CA2102412A1

CA2102412A1 - Stiff fabric composite and method of making

Info

Publication number: CA2102412A1
Application number: CA002102412A
Authority: CA
Inventors: Julius R. Schnegg; John Rinderman; Bobby L. Mcconnell; Manfred H. K. Hueneke
Original assignee: Individual
Current assignee: Burlington Industries Inc
Priority date: 1991-06-06
Filing date: 1992-06-08
Publication date: 1992-12-07
Also published as: WO1992021806A1; MX9202346A; AU2191992A

Abstract

A woven or non-woven fibrous material (18) has a substrate (22) formed of first (30) and second (32) thermoplastic fibers. The fabric (18) is passed through an oven (50) at a temperature sufficient to melt the first fibers (30) thereby fusing at least some of the first fibers (30) and second fibers (32) one to the other.
The second fibers (32) retain their discrete definition within the composite whereby the composite is provided such that, when cut for use, for example, to form a slat (16) of vertical blind (10) or a wall panel (fig. 2A), the composite (18) retains its shape.

Description

` 21~2~12 .: W0 92J21806 PCI`/US92/04800 STIE-F FABRIC COMPOS1113 AND ~3TE~OD OF ~AgING

BACRGROU~ AND ~N :

The present invention relates to a tiff fabr~c composite for various uses including, for example, slats or vanes for vertical blinds, pleated shades, coverings for the housings for the vertical blinds, automobile interior parts, furni~ure panels, large and small wall panels, partitions and the like. The present invention al50 relates to meth~ds of making the ~tiff fabric composite.

Fabrics, of course, are and have been used aR
coverings for a large variety of articles. Bacause of the flcxibility of the fabric material, they are freguently adhered, for ex~mple, by adhesive, to an underlying rigid substrate, ~uch as wood or pla terboard, which afford~ rigidity to the fabric.
The ease.of manufacture of fabrics in many diffexent color textures, patterns and raw materials lends their use in a wide variety of applications. ThQ

2102~
W092/218~ PCT/USg2/~

flexible nature of fabrics, however, frequently i~ a detriment to their application and end use. Thi8 will become apparent from the following discus~ion of the use of fabrics in window treatments and coverings, for example, wall panels, representative of the ofttime~ desirable but ~ometimes disadvantageous flexibility of the fabrics.

Window treatments are conventionally categorized as soft and hard treatments. For example, soft window treatments might include draperies, curtains and the like for windows or walls where the fabric forming the draperie~ or curtains is typically decorative and highly flexible. That is, they do not have a stiffness attributable to the fabric per e such that the fabric may have a self-supporting shape. Hard window treatments, on the other hand, may include blinds, both vertical and horizontal, including mini-blinds as wetl as pleated æhades.
This latter segment of the window treatment market ha~ grown rapidly, much to the detriment of the soft `~
window treatment market. That is to say, the materials normally employed in the hard window treatment market from which vertical and horizontal blind~ are made, for example, might comprise relatively inflexible plastic material, such as PVC, or aluminum, ~haped to ha~e a degree of stiffne-~ or rigidity. Very little of the hard window treatment market includes fabric materials, although certaln vertical bl~nds have previou~ly been formed of 2 1 ~ 2 ' ~ W092/218~ PCT/US92/~

treated, non-woven, a5 well as woven, fabrics. For example, there has been previously provided a stitch-through drapery fabric which may have various surface effects, ran~ing from casements to textures and which has been treated with resin3 or a polymer to achieve a stiff, self-supporting ~lat for vertical blinds. However, the treatment is a separate step, not part of the fabric formation and is thus limited to the addition of further materials to the fabric beyond those necessary to make it.

Also, there has been increasingly a demand for hard window treatments having a more elegant drapery look. Such fabrics have to be f~ni~hed in such a way that they have sufficient stiffness to make them suitable for such window coverings. The finish~ng proces~es reguired for this purpo~e are difficult, lengthy and expensive. The physical properties of the resulting fabrics are not always satisfactory because high humidity and heat, as typically oecur~
at a window, cause a variation from the predetermined fini~hed shape. For example, vertical ~lats or vanes formed of fini~hed fabric material~ will ~ometimes cup-in, i.e., form a non-controllable convex or concave surface, rather than retain a flat surface configuration, as desired. Alternately, original cup-~haped slats may become flat or obtain other ~hapeR upon application of hoat and/or h~midity.
Loss of definition ha~ been found to be e~pecially true with woven fabric~ made mo~tly with rayon wefts.

21~241'2 W092/21806 PCT~US92/~

Fabric coverings fcr wall panels is ano~her example of the undesirable flexibility of fabric for certain applications, although other attribute~ of fabrics, such as ready and inexpensive manufacture, wide variations in color, pattern~, texture, etc., make their use highly desirable as wall panels. Eor example, fabric coated wallpaper is relatively difficult to apply to a wall due in no small part to the flexibility of the fabric itself. Usually, a professional wallpaper hanger is required. Flexible fabrics are also difficult to cut to the required size and shape. Conseguently, the oftentimes highly desirable characteristic of flexibility is frequently detrimental to the use of fabrics in certain applications. Thus, there has developed a need for a stiff fabric composite which obtains and retains during use a predetermined stiffneæs but which does not reguire further treatments such as the application of additional materials to the fabric to obtain and retain the stiffness.

According to the present inYention, there is provided a stiff fabric composite which, when heat-treated and subsequently cooled, will provide the requisite stiffness for the use contemplated, for example, as slats in vertical or mini-blind~, pleated ~hade~, folding doors, wall panels, wall tile~, etc., and which fabric will not alter it~ self-~u~taining well-defined shape in the presence of high humidity and/or heat. To accomplish this, the ~tiff fabric ; ' W092/218~ 2~7t? PCT/US~2/~

composite hereof may be formed of a warp knit, ~titch through, stitch bonded, warp-knit weft-in~erted fabric or a woven fabric each in conjunction with a substrate comprised of a single type of fiber or a blend of fibers rendering the ~ubstrate thermally formable or thermobondable to impart the reguisite stiffne~s to the resulting fabric. Warp-Xnit, weft-inserted fabrics have, in recent year~, co~e - into vogue with fabric designer~ for applications typically re~erved for woven fabrics. For example, in decorative markets ~uch as window treatments, warp-knit, weft-inserted fabrics have recently been used as drapery fabrics. These fabrics have become popular, in lieu of woven fabrics, because of their versat~lity and the economics of manufacture.
Importantly, they retain the appearance of and resemblance to woven fabric~. Warp-knit (~titch through) fabrics without weft insertion have also come into vogue. Their patterning in the fabric is derived from the movement and type of the stitching yarns or their layering. While warp-knit fabric~ do not obtain a woven appearance, they are quite u~eful in certain application~, such as window treatment~.

