Abstract:
Provided is a woven, glass textile fabric comprised of glass sliver in the weft or cross direction and air texturized glass yarn in the machine direction having a titer of from 60 to 80 tex. The resulting fabric is aesthetically pleasing in appearance, strong, yet lightweight. The fabric finds excellent applicability as a wall covering.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a new glass textile fabric which is aesthetically pleasing, exhibits high strength, yet is extremely lightweight. The fabric is a woven glass textile fabric which finds particular applicability as a fabric for walls.  
           [0003]    2. Description of the Related Art  
           [0004]    Looms have been used for many decades in order to produce glass fabrics. This is also true for the production of fabrics woven with glass fiber yarns. Glass fabrics woven with a pattern are also known. For example, see U.S. Pat. No. 6,267,151, issued to Andre Moll of Vitrulan Textilglas GmbH.  
           [0005]    In the Moll patent, a method is described for producing a patterned glass fabric, especially suitable for wallpaper or similar materials having a fabric woven with glass fiber yarns. The glass fiber yarn has a titer between 130 tex and 150 tex, and preferably between 139 and 142 tex, which is used for the warp. A glass fiber yarn with a titer between 190 tex and 400 tex, and preferably of 215 tex, is used as the filling in the fabric. The yarn is generally processed on a pattern controlled Jacquard loom.  
           [0006]    One of the difficulties with a glass fabric which is woven, and particularly glass fabrics intended for use as wallpaper fabrics, is the importance of aesthetics, as well as strength, while being lightweight. Certainly patterned fabrics can add to the aesthetics of a wall fabric, but problems have arisen in intending to achieve high strength, as the fabric has generally been a bit heavier, and does not provide the soft touch or voluminous look desired of the fabric.  
           [0007]    Accordingly, it is an object of the present invention to provide one with a new and improved glass textile fabric which is aesthetically pleasing, has good strength, but is also lightweight in nature to provide the soft touch and look desired.  
           [0008]    Another object of the present invention is to provide a wall fabric exhibiting good strength, but which is also lightweight and aesthetically pleasing in nature.  
           [0009]    These and other objects of the present invention will become apparent to the skilled artisan upon a review of the following disclosure and the drawings attached hereto.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention provides a glass textile fabric which is aesthetically pleasing, exhibits high strength, yet is lightweight, thereby providing a soft touch and feel. The textile is a woven glass and finds distinct applicability as a wall fabric.  
           [0011]    The fabric is woven with a 60 to 80 tex yarn in the machine direction or warp, and a sliver is used as the weft or cross direction. For among other factors, it has been found that when the sliver in the cross direction is employed together with the fine, but strong, air texturized 70 tex yarn, a strong, yet lightweight product having excellent aesthetics is achieved. The product is much lighter and provides the soft look, voluminous touch and feel desired for wall fabrics. The economics of the fabric are also advantageous. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    The above and other objects, features, and advantages of the present invention will become more apparent in light of the following detailed description in conjunction with the drawings, in which like reference numerals identify similar or identical elements, and in which:  
         [0013]    [0013]FIG. 1 depicts a conventional process and set up for preparing sliver;  
         [0014]    [0014]FIG. 2 depicts a process for applying a standard chemical treatment, in a preferred method of a continuous process by a rotating screen;  
         [0015]    [0015]FIG. 3 shows a process for applying chemical dispersions, in a preferred method of a continuous process by a rotating screen.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]    Sliver, which is a staple fiber strand, is used in the weft of the fabric of the present invention. The manufacture of sliver is well known, and is described, for example, in  Fiber Glass,  by J. Gilbert Mohr and William P. Rowe, 1978, Van Nostrand Reinhold Company, which is hereby incorporated by reference in its entirety. The sliver can be, and is preferably manufactured from C-glass or E-glass pellets. Such chemical glass or electronic glass compositions are well known. Conventional production units for sliver are also known to the industry. Such production units have been developed, for example, by Schuller GmbH. FIG. 1 illustrates one such unit.  
         [0017]    In FIG. 1, a hopper, located on top of the sliver unit, contains the glass pellets. A pellet feeder draws the required pellet volume, time and weight controlled, and distributes it evenly into a glass fiber bushing. The bushing is comprised of an electrically heated trough made of precious metal. It is embedded in a set of heat resistant bricks and assembled on a frame. On the bottom of the trough, the bushing has numerous nozzle-like outlets called “tips” from which glass fibers are drawn. The bushing is temperature response power controlled.  
         [0018]    In the bushing the solid glass pellets are transformed into liquid glass. This glass penetrating through the outlets forms glass beads which in turn generate liquid glass fiber filaments. The fibers are vaporized with fiber forming promoter fluid and are wound onto a spinning drum. The glass drops are accelerated, broken from the filaments and disposed to the basement for recycling. Finally, the spinning drum attenuates the fibers to the desired diameter. The fibers adhere to the drum surface for less than one drum rotation and are then removed with a scraper blade. Good adhesion action firmly keeps the fibers on the drum surface. They are then released at the scraper blade edge.  
