The present invention relates generally to the field of woven geotextiles, and more particularly to water-permeable ground-covering geotextile fabrics used as underlayments for roadways.
Geotextile fabrics are commonly installed over the ground, to provide soil reinforcement and/or stabilization so less gravel is needed for this, before laying down covering layers. Such geotextile fabrics are used for example in road construction as underlayments over which are laid down roadway surfaces such as asphalt, concrete, gravel, dirt, or aggregate. Conventional geotextile roadway underlayment fabrics generally include a flat warp fiber across the entire width of the fabric in conjunction with a fibrillated weft fiber. While such existing geotextile underlayments provide some benefits in soil reinforcement and/or stabilization, and generally provide the coverage necessary for filtration (to keep sediment from passing through), there remain areas for improvements.
For example, conventional geotextile underlayments limit the amount of water that can pass through them, which tends to cause rainwater to sheet off to the roadway edges and cause erosion issues, or to simply pool on the roadway surface. And in applications in which the roadway is temporary, such as for roads on farmland temporarily used in the extraction of oil and gas, it can be difficult to locate the geotextile underlayments so they can be removed, and sometimes they are missed and left behind intact where they can cause damage during subsequent use of the land, such as damage to farm equipment when the land is next farmed.
Accordingly, it can be seen that needs exist for improvements in geotextile underlayments to provide for increased water pass-through drainage and increased ease of locating them for removal. It is to the provision of solutions meeting these and/or other needs that the present invention is primarily directed.
Generally speaking, the present invention relates to a water-permeable ground-covering woven geotextile fabric for providing soil reinforcement and/or stabilization, for example as an underlayment in road construction, that utilizes a series of round warp fibers, in combination with a series of flat warp fibers, across the width of the fabric to increase water flow while still providing desired filtration. In particular, the round warp fibers form angles that allow greater amounts of water to pass through the fabric. In addition, using both round and flat warp fibers results in increased roughness of the fabric surface, which makes the fabric more resistant to being pulled out of the soil. Furthermore, one or more of the round and/or flat warp fibers can include a color selected for high visibility to the human eye in daylight conditions.
These and other aspects, features, and advantages of the invention will be understood with reference to the drawing figures and detailed description herein, and will be realized by means of the various elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following brief description of the drawings and detailed description of the example embodiments are explanatory of representative and example embodiments of the invention, and are not restrictive of the invention, as claimed.
The present invention may be understood more readily by reference to the following detailed description of example embodiments taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions, or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be unnecessarily limiting of the invention as claimed. Any and all patents and other publications identified in this specification are incorporated by reference as though fully set forth herein.
Also, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” one particular value and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment.
With reference now to the drawing figures, wherein like reference numbers represent corresponding parts throughout the several views,
The geotextile fabric 10 is made or formed (e.g., cut) into sheets 12 that can be sized for a given use or application. For example, for typical applications the geotextile fabric 10 is provided in sheets 12 that are about 12 feet to about 18 feet wide, about 150 feet to about 900 feet long, rolled around a tube for compact storage until ready for use, and unrolled and cut to size for use.
The geotextile fabric 10 is woven from weft fibers 14 (arranged generally parallel in a weft direction) and transverse warp fibers 16a and 16b (collectively, the warp fibers 16)(arranged generally parallel in a warp direction), for example using conventional weaving techniques and equipment, and as such suitable weaving techniques and equipment are not detailed herein for brevity. The fibers 14 and 16 used to make the geotextile fabric 10 can be made of a conventional material known in the art, for example polypropylene monofilaments with UV stabilization, and as such suitable fiber materials are not detailed herein for brevity. The term “fibers” is intended to be broadly construed to include threads, yarns, tapes, and the like.
