Abstract:
Synthetic yarns are formed from polymer materials which preferably are self-twisted to give a multi-yarn effect. The yarns are used to form woven panels for use in furniture. The single strand yarns have the appearance of multiple strands, while saving on the heating and twisting involved with handling multiple strands.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to the field of furniture constructed with synthetic woven material. More particularly, the invention relates to synthetic wicker yarns, woven panels made from such yarns, and furniture constructed from such panels. The invention also relates to methods for forming the yarns, panels, and furniture. 
       BACKGROUND OF THE INVENTION 
       [0002]    Natural wicker has been used for many years for the manufacture of furniture, baskets, and other household goods. Natural wicker comes from plant fibers and is typically soaked in water to make it pliable. It can then be woven into the furniture, baskets, or other products. Wicker is generally lightweight and strong and is comfortable to sit or recline on. 
         [0003]    Wicker is available in numerous styles and designs and may be woven in numerous different patterns and arrangements. For example, wicker may be twisted or untwisted, flat or round, and may include surface features, such as stripes and grooves. Of course, these styles may be mixed and matched in a particular weave pattern as designed based on the purpose and aesthetic requirements of the product being manufactured. 
         [0004]    Natural wicker does have several drawbacks. Among these are the fact that wicker will soften when it gets wet. Excessive moisture could make the wicker susceptible to rot and mildew. 
         [0005]    In recent years, synthetic wicker has been developed from various polymers and similar materials that has the look and feel of natural wicker, but is not susceptible to the drawbacks of natural wicker. Synthetic wicker yarns are generally prepared by an extrusion process through an extrusion die and may then be arranged in the manner to achieve the desired look and feel of the yarn. 
         [0006]    Often, for reasons of aesthetics or to increase the strength and endurance of the weave, multiple strands of yarn are twisted together to form composite yarns. The method of twisting two or more single yarns together is sometimes referred to as doubling, folding, or ply twisting. Such twisted together yarns are sometimes referred to as a doubled, two ply, or composite yarns. Of course, this process requires the use of a two into one twisting device to produce the composite yarn. 
         [0007]    In order to keep the yarns that have been twisted together from untwisting prior to weaving the composite yarn into a woven panel, it is usually necessary to heat treat the composite yarn. This can be accomplished in a number of different ways. One way is to heat the yarns after the individual strands are twisted together. The yarns could also be heated prior to twisting. In that case, it is necessary to cool the yarns prior to twisting them together as they may become to hot to handle. The yarns are generally heated in an oven at temperatures of over 200° F. and even over 300° F. It is important not to heat the yarns to a temperature above the softening temperature of the polymers as this may result in the yarns adhering to each other or even in damage to the yarns themselves. 
         [0008]    Methods for twisting and heating the yarns and described in a number of patents, such as U.S. Pat. No. 6,625,970. These twisting, heating, and cooling steps are expensive and labor-intensive, while the twisted yarns and multiple strands of yarn woven together may be easily separated from each other. Thus, there is a need to provide a yarn having the appearance of a twisted yarn without the need to twist and heat the yarns. 
       SUMMARY OF THE INVENTION 
       [0009]    The invention relates to an elongated synthetic yarn having the appearance of multiple strands. The yarn is formed of a single strand of polymer material having multiple sub-strands with each sub-strand having the appearance of one or more strands. The sub-strands are integrally connected to each other. In a preferred embodiment, the sub-yarns are integrally connected along their entire length. The strand may be twisted about its own axis so as to appear to be formed from multiple strands of yarn. 
         [0010]    The yarn may include multiple sub-strands that are connected to each other by one or more bridges of polymer material. The bridges may be formed of the same or different polymer material from the sub-yarns. The bridges may be used to connect the sub-yarns in various configurations, such as in parallel, in series, or in a combination of parallel and series. 
