Composite geosynthetic fabrics with increased peel strength

Abstract

The composite geosynthetic fabric includes a woven fabric and a nonwoven fabric bonded to the woven fabric. The nonwoven fabric includes a plurality of fibers, each of which has a denier of about 2 to about 18 (about 2.2 to about 20.0) decitex per filament. Some of the fibers of the nonwoven fabric extend through the woven fabric and are fused together on a surface of the woven fabric opposite the nonwoven surface of the woven fabric.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 486,758, filed February 24, 2023, which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates to geosynthetic fabrics, and more particularly to composite geosynthetic fabrics having increased peel strength. [Background technology]

[0003] Composite geosynthetics comprise two or more fabrics (one or more each of woven and / or nonwoven) bonded together. Composite geosynthetic fabrics are manufactured using specially engineered fabrics and fibers to provide superior toughness, abrasion resistance, UV protection, and impact resistance, especially in hydro and marine environments. Such systems also trap sediment and other sediments, improving durability for extended life. Summary of the Invention [Means for solving the problem]

[0004] According to one or more embodiments, a composite geosynthetic fabric includes a woven fabric and a nonwoven fabric bonded to the woven fabric. The nonwoven fabric includes a plurality of fibers, each fiber of the plurality of fibers of the nonwoven fabric having a denier of about 2 to about 18 (about 2.2 to about 20.0) decitex per filament. A portion of the fibers of the nonwoven fabric extend through the woven fabric and are fused together on a surface of the woven fabric opposite the nonwoven surface of the woven fabric.

[0005] According to another embodiment, a method of making a composite geosynthetic fabric includes providing a preformed nonwoven fabric having a plurality of fibers, each fiber having a denier of about 2 to about 18 (about 2.2 to about 20.0) decitex per filament. The method also includes adhering a woven fabric to the preformed nonwoven fabric by extruding a portion of the plurality of fibers of the nonwoven fabric through the woven fabric such that a portion of the plurality of fibers extends from a surface of the woven fabric opposite the nonwoven fabric. The method further includes fusing a portion of the plurality of fibers extending from the surface of the woven fabric.

[0006] Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the advantages and features of the present invention, reference is made to the description and drawings.

[0007] For a more complete understanding of the present disclosure, reference is now made to the following brief description taken in conjunction with the accompanying drawings and detailed description, wherein like reference numerals represent like parts. [Brief explanation of the drawings]

[0008] [Figure 1A] FIG. 1 is a schematic diagram showing a partial cross section of a composite geosynthetic fabric. [Figure 1B] FIG. 1 is a schematic diagram showing a partial cross section of a composite geosynthetic fabric with fused knots. [Figure 2] FIG. 1 is a flow diagram illustrating a method for making a composite geosynthetic fabric. [Figure 3A] 1 shows a needleboard used to needlepunch a preformed nonwoven fabric into a woven fabric. [Figure 3B] A single barbed needle and a six barbed needle are shown. [Figure 4] Shown is a comparative non-preformed nonwoven composite abraded after 500 cycles (top) and a composite described herein abraded after 5,000 cycles (bottom). [Figure 5]1 shows a composite described herein abraded after 1,500 cycles (left) and a comparative non-preformed nonwoven composite abraded after 500 cycles (right). [Figure 6] 1 shows a composite fabric (99A) described herein after impact testing. DETAILED DESCRIPTION OF THE INVENTION

[0009] Composite geosynthetic fabrics must provide excellent toughness, abrasion resistance, ultraviolet (UV) protection, and impact resistance in hydro and marine environments, among other harsh environments. To provide such properties, fibers and fabrics are carefully selected. When composite fabrics include nonwoven fabrics, using larger fibers generally results in thicker composites with better abrasion resistance, improved UV protection, and increased water flow. When composite fabrics are formed by needle-punching nonwoven fibers through woven fabrics, the woven fabrics should generally be formed from yarns thin enough to be punched. In particular, woven fabrics with nonfibrillated tape yarns are preferred because they are thin—e.g., typically 1.5 mils to 2.5 mils (0.04 to 0.06 mm) thick—and therefore easier to penetrate by needle-punching.

[0010] In contrast, fibrillated tape yarns are less desirable for needlepunching because they thicken due to being cut during extrusion, providing a pattern that allows the tape yarns to be folded and compressed to reduce their respective cross sections. Such treatment of fibrillated tape yarns is necessary in order to weave them in the weft direction, because the projectile must be able to fit the yarns into its grippers and pull them across the loom.

[0011] Monofilament yarns in woven fabrics are generally too thick to be easily punched, typically at least 8 mils (0.20 mm), and therefore are not used in mechanically bonded needlepunched composites. Woven fabrics with monofilament yarns can and do cause needle damage when producing needled composites.

[0012] Additionally, the use of more fabric layers in a composite generally means greater abrasion resistance, impact resistance, and long-term durability in a variety of harsh environments, including those along coastlines where ice dams, waves, tree branches, wave action, boats, and propellers can create high-energy impacts on the composite.

[0013] Given the general limitations mentioned above, composite geosynthetic fabrics are typically made with large fibrous nonwovens and wovens made from fibrillated and / or nonfibrillated tapes and have more than two layers. The drawback of such resulting composites is that, although they are strong and resistant to abrasion and UV degradation, they are heavy and expensive to manufacture.

