Composite geosynthetic fabric with increased peel strength

Abstract

The invention relates to a composite geosynthetic fabric. The composite geosynthetic fabric comprises a woven fabric and a non-woven fabric adhered to the woven fabric. The non-woven fabric includes a plurality of fibers, wherein each fiber of the plurality of fibers of the non-woven fabric is from about 2 to about 18 deniers per filament. A portion of the fibers of the non-woven fabric extends through the woven fabric and is fused together on a face of the woven fabric opposite the non-woven face side of the woven fabric.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 486,758, filed on February 24, 2023, which is incorporated herein by reference in its entirety. Background Art

[0003] The present disclosure relates to geosynthetics, and more particularly, to composite geosynthetics having increased peel strength.

[0004] Geosynthetics consist of two or more fabrics (one or more of each of woven and / or nonwoven) adhered to one another. Geosynthetics are manufactured using specially engineered fabrics and fibers to provide superior durability, abrasion resistance, UV protection, and impact resistance in hydraulic and marine environments. These systems also retain sand and other sediments for enhanced durability and a longer service life. Summary of the Invention

[0005] According to one or more embodiments, a composite geosynthetic fabric includes a woven fabric and a nonwoven fabric adhered to the woven fabric. The nonwoven fabric comprises a plurality of fibers, wherein each of the plurality of fibers of the nonwoven fabric has a denier per filament of about 2 to about 18. A portion of the fibers of the nonwoven fabric extends through the woven fabric and is fused together on a side of the woven fabric opposite the nonwoven side of the woven fabric.

[0006] According to other embodiments, a method of making a composite geosynthetic fabric includes providing a preformed nonwoven fabric having a plurality of fibers, each fiber having a denier per filament of about 2 to about 18. The method further includes adhering the woven fabric to the preformed nonwoven fabric by pushing a portion of the plurality of fibers of the nonwoven fabric through the woven fabric such that the portion of the plurality of fibers extends from a face of the woven fabric opposite the nonwoven fabric. The method further includes fusing the portion of the plurality of fibers extending from the face of the woven fabric.

[0007] Additional features and advantages are achieved through the technology of the present invention. Other embodiments and aspects of the present invention are described in detail herein and are considered to be a part of the claimed invention. For a better understanding of the advantages and features of the present invention, reference is made to the specification and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] 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:

[0009] Figure 1Ais a schematic diagram showing a partial cross section of a geosynthetic composite fabric;

[0010] Figure 1B is a schematic diagram showing a partial cross-section of a composite geosynthetic fabric having fused bonds; and

[0011] Figure 2 is a flow chart showing a method of manufacturing a geosynthetic composite fabric;

[0012] Figure 3A A needle board for needling a preformed nonwoven into a woven fabric is shown;

[0013] Figure 3B Single and six-barb hook stitches are shown;

[0014] Figure 4 Shown are a comparative non-preformed nonwoven composite worn after 500 cycles (top panel) and a composite as described herein worn after 5,000 cycles (bottom panel).

[0015] Figure 5 shows a composite material as described herein worn after 1,500 cycles (left image) and a comparative non-preformed nonwoven composite material worn after 500 cycles (right image); and

[0016] Figure 6 Shown is a composite fabric (99A) as described herein after impact testing. DETAILED DESCRIPTION

[0017] Geosynthetics must provide excellent robustness, abrasion resistance, ultraviolet (UV) protection and impact resistance in hydraulic and marine environments and other harsh environments. In order to provide such performance, fibers and fabrics are carefully selected. When the composite fabric comprises a nonwoven, generally, using larger fibers results in a thicker composite material, which has better abrasion resistance, improved UV protection and increased water flow. When the fibers of the needle-punched nonwoven fabric are passed through the woven fabric to form the composite fabric, generally the woven fabric should be formed by yarns that are thin enough to pierce through. In particular, woven fabrics with non-fibrillated flat yarns are preferred because they are very thin, for example, generally 1.5 mils to 2.5 mils thick, and are therefore easy to penetrate through the needle.

[0018] In contrast, fibrillated tape yarns are less suitable for needle punching because they are thicker due to being cut during extrusion to provide a pattern that allows the tape yarns to be folded and compacted to make their corresponding cross-section smaller. This processing of fibrillated tape yarns is necessary to weave them in the weft direction because the projectile must be able to load the yarn into its gripper and pull the yarn through the loom.

[0019] Monofilament yarns in woven fabrics are generally too thick and difficult to penetrate, with a typical thickness of at least 8 mils, and are therefore not used in mechanically bonded needlepunched composites. Woven fabrics with monofilament yarns can and do cause needlepunch damage when making needlepunched composites.

