical polymerization with ultrasonic manipulation. The process comprises placing fibers according to the invention and a mixing fluid in a form or mold. The fluid is subjected to ultrasonic manipulation in a mixing step causing the fibers to be propelled, rotated and three-dimensionally engaged and held to one another. 
         [0014]    In accordance with another mode of the invention, the mixing fluid includes a resin or binder or a resin or binder is added to the mixing fluid. After the mixing step, additional premixed fibers are compressed into the form or mold for achieving a desired fiber density. If necessary, the mixing liquid is then evacuated, and the resin or binder and the engaged fibers are then allowed to harden. The fibers are bonded into a composite by setting, hardening or polymerizing with the resin or binder. The mixing liquid may be alcohol or water. The fibers may have lengths between 1 mm and several centimeters and aspect ratios of length to width of from 2:1 to 50:1. 
         [0015]    In accordance with a further mode of the invention, the ultrasonic manipulation of the fibers is controlled for three-dimensionally engaging the fibers and substantially fill all regions of the form or mold. In this way, a uniform strength is provided throughout the composite. 
         [0016]    In accordance with an added mode of the invention, the fibers are propelled by impacting a fiber surface having a shape which is concave, hemispherical, frustoconical, flat or acute-angled. This ensures that the fibers will move in a desired direction in the liquid. 
         [0017]    In accordance with a concomitant mode of the invention, the fibers are engaged and held together by causing the leading free ends of the fibers to penetrate gaps or holes in other fibers during the mixing step. Alternatively or additionally, the fibers are engaged and held together by causing protrusions or teeth of the fibers to interlock during the mixing step. 
         [0018]    Fibers and methods are presented to effectively cause self-interlacing (mechanical linking of independent elements into chains), cross-linking and locking of the fibers in situ (within the form or mold), by ultrasonic manipulation. The term ultrasonic, in this context, is defined in the broadest definition, and extends from the upper sound frequencies to the mid microwave frequencies. 
         [0019]    A new element or fiber is constructed to be affected by and set in motion by the application of ultrasonic energy through ultrasonic transducers, variable in frequency, amplitude, timing, pulse width and relative angles, attached externally to the walls of the form or mold and used in a synergistic manner. Ultrasonic wave stimulation increases the velocity or energy of the individual liquid molecules and because of this “more excited state”, the molecules begin a synergistic “movement in unison” or the phenomenon of “standing waves” in liquids. Standing waves occur at many frequencies with wave tip to wave tip distances inversely proportional to the frequency. This “movement in unison” is not confined to the surface but exists through out the liquid. 
         [0020]    The normally non-excited, non-usable “random molecular motion” has been raised to a higher order of “oscillations in synchronism” or “standing waves” according to the invention. This higher energy “cooperative motion” is controllable, steerable and therefore “usable” if focused on susceptibly shaped elements or fibers. The obstacle of directly manipulating elements or fibers by external energy is overcome by using the fluid medium itself, as the intermediate link to affect the susceptible fibers. A connection is established between the energy and the fluid as well as between the fluid and the fiber, and a much sought after “energy controllable fiber” is provided. These elements or fibers with specific structural features, which give them a “directional sensitivity”, have the ability to capture these physical impacts of molecules, particles or standing waves within the liquid, and be propelled in “linear motion” converting transduced energy into “work”. 
         [0021]    Other features which are considered as characteristic for the invention are set forth in the appended claims. 