The substrate used with either the warp-knit, warp-knit weft-inserted, stitch-through, stitch bonded or woven fabric, for example and preferably, may be a mixture of two different types of thermoplastic fibers or as ~ometimes desired only one type of fibers, ~uch as polye~ter, or polyolefin ?, 1 ~
W092/218~ PCT/US92/~

fiberæ, e.g., polypropylene or polyethylene, having different melting temperatures or times. When the substrate material, which may be needle-punched to intersperse the fibers throughout the substrate, is subjected to a heat treatment in the manufacturing proceQs, for example, dispo~ed in an oven having an operating temperature above the melting temperature of one of the first fibers but below the melting temperature of the other fibers, at least some of the fir t fibers may fuse in the ~ubstrate t~ stiffen th~
resulting fabric to the required degree ~f stiffne~s. Even though some subgtrates are designed this way, others, especially polyolefin-based ones, may or may not have only one type of fiber. Where ;~
only a single type of fiber is employed, first and second fibers may be different thicknesses, for example, ~uch that at least some of the first fibers of one thickness fuse in the substrate.while the second fibers of greater thickness remain intact with substantial definition. Substrates of the foregoing types may be variou~ly formed and the substrates and technique~ for making the substrates may, for example, be of the type disclosed in U.S. Patent Nos.
4,818,586, issued April 4, 1989; 4,424,2~0, issued -~
January 3, 1984 and 4,199,635, issued April 22, 1980, the disc}~sures of which are incorporated herein by reference. A commerclal form of the substrate for use with the pre~ent invention may be o~tained from either Gates Formed Fiber Products, Inc., Auburn, Maine, under the designation C-107C 6.5 ounce/~y 21!~2~12 W092/218~ PCT/US92/~

polyester, Foss Manufacturing, Hampton, New ~ampshire, identified as 24-Y-4 7.5 oz/yd or from Spartan Technologies, Spartanburg, South Carolina, identified as N470 8 ounce/sgy polypropylene.
Another apparently u~eful ~ubstrate available from Fos~ Manufacturing i~ a blend of different polye~ter f~bers, these constituent~ being available in variou~
proportion~. If the Gates sub~trate is u~ed, heating of the non-woven fabric to 325F for 90 æeconds has been found to be sufficient to impart the desired 6tiffness. Other possible ~ubstrates include Delnet, a product of Extrusion Technology Co. of Middletown, Delaware.

With a lOO~ olefin fiber substrate from Spartan Technologies, a temperature of about 310 to 360F
with a dwell time of 45-90 seconds is desirably used. At higher temperatures and longer dwell times, a stiffer and thinner product is obtained, and the precise conditions may be varied as desired to yield the properties desired. Eor example, for the manufacture of pleated ~hades, a thinner product i8 desired, 80 operation at the higher temperature~ and longer dwell times is preferred.

Generally speaking, thi~ technique, when u~ed for forming a warp-knit, weft-in~erted fabric or a warp-knit fabrie using meltable and fusible fibers of a fibrous sub~trate, provides added dimensional stability to what otherwise might be a poorly 2 1 0 ~
W092/21806 P~/US92/~

stabilized fa`bric. For example, while a ~atin ~titch in a warp-knit, weft-inserted fabric provides a mo~t pleasing weven-l~ke construction, it is one of the poorer dimensionally sta~le warp-knit, weft-inserted fabrics available. ~owever, it has been found that by combining that fabric with the ~ubstrate a5 ~dentified above, the resulting fabric may not only be dimensionally stabilized but have the regui~ite tiffne3s for the u~es contemplate~ herein.
Furthermore, tests of thi~ particular fabric have demonstrated that, when subjected to high temperatures, for example, 150E and hi~h humidity, i.e., 6S%, the fabric did not change its predetermined shape. This product has also been tested at 90F and 90% relative humidity with similar results. Even wetting the fabric did not eause it to change shape or lose definition.

When using a combina~ion of a woven fabric and ~;
non-woven sub.Qtrate for the composite fabric hereof, the non-woven substrate is preferably needled to the woven fabric. m at is, the needles move certain of the ~ubstrate fibers into the woven fabric and some of the non-woven fibers will extend through the woven fabric to its opposite face. When thi~ fabric composite is later 8ub~ ected to a heat treatment in the ma~ufacturing proce~s, for example, di~posed in an oven having an operating temperatur~ above the melting temperature of one of the thermoplast~c fibers of the ~ubstrate, but below the melt~ng 2!~02~
W092/21806 PCT/US92/~

temperature of the other flbers, at least some of the fîrst fibers may fu~e in the substrate and to the back of the woven fabric. Also, of those first fibers needled into and through the woven fabric, at leaæt some fu~e within and on the face of the woven fabric, thu~ affording a strong bond between the substrate and the woven fabric. Importa~tly, the fusing action stiffen~ the re~ulting fabric composite to the reguired degree of stiffne~s..

A further advantage of the stiff fabric composite according to the present invention, whether ~:
the ~ubstrate is combined with the warp-knit, weft-in~erted; warp-knit (~titch-through); or woven fabrics, particularly when thermoplastic yarns, for example, polye~ter and polyolefins, are u ed a~ the weft yarns and warp stitching (and laid in warp~
where used) in warp-knit fabric or both the warp and weft yarns in warp-knit, weft-inserted fabric, i~
that the fabric may be readily cut to the desired shape. For example, by employing hot knives to ~lit warp-knit, weft-inserted fab~ic, for example, in the machine direction, not only the weft~ and knitting yarns can be cut, but the hot knives fuse the ends of the cut~ to the substrate, preventing fraying.
Fusing, of course, also o~curs when using hot knives to cut in the cro~s-machine direction. This cutting may be employed e~ther at the fabrieating site or in~tallation site, depending upon the use of the fabric.

~lQ~2~ PCTJUS92/~0~ ~

It will be appreciated that there are a great variety of uses of the stiff fabric composite hereof. For example, the stiff composite fabric may form wall panels of the large variety type, on the order of four feet by eight feet or larger or smaller. Thus, unlike wood panelling, the stiff fabric composite panelling may ~e cut with sci~sors -~
and glued to an ~nderlying wall rather than being sawed or nailed. While the fabric-is stiff, it still ~-retains the capability to bend, for example, around corners, thereby facilitating installation. Such stiff fabric composite panels are also lighter in weight and therefore easy to handle and install. ~-Square tiles of the stiff composite fabric, e.g., on the order of one-foot square, may al~o be formed and in many different colors, patterns, textures and the ~-like. Similarly, the tiles can be rectangular, e.g., in the form of bricks on the order of 3-1/2x8 inche~. Thus, many and different decorative wall or ceiling effects can be provided and with simple or complex patterns, e.g., Dobby or Jacquard.

In a preferred embodiment according to the present invention, there i8 provided a ~tiff fabric composite comprising a fibrous woven or non-woven material, a non-woven substrate of thermoplastic fibers, the fabric composite having been heated to a temperature ~ufficient to fu~e at lea~t some of the fibers of the ~ubstrate to one another to provide the fabric composite with a stiffness such that a flat ~n2~12 . ~' ' ' ' - W~92/21~K ` P~T/US92/nU~
~ .

piece of the compos~te 3.5 inches (about 90 mm) wide cantilevered in a horizontal direction five inches (130 mm) from a support has a droop at its distal-end of from preferably about 0 to about 2 inches (or about 0 to about 50 mm). A range of about 0.5 inches to about 2.5 inches (or about 10 to about 70 mm) will be satisfactory.

In a further preferred embodiment according to the pre~ent invention, there i~ provided a fabric having incorporated therein a sub~trate formed of first and ~econd fibers, the first fibers being formed of a thermoplaQtic material having a predetermined melting temperature, the fabric having been heat-treated to a predetermined temperature sufficient to melt at le~st some of the first fibers such that the first fibers are fused with the second fibers in the substrate to provide a fabric havinq a predetermined stiffness. Different substrate suppliers may formulate their substrates in different ways, so that heat treatments should be v~ried in accordance with such variations to achieve the desired stiffnes~. Additionally, the fabric may be either a warp-knit (stitch through) fabric with or without laid-in warp yarns or a warp-knit, weft-in~erted fabric with or without laid-in warp yarns.