[0020] Additionally, the higher number of fabric layers typically used in composites means greater abrasion resistance, impact resistance, and long-term durability in a variety of harsh environments, including along coastlines where ice dams can surge and combine with tree branches, wave action, boats, and propellers to deliver significant energy to the composite.

[0021] Under the general limitations mentioned above, geosynthetics are usually made from large-fiber nonwovens and woven fabrics made from fibrillated and / or non-fibrillated tapes and have more than two layers. The disadvantage of the composite materials obtained in this way is that they are heavy and expensive to produce, although they are strong and resistant to wear and UV degradation.

[0022] One or more embodiments of the invention described herein address the above-mentioned shortcomings by providing a composite geosynthetic material and methods of making and using the same, the composite geosynthetic material comprising a woven fabric and a preformed nonwoven fabric adhered to the woven fabric, wherein the nonwoven fabric has a plurality of small fibers of about 2 to about 18 denier per filament, and wherein a portion of the fibers of the nonwoven fabric extend through the woven fabric and are fused together on the side of the woven fabric opposite the nonwoven side of the woven fabric. Unexpectedly, the use of significantly smaller fibers in the preformed nonwoven provides higher surface area coverage than larger fibers and results in a composite material having the same or better abrasion resistance, impact resistance, UV resistance, and peel strength adhesion as nonwovens having larger fibers, as well as higher water flow, and having a lighter composite weight.

[0023] In embodiments, the composite geosynthetic fabric comprises only one layer of woven fabric and only one layer of nonwoven fabric in a two-layer composite, or consists of one layer of nonwoven fabric and only one layer of nonwoven fabric. The two-layer composite is unexpectedly and advantageously lighter and less expensive to manufacture than composites having more than two layers, and unexpectedly has the same, similar, or better abrasion and impact resistance, peel strength, UV resistance, and water flow as a three-layer composite.

[0024] In other embodiments, the nonwoven fabric is a preformed, freestanding nonwoven fabric. In some embodiments, the composite geosynthetic fabric is formed by needle-punching a portion of a plurality of fibers from a preformed nonwoven fabric through a woven fabric, such that the portion of the plurality of fibers extends from a face of the woven fabric opposite the nonwoven fabric. In one or more embodiments, the woven fabric is formed from a monofilament yarn and a fibrillated tape yarn. In some embodiments, the method further includes fusing the portion of the plurality of fibers extending from a face of the woven fabric by applying flame heat or heat to the backside of the protruding, needle-punched fibers to melt and singe them to form fused knots or singed fibers.

[0025] Due to several reasons, it is expected that the composite material formed by loose carding web (non-preformed nonwoven) and the weaving fabric with flat yarn forms the desired geosynthetics. Those of ordinary skill in the art will expect that nonwoven fibers will be more easily needle-punched through the woven fabric with only fine fibrillation and / or non-fibrillation flat yarn, because monofilament yarn is too thick and tends to damage and break when penetrating the woven backing. In addition, independently preformed nonwoven has mechanically bonded fiber, which will expect to increase the difficulty of needle-punching through. Because the fiber of expectation nonwoven penetrates the bottom side of woven backing from nonwoven, thereby is locked in two layers, so fiber is looser, they are more easily needle-punched and transferred to the back side of strengthening woven backing. Usually, the woven fabric with only fibrillation flat yarn and / or non-fibrillation flat yarn can be needle-punched through to avoid excessive tensile loss. Unexpectedly, however, as described herein, a woven fabric having monofilaments in addition to fibrillated tape yarns can be needled through to adhere smaller denier fibers in a preformed nonwoven to the woven fabric.

[0026] Typical geosynthetic needles have multiple barbs, which are needed to secure a large number of fibers and transfer a portion of the fibers from the top side to the bottom side of the reinforcing backing. To needle the nonwoven fibers through the monofilaments in the woven fabric, a portion of the needles from the needle board machine are removed to reduce the density of needles in a particular pattern. In addition, 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 caused by the monofilament yarn not tearing from the needles and allows for a lighter backing. This reduction in tensile loss also allows for a lower initial pre-needling tensile strength backing because the resulting composite retains a higher percentage of its initial strength. As a result, essentially enough nonwoven fibers are needled through the woven fabric to leave a sufficient number of nonwoven fibers extending from the opposite side of the woven fabric to enhance peel strength.

[0027] Furthermore, one of ordinary skill in the art would generally expect that larger fibers would provide better adhesion and abrasion resistance. However, as described herein, the smaller denier fibers of the nonwoven are pushed through the woven backing in greater numbers, thereby creating a higher total surface area which, when lightly singed, forms "melted knots" on the back side of the woven (see Figure 1B The number of fused knots results in increased peel strength and greater adhesion between the woven and nonwoven fabrics in the composite. The higher fiber-to-fiber cohesion of the smaller denier fibers also contributes to this unexpected result.