         [0011]    Typical polymers used in the invention include polyvinyl chloride, polyethylene, and polypropylene, which may include foamed material. The sub-strands may differ from each other in color or be formed from different polymers. The surface of the yarn may include one or more grooves, stripes, or raised lobes, and the various lobes and surface features may have a different color from the remainder of the yarn. The sub-strands may include filaments or cores formed from different polymer materials as that of the outer layer. 
         [0012]    A plurality of yarns formed according to the present invention may be woven together to form woven panels. The panels may also be formed of one yarn having multiple sub-strands according to the invention and a different type of yarn, as known in the art. The woven panels may be attached to frames to form articles of furniture. The invention also relates to a method for forming such articles of furniture by attaching woven panels formed from yarns of the present invention to a furniture frame, as well as weaving the yarns directly onto the frame to form the woven panel. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The invention will be better understood in relation to the attached drawings illustrating preferred embodiments, wherein: 
           [0014]      FIG. 1  is a perspective view of an embodiment of the yarn of present invention showing a self-twisted yarn having a multi-yarn effect; 
           [0015]      FIG. 2A  is a cross-section view of one embodiment of the yarn of the present invention; 
           [0016]      FIG. 2B  is a cross-section view of one embodiment of the yarn of the present invention; 
           [0017]      FIG. 2C  is a cross-section view of one embodiment of the yarn of the present invention; 
           [0018]      FIG. 2D  is a cross-section view of one embodiment of the yarn of the present invention; 
           [0019]      FIG. 3  is a top plan view woven panel made according to the present invention; 
           [0020]      FIG. 4  is a perspective view of a chair made according to the present invention; 
           [0021]      FIG. 5  is a cross-section view of one embodiment of the yarn of the present invention; 
           [0022]      FIG. 6  is a cross-section view of one embodiment of the yarn of the present invention; 
           [0023]      FIG. 7  is a cross-section view of one embodiment of the yarn of the present invention; 
           [0024]      FIG. 8  is a cross-section view of one embodiment of the yarn of the present invention; 
           [0025]      FIG. 9  is a cross-section view of one embodiment of the yarn of the present invention; and 
           [0026]      FIG. 10  is a cross-section view of one embodiment of the yarn of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0027]    The invention relates to a single strand yarn that provides a multi-yarn effect. That is, the yarn of the present invention simulates multiple strand or composite yarns; when the yarn of the present invention is self twisted about its axis, it simulates composite yarns having separate strands that have been twisted together. In fact, however, the present invention is comprised of a single strand of yarn. Thus, the present invention enables the production of woven panels that are easier and less expensive to weave because the yarn is a single strand having a multi-yarn effect. Further, some embodiments of the present invention are easier to twist because they do not require a two into one twisting device. 
         [0028]    As used herein, the term “integrally connected” is used to designate that the sub-yarns are bridged together as a strand and may not be easily separated by conventional means, such as by simply pulling them apart during the course of weaving. That is, the sub-yarns are structural parts of a single yarn, but may appear to be separate. Further, as used herein, reference to a “yarn” refers to the complete yarn used for creating woven panels and the like. The present invention generally refers to yarns formed of a single strand, but a yarn could also include multiple strands twisted together to form a composite yarn. A single “strand” refers to a single part of a yarn that is connected and a single piece, as opposed to individual strands that may comprise a yarn. A “sub-strand” refers to individual lobes or sections of a strand that may appear to be separate from each other, but are in fact connected to each other by bridges or strips of polymer material, as discussed below. A single strand may be comprised of any number of sub-strands. 
         [0029]    Referring to the drawings,  FIG. 1  shows an embodiment of the present invention. The yarn  10  has been twisted about its axis, which makes it appear as if it were made from two separate strands twisted together. The yarn  10  may be a single color or it may be made in such a way that one or more sub-strands of the yarn are a separate color to further enhance the illusion of the yarn being comprised of separately twisted yarns. In this way, the yarn will have a more pronounced multi-yarn effect. 