[0014] One or more embodiments of the invention described herein address the aforementioned shortcomings by providing composite geosynthetics, and methods of making and using the same, including a woven fabric and a pre-formed non-woven fabric bonded to the woven fabric, the non-woven fabric having a plurality of small fibers of about 2 to about 18 denier (about 2.2 to about 20.0 dtex) per filament, with some of the fibers of the non-woven fabric extending through the woven fabric and fused together on a face of the woven fabric opposite the non-woven face side of the woven fabric. Unexpectedly, the use of significantly smaller fibers in the pre-formed non-woven fabric provides higher surface area coverage than larger fibers, has the same or better abrasion resistance, impact resistance, UV resistance, and peel strength adhesion, has higher water flow than non-woven fabrics with larger fibers, and results in a composite with a lighter composite weight.

[0015] In embodiments, a composite geosynthetic fabric comprises or consists of one layer of woven fabric and only one layer of nonwoven fabric in a two-layer composite. The two-layer composite is unexpectedly and advantageously lighter and cheaper to manufacture than composites with more than two layers, and unexpectedly has the same, similar, or better abrasion and impact resistance, peel strength, UV resistance, and water flow than a three-layer composite.

[0016] In other embodiments, the nonwoven fabric is a preformed, stand-alone nonwoven fabric. In some embodiments, the composite geosynthetic fabric is made by needlepunching a portion of the fibers of a preformed nonwoven fabric through a woven fabric such that a portion of the fibers extend from the surface of the woven fabric opposite the nonwoven fabric. In one or more embodiments, the woven fabric is formed from monofilament yarns and fibrillated tape yarns. In embodiments, the method further includes fusing a portion of the fibers extending from the surface of the woven fabric by applying open flame or heat to the backside of the protruding needlepunched fibers, melting and singeing them to form fused knots or singeed fibers.

[0017] Composites formed from loose carded webs (non-preformed nonwovens) and woven fabrics with tape yarns are expected to form desirable geosynthetics for several reasons. One skilled in the art would expect the nonwoven fibers to needlepunch more easily through woven fabrics with only thin fibrillated and / or non-fibrillated tape yarns, because the monofilament yarns are too thick and tend to be damaged and break as they penetrate the woven backing. Additionally, standalone preformed nonwovens have fibers already mechanically bonded, which is expected to increase the difficulty of punching. Since it is desirable for the nonwoven fibers to penetrate from the nonwoven to the underside of the woven backing, locking the two layers together means that the looser the fibers, the easier they are to punch and tend to migrate to the back of the reinforcing woven backing. Generally, only woven fabrics with fibrillated tape and / or non-fibrillated tape yarns can be needlepunched to avoid excessive tensile loss. However, unexpectedly, as described herein, woven fabrics having monofilaments in addition to fibrillated tape yarns can be needlepunched to adhere smaller denier fibers in the preformed nonwoven fabric to the woven fabric.

[0018] Typical geosynthetic needles have multiple barbs required to secure a large amount of fiber and transfer some of the fiber from the top to the bottom of the reinforcement backing. To needlepunch the nonwoven fibers through the monofilament of the woven fabric, some of the needles from the needleboard machine are removed to reduce the density of needles in a particular pattern. Additionally, reducing the needle density and the number of barbs per needle results in less tensile loss in the backing. This reduction in tensile loss is the result of the monofilament yarn not tearing from the needle, allowing for a lighter backing weight. This reduction in tensile loss also allows for a backing with a lower initial pre-needling tensile strength, since the resulting composite retains a higher percentage of its initial strength. As a result, substantially enough nonwoven fibers are needlepunched through the woven fabric, leaving a sufficient number to extend from the other side of the woven fabric and increase peel strength.

[0019] Furthermore, one skilled in the art would conventionally expect larger fibers to provide more adhesion and abrasion resistance. However, as described herein, the smaller denier fibers of the nonwoven fabric are extruded in greater numbers through the woven backing, creating a higher total surface area that, when lightly singed, forms "fused knots" on the backside of the woven fabric (see FIG. 1B). The fused knot population creates increased peel strength and greater adhesion between the woven and nonwoven fabrics in the composite. Higher fiber-to-fiber cohesion with the smaller denier fibers also contributes to this unexpected result.

[0020] While larger fibers in a nonwoven fabric are expected to resist abrasion, Figure 4 shows that the opposite is observed. Figure 4 compares the abrasion resistance of a composite formed as described herein with a preformed nonwoven fabric (bottom) and a comparative composite with a carded nonwoven fabric having larger fibers (top). Abrasion resistance is measured according to the ASTM 3884 test method. As shown, the carded loose web (top) has less mechanical fiber-to-fiber entanglement and less abrasion resistance after 500 cycles of abrasion compared to the preformed nonwoven fabric composite (bottom) after 5,000 cycles of abrasion, due to a lack of fiber-to-fiber cohesion, lower fiber compression due to larger fiber size, and lower bond strength to the woven fabric. Figure 5 also shows a composite (left) sanded after 1,500 cycles as described herein (face side shown, woven backing shown below) and a comparative non-preformed nonwoven fabric composite (right) sanded after 500 cycles.

