CA1123589A - Hydraulically needling fabric of continuous filament textile and staple fibers - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A lightweight composite fabric characterized by high retention of fiber content during initial laundering and exceptionally high strength as measured close to the edge of the fabric with cover and fabric aesthetics equiva-lent to conventional fabrics having 50% higher basis weight are produced by hydraulically needling short staple fibers and a substrate of continuous filaments formed into an ordered cross-directional array. The individual continuous filaments of the array are well spread and separated so that they have a spaced-apart relationship allowing interentangl-ing of the short staple fibers with the continuous filaments to form more than about two reversals in the staple fibers per cm of staple fiber length between the faces of the fabric. The staple fibers have a linear density of less than about .3 tex per filament, are from about .5 cm to about 1 cm in length and comprise about 20% to about 50% of the weight of the composite fabric.

Description

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Hydraulically Needling Fabric o~ Continuous Filament Textile and Staple Fibers DESCRIPTION
T_CHNICAL FIELD
This invention relates to composite fabrics z.nd more particularly, it relates to lightweight com-posite fabrics suitable for general purpose wearing apparel.
BACKGROUND A _ Lightweight fabrics having good cover, strength, and other aesthetics appropriate for the indicated end use are highly desired in the marketplace, especially when the weight of the fabric can be reduced while still maintaining the desired fabric properties.
In commercial practice, of course, a range of fabric weights is offered for sale in each end-use cate~ory.
While the final customer is the ultimate judge of quality, there is a minimum optimum weight in each end- ~ -use category at which fabrics can be expected to have good cover, stability, body, and other attributes of good quality.
Nonwoven fabrics are of interest because of their low cost of manufacture. For several yea~s non- ~-woven fabrics ~ade entireIy of staple fibers, either with a pattern of apertures by the process of Evans U.S. 3,4~5,706 or without apertures by the process :

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of Bunting et al. U.S. 3,508,308, have been produced commercialLy. Such fabrics have found widespread utility in such applications as house'nold drapes, bed~
spreads, mattress covers, diapers, and disposable wear-ing apparel such as operating room scrub suits. Manyof these are relatively lightweight fabrics. However, regardless of their basis weight, these fabrics have not penetrated the general purpose wearing apparel market, owing to ~heir poor seam strength, poor stability, and high fiber loss during laundering.
The reinforcement of nonwoven fabrics by incorporating into them one or more layers of woven fabric, knit fabric, random nonwoven webs of continuous filaments, or warps or cross-warps of continuous fila-ments or yarns thereof is disclosed in Evans U.S.3,485,706, Evans U.S. 3,494,821, and Britlsh Patents 1,063,252-253. Canadian 841,938 similarly discloses relnforcement of absorbent nonwoven fabrics of paper fibers of short length by assembling the layers of paper fibers with woven, nonwoven, or knitted fabrics and uniting the layers into a l.aminated structure.
However, the deficiencies of nonwoven fabrics made entirely of staple fibers are not fully resolved by reinforcing them with continuous filament abrics or cross warps in the ways disclosed in the prior art.
In particular, excessive loss of staple fiber during the initial laundering of the fabric is a problem.
Higher strength very near the edge of the fabric, i.e., within about 3 mm of the edge, is also desired so that the fabric will form strong seams.
SUMMARY OF THE INVENTION
In accordance with the present invention, lightweight composite fabrics are provided which have excellent retention of staple fibers during laundering, including the initial laundering, and which have an edge strength superior to conventional woven and knitted fabrics of -the same weight. The cover and fabric aesthetics provided by the composite Labrics of the invention are equivalent to those of conven-tional woven and knitted fabrics of 50~ higher basisweight.
The lightweight composite fabrics of the invention are produced by a hydraulic needling process from short staple fibers and a substrate of continuous filaments formed into an ordered cross-directional array by ensuring that the individual filaments are well spread and separated so that they have a spaced-apart relationship and interentangling the short staple fibers wi~h the continuous filaments while they are spaced apart, Eirst from one side of the fabric and then from the other, to form more than about two reversals in the staple fibers per cm of staple fiber length between the faces of the fabric. The filaments are considered well spread provided that the average spacing between any bundles of fiLaments is no larger than the average width of said bundles of filaments;
and they are considered to have a spaced-apart rela- .
tionship provided that in the densest observed area of the filament bundle the sum of the areas of the filament cross sections occupies less than 30~ of the densest observed area of the bundle. The individual continuous filaments are thus interpenetrated by the short staple fibers and locked in place hy the high frequency of staple fiber reversals. The staple fibers should have a linear density of less than about .3 tex per filament, should be from .5 cm to about 1 cm in length, and should comprise from ~0 to 50~ of the weight of the composite fabric. The substrate should be comprised of yarns or warps of continuous filament~, formed into an ordered cross~directional array, which are free of filament ~3~

intererltanglement which would prevent ready separation of the filaments from one another.
As used herein, the term "cross-directional array" designates a rilament pattern in which a first set of continuous filaments is disposed in a first direction from one side of the pattern to the other in such a way that the filaments maintain appro~imately the same distances from one another from one side of the attern to the other, while in a direction which crosses the first direction (preferably at ri~ht angles) the first set of continuous filaments is either (a) ~nitted to~ether in stitches aligned across the pattern in the second direction or (b) crossed in the second direction by a second set of continuous fila-ments which maintain approximately the same distancefrom one another as they proceed from one side of the pattern to the other in the second direction. One form of the cross-directional array is therefore a knitted fabric of continuous filament yarns, preferably a jersey knit construction. Another form of the cross-directional array is a woven scrim formed of con-tinuous filament yarns. Still another form of the cross-directional array is a cross-warp of continuous filaments, especially one in which the cross-warp is formed in at least one direction from continuous ~ilament yarns spread out to expose individual filaments.
The product of the invention is a light-weight composite fabric comprising: a substrate of continuous filaments formed into an ordered cross-directional array, said continuous filaments having aspaced-apart relationship visible throughout the array in at least one direction of the array, said filaments being well spread provided that the average spacing between any bundles of filaments is no larger than the average width of said bundles of filaments, said , 3~

filaments having a spaced-apart relationship provided that in the densest observed area of the filament bundle the sum of the areas of the filament cross sections occupies less than 30% o, the densest observed area of the bundle, said substrate being combined with staple fibers of less than .3 tex per filament and from about 0.5 cm to about 1 cm in length in the amount of from 20 to 50% of the weight of the composite fabric, said staple fibers extending through and entangled with said continuous filaments and having more than about two reversals in direction between the faces of the fabric per cm of staple fiber length; said composite fabric having an edge strength of from about 15 to 30 newtons and experiencing a loss of no more than 3~ of its fiber content during initial laundering. The fabric preferably has a basis weight of from about 50 to about 135 grams per square meter.
One embodiment of the inventlon is such a lightweight composite fabric in which the substrate i~s formed of continuous filament yarns knit together in stitches in an ordered array of courses and wales, said substrate having a construction density of from about 0.2 to about 1.4 stitches x gram/cm4.
In another embodiment of the invention the lightweight composite fabric has a substrate which is a woven scrim formed of continuous filament yarns and having from about 2 to 12 picks per inch.
In a further embodiment of the invention, the substrate is a cross-warp of continuous filamen-ts, one of the cross-warps preferably being formed in at least one direction ,rom continuous filament yarns.
In still another embodiment of the invention, the lightweight composite fabric of the invention is a corduroy fabric having a basis weight of from about 100 to about 200 grams per square meter, said substrate being a cross-warp of continuous filaments.

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~he process for makin~ the li~htweight com-posite fabrics of the invention comprises:
(a) forming continuous filament yarns into an ordered cross-directional array, S said yarns being free of filament inter-entanglement and twist which would prevent ready separation of the filaments from one another;
(b) placing a sheet formed of staple fibers of less than .3 tex per filament and from about .5 cm to about 1 cm in length over said array of continuous filament yarns;
(c) impinging the staple fibers and array of continuous filament yarns with columnar streams of liquid to spread the yarns so that the filaments are well spread and have a spaced-apart relationship throughout the axray in at least one direction and so that the staple fibers interentangle with said continuous filaments to form an integral composite fabric, said filaments being well spread provided that the average spacing between any bundles of filaments is no larger than the average width of said bundles of filaments, said filaments having a spaced-apart relationship provided that in the densest observed area of the fila-ment bundle the sum of the areas of the filament cross sections occupies less than 30~ of the densest observed area of the bundle; and (d) impinging the fabric so formed with columnax streams of liquid from the reverse side of the fabric to further interentangle the staple fibers, thereby forming more than about two reversals in the staple fibers in the direction between the faces of the fabric ?er cm of staple fiber length.

