Abstract:
An office panel assembly and fabric covering therefor. The panel assembly includes a supporting frame and a covering of textile fabric. The textile fabric is of a stitch bonded construction including a stitch yarns extending in a repeating stitch arrangement through a nonwoven fibrous substrate such that the stitch yarns cooperatively form a patterned show surface across one side of the said textile fabric.

Description:
TECHNICAL FIELD  
         [0001]    This invention relates to fabric systems and more particularly to a fabric of stitch bonded construction for covering the surface of office panel structures.  
         BACKGROUND OF THE INVENTION  
         [0002]    In office environments it is common to find work space partitions in the form of modular wall panels. These panels are typically not designed to run from floor to ceiling but rather are free standing and are assembled as modules to enclose or partially enclose a work space. Wall panel systems may range in complexity from simple planar surfaces to complex arrangements incorporating integral work and storage surfaces such as cabinets, writing surfaces, shelves and the like. Wall panel systems provide a substantial benefit in a work place environment by affording the ability to reconfigure a work place with minimum disruption. Thus, they have gained wide acceptance in recent times.  
           [0003]    Many forms of wall panel systems are known having various constructions and different aesthetic characteristics. By way of example only, one known form of office panel is constructed with steel frames surrounding cores of relatively lightweight material such as fiberboard or fiberglass having sound deadening capabilities. Often, these panels are covered with pieces of fabric supplied in colors which are meant to enhance the particular decor of the office environment. Illustrative wall panel constructions which incorporate outer fabric coverings are disclosed in U.S. Pat. No. 5,086,606 to Finses and U.S. Pat. No. 5,689,924 to Mason both of which are incorporated by reference as if fully set forth herein.  
           [0004]    In the past, the fabric material which is used in covering relation to the panels has typically been formed in a woven or pile-forming fabric construction so as to provide both the desired aesthetic characteristics and the requisite physical strength and abrasion resistance to be suitable for use in the intended application. While such constructions have generally proven to be adequate, construction of such woven and pile-forming materials requires the use of a substantial quantity of preformed yarn which is then woven or tufted into a desired construction according to standard manufacturing techniques as are well known to those of skill in the art. However, such weaving and pile-forming techniques may be relatively expensive to carry out. This expense arises both from the relatively high cost of using preformed yarns as the primary construction constituent as well as from the limited speeds and output rates for traditional weaving and pile-forming equipment.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention provides advantages and alternatives over the prior art by providing a fabric construction of potentially desirable aesthetic and performance character which makes use of highly efficient stitch bonding formation practices. The fabric utilizes a stitching yarn to form a surface covering across a support fabric of nonwoven fibrous material. The surface-forming stitching yarn provides a desirable aesthetic character across the selected surface which is visible during use. The stitch bonding arrangement also provides the fabric with suitable dimensional stability while nonetheless utilizing a relatively low cost nonwoven substrate.  
           [0006]    Other advantages and aspects of the present invention will become apparent through reference to the following detailed description and/or through practice of the invention as described therein. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    The following drawings which are incorporated in and which constitute a part of this specification illustrate exemplary embodiments and constructions of the present invention and, together with the general description given above and the detailed description set forth below, serve to explain the principles of the invention wherein:  
         [0008]    [0008]FIG. 1 is a plan view of the show surface face of panel covering textile fabric;  
         [0009]    [0009]FIG. 2 is a plan view of the underside of the fabric illustrated in FIG. 1;  
         [0010]    [0010]FIG. 3 is a magnified view of a segment of the face surface in the fabric illustrated in FIG. 1;  
         [0011]    [0011]FIG. 4 is a magnified view of a segment of the underside of the fabric as illustrated in FIG. 2;  
         [0012]    [0012]FIG. 5 is a cross-sectional view through a panel covering fabric taken along line  5 - 5  in FIG. 3; and  
         [0013]    [0013]FIG. 6 illustrates a panel construction in which the panel covering fabric may be utilized. 
     
    
       [0014]    While the invention has been illustrated and described above and will hereinafter be described in connection with certain potentially preferred embodiments and procedures, it is to be understood that in no event is the invention to be limited to such illustrated and described embodiments and procedures. On the contrary, it is intended that the present invention shall extend to all alternatives and modifications to the illustrated and described embodiments and procedures as may embrace the broad principles of this invention within the true spirit and scope thereof.  
       DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]    Reference will now be made to the drawings wherein to the extent possible like reference numerals are utilized to designate corresponding elements throughout the various views. In FIG. 1, there is illustrated in plan view the face of fabric  10  defining a show surface for use in covering visible portions of an office panel structure or other extended surface. According to the illustrated embodiment, the fabric  10  is of a stitch bonded construction wherein a plurality of stitch yarns  12  are passed repeatedly in stitch forming relation through a textile substrate layer  14  of nonwoven construction. In the illustrated arrangement the show surface illustrated in FIG. 1 corresponds to the so called “technical face” of the fabric  10 .  
         [0016]    In FIG. 2, the underside of the fabric  10  is illustrated showing the arrangement of stitch yarns  12  across the so called “technical back” of the fabric. As shown, while the stitch yarns are arranged in a configuration across the fabric face which results in substantial coverage, the stitch yarns  12  are preferably arranged across the underside in a substantially concentrated arrangement of stitch loops extending in the machine direction along the underside of the fabric  10 . Thus, the total quantity of preformed stitch yarns  12  is relatively low thereby enhancing the manufacturing efficiency and economic value of the formation process.  