[0021] The density of needles 302 in needle board 300 (FIG. 3A) is modified and smaller than conventional needle punch boards used to punch loose, non-preformed nonwoven fabrics. The needles 302 themselves are also modified compared to conventional needles, including a single barb 304 (FIG. 3B) rather than multiple barbs, such as six barbs 304. In some embodiments, the density of needles in the needle punch board is about 50 to about 100 needles (or punches) per square inch (pps). In other embodiments, the density of needles in the needle punch board is about 75 to about 95. In embodiments, the density of needles in the needle punch board is about 50, 55, 60, 65, 70, 75, 80, 85, 90, and 100 needles or ppsi per square inch (6.45 square centimeters), or any range therebetween. In one or more embodiments, the needle board has a plurality of single-barb needles.

[0022] Furthermore, one skilled in the art would expect that reducing the number of punches or needles per square inch (6.45 square centimeters) would result in a decrease in peel strength because fewer fibers are extruded to the backside of the reinforcing woven backing. However, unexpectedly, smaller denier fibers provide greater peel strength when needled with fewer punches per square inch (ppsI) compared to more ppsI and larger fibers. Such results are due, in part, to the increased surface area of ​​the total number of smaller fibers and the increased fiber-to-fiber cohesion that occurs with significantly smaller dpf fibers (e.g., 2-18 dpf fibers compared to fibers greater than 100 dpf).

[0023] Furthermore, the nonwoven fabric is a preformed fabric, not a carded fibrous web (not preformed). Compared to a carded web, a preformed nonwoven fabric as described herein has tightly bonded fibers that are needlepunched and mechanically entangled to create a fully formed, stand-alone nonwoven fabric. For acceptable peel strength adhesion and water flow, one would expect punching the mechanically bonded fibers of a preformed nonwoven fabric through a woven backing to be more difficult than the loose fibers of a carded web, but this was not the case.

[0024] By using a preformed nonwoven, the composite was formed in a single-step process in which the preformed nonwoven and woven fabrics were bonded together by needlepunching. The preformed nonwoven had much lower water flow than the carded web, which would be expected to result in a composite with lower water flow. However, the opposite was found. Composites with preformed nonwoven had higher water flow than composites with carded webs (see Table 8).

[0025] At least some of the fibers that are punched and extend from opposite sides of the woven fabric are fused together by applying heat to the fibers. Lightly scorching the fibers forms molten knots, increasing the adhesion of the nonwoven to the woven fabric. The larger number of smaller knots formed by fusing smaller denier per filament (dpf) fibers provides a better peel strength bond than a smaller number of larger dpf fibers (see Table 7).

[0026] In one or more embodiments, the composite geosynthetic fabric comprises a 20 ounce (0.57 kg) per square yard (0.84 square meters) (osy) nonwoven fabric made by needled 8 denier per filament (8.9 decitex) fibers into a woven fabric and singed on the woven side to increase peel strength.

[0027] 1A illustrates a schematic diagram of a side view of a composite geosynthetic fabric 100 according to one or more embodiments. The composite geosynthetic fabric 100 includes a woven fabric 103 and a nonwoven fabric 101 bonded to the woven fabric 103. The nonwoven fabric 101 includes a plurality of fibers 105. Some of the fibers 105 of the nonwoven fabric 101 extend through the woven fabric 103 and are at least partially fused together on a face of the woven fabric 103 opposite the face of the nonwoven fabric 101 (fused fibers 106, FIG. 1B).

[0028] In one or more embodiments, the composite geosynthetic fabric is a bi-component composite fabric having (consists of) only two fabrics or fabric layers (two-layer composite), woven fabric 103 and nonwoven fabric 101. Using two fabrics instead of three fabrics reduces the overall weight of the composite as well as manufacturing costs, without compromising performance or inadvertently increasing thickness in some areas.

[0029] In an embodiment, the nonwoven fabric 101 is a pre-formed stand-alone fabric. The nonwoven fabric 101 is, in an embodiment, formed by carding and needle punching before bonding the nonwoven fabric to a woven fabric to form a composite.

[0030] In embodiments, nonwoven fabric 101 has a basis weight of about 12 to about 32 ounces (about 0.34 to about 0.91 kg) per square yard (0.84 square meters). In other embodiments, nonwoven fabric 101 has a basis weight of about 15 to about 25 ounces (about 0.43 to 0.71 kg) per square yard (0.84 square meters). However, in other embodiments, nonwoven fabric 101 has a basis weight of about 18 to about 22 ounces (about 0.51 to 0.62 kg) per square yard (0.84 square meters). In embodiments, the nonwoven fabric 101 has a basis weight of about 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, and 25 ounces (0.34, 0.37, 0.40, 0.43, 0.45, 0.48, 0.51, 0.54, 0.57, 0.60, 0.62, 0.65, 0.68, and 0.71 kg) per yard, or any range therebetween.

[0031] In one or more embodiments, each fiber 105 of the plurality of fibers in nonwoven fabric 101 has a denier per filament of about 2 to about 18 (about 2.2 to about 20.0) dpf. In other embodiments, each fiber 105 of the plurality of fibers in nonwoven fabric 101 has a denier per filament of about 5 to about 10 (about 5.6 to about 11.1) dpf. In still yet other embodiments, each fiber 105 of the plurality of fibers in nonwoven fabric 101 has a denier per filament of about 7 to about 9 (about 7.8 to about 10.0) dpf. In embodiments, each fiber 105 of the plurality of fibers of the nonwoven fabric 101 is about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and 18 denier (2.2, 3.3, 4.4, 5.6, 6.7, 7.8, 8.9, 10.0, 11.1, 12.2, 13.3, 14.4, 15.5, 16.7, 17.8, 18.9, and 20.0 decitex) per filament, or any range therebetween.