In a further preferred embodiment according to the present invention, there ~s provided a warp-knit, ~IIR~TITIITF ~IFFT

.L
WO92/2180~ PCT/US92/~W~

weft-inserted fabric having incorporated therein a ~ub~trate formed of first and second fibers, the first fibers being formed of a thermoplastic material with at lea~t ~ome of the first fibers fused to the second fibers, the fabric having a ~tiffne~ ~uch th~t a flat piece of the fabric 3.5 inches (about 90 mm) wide cantilevered in a horizontal direction 5 inches (130 mm) from a support has a droop at its distal end of no more than about.2.0 inches (about 50 mm).

In another a~pect hereof, there is provided warp-knit fabric having incorporated therein a s~1bstrate formed of thermoplastic fibers having a predetermined melting temperature, the fabric having been }~eat-t1-e~ted to a predetermined temperature s~ffi.cient to melt at least Rome of the fiber~ such that the fibers ~r~ fl-sed in the substrate to provide a fabric having a predetermined stiffness.

In a further preferred embodiment according to the pre~ent invention, there i8 provided a blind for ~ window treatment comprising a plurality of slats, each slat being formed of stitch through warp yarns and fabric having a subRtrate formed of first and second fibers, the first fibers being formed of a thermoplastic material having a predetermined melting temperature, tl1e fflbric having been heat-treated to a predetermined temperature sufficient to melt at least some of the first fibe~ SUC}l that ~ome of the first ~IIRSTITOTE S~IEET

21 ~2~12 W092/21X~ PCT/US92~
:, ~

fibers are fu~ed with the ~econd fibers in the sukstrate to provide a slat having a predetermined stiffness.

In a further preferred embodiment according to the ~-present invention, there i8 provided a blind for ~ window treatment compri~ing a plurality of slats, each sl~t being formed of a warp-knit, weft-inserted fa~ric l~ving incorporated therein a substrate formed of first an~ ~.
~econd fibers, the fir~t fibers being formed of a thermopla~tic material with at least some of the first fibers fused t~ the second fibers, the slat h~ving ~
~tiffnes~ ~uch that a flat piece of the slat 3.5 inches ~about 90 mm) wide cantilevered in a horizontal direction 5 inche~ (about 130 mm) from a s~lpp~rt has a ~roo~ ~t its di~tal end of no more than about 2.0 inches (~bo~t ~0 mm).

In a ~till further preferred embodiment ~ccot~ing to the present invention, there are provided blinds f~r a window treatment comprising a pl~lrality of slats, each slat being formed of a warp-knit, weft-inserted fahric having incorporated therein a substrate forme~ of .. thermopla~tic fibers, the fibers having a predetermined melting temperature, the fabric having been heat-tteated to the predetermined temperature sufficient to melt at least some of the fibers such that the fibers are fl~ed in the ~ubstrate to provide a fabric having a predetermined stiffness, the slat having a sti~fnes.s SUeSTITUTE SaET

21~2~1~
WO92~21~K PCT/US92/~0 ~uch that a flat piece of the slat 3.~ inches ~abotlt 90 mm) wide cantilevered in a horizontal direction 5 inches (about 130 mm) from a ~upport has a droop at its d1stal end of no more than about 2.0 inches ~about 50 mm).

In a still further preferred embodiment accor~ing to the pre~ent invention, there i8 provided a method of forming a fabric having stitch through warp yarn~ and a substrate compri~ing the steps of, on a knitting m~chine, (a) providing a non-woven ~ubstrate for movement in the machine direction and formed of first and ~econd different fiber~ with the fir~t fibers formed of thermoplastic material having a predetermined melti.ng -:
temperature, and (b) stitchin~ the warp yarns and ~ubstrate each to the other and thereafter, heatil-g the fabric to a temperature to fuse ~t least some of t})~
fir~t fiber~ with the second fibers of the substr~te to provide a predetermined stiffness to the fabric. The method hereof may further incl~lde l~ying in w~ft y~rn~ in the cross-machine direction to form a warp-kn~t, weft-in~erted fabric.

Accordingly, it i~ a primary obj~ct of th~ pre~ent invention to provide a novel and improved fabric with ~
substrate wherein the fabric may be formed into A ~tiff, self-~upportin~ and su~taining fabric piece, for example, for hard window treatments and other end uses where a ~tiff f abri c may be ~15~TITI~T~ T

W092/21~K ~ PCT/US92/~U~O

desired, the fabric being a warp-knit fabric with or without laid-in warp yarns or a warp-knit, weft-in~erted fabric with or without laid-in warp yarn~.

These and further ob;ects and advantages of the pre~ent invention will become more apparent upon reference to the following specification, appended claims and drawings~

210~412 W092/218~ : PCT/US92/~

BRIEF DESCRIPTI~N OF T~E DRAWING FIGUMES

Fi~ure 1 i~ a fragmentary elevational view of vertical bl~nd~ formed of a fabric con~tructed in accordance with the present invention;

Figure lA i~ a fragmentary enlarged cro~ ectional view thereof taken generally about on line~ lA-l~ in F~gure l;

Figure lB iE a view similar to Figure lA but illustrating u~e of the ~tiff fabric composite hereof in pleated blinds;

Figure 2 i~ a fragmentary perspective view illustrating u~e of the ~tiff fabric compo~ite as a wall panel;

Figure 2A i6 a fragmentary perspective view illustrating u~e of the ~tiff fabric composite as a wall tile;

Figure 3 i8 an enlarged cross-~ectional vi~w of a fabric, con~tructed ~n accordance with the pre~ent invention, on the knitting machine ~llustrated schematically in Figure 4;

Figure 4 i~ a schematic repre~entation of a warp-knit, weft-inserted knitting machine with follow-on proce~es for forming the fabric heroof;

wo g2m806 2 ¦ ~,? ~ Pcr/usg2/04800 Figure 5 i~ a view ~imilar to Figure 3, illustrating the fabric after the heat treatment in the proces of Eigure 4;

Figure 6 is an enlarged plan view with parts broken out for ea~e of illu~tration of a wa~p-knlt fabric con~tructed in accordance with the present i~vention;

Figure 7 is an enlarged cross-sectional view thereof taken generally about on line 7-7 in Figure 6;

Figure 8 is a view similar to Figure 6 :;
illustrating a different warp-knit stitch pattern;

Figure 9 i8 a cro~-sectional view thereof taken generally about on line 9-9 in Figure 8;

Figure 10 is a view similar to Figure 6 illustrating a still furth~r warp-knit ~titch pattern; ~-Figure 11 is a cro~s-sectional view thereof -~
taken generally about on line 11-11 in Eigure 10;

Figur~ 12 i~ a view similar to Figure 6 ~llu~trating a warp-knit weft-inserted fabric having a different ~titch construction with additional l~id-in warp yarn~;

21~2~12 W092/21806 PCT~US92/~

Figure 13 i8 a cro~ ectional view thereof taken generally about on lines 13-13 in Figure 12;

Figure 14 is a ~chematic representation of another proces~ for ~orming a fitiff fabric compo~ite according to the pre~ent invention; and Figure 15 i~ an enlarged cros~-sectio~al view of a stiff fabric composite constructed in accordance with the pre~ent invention on the needle punch machine illustrated ~chematically in Figure 14.

DETAILED DESGRIPTION OF TR~ DRAWING FIGURES

Reference will now be made in detail to the present preferred embodiment of the ~nvention, an example of which is illustrated in the accompanying drawings.