[0028] Although larger fibers in nonwovens are expected to resist abrasion, Figure 4 showed that the opposite was observed. Figure 4 The abrasion resistance of the composite material with preformed nonwoven formed as described herein (bottom figure) and the comparative composite material with carded nonwoven of larger fiber (top figure) are compared. Abrasion resistance is measured according to ASTM 3884 test method. As shown in the figure, compared with the preformed nonwoven composite material (bottom figure) after 5,000 abrasion cycles, the carded loose web (top figure) has less mechanical fiber to fiber entanglement and lower abrasion resistance after 500 abrasion cycles, which is due to lack of fiber to fiber cohesion, low fiber compaction caused by larger fiber size and lower bond strength with the woven fabric. Figure 5 Similarly shown are a composite material as described herein (shown facing side with woven backing underneath) worn after 1,500 cycles (left) and a comparative non-preformed nonwoven composite material worn after 500 cycles (right).

[0029] Needle plate 300( Figure 3A The density of the needles 302 in the needle punch is modified and is less than a conventional needle punching plate used for needling loose, non-preformed nonwovens. The needles 302 themselves are also modified compared to conventional needles and include a single barb 304 rather than multiple barbs, such as 6 barbs 304 ( Figure 3B In some embodiments, the needle density of the needles in the needle punch plate is from about 50 to about 100 needles (or punctures) per square inch (ppsi). In other embodiments, the needle density of the needles in the needle punch plate is from about 75 to about 95. In embodiments, the needle density of the needles in the needle punch plate is about 50, 55, 60, 65, 70, 75, 80, 85, 90, and 100 needles per square inch or ppsi, or any range therebetween. In one or more embodiments, the needle plate has a plurality of single barbed needles.

[0030] Furthermore, one of ordinary skill in the art would expect that reducing the number of punctures or needles per square inch would result in lower peel strengths because fewer fibers would be pushed through the back side of the reinforced woven backing. However, unexpectedly, when needled with fewer punctures per square inch (ppsi), smaller denier fibers produced greater peel strength than with a higher number of ppsi and larger fibers. This result is due, in part, to the increased surface area of ​​the smaller fiber population and the increased fiber-to-fiber cohesion resulting from significantly smaller dpf fibers (e.g., 2-18 dpf fibers versus greater than 100 dpf fibers).

[0031] In addition, nonwoven fabrics are preformed fabrics, rather than carded webs (non-preformed). Compared to carded webs, preformed nonwovens as described herein have tightly bound fibers that have been needle-punched and mechanically entangled to produce a fully formed independent nonwoven fabric. It is expected that in terms of acceptable peel strength adhesion and water flow, it would be more difficult to needle-punch the mechanically bound fibers of a preformed nonwoven through a woven backing than the looser fibers of a carded web, but this is not the case.

[0032] By using preformed nonwovens, composite material is formed in a single-step process, wherein the preformed nonwoven and woven fabric adhere together by acupuncture.Preformed nonwovens has a water flow much lower than the carded web, and expects to produce a composite material with lower water flow. However, fact is just the opposite.The composite material with preformed nonwovens has a water flow higher than the composite material with carded web (referring to Table 8).

[0033] By applying heat to the fibers, the needle punches of the fibers are passed through and at least a portion extending from the opposite side of the woven fabric is fused together. The slightly singed fibers form fused knots, which cause the adhesion of the nonwoven to the woven fabric to increase. A larger number of smaller knots formed by fusing fibers with smaller deniers / filaments (dpf) provide greater peel strength adhesion than a smaller number of larger dpf fibers (see Table 7).

[0034] In one or more embodiments, the composite geosynthetic fabric includes a 20 ounces per square yard (osy) nonwoven having 8 denier per filament (dpf) fibers needle punched into the woven fabric and singed on the woven side to enhance peel strength.

[0035] Figure 1AA schematic diagram illustrates 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 adhered to the woven fabric 103. The nonwoven fabric 101 includes a plurality of fibers 105. A portion of the fibers 105 of the nonwoven fabric 101 extends through the woven fabric 103 and is at least partially fused together (fused fibers 106, Figure 1B ).

[0036] In one or more embodiments, the composite geosynthetic fabric is a bicomponent composite fabric (a two-layer composite material) having (consisting of) only two fabrics or two fabric layers, namely, a woven fabric 103 and a nonwoven fabric 101. The use of two fabrics instead of three fabrics reduces the manufacturing cost and overall weight of the composite material without compromising performance or inadvertently increasing thickness in some areas.