         [0030]    The present invention comprises a plurality of sub-strands integrally bridged or connected together over their length.  FIG. 2  shows several embodiments of the yarn  10  having different cross-sections. There are basically no limits on the configuration of the cross-section of the yarn or of the sub-strands, as shown. The cross-section may be uniform along the entire length of the yarn or it may be non-uniform. For example,  FIG. 2A  shows the yarn  10  appearing to be comprised of two completely separate yarn sub-strands  12 , 14 , but remaining integrally connected to each other by a very small bridge or strip of polymer material  15 .  FIG. 2B  shows the yarn  10  appearing to be comprised of separate yarn sub-strands  12 , 14  which are connected to each other along their entire body.  FIG. 2C  shows the yarn  10  appearing to be comprised of separate yarn strands  12 , 14  connected to each other by a small strip of polymer material  15  in the center between the separate sub-strands  12 , 14 . Finally,  FIG. 2D  shows the yarn  10  appearing to be comprised of separate yarn sub-strands  12 , 14  connected by a strip of polymer material  15  along one entire side of the yarn sub-strands  12 , 14 . In each of these examples, one sub-strand  12  of the yarn  10  has been colored separately from the other sub-strand  14  of the yarn  10 . When the yarn  10  is twisted about its axis, as shown in  FIG. 1 , the illusion of separate yarns is enhanced by the separation coloration. In a similar way, three or more sub-strands could be used within the present invention by adjustment of the bridge polymer material  15  to chain (i.e., sub-strands in series) or cluster (i.e., sub-strands in parallel) configurations. For example, the yarn  10  may be comprised of four sub-strands, five sub-strands, or six sub-strands. The number of sub-strands for each yarn  10  is only limited by the logistics of producing such a yarn. 
         [0031]    The yarn sub-strands  12 , 14  are shown in  FIG. 2  as having optional separate filaments  17 . Such filaments may be formed of the same or a different polymer material from the material forming the outer portion  19  of the yarn sub-strands  12 , 14 . A core filament is often used to add strength to the yarn and would be used in some circumstances where extra strength is required. In one embodiment, a yarn having a core is woven together with a coreless yarn. In such an embodiment, it is contemplated that the yarns with cores would run in the weft direction and the coreless yarns would run in the warp direction. It is also contemplated that each of the weft and warp directions may include a mixture of yarns having cores and coreless yarns. 
         [0032]    The yarns of the present invention may be formed of any material known by those of ordinary skill in the art to be suitable for such a purpose. Examples of suitable materials include polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), or a combination of the same, such as a PP/PE blend. Indeed, various portions of the yarn may be co-extruded from different polymer materials. For example, the yarn sub-strands  12 , 14  may be formed of different polymer materials to give them a different appearance and further add to the multi-yarn effect. The strips or bridges  15  connecting the sub-strands may be formed of the same or different polymer materials. The weft yarns may be formed of the same or a different material or combination of materials from the warp yarns. The yarn core (or filament), if one is used, may be formed of the same or a different material from the outer layer of the yarn. Indeed, different materials may also be mixed in the warp and weft directions. Any number of combinations are within the scope of the present invention. 
         [0033]    The strip or bridge  15  is shown in a number of figures in the present invention. The strip or bridge  15  may be of any shape as desired for the particular application or configuration. For example, it may simply appear as a straight or curved portion connecting two sub-strands as shown in  FIG. 2  or  5  or it may be Y-shaped to connect three sub-strands as shown in  FIG. 6 , or it may be X-shaped to connected four sub-strands as shown in  FIG. 7 . 
         [0034]    The yarn  10  may be formed of foamed polymer material, such as foamed PVC. By foaming the polymer material, the material is softer than with the standard unfoamed material and may be more easily manipulated. Further, foaming the polymer material increases the volume of the polymer material and may result in a cost savings over unfoamed material. Some of the yarns may be formed of foamed polymer material, such as the warp yarns or the weft yarns. Foaming is not a requirement of the present invention, but may be used as known to those of skill in the art. 