For clarity, Figures 1 and 2 illustrate representative examples of products in which the ~tiff fabric composite of the present invention may be e~bodied, the first product illustrated being vertical ~lat~ for blinds. Figures 3 and 5 illu~trate a warp-knit, weft-inserted fabric; Figure 4 illu~trates apparatu~ for fonming a warp-knit, we~t-in~erted fabric with laid-in warp yarns, it being appreciated that the apparatus for laying in the weft yarn~ a~ illustrated in Figure 4 may be omitted whereby a warp-knit fabric, with or without 2 1 ~ 2 ~- WOg2/218~ . PCT/US92/~

laid-in warp yarnc may be provided; Figures 6-11 ~ illuYtrate a warp-knit fabric; Figure~ 12 and 13 illustrate a different warp-knit, weft-inserted fabric with laid-in warp yarns; Figure 14 illustrate~
a method of making a ~tiff fabric composite u~inq a woven fabric and a non-woven sub~trate; and Figure 15 illustrates the stiff fabric CompoQite formed by the proce~s of Figure 14.

Referring now to drawing Figure 1, there is illustrated a vertical blind, generally designated 10, comprising a housing 12 for movably supporting, by means of pins 14, a plurality of vertically dispo~ed slats or vanes 16, hereafter referred to as slats 16. The housing 12 contains ~he conventional track and mechanisms for displacing the blind~
horizontally and rotating slat~ ~6 about vertical axes. The slats 16 are formed of a ~tiff fabric composite constructed in accordance with the present invention, and which slats have a self-sustaining, self-~upporting shape, unaffected by environmentally anticipated heat and humidity. Thu8, the ~hape of the slat, whether it i~ flat (Figure lA) or cup-~haped, i~ maintained by the fabric ~tself.

In Figure lB, there i~ illustrated pleated blinds. The mater~al for the pleated blinds may be lighter than that forming the blinds of Eigures 1 and lA. However, the same type of materials may be used.

2 ~ ?f806 Pcr/usg2/04800 In Eigure 2, there is illustrated a plurality of large wall panel~ W.P., e.g., 4x8 foot panels, formed of the stiff fabric compos$te hereof and applied to adjoining walls. Figure 2A illu~trate~ small tile~ T
of the ~tiff fabric compo~ite hereof. The tile~ T
may, for example, be one-foot-square tiles or smaller or larger as desired. Of cour e, because of the ea3e of cutting the compos~te hereof with sci~sor~, it will be appreciated that panels, tile~, etc. can be provided in different sizes, colors, patterns and textures, as desired. With respect to panels W.P.
and tile~ T, both may be readily adhesively or otherwise (e.g., stapled) to an underlying ~upport wall.

Referring now to Figure 3, a cross-section on an enlarged ~cale, o a stiff fabric compo~ite according to a fir~t embodiment of the present invention is illustrated and includes a warp-knit, weft-inserted fabric 18 looking in the weft direction having a ~ubstrate. The warp-knit, weft-in~erted fabric 18 include~ weft or filling yarns 20 overlying sub~trate 22. The weft yarn~ may be formed of any suitable material, althoug~. preferably a thermoplastic material, ~uch as polyester is u~ed. Also de~irable for decorative effects i~ a rayon filling. For decorative fabric~, ~uch a~, for example, as i8 uQed convent~onally in antique satin draperies, the yarn~
may be provided in relatively high-den~ity configuration, on the order of about 40-S0 single : ~
WO92/218~ 2 ~ J ~12 PCT/US92/~

picks per inch. It is to be under~tood that any - ~titch-through warp-knit fabric design can be u~ed i~
a very wide range of patterns and den~ities, as i8 done conventionally w~th any "soft" drapery fabric.

The weft or filling yarns 20 are held to the fabric by stitch yarn~ 24, including stitch loops 26 on the technical face of substrate 22. The stitch underlap 28 extends over weft yarns 20 binding the latter to the fabric. It will be appreciated ~hat one or more weft yarns, depending upon the effect desired, may be dispo~ed under each underlap depending upon the aesthetic effect desired. Any type of stitch may be used in the present invention, such as tricot or satin stitches, as di~closed in U.S. Patent No. 4,608,290 to Schnegg. The warp stitching yarns 24 may be formed of any conventional material but are preferably formed of a synthetic thermoplastic material such as polyester.

It will be appreciated that laid-in warp yarns may likewi~e be employed in fabric 18. Thus, one or more laid-in warp yarns may be provided between adjacent stitch wales or between alternate stitch wales and may be laid-in on top of such stitch wales. The warp yarns, where used, may all overlie or underlie or alternately overlie and underlie the weft yarnQ 20. In either case, the stit~hing yarns ultimately connect the laid-in warp yarns, where used, and the weft yarns in the fabri~.

2 1 ~
WO9~/21806 ~ PCT/USg2/~8 The substrate 22 may be formed of a blend or a single kind of thermally formable or thermobondable synthetic fibers. For example, a mixture of polyester fibers or two different thermoplastic fibers, one having a lower melting temperature than the other fiber, ~ay be employed. First and second different fiber~ are illustrated ~n Figure 3 by the heavy and light lines 30 and 32, respectiv~lyr the first fiberæ 30 ha~ing the lower melting temperature and the second fibers 32 having the higher melting temperature. The fiber~ may be initially in layered form and needle-punched to intermingle the fibers substantially as illu~trated, or two discrete layers -of different type fibers may be employed, preferably with the fibers ha~ing the lower melting temperature in regigtration with the weft yarn~ on the technical back of the fabric. As indicated previously, the substrate may be formed by any of the methods described and illustrated in the above-identified U.S. Patentæ Nos. 4,818,586; 4,424,250 and 4,l99,635.

In order to form the composite 18 of the present invention, reference is made to Figure 4, which illustrates a warp-knit, weft-in~ertion knitting machine, generally de~ignated 36. A single ~ubstrate feed i5 illustrated and comprises a substrate 22 previou~ly formed, for example, in accordance with any one of the three above-mentioned patents, and wound about a reel 38. Warp yarnQ 40 are illu~trated for laying in with the weft yarn~, although the warp 21~2~
WO92/21806 PCT/USg2/~00 yarns may or may not be used, depending upon the type and nature of the fabric desired. It is desirable to have the fifth bar 52 in place, even if no warp yarn is laid in, as a means of holding the substrate down when the needles rise, thus preventing disruption of the ~titch-forming process, especially when a new roll of ~ubstrate i~ introduced to the needle bar.
Weft yarns 20 of the same or various types are fed from cones 41 to the knitting area, generally designated 42, while the warp knitting yarns 44 are fed via guide bars 46 to the knitting area 42. The resulting fabric composite 18 manufactured by the Xnitting machine 36 i~ illustrated in Figure 3. If a relatively thick substrate is used, it may be desirable to install temple rollers with extra long studs to hold the ~ubstrate firmly in the cross-machine direction, as will be appreciated by those of ordinary skill in the art.