[0037] In an embodiment, the nonwoven fabric 101 is a preformed freestanding fabric. In an embodiment, the nonwoven fabric 101 is formed by carding and needle punching, and then the nonwoven is adhered to the woven to form a composite material.

[0038] In an embodiment, the nonwoven fabric 101 has a basis weight of about 12 to about 32 ounces per square yard (osy). In other embodiments, the nonwoven fabric 101 has a basis weight of about 15 to about 25 ounces per square yard. Yet in other embodiments, the nonwoven fabric 101 has a basis weight of about 18 to about 22 ounces per square yard. In an embodiment, the nonwoven fabric 101 has a basis weight of about or in any range between about 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 and 25 ounces per yard.

[0039] In one or more embodiments, each fiber 105 in the plurality of fibers of nonwoven fabric 101 is about 2 to about 18 deniers per filament (dpf). In other embodiments, each fiber 105 in the plurality of fibers of nonwoven fabric 101 is about 5 to about 10 deniers per filament. Additionally, in other embodiments, each fiber 105 in the plurality of fibers of nonwoven fabric 101 is about 7 to about 9 deniers per filament. In an embodiment, each fiber 105 in the plurality of fibers of nonwoven fabric 101 is about or in any range between about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 and 18 deniers per filament.

[0040] The use of fibers 105 having a small denier per filament (about 2 to about 18 denier per filament) in the nonwoven fabric 101 unexpectedly provides the composite with higher resistance to UV rays, impact, water flow, and abrasion than larger fibers (e.g., 110 denier per filament). The results are unexpected because larger fibers generally provide greater composite weight and larger interstices between fibers, which are the primary drivers of higher water flow.

[0041] The woven fabric 103 includes 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).

[0042] In one or more embodiments, the woven fabric is a twill fabric with a single or double pick inserted into the woven fabric. It is also important to note that although plain weave provides the greatest dimensional stability of any woven fabric, it has the greatest number of interlacings. Therefore, when using a woven fabric with monofilaments for needle-punching composites, plain weave is undesirable because its interlacing is too tight. The optimal weave pattern for forming a composite material is a loose weave with dimensional stability, such as a twill weave. Compared to plain weave, twill weave will have at least half the number of interlacings, depending on the number of weft yarns in each shed, and produces a structure in which the yarns can slide more easily, avoiding damage, and avoiding damage to the needles during the needling process. The aforementioned advantages reduce the tensile loss caused by yarn damage and needle damage in the resulting composite material. In contrast, composite materials needle-punched with non-fibrillated flat filament warp and weft yarns woven backing (rather than with monofilaments as described herein) preferably have plain weaves because they are easier to penetrate and do not cause needle damage because the yarns are very thin and therefore easy to penetrate.

[0043] In some embodiments, the composite geosynthetic fabric 100 has a total basis weight of about 24 to about 40 ounces per square yard. In other embodiments, the composite geosynthetic fabric 100 has a total basis weight of about 27 to about 34 ounces per square yard. Furthermore, in other embodiments, the composite geosynthetic fabric 100 has a basis weight of about or in any range between about 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, and 40 ounces per square yard.

[0044] In one or more embodiments, the composite geosynthetic fabric 100 has a UV retention of at least 90% after 1,000 hours of UV exposure, as measured by the ASTM D4355 test method. In other embodiments, the composite geosynthetic fabric 100 has a UV retention of about 92% to about 97% after 1,000 hours of UV exposure, as measured by the ASTM D4355 test method. Furthermore, in other embodiments, the composite geosynthetic fabric 100 has a UV retention of about or in any range between about 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, and 99% after 1,000 hours of UV exposure, as measured by the ASTM D4355 test method.

[0045] In some embodiments, the composite geosynthetic fabric 100 has a biaxial (in the machine and cross-machine directions) adhesion strength of about 8 to about 12 pounds per inch, as measured by the ASTM 6496 Peel Adhesion test method. In other embodiments, the composite geosynthetic fabric 100 has a biaxial adhesion strength of about 9 to about 11 pounds per inch, as measured by the ASTM 6496 Peel Adhesion test method. Furthermore, in some embodiments, the composite geosynthetic fabric 100 has a biaxial adhesion strength of about 10 to about 11 pounds per inch, as measured by the ASTM 6496 Peel Adhesion test method. Further, in some embodiments, the composite geosynthetic fabric 100 has a biaxial adhesion strength of about 10, or in any range between about 8, 9, 10, 11, and 12 pounds per inch, as measured by the ASTM 6496 Peel Adhesion test method.