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BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic illustration of a process for making the fabric of the invention in-volving two stages of hydraulic needling.
S Figure 2 is a schematic illustration of a process for maXing the fabric of the invention involv-ing one stage of hydraulic needling.
Figure 3 is a schematic cross sectional re-presentation of a fabric of the invention illustrating - 10 staple fiber reversals.
Eigures 4 - 5 are photomicrographs at 10x magnification of fabrics made according to Example 1.
Figures 6 - 16 are photomicrographs at 10x magnification of fabrics made according to Example 2.
Figures 17 - 20 are photomicrographs at 10x magnification of fabrics made according to Example 3.
Figures 21 - 25 and 21a - 25a are photo-micrographs at 10x magnification, face and back portions, respectively, of the fabrics made according to Example 4.
Figures 26, 26a are photomicrogra~hs at 10x magniication o face and back portions, respectively, of the fabric made according to Example 5.
DETAILED DESCRIPTION OF THE ILLUSTRATED E~ODIMENTS
. _. ............. _ Figure 1 illustrates schematically a two-stage hydraulic needling process for making the ~abric of the invention that generally includes as components an endless driven belt feed section 10, an endless driven belt needling section 12, a drum needling section 14 with squeeze roll section 15, a hot air dryer 16, and a windup 18. Details on the operating conditions are found in Example 1.
Figure 2 illustrates a single stage hydraulic needling process for making the fabric of this inven-tion wherein a scrim fabric substrate and overlaid staple fibers assembled in frame ~0 is passed beneatha line of closely spaced fine columnar streams o' liquid 42 (only one of which is visible) ~rom a mani-fold 4a. The frame ~0 is positioned on a reversibly S movable endless belt 46 traveling in a path determined by rollers 48. The passage of the frame 40 beneath the streams 42 is in effect a traverse of the streams across the top of the staple/substrate assemblage.
Again, further details on operating conditions are disclosed in Examples 2 - 5.
Figure 3 is a cross sectional schematic view of the fabric 50 of the invention showing the con-tinuous filaments 52 of the yarn in a well spread spaced-apart relationship permitting the staple fibers 54 to be intertangled with the filaments to form reversals 56 in the staple fiber.
The lightweight composite fabrics of ~he present invention comprise two components, the short staple fibers 54 and a substrate of continuous fila-ments 52 formed into an ordered cross-directional array. The fabrics of the invention are disti~guished from prior art fabrics in that these components are integrated together so intimately that they form a single entity of a highly unlform nature, as contrasted with laminated or reinforced fabrics. ~he fabrics of the invention therefore are strong and have good cover and other good fabric aesthetics even though they are light in weight. In particular, they exhibit excep-tionally high strength close to the edge of the fabric, a property associated with the ability to form strong seams. The novel ~abrics also exhibit high retention of their fiber content, experiencing a loss of no more than 3% of their fiber content during initial launder-i~g. Loose fibers which are not well integrated into the fabric structure tend to be lost during this initial laundering. Poorly integrated prior art fabrics have in some instances exhibited a fiber loss of 10~ or more during initial laundering.
The continuous filament component of the fabric of the invention has as its most important characteristic the ~roperty of being of a spreadable nature. Warps of individual continuous filaments may be used where applicable. However, spreadable con-tinuous filament yarns are commercially more practi-cable for cross-warps and are required for embodiments involving woven or knitted scrims as substrates. Such continuous filament yarns cannot have appreciable twist, or have a significant content of entangled nodes to permanently entangle the filaments together, either of which would prevent the yarn from being spread and the filaments disassociated from one another so that the filaments have a spaced~apart relationship t~rough-out the ordered cross-directional array in at least one direction. The spreading of the yarns has two im-portant aspect~: first, the process of spreadingbrings rilaments of nearby yarns close together, closing the space between adjacent yarns, making the fabric more uniform, and increa;,ing the cover; and second, gaps are opened between filaments within individual yarns which permit the short staple fibers to penetrate primarily between the filaments of individual yarns rather than between the yarn bundles.
The staple fibers thus act to interentangle with individual continuous filaments to form a highly integrated, uniform composite fabric rather than to interentangle with yarn bundles to form a reinforced or laminated structure.
Preferred continuous filament yarns for forming the ordered cross-directional array are false-twist textured (FTT) or false-twist set textured (FTST) continuous filament yarns composed of pol~ester, poly-amide, or other extrudable polymer.
The staple fiber component of the fabric of the invention can b of any fiber, natural or synthetic, such as cotton, rayon, polyester, acrylic, or nylon.
The fibers should have a linear density of less than .3 tex per filament, e.g., in the range of about .05 to .3 tex per filament, and be present in the amount of 20 to 50~ of the weight of the composite fabric.
Most importantly, the staple fibers are short, having a length of from about .5 to about l cm in length; and in the hydraulic needling process the short staple fibers are needled first from one side of the fabric and then from the other until they have more than about ~ reversals between the faces of the fabric per cm of staple fiber length. Because the staple fibers inter-penetrate individual continuous filaments, as de-scribed above, and because they are both short in length and have frequent reversals from one side of the fabric to the other, they act to interentangle the individual filaments to form a highly integrated, uniform composite fabric.
Figures 4 - 26 are photomicrographs at lOx magnification of portions of fabrics produced according to Examples l - 5.
DESCRIPTION OF TESTS
A. Reversal Frequency This is a test to determine the frequency with which staple fibers passing from one side of the fabric to the other rever,se themselves and pass through the fabric again. In this test, a sample is cut from the test fabric and placed between two sheets of trans-fer printing paper of different colors, described here as red and black. The resulting sandwich is hot pressed for 2.5 minutes at a temperature of 180C and .

~ ll a-t a ~ressure of about 7 ~IPa. This results in the samples belng dyed red on one side and black on the other. In the dyed fabrlc, s.aple fibers that have passed through the fabric from one side to the other side one or more times will then have alternating black and red sections, sometimes with an intervening undyed section. To determine the reversal frequency of these staple fibers, individual s,aple fibers are teased out from the cut edge of the fabric. In a pre-ferred form of the test, the sample is a 4 x 4cm squareand the fibers are pulled from the edges of a cut made through the middle of the dyed square of fabric (the cut preferably being made in the wale direction in the case of a knitted fabric). The fibers are then viewed under a stereomicroscope, and for each fiber, the total number N of dyed sections (number of red sections plus number of black sections? is noted. The number of reversals, R, of a staple fiber is two fewer than the total number of dyed sections: i.e., R = N - 2 Equation (I) For instance, a fiber having three dyed sections has one reversal, a fiber with four dyed sections has two reversals, etc. The lengths of the individual staple fibers, if not already known because of information known about starting material fibers from which the fabric was maae, are determined in centimeters. The reversal frequency for each individual staple fiber is then determined by dividing R by the length of the staple fiber. Results are obtained for approximately 100 individual staple fibers. The average of all the reversal length values is then determined and reported as ~he result for reversal frequency.
Bo Basis Weight and Staple Fiber Composition The weight and the area of a sample of fab-ric are measured, and the basis weight is determined 5~

lla by dividing the weight by the area, e.g., as expressed in units of g/m2. The percentage staple fiber content, if not already known, is determined by carefully teasing apart a small sample of the fabric, separating the staple fibers from the continuous filaments, weighing the collected staple fibers together, dividing the weight of the staple fibers by the weight of the fabric sample, and expressing the result as a percent-age value. The linear density of the staple fibers, if not already known, is determined in conventional manner by weighing a measured length of the staple fiber on a sensitive balance.