[0032] The use of a small denier per filament fiber 105 in the nonwoven fabric 101 (about 2 to about 18 denier per filament (about 2.2 to about 20.0 dtex)) unexpectedly provides a composite with higher UV, impact, water flow, and abrasion resistance than larger fibers (e.g., 110 denier per filament (122.1 dtex)). This result is unexpected because larger fibers typically provide higher composite weight and larger interfiber voids, which are the primary contributors to higher water flow.

[0033] The woven fabric 103 comprises monofilament yarns and fibrillated tape yarns. In an embodiment, the monofilament yarns are woven in the machine direction (MD) and the fibrillated tape yarns are woven in the cross machine direction (XMD).

[0034] In one or more embodiments, the woven fabric is a twill with a single-pick or double-pick insertion woven fabric. It is also important to note that a plain weave provides the greatest dimensional stability of any woven fabric, but also has the greatest number of interlaces. Therefore, for needle-punched composites using woven fabrics with monofilaments, a plain weave is undesirable because its interlacing is too tight. The optimal weave pattern for forming the composite is a loose, dimensionally stable weave, such as a twill weave. A twill weave has at least half the interlacing compared to a plain weave, depending on the number of picks in each shuttle, creating a structure in which the yarns can slide around more easily and avoid damage, and also avoiding damaging the needles during the needle-punching process. The above advantages reduce tensile loss in the composite resulting from yarn and needle damage. In contrast, composites needle-punched with a backing woven with non-fibrillating tape warp and weft yarns (rather than monofilaments as described herein) preferably have a plain weave because the yarns are thinner and therefore easier to penetrate, which does not cause needle damage.

[0035] In some embodiments, the composite geosynthetic fabric 100 has a total basis weight of about 24 to about 40 ounces (about 0.68 to about 1.13 kg) per square yard (0.84 square meters). In other embodiments, the composite geosynthetic fabric 100 has a total basis weight of about 27 to about 34 ounces (about 0.77 to about 0.96 kg) per square yard (0.84 square meters). Still further, in other embodiments, the composite geosynthetic fabric 100 has a basis weight of about 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, and 40 ounces (about 0.68, 0.71, 0.74, 0.77, 0.79, 0.82, 0.85, 0.88, 0.91, 0.94, 0.96, 0.99, 1.02, 1.05, 1.08, 1.11, and 1.13 kg) per square yard (0.84 square meters), or any range therebetween.

[0036] In one or more embodiments, after 1,000 hours of UV exposure, the composite geosynthetic fabric 100 has a UV retention of at least 90% as measured by the ASTM D4355 test method. In other embodiments, after 1,000 hours of UV exposure, the composite geosynthetic fabric 100 has a UV retention of between about 92% and about 97% as measured by the ASTM D4355 test method. In still other embodiments, after 1,000 hours of UV exposure, the composite geosynthetic fabric 100 has a UV retention of about 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, and 99%, or any range therebetween, as measured by the ASTM D4355 test method.

[0037] In some embodiments, the composite geosynthetic fabric 100 has a biaxial (machine direction and cross-machine direction) bond strength of about 8 to about 12 pounds per inch (about 3.63 to about 5.44 kg) as measured by the ASTM 6496 Peel Adhesion Test Method. In other embodiments, the composite geosynthetic fabric 100 has a biaxial bond strength of about 9 to about 11 pounds per inch (about 4.08 to about 5.00 kg) as measured by the ASTM 6496 Peel Adhesion Test Method. Still further, in some embodiments, the composite geosynthetic fabric 100 has a biaxial bond strength of about 8, 9, 10, 11, and 12 pounds per inch (3.63, 4.08, 4.54, 5.00, and 5.44 kg), or any range therebetween, as measured by the ASTM 6496 Peel Adhesion Test Method.

[0038] In one or more embodiments, the composite geosynthetic fabric 100 has a biaxial wide width (WW) tensile strength of at least 300 pounds per inch (lbs / in) in both the machine direction and cross-machine direction, as measured by ASTM D 4595 test method. In some embodiments, the composite geosynthetic fabric 100 has a biaxial wide width tensile strength of from about 300 lbs / in to about 550 lbs / in in both the machine direction and cross-machine direction, as measured by ASTM D 595 test method. Still further, in other embodiments, the composite geosynthetic fabric 100 has a biaxial wide width (WW) tensile strength in both the machine direction and cross-machine direction of about 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, and 550 pounds per inch (136.1, 147.4, 158.8, 170.1, 181.4, 192.8, 204.1, 215.5, 226.8, 238.1, and 249.5 kg) (lbs / in), or any range therebetween, as measured by ASTM D4595 test method.

[0039] In embodiments, the composite geosynthetic fabric 100 has abrasion resistance as indicated by maintaining about 90% to about 95% of its tensile strength after 80,000 revolutions, as measured by the ISO 22182 test method. In other embodiments, the composite geosynthetic fabric 100 has abrasion resistance as indicated by maintaining about 91% to about 94% of its tensile strength after 80,000 revolutions, as measured by the ISO 22182 test method. In still other embodiments, the composite geosynthetic fabric 100 has abrasion resistance as indicated by maintaining about 90%, 91%, 92%, 93%, 94%, and 95%, or any range therebetween, of its tensile strength after 80,000 revolutions, as measured by the ISO 22182 test method.