         [0035]    The yarns  10  of the present invention may be formed by extrusion of the polymer material through a die. The various shapes of the yarn  10  shown in  FIG. 2  will depend on the shape of the die orifice and similarly, the cross sections of sub-strands  12  and  14  may also vary. Various colors may be added to the yarns  10  during the extrusion process by the addition of pigmentation to the yarns. The dies may be constructed to include multiple colors for various portions of the yarns  10 . For example, the dies may be arranged to provide a major color to the entire yarn and then add secondary colors to each side of the yarn. By adding the colors at certain portions of the die, it is possible to have the colors coat the yarns  10  at various angles. In this way, the yarn coloring is uniform, but may include complex coloring schemes. 
         [0036]    The yarns of the present invention may be designed with various applications of color. As noted above, using a separate color for each sub-strand  12 , 14  of the yarn enhances the multi-yarn effect. The invention is not limited to the use of one or two colors. Indeed, by simply adding additional color chambers to the extruder, yarns having three, four, or even five or more different colors may be developed. In this way, various portions of the yarn  10  are co-extruded with different colors. The weft yarns may be different colors or the same colors as the warp yarns. The colors may be used in any combination desired. 
         [0037]    In  FIG. 2 , yarn  10  is shown in an aspect in which sub-strands  12  and  14  have a quatrefoil or four-lobed cross section; the present invention should be construed to encompass other cross sections for sub-strands  12  and  14 , whether triangular, semi-circular, tri-foil, penta-foil, star-shaped, circular, irregular, etc. Further, the yarns may include various surface features and configurations. For example, the yarn surface may include grooves, stripes, raised lobes, or other surface features as known to those of skill in the art. By using a foamed polymer material, yarns may be formed having deformed outer surfaces or non-uniform cross-sections. In this way, many different looks and feels for the yarn designs are possible, as the different configurations may be mixed and matched for the different yarn sub-strands  12 , 14 . The present invention is not limited by the combinations of various surface features. 
         [0038]    The yarn  10  may be self twisted by a conventional twisting apparatus known to those of skill in the art, depending on the material and configuration of yarn  10 . The twisting apparatus is operative for twisting the yarn  10  to form the self-twisted yarn having the multi-yarn effect, as shown in  FIG. 1 . It is well recognized in the art that a twist occurs when the strand is twisted to form either an s-twist or a z-twist. These twists correspond to clockwise and counter-clockwise twists, and one is the mirror image of the other. An s-twisted yarn will look different than a z-twisted yarn in a weave. In the case of a single yarn, the yarn will twist upon itself in a helix, thereby creating either an s-twist or a z-twist, depending upon the twisting direction. The twisting apparatus may be of any suitable construction such as known in the art where continuous lengths of filaments or strands are twisted. The yarn  10  of the present invention may be twisted in an s-twist or a z-twist depending on the desired look of the final product. 
         [0039]      FIG. 3  shows a woven panel  20  formed from the yarns  10  of the present invention. The yarns  10  have been twisted about their axes as described above and are woven into a panel. The weave pattern may vary as known to those of ordinary skill in the art. A plurality of the strands of the yarn  10  is attached to a frame. Weave patterns may include a 4×4 pattern of weft and warp strands, as well as other patterns known in the art, such as 2×2, 5×5, 6×6, 10×10, and others. Asymmetrical weave patterns may also be used, such as 2×3, 3×5, 4×7, 2×5, 2×6, and others. 
         [0040]    The woven panels may be used to form furniture, such as chairs, couches, benches, stools, tables, and the like. Other uses for the panels may include rugs, awnings, or similar materials. 
         [0041]      FIG. 4  shows a chair  30  formed from a woven panel  20  using the yarns  10  of the present invention. Such chairs are formed in a conventional manner with the woven panel  20  attached to the frame  34  to form a seat  36 . A second woven panel may be used to form the back portion  38 . Alternatively, the chairs may be formed by weaving the yarns together right on the frame  34 . The frame  34  includes legs and arms of the chair and may be formed of various metals or plastics as known to those of skill in the art. The chair  30  may be any standard size and shape and may be designed for indoor or outdoor use. The polymer materials of the present invention used to form the woven panels  20  are particularly suited for outdoor use, as they may withstand rain, sun, and other conditions. 