The weft fibers (aka the filling fibers) 14 can be of a conventional shape, size, and spacing. For example, the weft fibers 14 are typically flat (i.e., rectangular cross-sectionally and lying flat in the plane of the geotextile fabric sheet 12, see
At least some of the warp fibers 16 can be of a conventional shape, size, and spacing. For example, first warp fibers 16a are typically flat (i.e., rectangular cross-sectionally and lying flat in the plane of the geotextile fabric sheet 12, see
In a typical commercial embodiment, for example, the warp fibers 16a are flat, about 0.008-inch thick by about 0.033 inch wide, and about 1350 denier, with 34 warp fibers per inch in a slightly overlapping arrangement (e.g., see
A conventional geotextile product including such flat weft and flat warp fibers is commercially available under the designation G4×6 from Lumite, Inc. (Alto, Ga.). As such, further specifics of these elements will not be detailed herein for brevity.
In the present invention, however, not all of the warp fibers 16 are flat. Instead, the first warp fibers 16 a are flat and conventional, and second warp fibers 16 b are round. As used herein, the term “round” does not necessarily mean strictly circular in cross-section (i.e. cylindrical), but also includes elliptical or oval (or in some embodiments even extruded polygonal with at least five sides) in cross-section (and thus more accurately means “generally rounded”).
The round warp fibers 16b can be of a conventional shape, size, and spacing. For example, the warp fibers 16b are typically round (e.g., elliptical and lying generally flat with their major axis in the plane of the geotextile fabric sheet 12, see
Typically, the geotextile fabric 10 is formed with the sizes and spacings of the weft and warp fibers 14 and 16 selected for providing a sufficiently loose weave pattern to provide for sufficient flexibility of the fabric in the uses contemplated herein. This enables the use of more material in the cross-machine (weft) direction, which in turn results in the geotextile fabric 10 having a high strength such that it can resist the loads from heavy construction equipment in roadway applications.
In the depicted embodiment, the geotextile fabric 10 is formed by a generally planar serial arrangement of two flat warp fibers 16a, then two round warp fibers 16b, then two flat warp fibers 16a, then two round warp fibers 16b, and so on in a repeating fashion, as shown in
As shown in
Each weft fiber 14 is woven in an offset manner (offset by one warp-fiber space 20) relative to each adjacent parallel weft fiber. So going further with the specific example described in the preceding paragraph and as shown in
Accordingly, typically half of the warp fibers 16 are flat and the other half are round in a pattern that is nicely balanced. This tends to make it easier to get the fiber tensions correct and thus makes it easier to manufacture the geotextile fabric 10. This also tends to facilitate advantageous water-drainage features, as described in detail below. In alternative embodiments, the geotextile fabric is formed by an arrangement of alternating flat and round warp fibers (one of each in an alternating pattern, instead of two of each in an alternating pattern), of more than two flat warp fibers adjacent each other, and/or of more than two round warp fibers adjacent each other, while still in a balanced pattern.
In any event, the geotextile fabric 10 includes at least some round warp fibers 16a intermixed (preferably in a regular repeating manner) with the flat warp fibers 16a and extending across the width of the fabric so that there are adjacent round and flat warp fibers. Referring particularly to
In addition, including the round warps fibers 16b increases the edge-to-edge drain space 20 between the warp fibers while using the same number and center-to-center spacing of warp fibers. The strength of the fabric 10 can be maintained by using round warp fibers 16b having substantially the same mass and strength as the flat warp fiber 16a. But the round warp fibers 16b have a narrower cross-sectional width relative to the flat warp fibers 16a of the same mass and strength. Because the round warp fibers 16b have a smaller width (in the horizontal plane of the fabric sheet 12), when they are arranged with the same center-to-center spacing as the flat warp fibers 16a, the resulting non-matched/non-symmetrical warp-fiber spacings 20 as well as the resulting matched/symmetrical round-round warp-fiber spacings 20 are increased (relative to the matched/symmetrical flat-flat warp-fiber spacings 20. These increased warp-fiber spacings 20 provide for even greater water drainage through the geotextile fabric 10.