         [0022]    Although the invention is illustrated and described herein as embodied in a fiber for producing three-dimensional, self-interlacing composites, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
         [0023]    The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0024]      FIGS. 1A ,  1 B and  1 C are respective diagrammatic, front-elevational, top-plan and bottom-plan views of a first embodiment of a fiber according to the invention; 
           [0025]      FIGS. 2A and 2B  are respective front-elevational and bottom-plan views of a second embodiment of a fiber according to the invention; 
           [0026]      FIGS. 3A and 3B  are respective front-elevational and top-plan views of a third embodiment of a fiber according to the invention; 
           [0027]      FIG. 4  is a front-elevational view of a fourth embodiment of a fiber according to the invention; 
           [0028]      FIG. 5  is a front-elevational view of a fifth embodiment of a fiber according to the invention; 
           [0029]      FIG. 5A  is a top-plan view of the fifth embodiment of the fiber, shown in  FIG. 5 ; 
           [0030]      FIGS. 6A and 6B  are respective front-perspective and top-perspective views of a sixth embodiment of a fiber according to the invention; and 
           [0031]      FIGS. 7A and 7B  are respective front-perspective and bottom-perspective views of a seventh embodiment of a fiber according to the invention. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0032]    Referring now to the figures of the drawings in detail and first, particularly, to  FIG. 1A  thereof, there is seen a first embodiment of a fiber or element  10  having a base  11  and a body  12 . The body has a trailing end attached to the base and a leading free end. It can be seen from  FIGS. 1A and 1B  that the body  12  is spirally wound from the base  11  to a tip  13  at the leading free end of the body  12 . The spiral shape is created by twisting arms  14 ,  15  about one another to form connecting nodes  16  and gaps  17  between the nodes in the body  12 . The sizes of the gaps  17  increase toward the base  11 . One or both of the arms can penetrate the base  11 , as is shown by the arm  15  in  FIG. 1C . It is also seen from  FIG. 1C , which is a view from the bottom of  FIG. 1A , that the base  11  is hemispherical or dome-shaped with a hole  18  formed therein and that the bottom thereof is concave. The surface of the base  11  to be impacted by a fluid wave is therefore a concave surface. 
         [0033]    Therefore, the base  11  of the fiber  10  provides a generally concave gathering, capturing or impact energy summing surface in one direction and the base  11  and the body  12  provide generally convex shedding, deflecting or energy impact reducing surfaces as seen from the opposite direction. The concave surface of the base  11  is an impact summing shape because more of the impacts of molecules, particles or waves strike the surface at a higher angle of incidence, imparting more energy and with a higher percentage of secondary or “summation strikes” because the angle of reflectance still falls within the surface of the concavity. The convex shape of the surface of the base  11  and the body  12  is an impact reducing shape because more of the molecules, particles or waves strike the surface at lower angles of incidence, imparting less energy and an almost zero percentage of secondary summation strikes since the angles of reflectance fall outside the surface of the convexity. 
         [0034]    When the fibers  10  are subjected to a current caused by ultrasonic waves in a liquid in a form or mold, the fibers respond due to the fundamental features of their construction described above and move by intention in a controllable way, and due to other features of their construction, to seek out, interlink and interlock with other similar fibers in a semi-random but controlled “true three dimensional” cross-linked manner. The tips  13  of the fibers  10  can be driven into the gaps  17  of other fibers  10 , in a circular “stirring” motion caused by the spiral shape of the body  12 . They may be driven toward the center of the mold, driven toward one or more outer walls or into hard-to-fill contours of molds by controlling variables of the directable ultrasonic energy. The tips, bases and gaps in the bodies of such fibers form a locking system engaging and holding the fibers together. 
         [0035]    More specifically, with regard to the process according to the invention, the fibers  10  are loaded into a form or mold, which already contains a low to medium viscosity mixing liquid. The mixing liquid may be an intended or parent resin or binder “without catalyst,” if of suitable low viscosity, or other compatible liquids, which can be easily removed, such as alcohol or water. Any of the typical two-part resins or epoxies used with catalysts, which bond composites by setting, hardening, or polymerizing, may be used as the resin or binder. The liquid and the fibers  10  then react to the increased molecular activity and waveforms described herein, related to transducer stimulation. 
         [0036]    Interlinking begins and the uniting fibers  10  uniformly fill all areas of the form or mold regardless of its contours. The mechanical polymerization of the fibers requires a low to medium density liquid or fluid for the fibers to maneuver and interlink, but proper composites require compressed fibers and a high ratio in the fiber to binder content. Therefore, at the conclusion of the desired mixing, an adjacent column or “sprue” of surplus, similarly mixed fibers, are compressed into the form or mold to introduce additional three-dimensionally, pre-mixed fibers, for achieving proper fiber density and evacuation of the mixing liquid. 
         [0037]    The resin or binder (if different from the mixing liquid) is then introduced throughout the compressed, uniformly interlaced fiber mass and allowed to harden. Proper fiber density is generally accepted as the maximum amount of adequately wetted fiber to the minimum amount of binder. 