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C. Knit Construction DensitY
_ _ This test is a measure of the tightness of construction of knit fabrics. In this test, the number of courses per centimeter and the number of wales per 5 centimeter are determined. Knlt construction density is defined and calculated as the product of the number of courses per cm, the number of wales per cm, and the fabrlc basis ~eight in g/cm2. The knit construc-tion density parameter accordingly has the dimensions 10 of g/cm4.
D. Test ~or S~reading or Filaments _ _ . . _ _ _ . . .
In this test a photomicrograph of a repre-sentative area of the fabric sample is prepared and examined to determine whether the continuous filament 15 bundles (i.e., yarns or other groups of continuous filaments) which form the substrate of the fabric have been adequately spread so that the short staple fibers project through extensive areas of the spread bundles, as contrasted with spaces between bundles. The sample 20 is ~irst inspected to determine whether it contains continuous filaments, and if ~o, whether these are arranged in an ordered cross-directional array (knit structure, woven structure, or cross-warp). Those samples which do contain an ordered cross-directional 25 array of continuous filaments are handled further in accordance with the type of array present, as follows:
(D-l) Samples ~aving a Knit Construction or Continuous Filament 3undles A photomicrograph at 10x magnification, 30 taken from the wales side of the fabric by reflected light against a contrasting background, is prepared.
One stitch near the center of the photomicrograph is arbitxarily selected as a reference stitch. Two parallel straight lines are drawn on ~he photomicro-graph as guidelines, one line generally following the course direc~ion at the top (arbltrarily selected) of the reference stitch and the other line generall~
following the course direction at the bottom of the reference stitch. ~ig. 27 is a schematic illustra-tion in which the stitches are shown as being formed from continuous filament bundles 66 comprised of four continuous filaments 67, the staple fibers in the fabric being omitted in this illustration.
As illustrated in Fig. 27, guidelines 60t and 60b are drawn in the course direction at the top and bottom, respectively, of reference stitch 63 and measurements are then made on the reference stitch, the stitch 61 immediately to the left of it, and the stitch 65 immediately to the right of it--three stitches in all, encompassing five holes between the guidelines, one hole at the center of each of the three stitches and two holes 62 and 64 between stitches. For each of these holes, the maximum diameter of the hole between the guidelines, measured in a direction parallel to the guidelines, is determined. These diameters are 1' 2, 3, 4 d 5, where d3 is the diameter of the hole in the reference stitch. The width of the continuous filament bundle at the right of each o~ the holes is then also determined, the measurement being made midway between the guidelines and across the continuous filament bundle perpendicular to the general direc~ion in which the ~undle lies. These widths are shown as wl, w2, W3, W4 a 5 cases, the hole diame~er may be ~ero (continuous filaments of the bundle on the right side of the s-titch to~ching or overlapping the continuous filaments of the bundle on the left side of the stitch). The sum of the five bundle widths is calculated as wt and the 3r9~3 sum of the five hole diameters is calculated separately as dt. The degree of spreading, ~S, is then calcu-lated as a percentage in accordance with the equatlon %S = d +t _ x lO0~ Equatio~ (II) In this test, the continuous filaments are considered to be adequately spread if, in at least one direction, the degree of spreading is at least 50% as calculated by Equation II. Although Fig. 27 illustrates a jersey knit, the test is carried out in analogous manner on five adjacent holes between course lines with other knit patterns.
(D-2) Samples Having a Woven Construction of Continuous Filament Bundles . . ~
A photomicrograph at lOx magnification, taken from the face side of the fabric (the least fuzzy OL-the two sides) by reflected light against a contrasting background, is prepared. Near the center of the photo~
graph, a unit cell comprising the quadrilateral formed by the four crossover points of two adjacent continuous filament bundles (yarns) in each direction is selected as the reference unit cell. Fig. 28 is a schematic illustration in which the woven structure with refer-ence unit cell 71 is shown as being formed from con-tinuous filament bundles 75 comprised of four con-tinuous filaments 74, the staple fibers in the fabricbeing omitted in this illustration. Two parallel straight guidelines are drawn, one line 70t generally following the center line of the continuous filament bundle 72 at the top (arbitrarily selected3 of the reference unit cell and the other line 70b generally following the center line of the continuous filament bundle 73 at the bottom of the reference unit cell.
As shown in Fig. 2~, measurements are then made on the row of unit cells comprising the reference unit cell, the two unit cells immediately to the left of it, and ~2~
the two unit cells immediately to the right of it (five unit cells in all, each sharing at least one side with another unit cell). For each of these unit cells, the maximum diameter of the hole near the center of the cell, measured in a direction parallel to the guidelines, ,s determined. For each of these cells, ~he width or the continuous filament bundle at the right of each of the holes is then also determined, the measurement being made across the bundle perpendicular to the general direction in which the bundle lies. In Fig. 28, as in Fig. 27, the hole diameters are desig nated as dl, d2, etc. and the bundle widths are desig-nated as w~ 2~ etc. The sums of the bundle widths and the hole diameters are then calculated separately, after which the degree of spreading, S, is calculated in accordance with Equation II. If the degree of spreading determined in this way is less than 50%, the test is repeated with the same reference unit cell, using guidelines along the other sides of the unit cell in a cross direction to the original guidelines. In this test, the continuous filaments are considered to be adequately spread i~, in at least one direction, the degree of spreading is at least 50~ as calculated by Equation II.
(D-3) Samples Having Cross Warps o, Continuous Filaments .
Photomicrographs at lOx magnification are taken of each side of the fabric by reflected light against a contrasting background. The photomicrographs are e~amined to determine whether the continuous fila-ments in the fabric appear to be divided in both the machine direction and in the cross direction into bundles of continuous filaments with intervening spaces (e.g., into yarns or other groups or continuous fila-ments). If, in at least one direction, there is no 16such dlvision of the continuous filaments into bundles separated bv spaces, the value of dt in Equation II is taken to be zero and the de~ree of spreading, S, is 100%. If the continuous filaments are divided in both directions into bundles of filaments with intervening spaces, as shown schematically in Fig. 29, the pro-cedure described in Test D-2 for samples having a woven construction of continuous filament yarns is applied, bundles of filaments in the two cross direc-tions being regarded as forming unit cells comprisingquadrilaterals analogous to the unit cells in the woven construction. In Fig. 29 the cross-warp structure is shown as being formed from continuous filament bun-dles 85 comprised of four continuous filaments 84, the staple fibers in the fabric being omitted in this illustration. Two parallel straight g~idelines 80t and 80b are drawn at the top (arbitrarily selected) and bottom of the reference unit cell 81 generally follow-ing the center lines of continuous filament bundles 82 and 83 defining the top and bottom o the cell. Mea-sur~ments are ta~en on five unit cells in one direction, and, if necessary, in the other direction as described in Test D-2. In this test, the continuous filaments are considered to be adequately spread if, in at least one direction, the degree of spreading is at least 50%
as calculated by Equation II.
In making observations with respect to any of the above samples, the pattern to be examined is that of the continuous filaments. Although staple ibers are also present and may not be conclusively dis-tinguished from the continuous filaments in all cases, the ~eneral pattern of the continuous filaments can be ascertained and it is with respect to thls pattern that the criteria of the test should be applied.

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E. Test tor S~aced-Apart Relationshlp of Filam~nts In thls test, a photomicrograph of t~le fabric in cross section is taken bet~een courses or crossover points of continuous filaments and is examined to deter-mine whether the filaments have a spaced-apart rela-tionship to permit effective interpenetration of the individual con~inuous filaments by the short staple fibers. As in Test D above, the samples are handled in accordance with the type of ordered cross-directional array present, as follows:
(E-l) Samples ~aving a Knit Construction of Continuous Filament Bundles A cross section of the abric sample is prepared for examination by transmitted light under the microscope by embedding the sample in a clear epoxy resin which sets up to a hard block, rough-cutting the block with a razor blade in a direction essentially perpendicular to the wale direction, placing the rough-cut bloc]c in a microtome, and sectioning it across the wale direction with a steel knife into wafers approxi-mately 8 microns thick. A wafer is selected in which the cross sections of the continuous filament bundles (yarns) are primarily located between courses of the fabric sample, e.g., along line 60 m or Fig. 27, the conti.nuous filaments being cut predominantly across their filament a~es to ~ive transverse cross sections, rather than along the lengths of the filaments. The wa~er is then placed on a microscope slide and immersed in oil having approximately the same index of refrac-tion as the epoxy resin. ~ photomicrograph of thefabric in cross section is taken at about 44x mag-nification and, while the wafer is held for further observation, a representative filament bundle is selected for higher magnification. If necessary, more than one wafer is examined to select a representative .

