Patent Application
20130092281
The present invention relates generally to the fields of woven materials and turf management, and more particularly to a method of manufacturing fabrics for the reinforcement of natural turf.
According to the U.S. Environmental Protection Agency (EPA), high volume and high velocity storm water runoff can erode soil within the open channels, drainage ditches, and swales, and on steep exposed slopes, increasing the transport of sediments into receiving orders. Water quality impacts of increased sediment load include the conveyance of nutrient and pesticide pollutants, disruption of fish spawning, and impairment of aquatic habitat.
Traditionally, hard armor erosion control techniques such as concrete blocks, rock rip rap, and reinforced paving systems have been employed to prevent soil erosion in these highly erosive areas. Although these measures can withstand great hydraulic forces, they are costly, and they do not provide the pollutant removal capabilities of vegetative systems.
Turf reinforcement mats (TRMs) enhance the natural ability of vegetation to permanently protect soil from erosion. TRMs are composed of interwoven layers of non-degradable geo-synthetic materials such as polypropylene, nylon and polyvinyl chloride netting, stitched together to form a three-dimensional matrix. They are thick and porous enough to allow for soil filling and retention. In addition to providing its scour protection, the mesh netting of TRMs is designed to enhance vegetative root and stem development. By protecting the soil from scouring forces and enhancing vegetative growth, TRMs raise the threshold of natural vegetation to withstand higher hydraulic forces on stabilization slopes, stream banks, and channels. In addition to reducing flow velocities, the use of natural vegetation provides particulate contaminant removal through sedimentation and soil infiltration, and improves the aesthetics of the site.
TRMs offer high shear strength, resistance to ultraviolet degradation, and resistance to chemicals found in soils. TRMs, unlike temporary erosion control products, are designed to stay in place permanently to protect seeds in soils and to improve germination. TRMs can incorporate natural fiber materials to assist in establishing vegetation. However, the permanent reinforcement structure of TRMs is composed of entirely non-degradable synthetic materials. A variety of ground anchoring devices can be used to secure TRMs, including: U-shaped wire staples, metal pins, and wood or plastic stakes. Appropriate ground anchoring devices are chosen based on site-specific soil and slope conditions.
The use of TRMs allows vegetative cover to be extended to areas where site conditions would otherwise limit it. This helps to establish and maintain a continuous vegetative cover throughout the applied area. TRMs can be applied to most sites or structures where permanent erosion control is required. This technology has been effectively used in both urban and rural areas and in a variety of climactic conditions. Although most effective when used in fully vegetative areas, TRMs have been used to prevent erosion even in arid, semi-arid, and high altitude regions with limited vegetative growth. In these areas, vegetation establishment is slow or difficult, and the TRM matrix is typically filled with native soils for protection.
TRMs are being used to control erosion and stabilize soil to control runoff from land disturbing activities with steep slopes, and to prevent scouring in storm water detention ponds, water storage ponds, small open channels, drainage ditches, and runoff conveyance systems within the parking lot medians, and along stream banks and shorelines.
In addition to their use for new construction projects, TRMs have been used to retrofit existing hard armor systems. In addition to improving water quality, TRMs can provide aesthetic enhancement, especially in areas lacking vegetative growth.
TRMs provide water quality benefits by allowing the growth of vegetation in areas where impervious conveyance systems would otherwise be used. In general, the performance of TRMs is closely tied to the vegetative establishment and growth. The performance of the TRM-lined conveyance system depends on the duration of the runoff event to which it is subjected.
Known TRM materials are woven in a pattern that when exposed to heat, creates a loft or three-dimensional structure. In some instances, the loft must meet a minimum thickness specification (for example, 0.25 inch) in order to be considered a TRM. The energy required for heating the material, as well as the additional equipment required for carrying out the heating process, add considerably to the expense of the product. Also, the material typically shrinks in the lengthwise and widthwise dimensions as the fibers contract during heat-treatment process to create the loft. Thus, a loom width wider than the desired final product width is typically required.
Known TRM materials also typically include a single fiber or end at the peak and valley points of the weave pattern, and provide inadequate compression resistance for some applications.
It is to the provision of an improved TRM product and manufacturing process that the present invention is primarily directed.
In example embodiments, the present invention provides a turf reinforcement mat and a method of manufacturing a turf reinforcement mat without the need for the application of heat. The particular weave pattern, tension and materials used in fabricating the material create a three-dimensional product. In example embodiments, the turf reinforcement mat has, for example, a 0.25 inch or greater loft/thickness.
In one aspect, the present invention relates to a three-dimensional turf-reinforcement fabric. The three-dimensional turf-reinforcement fabric includes a woven array of fibers comprising a first plurality of fibers arranged in a first direction and a second plurality of fibers arranged in a second direction generally perpendicular to the first direction. The woven array of fibers defines rows and columns of cells, wherein each cell comprises fiber segments of the first plurality of fibers and the second plurality of fibers being spaced at differing heights in a third direction perpendicular to the first and second directions. The three-dimensional turf-reinforcement fabric is formed without the application of heat to shrink the fibers and produce a loft.
In another aspect, the invention relates to a method of forming a three-dimensional turf-reinforcement fabric. The method includes weaving a first plurality of fibers arranged in a first direction and a second plurality of fibers arranged in a second direction generally perpendicular to the first direction into a woven array having fiber segments being spaced at differing heights in a third direction perpendicular to the first and second directions, without the application of heat to produce a loft.