         [0038]    Formed or molded objects of almost unlimited contour or complexity can now be made from the most simple to the most exotic composite materials with a three-dimensional tensile strength never before achieved. The ability to cast complex objects in composites such as carbon fiber, is new in the art. 
         [0039]    More specifically, with regard to the fibers or elements, it is noted that they may be made of any suitable material, are widely variable in size because of the vast choices involved and variations of the interlocking technique, type and size of materials, binders, ultimate strength desired, and size of the objects formed. Lengths as short as 1 mm to many centimeters in length can be possible with this process, as well as aspect ratios of length to width of two to one, up to fifty to one. 
         [0040]    Although the structure of the fibers or elements and the process of producing the composites is described above with regard to the first embodiment of the invention, those descriptions can be applied to the second through seventh embodiments described below as well. 
         [0041]    A second embodiment of a fiber or element  20  shown in  FIGS. 2A and 2B  and a third embodiment of a fiber or element  30  shown in  FIGS. 3A and 3C , both have frustoconical bases  21 ,  31  and a single spirally-wound arm  25 ,  35 . A tip  23  at a leading free end of a body  22  attached to the base  21  of the second embodiment of the fiber  20  is rounded. However, a tip  33  at a leading free end of a body  32  attached to the base  31  of the third embodiment of the fiber  30  is pointed. Once again, the bases  21 ,  31  are concave as seen in  FIG. 2B  or from the bottom of  FIGS. 2A and 3A , but convex as seen from the top of  FIGS. 2A and 3A , and have holes  28 ,  38 , formed therein. The surface of the base  21 ,  31  to be impacted by a fluid wave is therefore a concave surface. It is clear that a wave traveling through liquid containing such fibers  20 ,  30  will impart a circular forward motion with the tips  23 ,  33  leading, to cause the bodies  22 ,  32  to become intertwined. The tips, bases and bodies of such fibers form a locking system engaging and holding the fibers together. 
         [0042]    In a fourth embodiment according to  FIG. 4  and in a fifth embodiment according to  FIG. 5 , respective fibers or elements  40 ,  50  have bases  41 ,  51  and bodies  42 ,  52  connected thereto. The bodies  42 ,  52  each have a respective single spirally-shaped arm  45 ,  55  with respective fins  48 ,  58  integral therewith. The fins or protrusions may be attached to the arms or formed in one-piece therewith and extend in different directions. Although the body  42  has a tip  43  at a leading free end with a substantially circular shape, a tip  53  at a leading free end of the body  52  is pointed. The top-plan view of  FIG. 5A  shows the appearance of the arm  55  and fins  58  from above. Due to the large and generally or substantially unobstructed surface area of the bottom of the bases  41 ,  51 , a wave traveling through liquid will impact most greatly on the bottom of the bases and cause the fibers to travel ahead with the tips leading. The fibers will become interlocked at the fins and the bodies. The bases can also have a non-illustrated concave shape as seen from the bottom of  FIGS. 4 and 5 . The tips, bases and fins on the bodies of such fibers form a locking system engaging and holding the fibers together. 
         [0043]    The sixth embodiment illustrated in  FIGS. 6A and 6B  and the seventh embodiment illustrated in  FIGS. 7A and 7B  respectively show fibers or elements  60 ,  70  having bases  61 ,  71  connected to bodies  62 ,  72  at apexes  61 ′,  71 ′. It is seen that although both bodies  62  and  72  have a certain spiral twist, the body  72  is twisted more than the body  62 . 
         [0044]    Regarding the embodiment of  FIGS. 6A and 6B , it is seen that the body  62  has a flat or blunt tip  63  at a leading free end and a triangular slot or gap  62 ′, dividing the body into two arms  64  over a portion of its length. The arms  64  have slits  64 ′ formed therein, defining teeth  65  on the arms. The base  61  has a planar web  66  and a structured web  67 , which can also be seen in  FIG. 6B . The webs meet at the apex  61 ′. The structured web  67  has bent portions  68  which in turn have additional bent portions  69 . 
         [0045]    Regarding the embodiment of  FIGS. 7A and 7B , it is seen that the body  72  has a pointed tip  73  at a leading free end and a triangular slot or gap  72 ′, dividing the body into two arms  74  over a portion of its length. The arms  74  have slits  74 ′ formed therein, defining teeth  75  on the arms. The base  71  has a planar web  76  and a structured web  77  meeting at the apex  71 ′, which can also be seen in  FIG. 7B . The structured web  77  has bent portions  78  which in turn have additional bent portions  79 . 