         [0019]    The fibers are whirl-vortexed in a funnel, twisted (closed), removed and continuously wound on bobbins. Should fibers break, the fiber drawing process automatically restarts. Glass drops and heavy fibers are separated from the standard glass fibers and collected for recycling.  
         [0020]    It is preferred that the dwelling time in the funnel is significantly abbreviated, for it has been discovered that especially evenness and uniform appearance are improved, thickness variation reduced and tensile increased by approximately 20% when the dwelling time in the funnel is significantly abbreviated. It is important to keep the drum speed—draw-off speed ratio as small a possible.  
         [0021]    The glass yarn used in the machine direction, or warp of the textile fabric of the present invention, is a 60 to 80 tex, air texturized yarn, more preferably a yarn with a titer between 65 and 75 tex, and most preferably about a 70 tex. The yarn can be air texturized by using any conventional process for glass fibers. Suitable machines are available, such as the air texturizing machine from Dietze and Schell Corporation, Greenville, S.C. Air texturizing machine DS60 and DS60D are examples of suitable machines useful in texturizing glass yarns using various jet streams of air to accomplish the texturizing. The machine can be supplied with glass yarn in various feedstock forms such as from flexible bobbins, spin cables and direct rovings.  
         [0022]    This glass yarn used as the warp is a very fine yarn which has been air-texturized. The fineness of the glass yarn, and its texturized state, combined with the use of the sliver in the cross direction, helps to give the final product its lightweight and voluminous look, feel and touch. The final textile, despite the lightweight characteristics, also exhibits good strength characteristics.  
         [0023]    The sliver and air-texturized yarn are combined into the final textile product using any conventional loom, e.g., a Dobby loom, Jacquard loom, a weaving machine such as a Dornier weaving machine. Woven-in patterns are possible, if desired.  
         [0024]    Once the textile product has been woven, it can be treated in conventional fashion to provide the final characteristics of the product. Chemical treatments of glass fabrics are known to finalize/adjust such characteristics as strength, volume, stability and opacity of the final textile product.  
         [0025]    [0025]FIG. 2 depicts a process for applying a normal chemical treatment to a glass fabric, preferably, the glass fabric is a woven product from fiber glass yarn. The weave is typically a simple pattern, of up to eight shafts. The weave is produced, for example, on Dornier weaving machines, Reapiers or Air-Jets, in typically two or three meter widths for collecting on roll beams of typically 1,500-6,000 meters of untreated woven fiberglass fabric. Preferred yarns in accordance with the present invention include, for the warp direction, continuous C-glass or E-glass of 60 to 80 tex, more preferably about 70 tex, which has been air-texturized. For the weft or cross direction, the sliver as described above is used.  
         [0026]    In the process of the present invention, the glass fabric  1 , preferred in roll form, is fed to an impregnation bath, typically through rollers  3  and conventional conveyance means, to contact a bath of, for example, a soft touch chemical mixture, or alternatively, for example, a pick up roll may convey the same mixture to at least one of the glass fabric surfaces. A preferred coating mixture consists of those components set out in Table 1 below.  
         [0027]    Alternatively, to the rollers  3 , double side rotary screens may be used to apply the chemicals to the glass fabric  1 . The chemical mixture is supplied to the interior of the two rotating screens and applied to the glass fabric by contact with the rotating screens.  
                           TABLE 1                                       Starch Binder   10-70% of dry substance           Latex Binder   20-80% of dry substance           Inorganic Cross-Linker    0-10% of dry substance           Pigments   10-30% of dry substance                      
 
         [0028]    All commercial available starch binders can be used. Starch binder derived from potatoes or corn is preferred. The soft latex binders are preferably based on vinyl acetate. However, other types of latex binders can also be used. Inorganic cross-linkers are materials which may improve the effect of that mixture by stabilizing the chemical mixture upon application. Ammonium zirconium carbonate is preferred, but also other chemistries can be used.  
         [0029]    The mixture is preferably water based, and has a dry substance percentage of between 5 and 20 weight percent, preferably between 10 and 20 weight percent in the chemical bath. Besides white pigments, colored pigments can also be added or used to create colored fabrics as well.  
         [0030]    Following the impregnation, the fabric may be conveyed to a drying means  4 , which in the preferred embodiment of FIG. 2 is depicted as steam heated cylinders  5 . After drying, the fabric is collected onto roll  6  and is usually cut into desired width. This first impregnation step adds additional volume, stability and opacity to the fabric.  
         [0031]    In FIG. 3, a dispersion  14  can also be added to improve tear strength of the fabric  12 . Typically, 10-60 g of the dispersion per square meter is sufficient to obtain an optimum adhesion strength combined with moderate tear forces. The wanted tear force can be adjusted by the amount of the applied dispersion. It also depends on the type and structure of the used fabrics. The optimum adhesion strength is necessary to obtain the same wear resistance and the same fire resistance as standard glass fiber wall covering.  
         [0032]    Following the application of the dispersions  14  to the fabric surface at  11 , the fabric may be conveyed to a drying means  16 , which in the preferred embodiment of FIG. 3, is depicted as air dryers. Alternatively, heated cylinders can be used without any drawbacks. The fabric is then collected on roll  18 .  
         [0033]    Having described preferred embodiments of the invention, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.