[0046] 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 the cross-machine direction, as measured by ASTM D4595 test method. In some embodiments, the composite geosynthetic fabric 100 has a biaxial wide width (WW) tensile strength of about 300 lbs / in to about 550 lbs / in in both the machine direction and the cross-machine direction, as measured by ASTM D 595 test method. In addition, in other embodiments, the composite geosynthetic fabric 100 has a biaxial wide width (WW) tensile strength of about or in any range between about 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, and 550 pounds per inch (lbs / in) in both the machine direction and the cross-machine direction, as measured by ASTM D4595 test method.

[0047] In an embodiment, the composite geosynthetic fabric 100 has abrasion resistance as demonstrated by retaining from 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 demonstrated by retaining from about 91% to about 94% of its tensile strength after 80,000 revolutions, as measured by the ISO 22182 test method. Furthermore, in other embodiments, the composite geosynthetic fabric 100 has abrasion resistance as demonstrated by retaining from about 80,000 revolutions, or within any range between about 90%, 91%, 92%, 93%, 94%, and 95% of its tensile strength, as measured by the ISO 22182 test method.

[0048] In one or more embodiments, the composite geosynthetic fabric 100 has an impact energy of at least 850 foot-pounds (ft*lbs), as measured by the ASTM E1886 test method, which demonstrates impact resistance. Sufficient impact resistance is essential in applications where the composite material will be subjected to impact from debris such as ships, anchors, trees, etc. In other embodiments, the composite geosynthetic fabric 100 has an impact energy of about 850 to about 2,000 ft*lbs, as measured by the ASTM E1886 test method. Furthermore, in other embodiments, the composite geosynthetic fabric 100 has an impact energy of about 1,000 to about 1,500 ft*lbs, as measured by the ASTM E1886 test method. In one or more embodiments, the composite geosynthetic fabric 100 has an impact energy of about or anywhere in the range of between about 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, 1950, 2000 ft*lbs as measured by ASTM E1886 test method.

[0049] In some embodiments, the composite geosynthetic fabric 100 has a water flow rate of about 10 to about 35 gallons per minute per square foot, as measured by the ASTM D4491 water flow test method. In other embodiments, the composite geosynthetic fabric 100 has a water flow rate of about 15 to about 25 gallons per minute per square foot, as measured by the ASTM D4491 water flow test method. Furthermore, in one or more embodiments, the composite geosynthetic fabric 100 has a water flow rate of about or in any range between about 10, 15, 20, 25, 30, and 35 gallons per minute per square foot, as measured by the ASTM D4491 water flow test method.

[0050] Composite woven fabrics include monofilament yarns, which require greater water flow than bidirectional (MD and XMD) tape yarn wovens, as well as higher UV resistance and abrasion resistance due to their greater thickness compared to finer slit tape yarns. In addition, the larger gaps in the warp crimp amplitude due to the thicker interwoven yarns in the machine direction (MD) provide higher water flow. As mentioned above, while it is not expected to be possible to needle-punch a woven with monofilament yarns to adhere the woven to a nonwoven, including monofilament yarns is crucial to maintaining the desired water flow and UV and abrasion resistance properties of the composite.

[0051] Figure 2 2 is a flow chart illustrating a method 200 for making a composite fabric according to an embodiment of the present invention. As shown in block 201, method 200 includes preforming a carded nonwoven fabric. A nonwoven fabric is provided by preforming the nonwoven fabric and then adhering it to a woven fabric to form a composite material. The preformed nonwoven fabric comprises a plurality of fibers, each having a denier per filament of about 2 to about 18. In some embodiments, the nonwoven fabric is preformed by carding the plurality of fibers through needle punching to form a nonwoven before adhering the nonwoven fabric to the woven fabric to form the composite material.

[0052] As shown in block 202, method 200 includes pushing a portion of a plurality of fibers of a nonwoven fabric through a woven fabric such that the portion of the plurality of fibers extends from a side of the woven fabric opposite the nonwoven fabric. In some embodiments, pushing a portion of the plurality of fibers of the nonwoven fabric through the woven fabric includes passing a needle through the nonwoven fabric and the woven fabric, such as by needle punching. The fibers of the nonwoven fabric are pushed through opposite sides of the woven fabric, leaving a portion of the fibers extending from a side of the woven fabric.

[0053] As shown in frame 203, the method includes fusing (or singeing) multiple fibers extending from the face (relative to nonwoven fabric) of woven fabric.In order to improve the adhesion of nonwoven fabric and woven fabric, for example, heat is applied to the fiber via a high-speed flame singeing device, to melt the loose fibers on the bottom side surface of the woven fabric. Fusion and melting fiber significantly increase the adhesion strength of composite material. Unexpectedly, the fiber of smaller denier provides greater adhesion and peel strength than the fiber of larger denier. Although the larger fiber of single root has a larger surface area than the smaller fiber of single root, the higher number of the fiber of smaller denier / filament fiber per unit area causes larger total surface area and is pushed through the fiber coverage of the back side of woven fabric, and once singeing, forms more fused knots. These fused knots produce much larger delamination force on the fiber of larger denier / filament fiber less in number.