         [0042]    In  FIG. 5 , yarn  10  is shown in an aspect in which sub-strands  12 ,  14  have a shape similar to that of a square having a curved surface and connected by the thin strip or bridge  15  of polymer material. This figure is used to show that any number of shaped sub-strands is within the scope of the invention. The sub-strands  12 ,  14  are shown having the optional separate filaments  17 . Sub-strand  12  is further shown having an outer surface  19  of different material. 
         [0043]    In  FIG. 6 , yarn  10  is shown as comprised of three sub-strands  14   a ,  14   b ,  14   c  having round shapes. This embodiment shows three separate sub-strands  14   a ,  14   b ,  14   c  connected by the strip or bridge  15  of polymer material in a Y-shaped configuration. 
         [0044]    In  FIG. 7 , yarn  10  is shown comprised of four sub-strands  12   a ,  14   a ,  14   b ,  12   b  connected by the strip  15  of polymer material in an X-shaped configuration. In this embodiment, sub-strands  12   a ,  12   b  are shown having different colors or outer surface materials from sub-strands  14   a ,  14   b.    
         [0045]    In  FIG. 8 , yarn  10  is shown in a rather complex configuration, with five separate sub-strands  12   a ,  12   b ,  14   a ,  14   b ,  14   c . Sub-strands  12   a ,  12   b  are shown having an outer surface of a different material  19 . Sub-strand  14   c  is shown attached to sub-strand  12   b  by a strip or bridge  15   b  which is separate from strip or bridge  15   a  which connects sub-strand  12   a  with sub-strands  12   b ,  14   a ,  14   b.    
         [0046]    The yarn  10  shown in  FIGS. 6-7  may be characterized as having the sub-yarns configured in “parallel.” These sub-yarns appear to be grouped in a cluster, in parallel spatial relation to each other by virtue of a central bridge. The yarn  10  configurations shown in  FIGS. 9-10  (below) may be characterized as having the sub-yarns in “series.” The sub-yarns appear to be in a chain with one another.  FIG. 8  shows the sub-yarns configured in a combination of parallel and series. 
         [0047]    In  FIG. 9 , yarn  10  is shown comprised of three sub-strands  14   a ,  14   b ,  14   c  connected in series by strips or bridges  15   a ,  15   b . The sub-strands  14   a ,  14   b ,  14   c  are shown having half-moon shapes or squares having a rounded side. In this embodiment, the strips or bridges  15   a ,  15   b  are aligned with the body edges of the sub-strands  14   a ,  14   b ,  14   c  to create a flat surface on one side of the yarn  10 . This yarn may be woven with a similar or dissimilar yarn to create a multi-yarn effect. In this embodiment, the yarn  10  would typically not be twisted, so as to present the rounded edges of the sub-strands to enhance the multi-yarn effect. 
         [0048]    In  FIG. 10 , yarn  10  is shown comprised of six sub-strands  14   a ,  14   b ,  12 ,  14   c ,  14   d ,  14   e  connected in series by strips or bridges  15   a ,  15   b ,  15   c ,  15   d ,  15   e . Sub-strand  12  is shown having a different outer surface  19  from the other sub-strands  14   a ,  14   b ,  14   c ,  14   d ,  14   e . Of course, those of skill in the art will appreciate that the various designs may be configured as desired according to the particular circumstances desired. For example, it is contemplated that embodiments of yarn  10  having many sub-strands connected in series may present a lateral, strap like profile. Such embodiments may be successfully woven as straps into panels. 
         [0049]    It is to be understood that the invention is not to be limited to the exact configuration as illustrated and described herein. Accordingly, all expedient modifications readily attainable by one of ordinary skill in the art from the disclosure set forth herein, or by routine experimentation therefrom, are deemed to be within the spirit and scope of the invention as defined by the appended claims.