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filament bundle cross section. The microscope is then adjusted for higher magnification of the representative filament bundle cross section such that a photomicro-graph can be prepared in which a 2.54 cm x 2.54 cm (1 in x l in) square containing the transverse cross sections of at least four continuous filaments can be inscribed substantially within the oeriphery of the representative filament bunle cross section; typically, a magnification of 200x can be used. ~ record is made of the magnification l~ actually used.
The photomicrograph so prepared is examined under a magnifier having a base with a square opening measuring 2.54 cm (1 inch) on each side, and having a 6x magnifica-tion viewing glass mounted about a cm akove the square opening ("linen tester" magnifier, Edmund Scientific Company, catalog ~o. 3875, item ~o. 40030).
The square opening of the magnifier is set down upon the area of the photomicroqraph which appears to con-tain the densest concentration of continuous filament - 20 transverse cross sections, i.e., the densest observed area of the bundle. The number of continuous filament transverse cross sections (including any fractional area of cross section) within the square opening is counted, ignoring any elongated cross sections from fibers or filaments intercepted which lie at a consid-erable angle (i.e., more than about 30~ to the wale direction.
Fig. 30 is a schematic illustration of the manner of carrying out the test for determlning %A, defined below, to provide a measure of the spaced-apart relationship of the contin~1ous filaments~ The square 90, which measures 2.54 cm on each side, is inscribed upon a photomicrograph of the fabric sample in cross section between courses of the ~abric sample within the periphery of a representative filament bundle cross section and represents the area within the continuous ~ilament bundle containing the densest concentration of continuous filament transverse cross sections which is being viewed within the square opening of the magnifier. Transverse cross sections 91 of the con-tinuous filaments, including fractional areas thereof,are counted; and the number of continuous filament transverse cross sections is designated as Tf. Trans-verse cross sections 92 of the staple fibers, which are of smaller area than the continuous fila-ments in this sample, are not counted. Elongatedcross sections 93 and 94 of continuous filaments and staple fibers, respectively, which lie at a considerable angle to the wale direction are also ignored in making this count.
If the continuous filament cross sections can be distinguished from the staple fiber cross sections (as, for example, if they are of different linear densit~ or cross sectional shape), then onl~ the continuous filament transverse cross sections are counted in arriving at the value for Tf. If the staple fiber cross sections cannot be distinguished from the filament cross sections, all of the transverse cross sections are counted and the nurnber of continuous fllament transverse cross sections is calculated in accordance with the following equation:
Wf Tf = T x Equation (III) where Tf is the number of continuous filament trans-verse cross sections, Tt is the total number of trans-verse cross sections counted, r~7f is the weight percent of filament yarns in the sample, and ~7s is the weight pe~cent of staple fibers in the sample; it being e~ected that about one-third of the staple fi~ers would lie in a direction sufficiently close to the ' -wale direction that their cross sections would be counted as transverse cross sections. The density of the continuous filaments (in g/cm3) and their linear density (in tex) is determined, if not already known.
The density of the continuous filaments can be deter-mined from a short segment of filament by the density sradient technique designated as Method "A" by G. Oster and ~. Yamamoto, described on pages 260 and 261 of Chemical ~eviews, Vol. 63, No. 3, June 1963; ~.~hile the linear density can be determined in conventional manner by weighing a segment of known length on a sensitive balance. The percentage of the area 90 within the interior of the continuous filament bundle in the xegion of the densest concentration of continuous fila-ment transverse cross sections which is actuallyoccupied by the sum of the areas of these continuous filament transverse cross sections is designated as %A. The examined area 90 of the interior of the bundle, in cm2, is given by the quantity(2 54)2 ;
and the area of each continuous filament transverse cross section is given by the quantity lo5L D ~ where L is the linear density of the continuous filaments in tex and D is the density of the continuous filaments in g/cm3. M is defined at the end oF the first para-graph of Test E-l~ The value for %A, which is t~ken as a measure of the spaced-apart relationship of the filaménts, is calculated in accordance with the follow-ing equation:
Tf x L
105x D x (2 - )2 Equation (IV) M

In accordance with this test, filaments are considered to have an acceptable spaced-apart relationship if %A, as calculated b~ Equation IV, is less -than 30%. At the lower limit, values for this parameter down to about 10~ may sometimes be seen.

(E-2) Samples Having a Woven Construction of Contlnuous Filament Bundles . . _ . _ . . _ . _ A cross section of the fabric sample is pre-pared for e~amination in the same manner described in Test ~-l above,~che wafers being cut essentially perpendicular to the direction in which the filament bundles have the highest degree of spreading as deter-mined in Test 3-2. The wafers are cut midway between and essentially parallel to adjacent continuous filament bundles (yarns) in a row of unit cells in the woven fabric, e.g. along line 70 m of Fig. 28. As in Test E-l above, a photomicrograph of the fabric in cross section is first taken at about 44x magnification and a representative filament bundle near the center of one of the sides of one of the unit cells is selected for higher magnirication. The remainder of the test is carried out in the same manner as Test E-l.
(E-3) Samples Having Cross Warps of Continuous Filaments A cross section of the ~abric sample is prepared essentially in the same manner employed in Test E-l above. Before making the wafers, the fabric sample is first examined in accordance with Test Description D-3 to determine the direction in which the filaments have the highest degree of spreading. The wafers are cut essentially perpendicular to ~he direc-tion in which filaments have the highest degree of spreading and essentially parallel to the continuous filaments running in the other direction. If the fila-ments are divided in at least one direction into groupsof fil~ments with intervening spaces and the filaments in the other direction are well spread, the wafers are cut in such a manner as to expose the transverse cross sections of the cut filaments essentially midway between groups of ilaments, e.g. along line 80 m of ~%~

Fig. 29. A representative group of continuous fila-ment transverse cross sections is then selected for higher magnification and the remainder of the test is carried out with respect to this representative group in the same manner as Test E-l.
F. Fiber Loss Test . ~
The fiber loss test is a measure of the degree to which a fabric suffers deterioration in its initial laundering through separation of fibers from the fabric. The test sample is a 2 x 1.25 cm rectangu-lar swatch, cut from the fabric on the bias and weighed to the nearest 0.0001 g. If it is known or suspected that the original fabric contains water-soluble materials, the fabric is rinsed gently to re-move them and then dried in an 80C air oven for twohours before the rectangular swatch is cut.
The equipment comprises a l-liter glass beaker provided with a magnetic stirrer ("Thermolyne"
magnetic stirxer, Sybron Corporation, Dubuque, Iowa), using a stirring bar 4.8 cm lonq and 1 cm in diameter.
The fabric sample is placed in the container together with the stirring bar and 300 ml of a 1.7 g/l solution of a synthetic detergent for home laundry use ("Tide"~
marketed by Procter & Gamble Distributing Company).
A wooden ruler 3.5 cm wide and 0.3 cm in thickness is submerged to a distance of 2.54 cm in the center of the bath to act as a baffle to increase turbulence.
The magnetic stirrer is turned on and the sample is stirred in the solution for one hour with the stirring bar rotating at 1800 revolutions per minute. The sample is removed, the aqueous detergent solution is discarded, and the sample is then placed back in the container with 800 ml of distilled water. The sample is stirred again at the same speed for three minutes as a rinse, after which it is removed from the ~ rr~ r~

container and dried in an 80C air oven ror two hours.
The sample is then weighed again, and the percentage weight loss is caiculated and reported as the test result.
G. Ed~e Strength Test This test is a measure of the ability of a fabric to maintain its integrity when a hook penetrat-ing very close to the edge of the fabric is pulled in the direction of that edge. The test sample is a