Further proce~sing of the fabric composite 18 to provide it with the re~uis~te stiffne~s is accompli~hed by applying the resulting fabric to a ~-tenter frame 48 where the fabric is tensioned in it~
width direction. m e fabric iQ then advanced into an oven 50 where heat i~ applied to the fabric. For example, oven S0 provides a sufficiently high tempeFature such that the melting temperature of the first fibers 30 in substrate 22 i~ exceed-d.
However, the temperature in the oven does not reach the melting temperature of the second fibers 32 of /!J ~

W~92/218~ ~ PCT/US92/~

substrate 22. In this manner, at least ~ome of the first fibexs 30 are melted whe~ the fabric i8 pas~ed through oven 50. Conseguently, by melting some of the first fibers 30, the plastic material of tho~e fibers fuses with the second fibers 32. Prior to advancing the fabric composite 18 into the oven, the fabric may be sprayed with or dipped in a solution containing a resin/catalyst system and/or fluorocarbon polymer to reduce shrinkage or add 80il resistance properties and is then dried and heated to a temperature sufficient to cause melting of the first fiber and not of the second fiber all in one pa88 down the oven. A flame retardant finish may be added at the same time. Thi~ is an advantage because the heat stiffening of the fibers occurs at the same time as any chémical finish(es) that is(are) added are cured. Therefore, one or more additional pas~es through the oven (tenter frame) is eliminated. The fusing of ibers 30 in the fabric 18 provide~ a predetermined ~tiffness to the fabric, depending upon the den~ity of the first fibers 30 in the ~ubstrate.
Substrate manufacturers may in some ca~es prefer to use only one kind of fibers, with similar re~ults.
The fabric composite of the present invention sub~equent to fusing the first fibers 30 i8 illustrated in Figure 5. It is noted there that the pla~tic has fused to the fiecond fiber~ 32. Upon removal of the fabric from the oven, the fabric i~
cooled and ready for u~e, for example, by cutting it to elongated trips to form the alats 16 of the 2 ~ 2 . WO 92/Z1806 PCI`/US92/04800 vertical blind 10 illustrated in Figure 1 or in p~nels, large or small, a~ illustrated in Figures 2 and 2~. As will be appreciated, the fabric can be set in noll-pl~-lar configurations, as de~ired, by heating in a sllitabl.e mold.

Importantly, and according to the present invention, a degree of stiffness is provided the fabric such that the fabric will remain self-s~pporting and substatltially rigid when subjected to elevated temperatures an~/~r humidity, for example, tho~e temperature~ and/or ~umidities as may be typically encountered in the window treatment, wall panels, environment, etc. In orde~: t~
provide a measure of the degree of stiffness obtai~d by the fabric of the prese~t invention, a ~imple te~t m~y be performed on the fabric. The fabric emanating from the ~
~titching mach~ne 36 prior to being ~laced on the -.
tentering frame and advanced into the oven, of co~lrse, has substantial flexibility and virtl~ally no .~tiffne~s or capacity to maintain a predetermined shape. ~lowever, the warp-knit, weft-inserted fabric with substrate of the present invention after passing thro~lgh the oven a being cooled, ha~ A degree of stiffness which can b~
measured by forming A pie~e of fabric in a 3.5 inch (about 90 mm) widtll of approximately 7 inches (abo~lt 180 mm) in lenqth and clamping the fabric piece in horizontal cantilevered fashion such that 5 inclles of the f~b~i~
hang~ free from the cl.amping edge. ~fter waiting approximately ~IIR~TIT1ETr ~ T

210~2 W092/21806 PCT/VSg2/~00 30 second , it ha been found that the fabric, in accordance with the present invention, ha~ a stiffneæs such that the distal end of the cantilevered fabric obtains a droop from the horizontal of no more than about 2 inches (about 50 mm). This has been *ound ~atisfactory fo~r many applications, including for use as slate in a vertical blind. It w~ll be appreciated that while the slats are about 3.5 inches wide, the above-de~cribed stiffness test may be used for fabric used in any configuration or dimension.

In another preferred embodiment hereof, the substrate may be formed of homogenous fibers, i.e., fibers of the same size, material type and generally non-distingui~hable one from the other. Thus, when the fabric including a sub~trate of this type is heated in the oven, the web of fibers bond together by fusing and the ~ubstrate stiffen~ the resulting fabric to the required degree of stiffness, as previou~ly mentioned. With a homogenou~ Qub~trate, more precise temperature and dwell time~ in the oven are necessary. In this manner, however, melting of ~ome of the fibers but not all i8 accomplished and, of those fibers melted, not the entirety of each ~uch fiber i8 melted. That is, it is snly necessary to melt portions of the fibers, not necessarily all of the fiber~ or the entirety of each fiber.

W092/21806 2 ~ ~ 2 ~ 1 ~ PCT/US92/~

With reference to the warp-knit fabrics illustrated in Figure~ 6-ll, which do not hav~
weft-in~ertion, the foregoing descriptio~ ~f the various features of ~he substrate, including the types of materials and characteri stics are applicable to the following de~cribed warp-knit fabric~.
Referring particularly now to Figure 6, there is illustrated a warp-Xnit fabric, generally designated 60, compri~ed of a substrate 22a in which the warp yarns may compri~e conventional chain stitche~ 62.
In Figure 6, the fabric is illustrated as viewed from the technical back, with only the underlaps 64 of the chain ~titche~ 62 being exposed to view through the technical back. The apparatus ~llustrated in Figure 4, of cour~e, may be used to construct the fabric 60, for example, without the weft insertion or warp laid-in yarn~, as illustrated in that drawing figure. Mali-type, Arachne, Tricot, or Raschel warp-type ~nitting machines may be used to form the fabric. Thus, after the fabric is formed by stitchin~ the warp yarns through the substrate 22a, the fabric, ~imilarly as illustrated in Eigure 4, i8 laid on the tenter frame 48 and pa~sed to the oven 50, where the fabric is heated and the fiber~
interact as previously de~cribed to form a stiffened fabric.

In abric~ of thl8 type, the patterning may be provided by the movement of the ~titching bars.
Alternatively, laid-in warp yarns 66 and 68 may be 2ln2Al2 W092/21~06 PCT~US92/~8 .

employed to achieve a patterning effect. Warp yarns 66, as illustrated, may extend between the various stitch wal~ and in different ~titch course The laid-in warp yarn 68, for example, lie~ sinuou~ly in a ~ingle ~titch wale. It will be appreciated that the stitching ~ecure~ the laid-in warp yarns to the fabric.

Referring now to the fabric illu~trated in Figure 8 and 9, again there is illustrated a warp-knit fabric having a substrate 22b similarly as previously described. Here, however, the stitch pattern i~ of a zigzag type. That i8, the underlap~
64b of the ~titches extend diagonally from one stitch wale to the next and then reverse their direction to achieve a zigzag pattern over a plurality of stitch wales and cour~es.

In Figures 10 and 11, there is illustrated a ~till further form of a warp-knit fabric 60c incorporatin~ the principles of the present invention. In thi~ form, it will be appreciated that the patterning in the fabric is achieved solely by the stitch pattern provided by stitche~ 62c. A~
viewed from the technical back, the stitch pattern comprises a plurality of cros~ed underlaps spaced from one another in both the machine and cro~-machine directions.

WO92/21~K 210~ PCT/US92~U~0 Referring now to Figures 12 and 13, there is ::
illus rated a warp-knit, weft-inserted fabric gener~lly designated 70 comprised of a substrate 22d with laid-in weft yarnæ 72, stitch yarns 74 and a number of laid-in warp yarns 76. The warp and weft yarns 76 an~i 72, ;~
re~pectively, and the underlaps of the stitch patt~rn lie on the technical back of the fabric. It will be appreciated that various types of warp yarns may be laid -`
in at various locations to achieve desired decor~t.ive effect~

Referring now to Figure 15, there is illllstrated a cro~s-~ection on an enlarged scale of a stiff fabric compo~ite according to another embodiment of the rl~esent invention. The fabric compoæite is generally design~ted 120 and includes a woven fabric 122 underlying a substrate 124. The woven fabric 122 may have ~ picl~
level between about 6 PPI ~about 24 picks per 10 cm) and about 55 PPI (about 217 per 10 cm). The warp and weft yarns 126 and 128 of the woven fabric 122 may be formed of any suitable material. ~or example, the warp may comprise natural fibers or synthetic fibers, S~lC}l a~
polyester or polypropylene. The filling yarns may compri~e any number of fibers ~uch as rayon, COttOl-, polye~ter or a~rylic in regular or novelty yarns. The woven fabric may range in weight from about 0.14 lb~/square yd. (about 75 gm/m2) to about 0.60 lbs/square yd. (about 325 gm/m ), or 0.17 lbs./lin.yd. to 0.7~
lbs./lin.yd., depending on the width of the fabr.ic, i.e., typically 45-55 inches (115-140 cm).