         [0046]    The surface of the base  61 ,  71  to be impacted by a fluid wave is therefore formed of surfaces of the two webs  66 ,  67  and  76 ,  77  that describe an acute angle therebetween. 
         [0047]    Once again, the concave shape of the bases  61 ,  71 , as seen from below, will cause the waves to move the fibers forward with the tips  63 ,  73  leading. The twisted shape of the bodies will impart a spiral motion as well. Therefore, the tips  63 ,  73 , the teeth  65 ,  75 , the webs  66 ,  67 ,  76 ,  77  and the slots or gaps  62 ′,  72 ′ will become impaled on one another, locking the fibers together. The flat webs  66 ,  76  and structured webs  67 ,  77  together impart turbulence to the fiber. 
         [0048]    The tips, bases and teeth and slots or gaps of the bodies of such fibers form a locking system engaging and holding the fibers together. 
         [0049]    It should also be understood that the fibers of two or more of the embodiments described above can be mixed together in a mold. 
         [0050]    These self-interlacing, interlinking elements or fibers of the seven embodiments described above each have one or more of the following physical features: 
         [0051]    1. One or more motion-inducing surfaces, such as the bases, bodies, fins and teeth, causing the element or fiber to move in a nonrandom, intentional direction of motion within a fluid when acted upon by an oscillation-type, external energy introduced into the system and reacting with the fluid or liquid molecules or particles. These one or more motion inducing surfaces may be isolated, grouped, separated or placed more uniformly along a greater portion of the element. 
         [0052]    2. Motion-inducing surfaces on the element or fiber, such as the concave surfaces of the bases, having generally concave or other effectively shaped surfaces to gather, contain and concentrate the sum of the vector forces or impacts by the oscillating fluid or liquid molecules, particles or standing waves, acting on the element or fiber, and having these concavities facing generally away from the direction of intended motion. 
         [0053]    3. Motion-inducing surfaces on the element or fiber, such as the bodies and convex surfaces of the bases, having generally convex or other effective shaped surfaces to shed, deflect, or reduce the sum of the vector forces or impacts by the oscillating fluid or liquid molecules, particles or standing waves acting on the element or fiber and having these convexities facing generally in the direction of intended motion. 
         [0054]    4. A generally-changing overall spiral shape, in both diameter and rate of spiral, such as the bodies, to initiate or assist in an intentioned rotational motion generally at right angles to the intended linear motion. The portion toward the direction of intended linear motion would have the least spiral per degree of rotation and appear almost inline with the linear axis of the element and the portion toward the stem or base or away from the direction of intended linear motion would have increasing spiral appearing generally almost or at right angles to the axis of the element and direction of linear motion. 
         [0055]    5. Other separate spiral-shaped elements or fibers as described in item 4, such as the fins or teeth, formed in a “mirror image” or with oppositely oriented features as to cause rotation in the opposite or reverse direction, as in clockwise to counter clockwise manners, to increase and improve interlinking by adding more competing angles of interactions and more lateral areas for engagement. 
         [0056]    6. An offset pivot point of linear axial movement which will cause the forward point or points of the fiber or element in its intended linear motion and its simultaneous intended rotational motion to “hunt or seek”, with a pivoting or searching motion to enhance the finding, impaling, engaging and/or interlinking with the other similar elements or fibers. The element or fiber having this offset “pivot point of rotation”, is located at a point along the element at approximately 10% to 40% of its total length, as measured from bow or pointed tip to stern. 
         [0057]    7. One or more pointed end portions, teeth or fins of the element or fiber, in the direction of nonrandom or intended direction of motion, intended to initiate, assist and accomplish the impaling, engagement and interlinking of or into other similar elements or fibers. 
         [0058]    8. A surface or surfaces, such as at the slots or gaps, holes, slits, teeth, fins and webs on the elements or fibers, intended to receive the pointed end portion or portions of other elements to assist and accomplish the interlinking of and with other similar elements or fibers. 
         [0059]    9. A surface or surfaces, such as at the slots or gaps, slits, teeth, fins and webs on the elements or fibers, which once engagement and interlinking is accomplished, attempt or tend to hold the other similar elements or fibers engaged or interlinked.