2 x 1.25cm rectangular swatch, cut from the fabric on the bias. One of the 1.25-cm edges of the fabric is mounted in a clamp of the same width. Using a micro-scope with a calibrated reticle, a mark is made at a distance of 0.29 cm from the other 1.25 cm edge of the fabric at about its midpoint. A latched knitting needle (straight blade wire butt; 12 gauge hook and 12 gauge needle) is then inserted into the fabric at the marked point, hooking the entire fabric thickness.
The clamp is then mounted in the cell of a tensile test-ing machine (Table Model Instron~manufactured by theInstron Engineering Corporation, Canton, Massachusetts), with the k~itting needle being clamped in the bottom clamp of the tensile testing machine. The bottom clamp of the machine is then lowered at the rate of 2.54 cm/
min. As it is lowered, the force builds up until the knitting needle brea~s through the entire thickness of the fabric from the measured mark to the bottom of the fabric. The maximum force (in newtons) required to break the fabric in this way is recorded.
H. Loop Snag Test The loop snag resistance test, a variation of the Edge Strength Test, is a measure of the resist-ance of a knitted type fabric to snag, run, and ravel.
In this test, a sample of the knit fabric to be characterized is cut with dimensions 1.25 cm in the ~ T?~ m~7k' course dlrection and 2 cm in the wale direction. The sample is clamped in a 1.25c~ wide clamp at about the midpoint of the sample in the wale direction. T~e edge of the clamp is parallel to the course direction and between courses. A small crochet hook (no. 13 Boye) is then completely hooked into a single loop at the midpoint in the second row of courses below the clamp. The clamp is then mounted in the cell of the tensile testing machine as in the Edge Strength Test, with the crochet hook being clamped in the bottom clamp of the machine. The bottonl clamp of the machine is then lowered at a rate of ~.54 cm/min. As the bottom clamp is lowered, the force builds up and then reduces to zero because the loop breaks or completely ravels or runs. The maximum force achieved (in newtons) and the distance (in cm) the bottom clamp moved when the force went to zero are recorded.
~ he maximum fo~ce is a measure of the re-sistance afforded by the fabric towards permitting a snasged loop to break, cause a run, or ravel; whereas the distance the bottom clamp moved is a measure of the length of the snag.
When loops are snagged in certain kinds of knitted fabrics, such as conventional Jersey knits, the fabrics may be permanently distorted; or i~ the loop breaks a hole is left, which allows the fabric to run or ravel. However, knitted fabrics of the invention that have been modified by interlocking short staple fibers into them by hydraulic needllng are character-30 ized by resistance to permanent distortion and fromrunning or raveling if a loop is snagged and broken.
I. Contact Cover The contact covering power of a fabric is determined by calculating the ratio of the difference 35 in the reflectance of the ~abric when it is placed ln tur~ agains~ white and gray standard backgrounds, as compared to the difference in the reflectance of the standard bac~grounds, and expressing the ratio as a percentage value. The equipment emplo~ed in .his test comprises a photoelectric reflection meter, a search unit, a green tristimulus fil~er, a white enamel work-ing standard which is calibrated and has 70-75% re-flectance with the green tristimulus filter, and a gray enamel wor~ing standard which is calibrated and has 0-10~ reflectance with the green tristimulus filter (specific units of such equipment being obtainable from Photovolt Corporation, 95 Madison Ave., New York as Model 610, Model 610-Y, Catalog ~o. 6130, Cataloy ~o. 6162, and Catalog No. 6163, respectively; or equi~
valent e~uipment). Five specimens of the fabric measuring at least 38.1 ~ 38.1 mm (1.5 x 1.5 in.) are required, no two specimens containing the same warp or filling yarns or being taken nearer to the selvedge than 10% of the width of the fabric. The specimens may be tested without cutting, providing that they conform to these specifications. Before testing, the fabric or specimens thereof are conditioned at 21 ~ 1C ~70 1 ~F) at 65 -~ 2% relative humidity for a minimum of 16 hrs.
Before carrying out the test, the reflection meter is adjusted and calibrated in accordance with pro-cedures provided by the manu~acturer. To beg~ the test, the search unit is placed on the white working standard and its reflectance is measured and recorded as P~Wb.
The reflectance of the gray working standard is then measured and recorded as Rg~. A single thickness of the fabric specimen is then placed over the white work-ing standard, the search unit is set on top of the specimen and carefully centered upon it, and the re-flectance of the specimen is then measured and recorded as RfWb. The procedure is then repeated with the same ~23~

specimen placed on top of the gray wor.~ing standard, and the reflectance is measured and recorded as Rfgb.
The test ls repeated for each fabric specimen in turn.
The contact coverins power, ~ (IR), is then determined for each fabric specimen in accordance wlth .he equation:
R wb gb ( f~.~b Rfgb) 100~ q lon (V) RWb - R5b The results for contact covering power for each indi~
vidual sample are calculated to the nearest 0.1~, and these results are then averaged and reported as the final result for the fabric.
E ~PLE 1 An 18-cut jersey scrim tubing was knitted from 34~filament, 16.7 tex (150-denier) false twist set~
textured polyethylene terephthalate filament yarn on a 66 cm (26 in) circular knitting machine at ma~imum in-put feed of 716 cm (282 in) per revolution. The tubing was slit open and the resulting knitted scrim fabric, which had a width of 147 cm (58 in), was heat set on a pin tenter frame (manufactured by H. Xrant2 Appreturmaschinen~Fabrik, Aachen, Germany) at 140C
with 8~ overfeed in both the course and wale directions, resulting in an increase in basis weight from 67.8 to 79.7 g/m2 (2.0 to 2.35 oz/y~ ) with a concomitant bulk~
ing or blooming of the yarns, especially in the wale direction. The overfeed rates were determined by measurement of the initial and final dimensions of a square drawn Witil an indelible marker on the fabric before tension was applied. Rolls of this fabric, edge trimmed to a width of 130 cm (51 in) on the tenter frame, were rewound to position the course side of the fabric down, e.g., towards the core of the roll.

~3~

The heat-set knitted scrim fabric was fed from the rolls to a 142-cm (56 in) two-stage continuous hydraulic needling machine equipped with four high pressure jets on the first stage needling belt, con-structed of 37.8/cm x 39.4/cm semi-twill wire screen (96/in x 100/in screen), and three high pressure jets on the drum section, also clothed with semi-twill wire of the same mesh. All jets were provided with jet strips having a single row of 127 ~m (S mil) holes spaced 15.75 holes per cm (ao holes per in). The unit also included a feed belt upon which the roll of knlt scrim rested to provide surface driven unwind, a power driven unwind stand for supplying staple paper overlay on top of the scrim, squeeze rolls to remove excess water after second stage needling on the drum, a flow-through hot air dryer maintained at 93C, and a windup.
The needling machine is shown schematically in Figure 1.
Throughout the process, as the heat-set knitted scrim rabric was laid continuously upon the first stage needling belt (course side up), staple paper having a width of 102 cm (42 in) was overlaid upon the fabric prior to the ent:rance to the jet section. The staple paper, manufactured from .167 tex (1.5 dpf) 0.64 cm (0.25 in) cut length polyester staple fiber with 10~ by wt of highly beaten wood pulp binder, had a ~as~s weight of 27 g/m2 (0.8 oz/yd ) including binder. By gravimetric analysis it was determined that essentially all of the binder was washed from the paper during the subsequent needling step.
The four jets on the fixst stage needling belt were operated at 6895, 13790, 13790, and 13790 kPa (1000, 2000, 2000 and 2000 psi), and the three drum needler jets at 6895, 13790 and 13790 kPa (1000, 2000 and 2000 psi). All jets were operated at a jet height above the screens of 2 Sa cm (1.0 in). A~ter process-ing through the unit the first time (two side needling), the fabrlc was wound on rolls and the rolls were then returned to the feed belt and the fabric was repro-cessed at the same jet profile on the belt washer--but with the drum jets turned off--so that the complete process provided three side needling of the fabric.
The speeds of the various elements of the unit were set to avoid wrinkling and provide good ~uality rolls of semi-finished product, and these speeds were measured and found to be as follows:
Speed_- mpm(ypm) feed belt 14.0 (15.3) belt needler 14.4 (15.8) drum needler 14.4 (15.8) squeeze rolls 14.6 (16.0) windup 15.1 (16.5) These speeds resulted in an 8~ increase in the length of the finished fabric and a corresponding loss in width of the fabric. Propertles of the fabric, a portion of which is shown in Figure 4, are shown in Table I.
Panels of the final fabric measuring 56 x 102 cm (22 x 40 in) were pot dyed at the boil and heat set at 180C tc a final size of 60 ~ 80 cm (23.5 x 31.5 in) and a final weight of 56.1 g (1.98 oz). Properties of 2S the dyed and heat-set fabric, a portion of which is shown in Figure 5, are shown in Table I.