[0040] In one or more embodiments, the composite geosynthetic fabric 100 has an impact energy of at least 850 foot*pounds (ft*lbs) (1152.4 J), as measured by the ASTM E1886 test method, indicating impact resistance. Sufficient impact resistance is essential in applications where the composite may be impacted by debris such as boats, anchors, or trees. In other embodiments, the composite geosynthetic fabric 100 has an impact energy of about 850 to about 2,000 ft*lbs (about 1152.4 to about 2711.6 J), as measured by the ASTM E1886 test method. In yet other embodiments, the composite geosynthetic fabric 100 has an impact energy of about 1,000 to about 1,500 ft*lbs (about 1355.8 to about 2033.7 J), as measured by the ASTM E1886 test method. In one or more embodiments, the composite geosynthetic fabric 100 has an impact energy of at least 850 foot*pounds (ft*lbs) (1152.4 J), as measured by the ASTM E1886 test method. Measured according to E1886 test method, the strengths are approximately 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950, and 2000 ft*lbs (1152.4, 1220.2, 1288.0, 1355.8). , 1423.6, 1491.4, 1559.2, 1627.0, 1694.7, 1762.6, 1830.3, 1898.1, 1965.9, 2033.7, 2101.5, 2169.3, 2237.1, 2304.8, 2372.6, 2440.4, 2508.2, 2576.0, 2643.8, 2711.6 J), or any range therebetween.

[0041] In some embodiments, the composite geosynthetic fabric 100 has a water flow rate of from about 10 to about 35 gallons (about 37.9 to about 132.5 liters) per square foot (0.09 square meter) per minute as measured by the ASTM D4491 Water Flow Test Method. In other embodiments, the composite geosynthetic fabric 100 has a water flow rate of from about 15 to about 25 gallons (about 56.8 to about 94.6 liters) per square foot (0.09 square meter) per minute as measured by the ASTM D4491 Water Flow Test Method. Additionally, in one or more embodiments, the composite geosynthetic fabric 100 has a water flow rate of 10, 15, 20, 25, 30, and 35 gallons (37.9, 56.8, 75.7, 94.6, 113.6, and 132.5 liters) per square foot (0.09 square meters) per minute, or any range therebetween, as measured by the ASTM D4491 Water Flow Test Method.

[0042] The composite woven fabric contains monofilament yarns, which are necessary for greater water flow than bidirectional (MD and XMD) tape yarn woven fabrics, as well as higher UV and abrasion resistance resulting from their greater thickness compared to thinner slit tape yarns. Additionally, the gaps from their greater warp crimp amplitude resulting from the thicker interlaced yarns in the machine direction (MD) provide higher water flow. As mentioned above, needlepunching a woven fabric using monofilament yarns was not expected to be achievable for bonding the woven fabric to a nonwoven fabric, but the inclusion of monofilaments is important to maintaining the desired water flow, as well as UV and abrasion resistance, of the composite.

[0043] FIG. 2 is a flowchart illustrating a method 200 of making a composite fabric according to an embodiment of the present invention. As shown in box 201, method 200 includes preforming a carded nonwoven fabric. The nonwoven fabric is provided by preforming the nonwoven fabric before bonding the nonwoven fabric to a woven fabric to form a composite. The preformed nonwoven fabric comprises a plurality of fibers, each fiber having a denier of about 2 to about 18 (about 2.2 to about 20.0) decitex per filament. In some embodiments, the nonwoven fabric is preformed by carding a plurality of fibers via needle punching to form a nonwoven fabric before bonding the nonwoven fabric to a woven fabric to form a composite.

[0044] As shown in box 202, method 200 includes extruding a portion of the fibers of the nonwoven fabric through the woven fabric such that a portion of the fibers extend from a side of the woven fabric opposite the nonwoven fabric. In some embodiments, extruding a portion of the fibers of the nonwoven fabric through the woven fabric includes punching needles through the nonwoven fabric and the woven fabric, such as by needle punching. The fibers of the nonwoven fabric are extruded to the opposite side of the woven fabric, leaving a portion of the fibers extending from a side of the woven fabric.

[0045] As shown in box 203, the method includes fusing (or singeing) a portion of the fibers extending from the face of the woven fabric (opposite the nonwoven fabric). To improve adhesion of the nonwoven fabric to the woven fabric, heat is applied to the fibers at high speed, for example, via a flame singer, to melt loose fibers on the underside of the woven fabric. Fusing and melting the fibers significantly increases the bond strength of the composite. Unexpectedly, smaller denier fibers provide better adhesion and peel strength than larger denier fibers. While individual larger fibers have a greater surface area than individual smaller fibers, the greater number of smaller denier fibers per filament fiber creates a much greater overall surface area, allowing the fibers to be extruded to the backside of the woven fabric, forming more fused knots once scorched. These fused knots generate a much greater force to delaminate than larger denier fibers per fewer filament fibers.

[0046] As used herein, the term "preformed nonwoven" and other similar terms refer to a fabric formed from a staple fiber carded web that has been mechanically needlepunched to bond the fibers together crisscross to provide a mechanically bonded stand-alone fabric.

[0047] As used herein, "carded web" and other similar terms mean a web of loose staple fibers arranged crisscross, where the fibers are stacked against each other to create a non-mechanically entangled batting. [Example]

[0048] Example 1: Composite Fabric The composite fabrics described herein were constructed as shown in Tables 1 and 2.