In the depicted embodiment, the flat warp fibers 16a have a larger width than the round warp fibers 16b, but the flat warp fibers have a smaller thickness (height) than the round warp fibers. So where the weft fibers 14 traverse between adjacent shorter/flat and taller/round warp fibers 16a and 16b, they are angled up or down and thus spaced above or below the top or bottom surface of the flat warp fiber 16a. This results in a weft clearance space 22 (above or below the top or bottom surface of the flat warp fiber 16a) at locations where the weft fibers 14 cross adjacent flat and round warp fibers 16a and 16b (see
It should be noted that in
In addition, because the inclusion of the round warp fibers 16b mixed in with the flat warp fibers 16a produces the unevenness of the top and bottom surfaces of the fabric 10, the angled drain openings 18 tend to trap soil in them. This results in a roughness of the fabric top and bottom surfaces such that the fabric is more resistant to being pulled out of the soil (especially when pulled generally parallel to the soil for example when accidentally caught or snapped by equipment). This retention feature helps keep the geotextile fabric 10 in place during use.
Furthermore, in the depicted embodiment, some of the fibers 14 and 16 have a color selected for high visibility to the naked human eye in daylight and lowlight conditions. For example, the round warp fibers 16b can be a bright yellow (e.g., using a conventional method of blending color/dye into fiber during fiber extrusion), or another color for high visibility and/or sharp contrast with the flat warp fibers 16a and/or with the weft fibers 14 (e.g., which can be provided for example in a black or other contrasting color). In the depicted embodiment, the high-visibility round warp fibers 16b are indicated by hatching in
The typical commercial embodiment of the geotextile fabric 10 as depicted and described herein has been tested and proven to provide strength and water-flow benefits. Ranges of this typical fabric 10 are listed below in Table 1.
Additional details of the manufacture of example embodiments of the geotextile fabric 10 include the weave pattern and the harness draw, showing how the harnesses work to weave in the pattern. Details of a sample weave pattern are provided in Table 2.
And details of a sample harness draw graph are provided in
In other embodiments, the geotextile fabric includes some round weft fibers mixed in with some flat weft fibers and extending along the length of the fabric sheet. And in still other embodiments, the geotextile fabric includes some round weft fibers mixed in with some flat weft fibers and extending along the length of the fabric sheet and also some round warp fibers mixed in with some flat warp fibers and extending across the width of the fabric sheet.
In the depicted embodiment, the warp fibers 16 are provided in spaced pairs of like type (i.e., a flat pair or a round pair), with a flat warp fiber 16a pair, then a round warp fiber 16b pair, then a next flat warp fiber 16a pair, then a next round warp fiber 16b pair, and so on, with a warp-fiber space 20 between each warp fiber. In other embodiments, the warp fibers are provided in rows of three or more spaced fibers of like type, or arranged with individual alternating flat and round fibers, with a flat warp fiber row, then a round warp fiber row, then another flat warp fiber row, then another round warp fiber row, and so on, with a warp-fiber space between each warp fiber. As such, as used herein reference to a “fiber row” includes a pair of parallel adjacent spaced fibers, more than two such spaced fibers, or a single fiber.
In the depicted embodiment, the warp fibers 16 are woven through every other one of the spaces between adjacent weft fiber 14 pairs. In other embodiments, the warp fibers are woven through each/every one of the spaces between adjacent weft fiber pairs, through every third or more of the spaces, or through similarly selected spaces between individual weft fibers (not paired). For example, in an embodiment in which each warp fiber set includes three warp fibers of like type, the weft fibers can be woven through every warp-fiber space, through every other warp-fiber space, through every third warp-fiber space, etc. Similarly, in an embodiment in which each warp fiber set includes a single warp fiber (flat or round), the weft fibers can be woven through every warp-fiber space, through every other warp-fiber space, through every third warp-fiber space, etc.
In the depicted embodiment, the weft fibers 14 are arranged in pairs immediately adjacent to each other (see
In another aspect, the invention relates to a roadway including the geotextile fabric 10 positioned over soil and a roadway surface (e.g., gravel, asphalt, concrete, and/or dirt) positioned over the fabric. And in another aspect, the invention relates to a method of installing a roadway, including installing the geotextile fabric over soil and then installing a roadway surface over the fabric.
While the invention has been described with reference to preferred and example embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions are within the scope of the invention, as defined by the following claims.
Number | Date | Country | Kind |
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2912108 | Nov 2015 | CA | national |
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/169,043 filed Jun. 1, 2015, the entirety of which is hereby incorporated herein by reference for all purposes.
Number | Date | Country | |
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62169043 | Jun 2015 | US |