In a series of experiments for which the process conditions employed are listed in Table II, fabrlcs of Figures 6 - 16 were made by interlocking short staple fibers into knitted scrim fabrics of false-twlst set-textured continuous filament polyester yarns. The properties and characteristics of the pro-duct fabrics are reported in Table I along with the corresponding Example l data. The starting material fabric of Figures 6 - 12 was tne same heat~set ~nitted scrim fabric employed as the starting material in Example 1, the preparation of which is described in the first paragraph thereof. Similar knitted scrim fabrics were employed as starting materials to make the remain-ing samples listed in Tables I and II. In each case an 18-cut jersey scrim tubing was knitted from a 16.7 tex (150-denier) false twist set-textured polyethylene terephthalate filament yarn and the tubing was slit open and heat-set as in Example 1. The number o~ filaments in the yarn and the scrim heat-settlng temperature are listed in Table II.
To make the fabrics of Figures 6 - 16 rec-tangular panels of the heat-set knit scrim fabric measuring approximately 100 cm ~39.4 in) in the wale direction and 50 cm (19.7 in) in the course direction were placed course side up on a 37.3/cm x 39.4/cm semi-twill wire screen(96/in x 100/in screen) of a needling machine, with the long dimension of the panel in the machine direction. In each experiment, the knit scrim panel was overlaid with one or l_wo sheets (as indicated in Table II) o~ staple paper ha~ing about the same di-mensions as the panel, any curled edges o~ the panel being smoothed and narrow brass bars being placed along each edge of the paper so that the scrim and the over-lying paper lay flat. The sandwich of scrim and paper was then wet down with water. The staple paper employed was made of 0.64 cm (0.25 in) cut length poly-ester staple fibers containing polyvinyl alcohol as a binder. The sandwich was then hydraulically needled for the number of cycles indicated in the table, with the indicated needling conditions during each pass, from a row of 127 m~ (i mil) holes spaced 15.75 holes per cm (40 holes per in) and located at a distance of 1.9 cm (0.75 in) above the staple paper. At the conclusion of each cycle, the fabric sample was turned over so that it would be hydraulically needled from the side opposite to the side needled during the previous cycle. At the conclusion of the needling operation, the fabrics were 5 boiled off and heat-set.
EX~MPLI~ 3 In a series of experiments for which the process conditions employed are listed in Table III, fabrics, portions of which are shown in Figures17 - 20, 10 were made by interlocking short staple fibers into woven scrim fabrlcs of false-twist textured continuous filament polyester yarns. The properties and character-istics of the product fabrics are reported in Table IV.
The scrim fabrics were woven in each case from 34-fila-15 ment, 16.7 tex (150-denier) false twist textured poly-ethylene terephthalate filament yarn. The scrim fabric of Figure 17 was woven from a sized warp of 12.6 ends/cm (32 ends/in) at a pick count of 3.1 ends/cm (8 ends/in.). The shuttle of the loom carr~in~ the same 2C yarn was passed back and forth four times between each closing and opening of the shed. Selvedges were woven at each edge at each passage of i:he shuttle to stabilize the filling yarns and permit winding on the loom without distortion. The construction of each of the scrims 25 employed is listed in Table III. Unsized yarn was employed to make the scrims for the fa~ric of Figures 18-~0 .
To make the fabrics of Figures 17-20, rectangu-lar panels of the woven scrim fabric were cut out, 30 placed on the needling machine, overlaid with one or two sheets (as indicated in Table III) of staple paper having about the same dimensions as the ?anel, and hydraulically needled in accordance with the procedure already descri~ed in E~ample 2 with respect to the knit 35 scrim fabrics of that example. The staple paper used was the same paper used in Example 2. In the case of Elgure 17, the fabric was given a preliminary treatment to remove size from the warp yarns, in which th2 rec-tangular panelwas first covered with a nylon monofil S fabric having a 39.4/cm x 39.4/cm weave (100/in x 100/in) and a hot 1% solution of a detergent was poured over the surface of the cover fabric, causing the scrim to shrink about 5% in length and 10~ in width with accom~
panying increase in yarn spreading. Before overlaying 10 thls sample with paper, it was given a light hydraulic needling to further increase yarn spreading by passing it twice at a pressure of 3447 kPa (500 psi) and twice again under a pressure of 6895 kPa. (1000 psi). At the conclusion of the needl1ng operation, each of the 5 fabrics was boiled off and heat-set.
EX~PLE 4 Cross warps of 34-filament, 16.7-te~
(150-clenier) false twist textured con~inuous filament arns of polyethylene terephthalate were taped under ~ension on metallic frames having an interior rectangu-lar space measuring about 96 cm x 55 cm, with the e~terior dimensions about 4 cm greater in each direc-tion. To form the cross warp, the frame was first clamped along one side of a bar of 5 cm x 5 cm 25 (2 in x 2 in) square cross section mounted for axial rotation on a lathe, with the long sides of the frames parallel to the bar and equally spaced from it. In most cases, for better utilization of the yarn, two frames were mounted on opposite sides of the bar for simultaneous winding. The long sides of the frame were then covered with tape having adhesive on both sides and the yarn was continously wound across the face of the frame to form, as the lathe advanced, a warp upon each frame having the desired spacing. The winding tension is about 0.3 gpd, and on each turn the yarn ~23~8~

~asses to the rear of the bar bet~een passages across the face of the frame (across the face of the other frame when two frames were used). When the frame was fully wound, the sides of the frame were taped again over the yarn to hold the warp ln place, and the ends of yarn along the exterior of the frame were cut. The frame was then removed and clamped again on the bar -~-th the short sides of the frame parallel to the bar ~nd equally spaced from it. The short sides ~ere then covered with doubly-faced adhesive tape, the yarn was continuously wound across the face of the frame to form a warp in the cross direction having the desired spacing, the edges of the frame were then taped again to hold the cross warp in place, and the frame was cut free by cutting the yarns along the edges of the frame.
In a series of experiments for which the 3rocess conditions are summarized in Table V fabrics, portions of which are shown in Figures 21-25 (face) and in Figures 21a-25a (back), were made by interlocking 20 short staple fibers into cross-warps prepared as des-cribed above. The frames were placed on a 37.8/cm x 39.4/cm mesh semi-twill screen. One or more sheets (as indicated in Table V) of staple paper having the basis weight indicated in the Table were placed on top 25 Of the cross warp. Both papers were made from 0.64 cm (0.25 in) cut length polyester staple fibers. The assembly was placed on a belt and was hydraulically needled for the number of cycles indicated in the table, with the indicated needling conditions during each pass, 30 from a row of 127 m~ holes spaced 15.75 holes per cm and located at the indicated distance above the staple paper. At the conclusion of each cycle, the fabric sample was turned over so that it would be hydraulically needled from the side opposite the side needled during 35 the previous cycle. At the conclusion of the needling

3~

operation, the fabrics were bolled off and heat set.
The properties and characteristics of the ~roduct fabrics are reported in Table VI.
EX~PLE S
Cross warps of 34-filament, 16.7-te~ ~150-denier) false twist textured continuous filament yarns of poly-ethylene terephthalate were taped under tension on metallic frames as ln Example 4. The warp in the machine direction was laid down as single ends of varn at a spacing of 16 ends per cm under a tension cf 90 g., while the warp in the cross directlon was laid down in sets of four ends of yarn together at a spacing of 4 ends per cm under a tension of 50 g. The frame having the cross warp mounted upon it was laid on the semi-twill screen as in Ex. 4 and three sheets of staple paper were placed on top of the cross-warp. The staple paper had a basis weight of 27.1 g/m (0.8 oz./yd. ) and was formed of 85~ by weight polyethylene terephthalate staple fibers of 0.167 tex (1.5 denier) having a cut length of 6.35 mm (0.25 in.) and 15~
by weight of a binder (which was washed out in the sub-sequent hydraulic needling) comprising equal parts of polyvinyl alcohol and glass microfibers. The assembly was placed on a bel~ and was hydraulically needled by 25 passing it at a speed of 13.7 mpm (lS ypm) under streams of water from a row of 127 m~ holes spaced 15.75 holes per cm and located 38.1 mm above the staple paper, the assembly being passed under the streams first in one direction and then in the reverse 30 direction. During the first si~ passes the streams of water were supplied at a pressure of 3448 KPa (500 psi), after which the assembly was needled at 10343 KPa (1500 psi) for four more passes. The assembly was turned over and needled at 6895 KPa (lO00 psi) for four 35 passes, then turned over again and needled for eight passes at a pressure of 1103~ KPa (1600 psi). The panel of fabric so formed was then cut in half and placed back on the screen in a direction perpendicular to its previous direction (with the warp formed from four ends of yarn laid down together now lying in the machine direction). A patterning plate consisting of a group of bars, each having a height of 2.3 mm (0.09 in), a width at the base of 1.65 mm (0.065 in), and a somewhat rounded top having a width of 0.8 mm (0.0315 in) with a spacing of 5 bars per cm was tnen placed on top of the fabric, with the bars lying in the machlne direction of the fabric. The assembly was then needled at 10687 XPa (1550 psi) for two more passes at a belt speed of 9.12 mpm and the holes 50.8 mm above the fabric. Needling the fabric through the patterning plate caused the warp yarns originally laid down singly at a spacing of 16 ends of yarn per cm to be pushed together into wales having a spacing of 5 wales per cm. The product was heat set for 5 minutes at 180C.
It had a basis weight of 144.1 g/m2 (4.25 oz/yd2) and had the appearance and hand of a conventional corduroy fabric of good quality. A photomicrograph at lOx mag-nification of the side of the fabric opposite the wales of corduroy pattern revealed that the filaments lying in the direction perpendicular to the wales were very weli spread and exhibited a spaced-apart relationship, the degree of filament spreading (~S) being 100~ and the test for spaced-apart relationship of filaments (%A) giving a value of 19.5~. The reversal frequency test established that the staple fibers had 3.9 reversals per cm of staple length. The fabric was found to have excellent strength, measuring 26.11 newtons in the edge strength test. In the fiber loss test it was deter-mined that the fabric lost only 1.2~ of its fiber content during initial laundering. The fabric had .
, excellent cover, the value for contact cover being 81.8% for the undyed fabric. Portions of the fabric are shown in Fig. 26 (face) and Fig. 26a (back).