SUBSTITUT~ SUEET

2102~1~
WO 92/2180~ ` PCI'JUS92/04800 30 ~

l~e sub~trate 124 may be of the type described above in connection with the first embodiment hereof. Two examples of the fibers for u~e in the substrate are given as fs)llow~. One example comprises a non-woven substr~te formed of 100% polypropylene having a weight range of about 4.5 to about 9 oz/yd2 (about 160 to about 310 gm/m2) and being formed of staple fibers in the 3.25 to 5.5 Denier range and a staple length of about 3.25-4.5 inches (about 83 to 115 mm). Such s-lbstrate may be obtained from Spartan Technologies, Spartansbllrg, ~outh Carslina, under the designation N470 (7.5 oz/yd2, .i.e., 255 gm/m2). Another substrate useful in the ~resent invention may be formed of a needled non-woven 100~ ;
polyester in a weight ran~e of about 5-9 oz/yd2 (abollt 170-310 gm/m ) as manufactured by Foss Manufacturin~, Hampton, New Hampshire, under the designation 24-~-4 7.5 oz/yd2 (255 gm/m2).

With reference to Figure 14, the stiff fabric ~.
compo~ite of the present invention is formed by initially adhering the non-woven sllbstrate and the woven fabric in a manner which, when the process is completed, will a~sist in the bonding of the two fabrics one to the other. Particularly, the non-woven substrate 124 and woven fabric 122 are laid one over the other along suitable guides 134. Preferably, the non-woven ~ubstrate is laid over the woven fabric 122, the back of which faces the substrate, so that nee~le punch 136 may be di~posed SUaSTlTUTE SH~T

~: WO92/21806 2 1 f~ 1 2 PCT/US92/Q4800 above the overlaid abric~, with the needles passi~g fir8t through the non-woven ~bstrate and penetrating to a limited extent the woven fabric 122. ~t will be appreciated, however, that, for some fabric composites, the needling may pass first throuqh the woven fabric and then into the substrate. Thi~
depends on the type of fil}ing yarn, e.g., heavy, sturdy novelty yarn~ versus ~traight regular yarns.
Needling fir~t through the substrate is preferred because a better bond is formed between the woven fabric and the non-woven substrate. The needle-punch machine may be any conventional type such a~ Model NL-21 manufactured by the Fehrer Company, Linz, Austria. Thus, needles 137 of the needle punch 136 in the cour~e of their penetration of the non-woven substrate displace the thermoplastic fibers into and about the woven fabric 122, as illustrated i~ Figure 14. Only a small percentage cf the fibers of the -~
non-woven substrate 124 pass entirely through the woven fabric 122 to terminate in the face of the f~bric, as illu~trated in Figure 14. The penetration -~
depth of the needle~ can vary between S-lO mm, :~:
depending upon the thickne~s of the wo~en fabric and the desirable amount of substrate fibers on the face of ~he woven fabric for additional bonding between the ~ubstrate and the woven fabric after thermofu~ing. The needle penetration can vary between 600 to 1200 penetrations/in.2 (120 to 240 per cm2), depending upon the density of the woven fabric and the type of needle used without significantly îln~l2 WO92/218~ PCT/US92~n#~0 weakening the warp and/or the filling yarns of the woven fabric or affect alteration of the face of the -finishing fabric composite. The needle used in the proces~ may be the ~Foster Formed Barb" ~DB (high density barb) needled in 36, 40 and 42 gauge sizes or RBA 40 gauge needles. Con~eguently, by needle-punching the fabrics, the woven fabric and non-woven sub~trates are initially adhered one to the other and form a bond which will be con~olidated during the thermofusing process.

Further processing of the composite fabric to provide it with the requisite stiffness is provided by applying the fabric composite to a tenter frame 138 where the fabric is ten~ioned in its width direction. The fabric i~ then advanced into an oven 140 where heat is applied to the fabric, similarly as - in the first embodiment. For example, oven 140 provides a sufficiently high temperature such that the melting temperature of the firet fibers 130 in ~ubstrate 122 is exceeded. The oven temperature may range from about 310F to about 370E, depending on the type of substrate used and whether added treatment~, such as resin or fluoro-carbon topical treatments, are used. Fabric composite speeds through the oven may range between about 20-30 yards per minute (about 18-27 m/m~n.). Heated steam can~
can be used at the exit end of the tenter frame to further enhance the ~moothness of the face and back of the woven fabric and the fu~ed substrate.

;;~ WO92/218~ 21~2 q 12 PCT/USg~

However, the temperature in the oven does not reach the melting temperature of the second fibers 132 of substrate i22. In this manner, only the first fibers 130 are melted when the fabric is passed through oven ~-140. Consequently, by melting first fibers 130, the plastic material of those fibers fu~e with the fiecond fiber~ 132. The fibers 130 interspersed in woven fabric 122, as well as tho~e few fibers 130 which have passed through woven fabric 122 to it~
opposite face are fused to the fabric 122. Thiæ
provides added strength to the mechanical bond between the substrate 124 and woven fabric 122 afforded by the needling. The fusing of fibers 130 in the substrate 124 and to the woven fabric 122 thus provides a predetermined stiffness to the fabric composite, depending upon the density of the first fibers 130 $n the substrate and, to a limited extent, their adherence in the woven fabric. Dwell time in the oven may be on the order of 45-90 seconds.
Substrate manufacturers may in some cases prefer to u~e only one kind of fiberR, with ~imilar results.
The fabric composite of the pre~ent invention ~ubsequent to fusing the fir~t fibers 130 is illustrated in Figure 14. It i~ noted there that the thermoplastic fibers 130 have fused to the second fibers 132. Upon removal of the fabric from the oven, the fabr~c i8 cooled and ready for use, for example, by cutting it to elongated ~trips to form the slat~ 16 of the vertical blind 10 illustrated in Figure 1 or the panel~ P or tile~ T. The stiffened 2102~t~ ~
WOg2/21806 ~ : PCT~US92/~

composite may also be pleated into any size pleat on a pleating machine, not shown, with the pleats being ~tiff and having good retention. The degree of pleat retention and pleat spring~ness can be vari ed by the degree of softening/fusing of the non-woven substrate and the weight of ths substrate. As will be appreciated, the fabric can be set in other non-planar configurations, a desired, by heating in a suitable mold.

Importantly, and according to the present invention, a degree of ~tiffness is provided the fabric composite of thi~ embodiment, ~imilarly as in the first emhodiment, such that it will remain self-supporting and substantially rigid when subjected to elevated temperatures and/or hilmidity, for example, those temperature~ and/or humidities as may be typically encountered in the window treatment environment. Using a ~imilar sized piece of the composite as in the first embodiment, the composite piece is disposed in horizontal cantilevered fashion such that about 5 inches labout 130 mm) sf the fabric hangs free from the clamping edge.
After waiting approximately 30 seconds, it has been found that the fabric, in accordane with this embodiment, ha~ -a stiffness such that the distal end of the cantilevered abric composite obtains a droop from the horizontal from about 0 inches (0 mm) to abo~lt 2.0 inches ~about 50 mm) depending on the types of substrate and woven fabric u~ed. This has been found lTl~T~ E~

,- WO92/21806 2 ~ ~ 2 1 1 2 PCT/US92f~00 ;~

satisfactory for many applications, including for use as slats in a vertical blind, wall panels, tiles and the like. It will be appreciated that while the slats are about 3.5 inches (about 90 mm) wide, the above-described stiffness test may be u~ed for fabric u~ed in any configuration or dimension. ~-Additional sub_trate layers may be included in any one of the embodiments hereof, as well to add to the thermal insulating character of the fabric or to add opacity or black-out effects. The composite fabric is also moldable if different shapes should become of interest to the market.