[0049] [Table 1]

[0050] [Table 2]

[0051] Example 2: Impact test Impact testing was performed on various composites and compared to a control. The results are shown in Table 3 below and include the fabrics described in Tables 1 and 2 above. The control fabric was a 20-ounce (0.57 kg) loose, 110 denier (122.1 dtex) three-layer composite that was needled in both the machine and cross-machine directions through a 4-ounce (0.11 kg) preformed nonwoven fabric per square yard (0.84 square meters) and then through a woven fabric with fibrillated tape yarns. The preformed 4 osy fabric was placed between the carded web and the backing to provide a larger surface area for fiber retention, thereby promoting better adhesion. The need for the 4 osy preformed fabric was eliminated when the smaller dpf fibers showed better adhesion than expected, thereby reducing the overall composite weight and, as Table 3 shows, without compromising tensile strength or other properties desirable for shoreline protection.

[0052] Impact testing was performed according to ASTM E1886 test method. Estimated impact energy is expressed in mV using 1.46667 feet (44.7 cm) per second (ft / sec) = 1 mile (1.61 km) per hour (mph). 2 The impact energy was measured in ft*lb, which is equivalent to 1 / g. The cannon used had a 4-inch (10.16 cm) diameter barrel. To "pass," the impact energy was greater than 850 ft*lbs (1152.4 J) without any sediment loss. Figure 6 shows the composite (99A) after the impact test.

[0053] [Table 3-1]

[0054] [Table 3-2]

[0055] [Table 3-3]

[0056] Example 3: Abrasion and Tensile Tests Abrasion tests were performed according to the ISO 22182 test method. Wide width (WW) tensile measurements were performed according to the ISO 10319 test method. Tests were performed on three fabrics: Fabrics 98A, GT100MG, and TC1200MB (control) were tested (see Tables 1 and 2).

[0057] The 99A fabric of the present invention had an initial average MD ultimate strength of 3005 lbs*force (Table 4). After being subjected to 80,000 revolutions of abrasion, the fabric had an average MD ultimate tensile strength of 2811 lbs*force. Thus, the fabric of the present invention maintained about 93.5% of its MD ultimate tensile strength after 80,000 revolutions, as measured by the ISO 22182 test method.

[0058] [Table 4]

[0059] The GT1000MG fabric (Table 5) had an initial average MD ultimate strength of 8,312 lbs*force. After being subjected to 80,000 revolutions of abrasion, the fabric had an average MD ultimate tensile strength of 41.8 lbs*force. Thus, the fabric of this invention maintained 0.01% of its MD ultimate tensile strength after 80,000 revolutions, as measured by the ISO 22182 test method. The absence of an attached nonwoven in the stand-alone woven fabric caused significant loss after abrasion. Considering these results, in shoreline applications, the composite with the nonwoven facing the shoreline is important to resist abrasion, and the woven backing is important to provide the tensile strength necessary to withstand pumping forces while filling the composite geotube.

[0060] [Table 5]

[0061] The control TC1200MB fabric (Table 6) had an initial average MD ultimate strength of 3,214 lbs*force. After being subjected to 80,000 revolutions of abrasion, this fabric had an average MD ultimate tensile strength of 3,369 lbs*force. Thus, this control fabric retained 95.3% of its MD ultimate tensile strength after 80,000 revolutions, as measured by the ISO 22182 test method.

[0062] [Table 6]

[0063] Example 4: Tensile and Adhesion Loss The composites were tested for tensile and adhesion loss. As shown in Tables 7-9, the 4 ounces (0.11 kg) of pre-formed nonwoven fabric per square yard (0.84 square meters) in the control was not necessary to provide the same tensile, adhesion, and / or water flow. Removing the 4 ounces (0.11 kg) of nonwoven fabric per square yard (0.84 square meters) resulted in a lighter fabric that provided comparable wide width (WW) tensile values ​​and greater peel strength.

[0064] As shown in Table 7, composites needlepunched with six-barb needles had a significantly higher average tensile loss (48%) after needling compared to composites formed with single-barb needles (16%). Therefore, needlepunching with single-barb needles can reduce tensile loss and allow the use of woven backings with monofilament yarns in the machine direction, since such thick yarns are more resistant to tearing when needlepunched compared to slit tape. When monofilament yarns were used, the needles tended to break during composite fabrication because such thick needles did not provide sufficient space for needle passage. Because monofilament yarns are round, as opposed to flat tape yarns, the needles can deflect around the yarn rather than penetrate it. Typical widths of monofilament yarns ranged from 8 mil to 20 mil (0.20 mm to 0.51 mm), while typical slit tape widths ranged from 45 mil to 100 mil (1.14 mm to 2.54 mm). The single-barb needle still delivered a sufficient amount of fiber underneath through the woven fabric to increase peel strength adhesion. Furthermore, by reducing the barbs, the needle caused less damage to the woven backing, and in combination with using smaller dpf fibers in the preformed nonwoven, the single-barb needle still delivered more fiber through the woven backing for greater adhesive peel strength. The monofilament MD yarn provided additional void space to facilitate needle penetration, delivering a greater amount of fiber underneath through the woven backing.

[0065] [Table 7]

[0066] Loose carded webs were expected to be easier to punch and therefore were used to form composites with high bond strength. Furthermore, larger fibers were expected to provide greater adhesion to the backing, but such large fibers did not perform as expected. Rather, smaller fiber monofilaments with fibrillated tape in woven and preformed nonwoven fabrics, which have more void spacing and less fiber bonding (i.e., the ability of the backing to hold the needle-punched fibers through the woven fabric to its underside), unexpectedly had the highest bond strength, as shown in Table 8. Scorching remained consistent between samples.