[0054] As used herein, the term "preformed nonwoven" and other like terms means a fabric formed from a carded web of staple fibers that has been mechanically needled to bond the fibers together in a matrix and provide a mechanically bonded, freestanding fabric.

[0055] As used herein, the term "carded web" and other like terms means a web of loose staple fibers arranged in a matrix wherein the fibers are stacked upon each other to create a non-mechanically entangled batt.

[0056] Examples

[0057] Example 1: Composite fabric

[0058] The composite fabrics described herein were constructed as shown in Tables 1 and 2.

[0059] Table 1: Composite fabrics

[0060]

[0061] Table 2: Composite fabric description

[0062]

[0063] NW: nonwoven dpf: denier per filament osy: ounces per square yard IR: infrared

[0064] PPSI: punctures per square inch

[0065] Example 2: Impact test

[0066] Various composite materials are carried out impact test, and compare with contrast.The results are shown in the table 3 below, and comprise the fabric described in the upper table 1 and 2.The control fabric is a three-layer composite material, and it is by 20 ounces of loose, 110 denier / filament fibers needle-punched through the preformed nonwoven of 4 ounces / square yards, and then on machine direction and cross machine direction, passes the weaving fabric with fibrillated flat yarn and forms.Preformed 4osy fabric is arranged between carded web and backing, and is used to provide larger surface area to keep fiber, and therefore promotes larger adhesive force.When less dpf fiber demonstrated the adhesive force bigger than expected, eliminated the needs to the 4osy preformed fabric, this reduced total composite weight, and as shown in table 3, can not damage tensile properties or shoreline protection required other performances.

[0067] Impact testing was performed according to ASTM E1886 test method. The estimated impact energy is measured in ft*lb which is equivalent to mV 2 / g, using 1.46667 feet per second (ft / sec) = 1 mile per hour (mph). The barrel diameter of the cannon used is 4 inches. To "qualify", the impact energy must be greater than 850 ft*lbs without any sand loss. Figure 6 The composite material (99A) is shown after impact testing.

[0068] Table 3: Impact test results

[0069]

[0070]

[0071] Example 3: Wear and tensile testing

[0072] Abrasion testing was performed according to ISO 22182. Wide width (WW) tensile measurements were performed according to ISO 10319. Three fabrics were tested: test fabrics 98A, GT100MG, and TC1200MB (control) (see Tables 1 and 2).

[0073] 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 abrasion cycles, the fabric had an average MD ultimate tensile strength of 2811 lbs*force. Thus, the fabric of the present invention retained approximately 93.5% of its MD ultimate tensile strength after 80,000 cycles, as measured by the ISO 22182 test method.

[0074] Table 4: Wear test on 99A

[0075]

[0076]

[0077] *BAW: Body Abrasive Wear

[0078] The GT1000MG fabric (Table 5) had an initial average MD ultimate strength of 8,312 lbs*force. After being subjected to 80,000 cycles of abrasion, the fabric had an average MD ultimate tensile strength of 41.8 lbs*force. Thus, the fabric retained 0.01% of its MD ultimate tensile strength after 80,000 cycles, as measured by the ISO 22182 test method. The absence of an attached nonwoven in the stand-alone woven fabric resulted in a significant loss after abrasion. Given these results, in shoreline applications, a composite with a shoreline-facing nonwoven is critical to resist abrasion, and a woven backing is critical to providing the necessary tensile strength to withstand pumping forces when filling the composite geotube.

[0079] Table 5: Wear test on GT1000MG

[0080]

[0081]

[0082] The control TC1200MB fabric (Table 6) had an initial average MD ultimate strength of 3,214 lbs*force. After being subjected to 80,000 abrasion cycles, the fabric had an average MD ultimate tensile strength of 3369 lbs*force. Thus, the control fabric retained 95.3% of its MD ultimate tensile strength after 80,000 cycles, as measured by the ISO 22182 test method.

[0083] Table 6: Wear test on TC1200MB (control)

[0084]

[0085]

[0086] Example 4: Stretch and Adhesion Loss

[0087] The composites were tested for tensile and adhesion loss. As shown in Tables 7 to 9, the preformed 4 oz / sq yd nonwoven in the control was not required to provide the same tensile, adhesion, and / or water flow. Removing the 4 oz / sq yd preformed nonwoven resulted in a lighter fabric that provided equivalent wide width (WW) tensile values ​​and greater peel strength.