In another preferred embodiment of the fabric -composite of Figures 14-15, the substrate may be formed of homogenous fibers, i.e~, fibers of the same size, material type and generally non-distingui~hable one from the other, ~imilarly as in the prior embodiment of Figures 3-5. With a homogenous ~-substrate, more precise temperature and dwell times in the oven are necessary. In this m~nner, however, melting of some of the fibers but not all i~
accomplished and, of thoQe fibers melted, not necessarily the entirety of each ~uch fiber i~
melted. That is, it is only necessary to melt portion~ of the fibers, not necessarily all of the fibers or the entirety of each fiber.

21~?~1,.2 W092/218~ PCT/US~2/~

It will be appreciated that in all of the embodiments hereof, the composite fabric i3 pa~sed through an oven at a temperature sufficient to melt at least some of the fibers of the substrate, thereby fusing the fibers of the substrate one to the other affording a stiffne~s to the fabric. By u~ing especially the warp-knit or warp-knit, weft-in3erted insertion technique, various decorative pattern~ may be formulated and the resulting fabric stiffened to form the highly desirable stiff fabric composite hereof.

Further, when the thermoplastic fibers of the substrate are melted, certain of those fibers at the interface of the substrate and the woven or knitted material fuse with the woven or knitted material.
Such fusi~g at the interface, however, does not substantially contribute to the bonding of the substrate and woven or knitted material to one another, it being appreciated that the knitted material i5 mechanically bonded in the substrate by the stitch through threads and that the woven material is mechanically bonded to the substrate by needle-punching certain of the substrate fibers into the woven material.

The following chart identifie~ a number of fabric ~tyles which have been tested for stiffnes~
usqn~ the droop te~t set forth previou~ly in the application. ~articularly, pieces of the identified ~ WO g2/21806 2 ~ O .~ ~ 1 2 fabric- 3.5 inch~s wld~ (~bout ~g mm) ar-eantll-ve~ed f~ve lnche~ (a~out ~ mm). At-r t~lrty -cc~nd~, t~e dro:>p ~t t~o dlst~l ~nd w~
m~a~ur-~. Two t~t- w~r~ s~n for ~ch f~rlc tyl-w~ f~rlc ~ac~ up (kn~ttod ~r wo~r-n d~lgn up) and f~brl~ fac- dc~ cnltted or woven ~o~ o~n).

2102 ~12 WO 92/21806 PCI~/US92/04800~ ~ :

~I c ~ c c c ~ c c c ~_ cs e: c a a c a ~ c . I ~ ~ 0 L.

~i ' .

O ~
~ ~ .

~ `~
. - ~o -- ~ u~ o u~
.:

a~ e ~ e ~ ~ ~ ~ r ;~ ~

# ~ # ~ ~ o >~ # ~ ~ ~ o ~ #

~

8 :~ 5 ~ u~ a~

,~

~"1 TC ~ o ~102~2 ~;~ W092/218~ PCT/USg2/~

As a check that the droop of the fabric according to the above tests is not time dependent, the Montana face up fabric wa~ measured after -twenty-four hour~ in the droop test assembly. The measured droop after 24 hour~ for the face up fabric was 5/8 inch, an insign~ficant change from the 30 second test.

While the invention has been described in connection with what is presently considered to be :
the most practical and preferred embodiment, it is to ~-be understood that the invention i 8 not to be limited :~-to the di closed embodiment, but on the contrary, is intended to cover variouc modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A-stiff fabric composite comprising:
a fibrous woven or non-woven material;
a non-woven substrate of thermoplastic fibers, said fabric composite having been heated to a temperature sufficient to fuse at least some of the fibers of said substrate to one another to provide the fabric composite with a stiffness such that a flat piece of said composite 3.5 inches wide cantilevered in a horizontal direction five inches from a support has a droop at its distal end of from 0 inches to 2.0 inches, with face side up or down.

2. A stiff fabric composite according to Claim 1 wherein said stiffness is attributable solely to the fibrous material and said substrate.

3. A stiff fabric composite according to Claim 1 wherein said substrate is formed of first and second fibers with said first fibers having at least one characteristic enabling at least some of said first fibers to melt at a predetermined temperature while said second fibers retain discrete definition within said substrate at said predetermined temperature.

4. A stiff fabric composite according to Claim 1 wherein said substrate is formed of first and second fibers with said first fibers having a lower melting temperature than the melting temperature of said second fibers, said stiffness being attributable solely to the fibrous material and said first and second fibers of said substrate.

5. A stiff fabric composite according to Claim 1 wherein said non-woven material comprises a warp-knit fabric.

6. A stiff fabric composite according to Claim 1 wherein said non-woven material comprises a warp-knit, weft-inserted fabric.

7. A stiff fabric composite according to Claim 1 wherein said fibrous material comprises a woven fabric.

8. A slat or a vane for a vertical blind formed of the stiff fabric composite of Claim 1.

9. A panel for a wall covering formed of the stiff fabric composite of Claim 1.

10. A wall tile for a wall covering formed of the stiff fabric composite of Claim 1.

11. An integral pleated shade formed of the stiff fabric composite of Claim 1.

12. A warp-knit fabric having incorporated therein a substrate formed of first and second fibers, said first fibers being formed of a thermoplastic material having a predetermined melting temperature, said fabric having been heat-treated to a predetermined temperature sufficient to melt at least some of said melted first fibers such that said melted first fibers are fused with said second fibers in the substrate to provide a fabric having a predetermined stiffness.

13. A fabric according to Claim 12 wherein said second fibers are formed of a thermoplastic material, said first fibers having a predetermined melting temperature lower than the melting temperature of said second fibers.

14. A fabric according to Claim 13 wherein said second fibers are formed of a thermoplastic material, said first fibers having a predetermined melting temperature lower than the melting temperature of said second fibers, said second fibers remaining substantially wholly unmelted during the heat treatment.

15. A fabric according to Claim 12 wherein aid substrate is non-woven.

16. A fabric according to Claim 12 wherein said fabric is a warp-knit, weft-inserted fabric.

17. A fabric according to Claim 16 wherein said second fibers are formed of a thermoplastic material, said first fibers having a predetermined melting temperature lower than the melting temperature of said second fibers, said second fibers remaining substantially wholly unmelted during the heat treatment, said substrate being non-woven.

18. A slat for a vertical blind formed of the fabric of Claim 12.

19. A panel for a wall covering formed of the fabric of Claim 12.

20. A wall tile for a wall covering formed of the fabric of Claim 12.

21. A blind for a window treatment comprising:
a plurality of slats;

each slat being formed of a fabric having stitch through warp yarns and a substrate formed of first and second fibers, said first fibers being formed of a thermoplastic material having a predetermined melting temperature, said fabric having been heat-treated to a predetermined temperature sufficient to melt at least a portion of said first fibers such that said first fiber portion is fused with said second fibers is said substrate to provide a slat having a predetermined stiffness.