[0067] Table 8 shows that preformed nonwovens with entangled fibers that are more difficult to punch provide higher peel bond strength and fewer punches per inch (2.54 cm). Unexpectedly, reinforced backings using punched monofilament warp yarns and fibrillated tape weft yarns with smaller denier fibers in the nonwoven provided significantly higher peel strength bonds due to increased fiber-to-fiber cohesion with the smaller denier fibers and the use of a looser backing for more fiber penetration.

[0068] [Table 8]

[0069] Table 9 shows that the water flow of the composites of the present invention with preformed nonwovens was higher than the control with carded web nonwovens having looser fibers, essentially having higher water flow. The higher dpf fibers had more voids between the fibers, more bulk, and higher flow rates through the material. As shown, the 99A fabric with 100% small dpf fibers had higher water flow than the control.

[0070] The higher dpf fibers from the control were approximately 10 times larger by weight and had larger diameters and bulk. Therefore, these larger fibers (i.e., >100 dpf) had more void space between fibers, resulting in higher flow rates through the material. Inventive fabric 99A, which has 100% smaller dpf fibers, preferably 2 dpf to 18 dpf, still had greater water flow in the resulting composite, as shown in Table 9 below.

[0071] [Table 9]

[0072] Various embodiments of the present invention are described herein with reference to the associated drawings. Alternative embodiments are contemplated without departing from the scope of the present invention. While various connections and relationships (e.g., above, below, adjacent, etc.) are described between elements in the following description and in the drawings, those skilled in the art will recognize that many of the relationships described herein are orientation-independent, provided that the described functionality is maintained even when the orientation is changed. These connections and / or relationships may be direct or indirect, unless otherwise specified, and the present invention is not intended to be limited in this respect. Thus, a connection of entities may refer to either a direct connection or an indirect connection, and a relationship between entities may be a direct or indirect relationship. As an example of an indirect relationship, reference in this description to forming layer "A" on layer "B" includes a situation in which one or more intermediate layers (e.g., layer "C") are between layer "A" and layer "B," as long as the relevant properties and functionality of layer "A" and layer "B" are not substantially altered by the intermediate layer(s).

[0073] The following definitions and abbreviations will be used in interpreting the claims and the specification. As used herein, the words "comprises," "comprising," "includes," "including," "has," "having," "contains," or "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, mixture, process, method, article, or device that includes a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent in such composition, mixture, process, method, article, or device.

[0074] Additionally, the term "exemplary," as used herein, means "serving as an example, instance, or illustration." Any embodiment or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. The terms "at least one" and "one or more" are understood to include one or more, i.e., any integer number such as 1, 2, 3, 4, etc. The term "plurality" is understood to include two or more, i.e., any integer number such as 2, 3, 4, 5, etc. The term "connected" can include an indirect "connected" and a direct "connected."

[0075] References herein to "one embodiment," "embodiment," "exemplary embodiment," etc., mean that the described embodiment may include a particular feature, structure, or characteristic, but every embodiment may or may not include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one of ordinary skill in the art to affect such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly stated.

[0076] For purposes of the following description, the terms "upper," "lower," "right," "left," "vertical," "horizontal," "top," "bottom," and their derivatives refer to the structures and methods described as oriented in the drawings. The terms "overlying," "atop," "on," "positioned on," or "positioned atop" mean that a first element, such as a first structure, is on a second element, such as a second structure, where an intervening element, such as an interface structure, may be present between the first and second elements. The term "direct contact" means that a first element, such as a first structure, and a second element, such as a second structure, are connected without an intermediate conductive, insulating, or semiconducting layer at the interface of the two elements.

[0077] The terms "about," "substantially," "approximately," and variations thereof are intended to include the degree of error associated with measurement of the particular quantity based on the equipment available at the time of filing. For example, "about" can include a range of ±8%, or 5%, or 2% of a given value.

[0078] The flowcharts and block diagrams in the Figures illustrate possible implementations of methods of manufacture and / or operation according to various embodiments of the present invention. Various functions / acts of the methods are represented by blocks in the flow diagrams. In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the functionality involved.

[0079] In the following claims, corresponding structure, material, acts, and equivalents of all means-plus-function or step-plus-function elements are intended to include any structure, material, or act for performing that function in combination with other specifically claimed elements. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or to limit the invention to the form disclosed. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the invention. The present embodiment was chosen and described in order to best explain the principles and practical application of the invention and to enable others skilled in the art to understand the invention in various embodiments with various modifications as suited to the particular uses contemplated.

[0080] While preferred embodiments of the present invention have been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and modifications that fall within the scope of the following claims, which should be interpreted to maintain the proper protection for the invention as first described.

Claims

1. A composite geosynthetic fabric comprising: Woven fabric and a nonwoven fabric adhered to the woven fabric, the nonwoven fabric comprising a plurality of fibers, each fiber of the plurality of fibers of the nonwoven fabric having a denier of from about 2 to about 18 (from about 2.2 to about 20.0) per filament; A composite geosynthetic fabric, wherein a portion of the plurality of fibers of the nonwoven fabric extend through the woven fabric and are fused together on a surface of the woven fabric opposite the nonwoven surface of the woven fabric.

2. 2. The composite geosynthetic fabric of claim 1, wherein the composite geosynthetic fabric is a bicomponent composite fabric having only the woven fabric and the nonwoven fabric.