.
` ` ` :

.

. .
.

~BLE I
Properties and Characterlstics Of Fabrics :~lade From Knitted Scr~m Fabrics Figure No.
~ . . -- _ Pabric Prooer~v or Character-s~ic 4 5 6 ~ 3 .
Basis wt., g/;n2 lC0,3101.0 113.6 98,3 106,1 ljl.9 Reversal Freq.
revs./cm , ;,1 3.8 4.5 3-5 4.6 3.3 Degree of filament spreading, ~S73.369.3 8~1 73.2 84.7 92.2 Test for soaced-apart relationsnip o filaments, ~ 17.~17.~ 19.; 15.2 2 21.7 Xnit construction density, g/cm'0,900,851.l0 0.91 1.07 1.33 Fiber Loss, ~ 2,4 2,2 2,g 2,8 2.4 o,84 Edge Strength, newtons 15,7018.2q18.2421,7517.97 21.80 newtons 12.3 13.014,4 13,0 11,4 13.1 Sn~g length, cm. o,6350.4830.4830.4570,559 0.406 Contact cover,~ 67.5 93.7* 71.9 66,5 66.9 73.9 ~Fabric dved blue , .
.

' ', ' ,, . ' ' ' ' .

~ 3~

TA8r E I

Properties ar.d Characteristics Of Fabrics ~lade From Xnitted Scrim ~abrics __ _ _ Figure No.
Fabric Property _ __ _ or Ch _ cter~s~:c 10 11 12 13 1l 15 16 ~3asis wt., q/m2 11.2 112.6llS.9100.3 98,3 97.0 112,9 0 Reversal Freq., reYs./cm 2,7 3.5 4.8 2.8 3.0 2.9 4,2 Degree of fila~en~
spreading, ~S 74.575.5 72.777.4 68.6 67.4 67.i Test for spaced-15 apart relationship of filaments, ~A 14.122.~ 1~.917.424.4 15.2 22.8 Knit constructi ~.
density, g/cm 1.121.13 1.260.96o.87 0,94 0.96 Fiber Lass, ~ 1.5 1.8 2,7:2.4 2,1 2.2 2.4 Edge Strensth, newtons 15,21 18,46 17.3016.9919.39 19,17 21.0"
newtons 11. 7 13.4 12.211.512.5 12,9 12, 8 Snag length cm. , 0.533 0.4830.4570.6100.4570.483 0,457 Contact cover,~ 70.169.5 71.9 68.5 73.6* 71.3* 73~

tFabric dyed yellow ~

- , , ., , TABL~
P~'ocess Conditio~s ~ ? oyed 'n "aXlnf~ Fabrlcs ,ro~
Xnltted Scrlm Faorlcs o~ ~Ia~?le 2 Startlng `Jaterlal F_qure No.
or Process S~,ep ~, 7 ~ 9 10 No, Or rlla~.sntS in yarr 34 34 34 34 34 IEeat_set Tentp, 'C. 140 140 140 140 140 ~o. o~ sheets o~ paper 1 1 1 2 Jat pressures, MPa . _ _ _ _ _ _ _ 0 Flrst cycle, pass 1 6,9 6,,c 6,9 6,9 6,9 2 13.8~L3.8 13.8 13.8 13.8 3 13,8 13,8 l~,a 13,8 ;3,8

4 13 813 ~3 13 8 13,8 ~3 ~3 SecondCycle,pass 16.9 6,9 5,9 5,9 6,9 2 13,813.~3 13.8 13.8 13,8 3 13,813.~3 13,8 13,8 13.88 ----.... ___ 13 20~hird Cycle~ pass 16.9 6.9 5,c, 6,9 ___ 2 13,81~,~3 13,8 13,8 ---3 13.813,'3 13,8 13,8 ___ 4 13,813 8 13.8 13 8 - -Footnotes- a, Follo~:ed by a ~ourth crcle lder.tlcal to the third.
b, ~ollo~ed by t~o ~.ore cycles ldentical o the ~h'rd.
c. Fabrlc rlnsed ~t~h hot ~ater arter ~hls pass.

, .

,. ' 35~

TA~LE IT
(cont.) P,ocess Condltlons E-.plo1,ed ln Maklnf; ~ abrlcs F-om ~nItted Sc-1 7 Fabrlcs of Exar~?le '' Startlne l~a~erlal _ _ _ Fi~uro No.
Or ~rOCeS5 StD11 12 1314 15'~ 6 NO. Or r11a~.rltS 1n Yarn 34 34 34 68 68 6~
Xeat_Set Te:nP~ C,140 140149140140 140 ~lo, of shsets Or paper 1 1 1 1 1 2 0 Jct p-ossurss, Ml?a _. _ ~
Flrstcycle, PaSS 1 6,9 6,9 13~C ~3,3C 8,3C 8,3C
2 13,813,8 13,8 12,4 12,4 12.4 3 13,813,8 13,8 12,~ 12,4 12,4 4 13,813,8 13,8 12, lI 12 4 12 4 -~ '2,~
S~¢oldCycle, pass 1 6,9 6,9 5'9 8,3C 8,3C 8'3C
213,813,8 13,8 12,~ 12,4 12,4 313,813,8 13,8 12,4 12,4 12,4 413,813,9 13,8 12,4 12,4 12 4 --- ---13.8 ~2,4 12,4 12 4 ThlrdCycle, pass 7 6,9 6,9 ~~~ 8.3 8,3 8,3 13,813,8 ___ 12,4 12.4 12,4 3 13,8~ 13,8 ~ 2 4 12 4 12 4 4 13.8;3.8b ___ 12 1: 12 4 12 4 ~~~ ~ 12,4 12O4 12,4 FOOtZ~OteS: O~ '~ol~owed by a f'ou-th cycle ldentical to ~he thl-d.
b, ~ollo~"ad b~ two ~O.e c~cles lds~.tical to the thlrd c. Pabrlc rl;'~sed wlt~ .ot h~ater a''tCr t;~15 pass.
.

35~3~

~o ~ABLE III
Proces3 Condltion3 ~moloyed In Makln~ ~abrlcs From '~oven Sc-lm Pabrics . . _ .

Startin~ ~ateriAl Fisure ~o.
or Process SteD 17 18 19 20 _ _ _ _ _ _ _ _ _

5 Scrlm Cons~ruction ends,c.~ 1~ warp 12.6 16.5 12.6 11.8 picks/cm 12.6 15.8 1l. a 18.9 picks/shed 4 2 'lo. o~ sheets o~ oaoer 2 0 J~t ~elF,ht, cm 3.a 1.9 1.9 3.8 Jet ~re..surest ~4~a ~Flrs~~c cle, ?ass 1 3,51 6.9 2,8 2.8 pas~ 2 6,9 13.8 5'5b 7'5 ~ass 3 8.3~ 13.8 ~,3 a.3 pas~ ~ 8.3 13. a 12,4 12,~
pass 5 ~ 12.4 12.4 pass 6 ___ --- 12.4 12.4 Second oycle~ pa~s 1 3.5 6,9 6,9 6~9 pa5s 2 6,9 13.8 12.4 ~2.4 pass 3 8.3 13.8 12.4 12,4 pQSS 4 8.3 13,8 12.4 12.4 pass 5 8.3 ___ ___ ___ pass 6 8,3 -__ _-_ ___ Third c~ole, pass 1 6.9 6,9 6.9 6,9 pass 2 11.7 13.8 12 q 12 4 pass 3 11. 7 13. 8 12 4 12 4 pass 4 11.7 13.8 l~,4C 12.4 pass 5 11,7C
~oot~te~: a. ~.ellminary treatment descrlbed ln ~x. 3, b, ~b~lc rlnsed ~lth .bot wate- a~ter thls oass c, ~ollowed by twc more cycles identlcal tc~ 'he thlrd.