         [0017]    In the fabric  10 , the stitch yarns  12  serve the dual function of both establishing the aesthetic face covering illustrated in FIG. 1 as well as imparting stability to the overall structure. In practice, the substrate is preferably a spun laced hydroentangled nonwoven fabric formed from a multiplicity of individual staple fiber elements which have been entangled with one another so as to establish a substantially cohesive structure. Such fiber elements are preferably formed of polyester but may also be of any suitable natural or synthetic fiber type as may be desired. In the event that additional stability is desired, it is contemplated that the textile substrate layer  14  may be of a nonwoven spunbonded construction. As will be understood by those of skill in the art, such spunbonded nonwoven material is formed by the substantially random deposit of semi-molten strands of polymeric material across a support surface to build up a coordinated structure.  
         [0018]    The stitch yarns  12  are preferably formed from polyester although any other suitable natural or synthetic fiber such as nylon and the like may likewise be used if desired. According to one potentially preferred embodiment, stitch yarns  12  are formed from a so called “bright” or lusterous polyester of relatively large denier so as to provide a substantially lustrous covering affect across the face of the fabric  10 . In such a construction the stitch yarns  12  preferably have a linear density in the range of about 300 to about 1,000 denier and most preferably have a linear density of about 450 denier. The substrate layer is preferably formed from solution dyed polyester fibers which are hydroentangled to form a fleece structure having a mass per unit area of about 30 to about 100 grams per square meter and most preferably about 50 grams per square meter. The use of a textile substrate layer  14  which is solution dyed to a dark color such as black or dark gray in combination with bright stitching yarns  12  has been found to provide a substantially metallic appearance across the face which may be desirable in some applications.  
         [0019]    According to one exemplary formation practice, the stitch yarns  12  are inserted through the substrate layer  14  using a two bar Liba type stitch bonding machine although it is contemplated that other stitch bonding equipment such as a Malliwatt machine or the like as will be well known to those of skill in the art may also be utilized. According to the exemplary formation practice using the two bar Liba machine, both bars are preferably fully threaded at a 7 gauge spacing. Stitches are applied at about 12 stitches per inch according to a stitch pattern at the rear bar of 0-1/3-2// (or reverse) and a stitch pattern at the front bar of 1-2/1-0// (or reverse).  
         [0020]    In some instances, it may be desirable to have the ability to mold the fabric  10  to a three-dimensional geometry so as to facilitate application across a contoured panel surface. It is contemplated that this moldability may be imparted by thermoforming a low melt constituent incorporated within the fiber arrangement forming the nonwover substrate layer  14 . According to one exemplary procedure, the nonwoven substrate layer  14  may include a percentage of low melting point polyester in combination with higher melting point polyester. In such a construction, the melting point of the higher melting point polyester is preferably in the range of about 250-400° F. and the melting point of the lower melting point polyester constituent is about 50° F. lower. It is contemplated that the lower melting point material may be present in the range of about 5% or greater and will most preferably be present in the range of about 5% to about 60% by weight of the overall textile substrate layer  14 . The lower melting point material may be present as a constituent of a bicomponent fiber such as a core/sheath fiber wherein the lower melting point material is disposed in surrounding relation to the higher melting point material. Of course, the lower melting point material may also be present in the form of discrete fiber elements. Combinations of multi-component fibers and discrete fibers may also be utilized if desired.  
         [0021]    In a structure incorporating differential melting point fiber constituents the fabric  10  may be molded by raising the temperature following introduction of the stitch yarns  12 . In practice, the temperature is raised to a level greater than the melting point of the lower melting point constituent but below that of the higher melting point constituent. While the fabric is in the elevated temperature state, the fabric is molded to the desired configuration and thereafter allowed to cool. The resulting resolidification of the lower melting point constituent thereafter forms a bonding matrix between the higher melting point fibers resulting in a shape retaining structure which may be useful in three-dimensional covering applications such as covering raised or depressed portions of an office panel structure.  
         [0022]    While the use of lower melting point and higher melting point polyester fibers may be preferred, it is also contemplated that other fiber blends of differential melting point may likewise be useful to impart moldability. Thus, by way of example only and not limitation, it is contemplated that the high melting point fiber constituent may be polypropylene and the lower melting point fiber constituent may be polyethylene. Likewise, the higher melting point constituent may be high density polypropylene intermixed with a low density polypropylene as the lower melting point constituent. Likewise, the higher melting point material may be nylon with the lower melting point material being either polyester or polypropylene or mixtures thereof. Of course, virtually any other combination of suitable fibers having differential melting points may likewise be utilized if desired.  
         [0023]    Regardless of the composition of the fabric  10 , it is contemplated that the fabric  10  may have useful application as a covering material for an office panel or other high surface area structure. An exemplary office panel structure  20  is illustrated in FIG. 6. In the office panel structure  20 , two individual panel assemblies  22 ,  24  are connected together at a supporting frame so as to form a free standing wall barrier. The fabric  10  is arranged across the panel assemblies  22 ,  24  with the face of the fabric (FIGS. 1 and 3) facing away from the panel assemblies so as to establish the desired surface covering facing towards a user. Of course, the fabric  10  may also be applied across the exterior of the panel assemblies if desired. While the panel assemblies  22 ,  24  are illustrated as being substantially planar, it is contemplated that such assemblies may also have raised and lowered surfaces across their expanse. In such arrangements, it is contemplated that the fabric  10  may be molded to a mating geometry so as to extend in matable relation over such raised and lowered surfaces.  
         [0024]    While the present invention has been described in connection with certain potentially preferred embodiments and practices thereof, it will be apparent to those if skill in the art that many changes and modifications may be made without departing from the true spirit and scope of the invention. Accordingly, it is intended by the appended claims to cover all such changes and modifications as may fall within the full spirit and scope of the invention.