[0088] As also shown in Table 7, the composite material formed with a single barb needle (16%) has a significantly higher average tensile loss % (48%) after needling with a 6-barb needle needle. Therefore, needling with a single barb needle and using a woven backing with a monofilament yarn in the machine direction can alleviate tensile loss because, when needling, this thicker yarn is more resistant to tearing than slit tape. When using monofilament yarn, the needle has a tendency to break during composite material manufacturing because this thick needle does not have enough space for the needle to pass. Compared with flat tape yarn, monofilament is round, which allows the needle to deflect around the yarn, rather than piercing the yarn. The typical width of monofilament yarn is 8 mils to 20 mils, and the typical slit tape width is 45 mils to 100 mils. A single barb needle still carries enough fiber to pass through the fabric to reach the bottom side to increase peel strength adhesion. Furthermore, by reducing the number of barbs, the needle causes less damage to the woven backing, and combined with the use of smaller dpf fibers in the preformed nonwoven, a single barbed needle still carries a greater number of fibers through the woven backing for greater adhesive peel strength. Monofilament MD yarns provide additional void space to allow easier needle penetration and carry a greater number of fibers through the woven backing to its underside.

[0089] Table 7: Stretch loss

[0090]

[0091] Loose carded webs were expected to be easier to needle and therefore used to form composites with high adhesion strength. Furthermore, larger fibers were expected to provide greater adhesion to the backing, but such large fibers did not perform as expected. Conversely, smaller fiber monofilaments with fibrillated tapes in wovens and preformed nonwovens, which had greater void space and less fiber bonding (i.e., the ability of the backing to retain fibers that had been needled through the woven to its underside), had unexpectedly the best adhesion strength, as shown in Table 8. Singeing remained constant between samples.

[0092] Table 8 shows that preformed nonwovens with entangled fibers that are more difficult to needle through provide higher peel adhesion strength with fewer punctures per inch. Unexpectedly, a reinforced backing with monofilament warp yarns and fibrillated tape weft yarns needled with smaller denier fibers in the nonwoven provides significantly higher peel strength adhesion due to increased fiber-to-fiber cohesion when using smaller denier fibers and using a looser backing to allow a greater volume of fibers to penetrate.

[0093] Table 8: Adhesion loss

[0094]

[0095] Table 9 shows that the composite materials of the present invention with preformed nonwovens have higher water flow rates than the control carded web nonwoven, which has looser fibers and inherently higher water flow rates. Fibers with higher dpf have larger spaces between fibers and are more bulky, which results in higher flow rates through the material. As shown, fabric 99A, which has 100% low dpf fibers, has a greater water flow rate than the control.

[0096] The higher dpf fibers from the control are approximately 10 times larger by weight and also have larger diameters and volumes. Consequently, these larger fibers (i.e., >100 dpf) have larger spaces between the fibers, resulting in higher flow rates through the material. Fabric 99A of the present invention, which has 100% low dpf fibers, preferably between 2 and 18 dpf, still has a greater water flow rate in the resulting composite, as shown in Table 9 below.

[0097] Table 9: Water flow

[0098]

[0099] Various embodiments of the present invention are described herein with reference to the accompanying drawings. Without departing from the scope of the present invention, alternative embodiments may be designed. Although various connections and positional relationships (e.g., above, below, adjacent, etc.) between elements are described in the following description and the accompanying drawings, it will be appreciated by those skilled in the art that many positional relationships described herein are orientation-independent when the described functions are maintained even when the orientation changes. Unless otherwise indicated, these connections and / or positional relationships may be direct or indirect, and the present invention is not intended to limit this aspect. Therefore, the coupling of entities may refer to direct or indirect coupling, and the positional relationship between entities may be direct or indirect positional relationship. As an example of an indirect positional relationship, the present specification mentions that forming layer "A" on layer "B" includes a situation in which one or more intermediate layers (e.g., layer "C") are located between layer "A" and layer "B", as long as the relevant characteristics and functions of layer "A" and layer "B" do not substantially change due to the intermediate layer.

[0100] The following definitions and abbreviations are used to interpret the claims and description. As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," "contains," or "containing" or any other variations thereof are intended to cover a non-exclusive inclusion. For example, a composition, mixture, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, mixture, process, method, article, or apparatus.

[0101] Additionally, the term "exemplary" is used herein to mean "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 any integer greater than or equal to one, i.e., one, two, three, four, etc. The term "plurality" is understood to include any integer greater than or equal to two, i.e., two, three, four, five, etc. The term "connected" may include both indirect and direct connections.