3~

Propertie3 and Characteri~tlcs .Or Fabric3-;lade From S Fabrlc Property Fisur2 No or Characterlstic _ _ .
_ ~17 18 _19 20 R~5~ wt,, e~m l23.7 106,8 101,7 106.8 Reversal ~`requenc-~, 4.1 5.0 4.9 4.5 0 revs~cm Degree of filament spreading, ~5 i4.577.1 69.1 59.4 Test ~or spaced-apart rel~tionship of filaments, %A 22.829.328.2 20.6 Flber Los3, ~ 1.8 1.2 1.3 1.5 ~dge stren~th~ ne-~ton3 2'.1~22.6023,0422,02 Contact cover, ~ 75.0 ~3.6~3,7*70.7 *Pahric dyed red ~3~

TABL~ V
Process CondLtions Eml~loved in ~!akinc~ Fabric From Cross waros Figure ~o.
StartlnS Mate-lal or `rocess Steo ¦ 21 Z!~ 22 22a 23 23a 5 ha-~? Constructlon tac~Lne dlrectlon: ends~c.-. x yz~ns~end 15.75 x 2 12 5 x 1 9 !l5 x 1 Cross d~re-tlon: ends~cm x yarns~e:ld 3.3': x 4 3.15 x 4 3 15 x 3 St-~ple Pa?er 14.4 ~/m2 bas~s wt no oî s~eets O 0 ~ 1 0 27 1 s/J2 basls ~t; no of sheets 1 2 Set llc!~n.. cm. S~l 3.8 .2.5 Jet Pressure~` MPa Flrst c~rcle pa~ 1 3 5 53 3b 5 gbd 3 5.2 12.4 a.3 ll 6.9 12.4 12.4 ___ 12 4 12.4

6 . --- 12.4 12 4

7 ~~~ 12 4 20 Second cycle pas 1 3 5 6 9 6 9 2 6 9 12.4 12.4 3 --- 12.4 12.4 25 Thlrd cycle pass 1 6 9 6.9 6.9 2 6 9 12.4 12.4 3 6.3 12 4 4 6 9~12.1~ 12.
___1~.4C 12.11-(cont;) Proccss Conditions Em~loycd in Mnking F~brics Prom Cross war?3 _ _ _ Figure ~o.
Star~ln~ '~zter'al or ?rocess Step ~ _ 24,24a 25,25a ar~ Construct~on ~achlne direct'on: end3/cm x ya.ns~end 9,45 x 1 12.6 ~ 1 Cross directlon: ends~cm c yarns~end 3.15 x 4 , 3,1~ ~ 4 St~pls ?aper 0 14.4 ~fm22 basis ~t; no Or sheets 27.1 ~/~ basls we no Or sheets Jee l~clr,nt, cm, 2.5 3.8 Jet Prcssures, ;~a ~ Flrst cycle, pas3 1 6 9~ 6,~
3 .3 12.4 4 12.4 12.4 5 12.4 12 4 ~lZ.il lZ
7 12.
Second cycla, pa93 1 8:3 6.
212.4 12 4 312.4 12 1~
412.4 12.4 . 5 12.4 12.4 Thlrd cyclc, pas~ 1 ~ 8,3 6,~
2 12.4 12.4 3 12,4 12,4 4 12.4 12 4 --~2,4e 12 llc Fooenotc~: a. Pollowecl by two more cycles identical to thc ~hird, ehen a single pass at 2.1 .~Pa in the sixth cycle. b.
P~,ric rinsed with hot water artor this ,oass. c. Followed by onc more cycle idcntical to thc third. d. Cut erom fr~e. c. Pollowed by t~o morc c~clcs identical to the ~hird.

TABLE VI
Pro~erties and C~a-acteristics o~
Fabrlc Propert~ Fabrics :~ade From Cross WarDs or Characterlstlc ~ g~re ~o.
21,21a22,22a2~,23a24,24a 75,'5a _._ _ ___ . . _ _. ~
5asls Wt., g/~ 105,1 120.386,4 100,0 34,9 ~ ., Reversal ~requency, reva~cm 4,8 4.36,5 5,0 5.4 3egree of filament Ospreading, ~s 62.3 65.1lO0 74-9 lO0 Test for spaced-apart relationship of filaments, 3A 10.6 15.2ll.9 19.5 22.8 r~c. Lo~s~ ' ~,~4 1.400,9 1.3 0,92.
Edge strength, newtons18.19 24.73 18,15 18,a2 23.35 Contact cover, S95.4~92.7* 68.7~ 70.4** 74.2 Fabrlc TypePrlnt Flan-Flan- Flan- Pillow Cloth nelette r.elette nelette Ca9e *Fabric dyed blue ~*Fabric dyed yellow

Claims (8)

I CLAIM:

1. A lightweight composite fabric com-prising: a substrate of continuous filaments formed into an ordered cross-directional array, said continuous filaments being well spread and having a spaced-apart relationship throughout the array in at least one direc-tion of the array, said filaments being well spread provided that the average spacing between any bundles of filaments is no larger than the average width of said bundles of filaments, said filaments having a spaced-apart relationship provided that in the densest observed area of the filament bundle the sum of the areas of the filament cross sections occupies less than 30% of the densest observed area of the bundle, said substrate being combined with staple fibers of less than .3 tex per filament and from about 0.5 cm to about 1 cm in length in the amount of from 20 to 50% of the weight of the composite fabric, said staple fibers extending through and entangled with said continuous filaments and having more than about 2 reversals in direction between the faces of the fabric per cm of staple fiber length; said composite fabric having an edge strength of from about 15 to 30 newtons and experiencing a loss of no more than 3% of its fiber contents during initial laundering.

2. The fabric as defined in claim 1, said fabric having a basis weight of from about 50 to about 135 grams per square meter.

3. The fabric as defined in claim 2, said substrate being formed of continuous filament yarns knit together in stitches in an ordered array of courses and wales, and having a construction density of from about 0.2 to about 1.4 stitches x gram/cm4.

4. The fabric as defined in claim 2, said substrate being a woven scrip formed of continuous filament yarns and having from about 2 to 12 picks per inch.

5. The fabric as defined in claim 2, said substrate being a cross-warp of continuous filaments.

6. The fabric as defined in claim 5, said cross-warp being formed in at least one direction from continuous filament yarns.

7. The fabric as defined in claim 1, said fabric being a corduroy fabric having a basis weight of from about 100 to about 200 grams per square meter, said substrate being a cross-warp of continuous fila-ments.

8. A process for making a composite fabric of low basis weight exhibiting a high edge strength and low loss of fiber during initial laundering comprising:
(a) forming continuous filament yarns into an ordered cross-directional array, said yarns being free of filament interentanglement and twist which would prevent ready separation of the fila-ments from one another;
(b) placing a sheet formed of staple fibers of less than .3 tex per filament and from about 0.5 cm to about 1 cm in length over said array of continuous filament yarns;
(c) impinging the staple fibers and array of continuous filament yarns with columnar streams of liquid to spread the yarns so that the filaments are well spread and have a spaced-apart relationship throughout the array in at least one direction and so that the staple fibers interentangle with said continu-ous filaments to form an integral composite fabric, said filaments being well spread provided that the average spacing between any bundles of filaments is no larger than the average width of said bundles of fila-ments, said filaments having a spaced-apart relationship provided that in the densest observed area of the fila-ment bundle the sum of the areas of the filament cross sections occupies less than 30% of the densest observed area of the bundle; and (d) impinging the fabric so formed with columnar streams of liquid from the reverse side of the fabric to further interentangle the staple fibers, thereby forming more than about 2 reversals in the staple fibers in the direction between the faces of the fabric per cm of staple fiber length.