3. 10. The composite geosynthetic fabric of claim 1, wherein the nonwoven fabric is a preformed stand-alone fabric.

4. 10. The composite geosynthetic fabric of claim 1, wherein the nonwoven fabric has a basis weight of about 12 to about 32 ounces (about 0.34 to about 0.91 kg) per square yard (0.84 square meters).

5. 10. The composite geosynthetic fabric of claim 1, wherein the woven fabric comprises monofilament yarns and fibrillated tape yarns.

6. 10. The composite geosynthetic fabric of claim 1, wherein the composite geosynthetic fabric has a basis weight of about 25 to about 40 ounces (about 0.71 to about 1.13 kg) per square yard (0.84 square meters).

7. 10. The composite geosynthetic fabric of claim 1, wherein after 1,000 hours of ultraviolet light exposure, the composite geosynthetic fabric has a UV light retention of at least 90% as measured by ASTM D4355 test method.

8. 10. The composite geosynthetic fabric of claim 1, wherein the composite geosynthetic fabric has a biaxial bond strength of about 20 pounds (9.07 kg) per inch (2.54 cm) to about 50 pounds (22.7 kg) per inch (2.54 cm) as measured by the ASTM 6496 peel adhesion test method.

9. 10. The composite geosynthetic fabric of claim 1, wherein the composite geosynthetic fabric has a biaxial wide width tensile strength of at least 300 pounds per inch (136.1 kg) in both the machine direction and cross-machine direction as measured by ASTM D 4595 test method.

10. 10. The composite geosynthetic fabric of claim 1, wherein the composite geosynthetic fabric has abrasion resistance as indicated by retaining about 90% to about 95% of its tensile strength after 80,000 revolutions as measured by ISO 22182 test method.

11. 10. The composite geosynthetic fabric of claim 1, wherein the composite geosynthetic fabric has an impact energy of at least 850 ft*lbs (1152.4 J) as measured by ASTM E 1886 test method.

12. 1. A method of making a composite geosynthetic fabric, comprising: providing a preformed nonwoven fabric comprising a plurality of fibers, each of the fibers having a denier per filament of from about 2 to about 18 (about 2.2 to about 20.0) dtex; adhering the woven fabric to the preformed nonwoven fabric by extruding a portion of the plurality of fibers of the preformed nonwoven fabric through the woven fabric such that the portion of the plurality of fibers extends from a side of the woven fabric opposite the preformed nonwoven fabric; fusing the portion of the plurality of fibers extending from the surface of the woven fabric.

13. The method of claim 12 , wherein said fusing comprises applying heat to fuse at least the portion of the plurality of fibers extending from the face of the woven fabric.

14. The method of claim 12 , wherein the bonding of the woven fabric to the preformed nonwoven fabric comprises needling the preformed nonwoven fabric through the woven fabric.

15. 13. The method of claim 12, wherein needling the preformed nonwoven fabric through the woven fabric comprises using a needle board having a needle density of about 55 to about 105 needles per square inch (ppsi).

16. 13. The method of claim 12, wherein needling the preformed nonwoven fabric through the woven fabric comprises using a needle board with single barbed needles.

17. The method of claim 12 , wherein providing the preformed nonwoven fabric comprises carding and needlepunching the plurality of fibers.

18. The method of claim 12 , wherein the woven fabric comprises monofilament yarns and tape yarns.

19. 13. The method of claim 12, wherein extruding the portion of the plurality of fibers of the nonwoven fabric through the woven fabric comprises punching needles through the nonwoven fabric and the woven fabric.

20. 13. The method of claim 12, wherein the composite geosynthetic fabric is a bicomponent composite fabric having only the woven fabric and the pre-formed nonwoven fabric.

21. The method of claim 12 , wherein the preformed nonwoven is a stand-alone fabric.

22. 13. The method of claim 12, wherein the preformed nonwoven fabric has a basis weight of from about 12 to about 32 ounces (about 0.34 to about 0.91 kg) per square yard (0.84 square meters).

23. The method of claim 12 , wherein the woven fabric comprises monofilament yarns and fibrillated tape yarns.

24. 13. The method of claim 12, wherein the composite geosynthetic fabric has a basis weight of about 25 to about 40 ounces (about 0.71 to about 1.13 kg) per square yard (0.84 square meters).

25. 13. The method of claim 12, wherein after 1000 hours of ultraviolet light exposure, the composite geosynthetic fabric has a UV light retention of at least 90% as measured by ASTM D 4355 test method.

26. 13. The method of claim 12, wherein the composite geosynthetic fabric has a biaxial bond strength of about 20 pounds (9.07 kg) per inch (2.54 cm) to about 50 pounds (22.7 kg) per inch (2.54 cm) as measured by the ASTM 6496 peel adhesion test method.

27. 13. The method of claim 12, wherein the composite geosynthetic fabric has a biaxial wide width tensile strength of at least 300 pounds per inch (136.1 kg) in both the machine direction and cross-machine direction as measured by ASTM D 4595 test method.

28. 13. The method of claim 12, wherein the composite geosynthetic fabric has abrasion resistance as indicated by retaining about 90% to about 95% of its tensile strength after 80,000 revolutions as measured by ISO 22182 test method.

29. 13. The method of claim 12, wherein the composite geosynthetic fabric has an impact energy of at least 850 ft*lbs (1152.4 J) as measured by ASTM E 1886 test method.

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