[0102] References in the specification to "one embodiment," "an embodiment," "an example embodiment," etc., indicate that the described embodiment may include a particular feature, structure, or characteristic, but each embodiment may or may not include the particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is considered within the knowledge of those skilled in the art to implement such feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described.

[0103] For the purposes of the description below, the terms "upper," "lower," "right," "left," "vertical," "horizontal," "top," "bottom," and their derivatives shall refer to the described structures and methods as oriented in the accompanying drawings. The terms "overlying," "on top," "located on top," "located on top of," or "located on top of" mean that a first element (such as a first structure) is present on a second element (such as a second structure), wherein intermediate elements (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 any intermediate conductive layer, insulating layer, or semiconducting layer at the interface of the two elements.

[0104] The terms "about," "substantially," "approximately," and variations thereof are intended to include the degree of error associated with measurement of a particular quantity based on the equipment available at the time this application is filed. For example, "about" may include a range of ±8%, 5%, or 2% of a given value.

[0105] The flow charts and block diagrams in the accompanying drawings illustrate possible implementations of manufacturing and / or operating methods according to various embodiments of the present invention. The various functions / operations of the method are represented by blocks in the flow charts. In some alternative implementations, the functions marked in the blocks may not occur in the order marked in the figures. For example, two blocks shown in succession may actually be performed substantially simultaneously, or these blocks may sometimes be performed in reverse order, depending on the functions involved.

[0106] The corresponding structures, materials, actions, and equivalents of all means or step plus function elements in the appended claims are intended to include any structure, material, or action for performing the function in combination with other claimed elements specifically claimed. The description of the present invention has been presented for the purposes of illustration and description, but is not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiments are selected and described in order to best explain the principles of the invention and practical application, and to enable others of ordinary skill in the art to understand the various embodiments of the invention with various modifications suitable for the intended specific use.

[0107] While the preferred embodiment of the invention has been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the appended claims. These claims should be construed to maintain the proper protection for the invention first described.

Claims

1. A composite geosynthetic fabric comprising: weaving fabrics; 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 per filament of about 2 to about 18; wherein a portion of the plurality of fibers of the nonwoven fabric extends through the woven fabric and is fused together on a side of the woven fabric opposite the nonwoven side of the woven fabric. 2 . The composite geosynthetic fabric according to claim 1 , wherein the composite geosynthetic fabric is a bicomponent composite fabric having only the woven fabric and the nonwoven fabric.

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

4. The composite geosynthetic fabric of claim 1 , wherein the nonwoven fabric has a basis weight of about 12 to about 32 ounces per square yard.

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

6. The composite geosynthetic fabric of claim 1, wherein the composite geosynthetic fabric has a basis weight of about 25 to about 40 ounces per square yard.

7. The composite geosynthetic fabric of claim 1, wherein the composite geosynthetic fabric has a UV retention of at least 90% after 1,000 hours of UV exposure as measured by ASTM D 4355 test method.

8. The composite geosynthetic fabric of claim 1, wherein the composite geosynthetic fabric has a biaxial adhesion strength of about 20 lbs / inch to about 50 lbs / inch as measured by the ASTM 6496 Peel Adhesion test method.

9. The composite geosynthetic fabric of claim 1, wherein the composite geosynthetic fabric has a biaxial wide width tensile strength of at least 300 lbs / in in both the machine direction and the cross-machine direction as measured by ASTM D 4595 test method.

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

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

12. A method for manufacturing a composite geosynthetic fabric, the method comprising: providing a preformed nonwoven fabric comprising a plurality of fibers, each fiber having a denier per filament of about 2 to about 18; adhering the woven fabric to the preformed nonwoven fabric by pushing 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; as well as The portions of the plurality of fibers extending from the face of the woven fabric are fused.

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

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

15. 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 punctures per square inch (ppsi).

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

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

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

19. The method of claim 12, wherein pushing 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. The method of claim 12, wherein the composite geosynthetic fabric is a bicomponent composite fabric having only the woven fabric and the preformed nonwoven fabric.

21. The method of claim 12, wherein the preformed nonwoven fabric is a freestanding fabric.

22. The method of claim 12, wherein the preformed nonwoven fabric has a basis weight of about 12 to about 32 ounces per square yard.

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

24. The method of claim 12, wherein the composite geosynthetic fabric has a basis weight of about 25 to about 40 ounces per square yard.

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

26. The method of claim 12, wherein the composite geosynthetic fabric has a biaxial adhesion strength of about 20 lbs / inch to about 50 lbs / inch as measured by the ASTM 6496 Peel Adhesion test method.

27. The method of claim 12, wherein the composite geosynthetic fabric has a biaxial wide width tensile strength of at least 300 lbs / in in both the machine direction and the cross-machine direction as measured by ASTM D 4595 test method.

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

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

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