22. A blend according to Claim 21 wherein said second fibers are formed of a thermoplastic material, said first fibers having a predetermined melting temperature lower than the melting temperature of said second fibers.

23. A blend according to Claim 22 wherein said substrate is non-woven.

24. A blend according to Claim 21 wherein said second fibers are formed of a thermoplastic material, said first fibers having a predetermined melting temperature lower than the melting temperature of said second fibers, said second fibers remaining substantially wholly unmelted during the heat treatment.

25. A blend according to Claim 21 wherein said fabric is a warp-knit, weft-inserted fabric.

26. A blend according to Claim 25 wherein said first fibers are fused with the weft yarns of said warp-knit, weft-inserted fabric.

27. A blend according to Claim 26 wherein said substrate is non-woven and said second fibers are formed of a thermoplastic material, said first fibers having a predetermined melting temperature lower than the melting temperature of said second fibers, said second fibers remaining substantially wholly unmelted during the heat treatment.

28. A warp-knit fabric having incorporated therein a substrate formed of thermoplastic fibers having a predetermined melting temperature, said fabric having been heat-treated to said predetermined temperature sufficient to melt at least some of said fibers such that said melted fibers are fused in said substrate to provide a fabric having a predetermined stiffness.

29. A blind for a window treatment comprising:

a plurality of slats;

each slat being formed of a warp-knit, weft-inserted fabric having incorporated therein a substrate formed of thermoplastic fibers, said fibers having a predetermined melting temperature, said fabric having been heat-treated to said predetermined temperature sufficient to melt at least some of said fibers such that said melted fibers are fused in said substrate to provide a fabric having a predetermined stiffness, said slat having a stiffness such that a flat piece of said slat 3.5 inches wide cantilevered in a horizontal direction 5 inches from a support has a droop at its distal end of no more than 2 inches.

30. A blind for a window treatment comprising:
a plurality of slats;

each slat being formed of a warp-knit, weft-inserted fabric having incorporated therein a substrate formed of first and second fibers, said first fibers being formed of a thermoplastic material with at least some of said first fibers fused to said second fibers, said slat having a stiffness such that a flat piece of said slat 3.5 inches wide cantilevered in a horizontal direction 5 inches from a support has a droop at its distal end of no more than 2 inches.

31. A fabric according to Claim 30 wherein said stiffness is attributed solely to the yarns forming the warp-knit, weft-inserted fabric and said incorporated substrate.

32. A fabric according to Claim 30 wherein said first and second fibers are formed of thermoplastic material with said first fibers having a lower melting temperature than the melting temperature of said second fibers, said stiffness being attributable solely to the yarns forming the warp-knit, weft-inserted fabric, and said incorporated substrate.

33. A fabric according to Claim 31 wherein said substrate is non-woven.

34. A method of forming a stiff fabric having stitch through warp yarns and a substrate comprising the steps of:

on a knitting machine, (a) providing a non-woven substrate for movement in the machine direction formed of first and second different fibers with said first fibers formed of thermoplastic material having a predetermined melting temperature, and (b) stitching the warp yarns and substrate each to the other, and thereafter, heating the fabric to a temperature to fuse at least some of said first fibers with said second fibers of the substrate to provide a predetermined stiffness to the fabric.

35. A method according to Claim 34 wherein the fabric is a warp-knit, weft-inserted fabric, including the steps of, on said knitting machine, laying in weft yarns in the cross-machine direction and stitching the weft yarns and substrate each to the other.

36. A method according to Claim 34 including the step of laying in warp yarns on the substrate.

37. A stiff fabric composite comprising:

a woven material;

a non-woven substrate of thermoplastic material comprised of a plurality of thermoplastic fibers, said non-woven substrate being needled to said woven material so that thermoplastic fibers thereof lie within the woven material;

said fabric composite having been heated to a temperature sufficient to fuse at least a portion of said thermoplastic fibers in said non-woven substrate to one another to provide a fabric composite having a predetermined stiffness.

38. A fabric composite according to Claim 37 wherein said non-woven substrate is needled sufficiently to mechanically adhere the woven material and the non-woven substrate one to the other.

39. A fabric composite according to Claim 37 wherein said substrate comprises polypropylene.

40. A fabric composite according to Claim 37 wherein said substrate comprises polyester.

41. A fabric composite according to Claim 37 wherein said substrate comprises a combination of polypropylene, polyester and polyethylene.

42. A slat for a vertical blind formed of the fabric composite of Claim 37.

43. A pleated blind formed of the fabric composite of Claim 37.

44. A panel for a wall covering formed of the stiff composite fabric of Claim 37.

45. A tile for a wall covering formed of the stiff composite fabric of Claim 37.

46. A fabric composite according to claim 37 wherein at least a portion of the thermoplastic fibers needled to said woven material are fused to said woven material.

47. A blind for a window treatment comprising:

a plurality of slats;

each slat being formed of a composite of a woven fabric and a non-woven substrate formed of thermoplastic material needled so that thermoplastic fibers of said non-woven substrate are interspersed among the fibers of the woven fabric, said composite having been heat-treated to a predetermined temperature sufficient to fuse at least a portion of said thermoplastic fibers of said non-woven substrate in said non-woven substrate to provide a blind formed of said composite and having a predetermined stiffness.

48. A fabric composite comprising:

a woven material;

a non-woven substrate of thermoplastic material needled to said woven material;

said substrate being formed of first and second fibers, said first fibers being formed of a thermoplastic material having a predetermined melting temperature, said fabric having been heat-treated to a predetermined temperature sufficient to melt at least some of said first fibers such that said melted first fibers are fused with said second fibers in the substrate to provide a fabric composite having a predetermined stiffness.

49. A fabric composite according to Claim 48 wherein said second fibers are formed of a thermoplastic material, said first fibers having a predetermined melting temperature lower than the melting temperature of said second fibers.

50. A fabric composite according to Claim 48 wherein said second fibers are formed of a thermoplastic material, said first fibers having a predetermined melting temperature lower than the melting temperature of said second fibers, said second fibers remaining substantially wholly unmelted during the heat treatment.

51. A fabric composite according to Claim 48 wherein at least a portion of said first fibers are needled in said woven material, at least some of said first fiber portion being fused to said woven material.

52. A fabric composite comprising:
a woven material;

a non-woven substrate of thermoplastic material needled to said woven material;

said non-woven substrate being formed of first and second fibers, said first fibers being formed of a thermoplastic material having a melting temperature lower than the melting temperature of said second fibers, at least some of said first fibers being fused to said second fibers by heat treatment whereby said non-woven substrate and said woven fabric form a fabric composite, said fabric composite having a stiffness such that a flat piece of said composite 3.5 inches wide cantilevered in a horizontal direction five inches from a support has a droop at its distal end of from 0.0 inches to 2.0 inches.

53. A slat for a vertical blind formed of the fabric composite according to Claim 52.

54. Pleated material for a window treatment formed of the fabric composite of Claim 52.

55. A method of forming a stiff fabric composite comprising the steps of:

needling a non-woven substrate formed of thermoplastic fibers and a woven material one to the other and heating the needled non-woven fabric and woven fabric to a temperature to fuse at least some of said fibers in said substrate and to said woven fabric to provide a fabric composite of predetermined stiffness.

56. A method according to Claim 55 including the steps of providing a non-woven substrate formed of first and second thermoplastic fibers wherein said first fiber has a melting temperature lower than the melting temperature of said second fiber and the step of heating includes melting at least some of the first fibers without substantial melting of the second fibers such that some of the first fibers are fused with the second fibers.