In another aspect, the invention relates to a turf reinforcement mat including a weave formed of a plurality of warp fibers, a plurality of weft fibers extending generally crosswise to the warp fibers, and defining a loft thickness of at least about 0.25″, wherein the loft thickness is produced without heat treatment.
In another aspect, the invention relates to a three-dimensional turf-reinforcement fabric comprising a woven array of fibers comprising a first plurality of fibers arranged in a first direction and a second plurality of fibers arranged in a second direction generally perpendicular to the first direction. The second plurality of fibers are interwoven with the first plurality of fibers to form an interlaced weave, and the woven array of fibers defines rows and columns of cells, wherein each cell comprises fiber segments of the first plurality of fibers and the second plurality of fibers being spaced at differing heights in a third direction perpendicular to the first and second directions to define crests within the woven array. At least one of the first plurality of fibers proximal at least one of the crests has an increased diameter relative to the remainder of the first plurality of fibers.
In still another aspect, the invention relates to a three-dimensional turf-reinforcement fabric comprising a woven array of fibers comprising a first plurality of warp fibers arranged in a first direction and a second plurality of weft fibers arranged in a second direction generally perpendicular to the first direction. The second plurality of weft fibers are interwoven with the first plurality of warp fibers to form an interlaced weave of warp and weft fibers, and the woven array of fibers defines rows and columns of cells, wherein each cell comprises fiber segments of the first plurality of fibers and the second plurality of fibers being spaced at differing heights in a third direction perpendicular to the first and second directions and defining a material loft. The three-dimensional turf-reinforcement fabric is formed without the application of heat to produce the loft. The three-dimensional turf-reinforcement fabric further comprises a flame retardant.
In another aspect, the invention relates to a three-dimensional turf-reinforcement fabric comprising a woven array of fibers comprising a first plurality of warp fibers arranged in a first direction and a second plurality of weft fibers arranged in a second direction generally perpendicular to the first direction. The second plurality of weft fibers are interwoven with the first plurality of warp fibers to form an interlaced weave of warp and weft fibers, and the woven array of fibers defines rows and columns of cells, wherein each cell comprises fiber segments of the first plurality of fibers and the second plurality of fibers being spaced at differing heights in a third direction perpendicular to the first and second directions and defining a material loft. The three-dimensional turf-reinforcement fabric is formed without the application of heat to produce the loft. The three-dimensional turf-reinforcement fabric further comprises a UV stabilizer.
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 invention are exemplary and explanatory of preferred 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 the invention 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 limiting of the claimed invention. 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 including 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” or “approximately” one particular value and/or to “about” or “approximately” 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.
In an example form, a manufacturing process according to the present invention creates a turf reinforcement mat or three-dimensional geotextile fabric without the need for the application of heat during the manufacturing process, to produce a woven material having a three-dimensional lofted profile. For example, by selective application of tension in the weaving process and/or control of the weave and fiber arrangement of the product, it has been discovered that a three-dimensional lofted profile can be formed, without the need for application of heat to generate the material's loft. In example embodiments, the material has a thickness or loft of about 0.25 inch or more.
Various types of natural and synthetic yarns can be used to weave the turf reinforcement mat of the present invention, including but not limited to polyethylene, nylon, polyester, PVC, polypropylene, etc. In an example embodiment, the yarn is polypropylene. A monofilament, multi-filament, fibrillated tape or slit tape yarn in various yarn sizes, for example from 400 denier to 3000 denier, can be used to produce a turf reinforcement mat according to the present invention. In an example embodiment, a monofilament having a yarn size of 1675 denier is utilized. The denier of the yarn and the draw ratio used in extruding the yarn provide rigidity to retain loft thickness. An example range of draw ratio is between about 5:0:1 to about 9:0:1 and the value depends upon the yarn denier and required strength. A particular example draw ratio used is 6:0:1. The yarn can be UV stabilized during manufacturing. Coloring is optionally added to the yarn during the extrusion process.
Beams can be made with either direct or sectional warping machines. The number of beam ends is determined by the width of the fabric in conjunction with the machine direction construction on the final fabric. Machine direction construction is determined by the reed that will be used on the loom in the weaving process. The beaming process can be eliminated if a creel is available to be placed behind the loom and weave directly off the yarn packages.
Different weave patterns can be generated on a loom to weave a turf reinforcement mat within the scope of the invention. One example of a weave used is a honeycomb pattern, for example as shown in
In the example embodiment, the loom setting has a worm gear let-off range of either 3:38 or 2:39 which can be based on the type of mechanical or electronic let-off used on the loom. In conjunction with projectile looms the whip roll setting is in the front position. An example honeycomb weave can be woven on a range of between about 8 and 18 harnesses. The example embodiment honeycomb is woven on 14 harnesses.
Each box shaped cell 12 is created by weaving warp (machine direction) 20 and weft or fill (cross-machine direction) 22 filaments in a perpendicular weave pattern and manner with respect to each other. At the peaks and valleys 16 of each box shaped cell 12, a plurality of fill filaments 22 are set on top of a central warp filament 20 in perpendicular or crosswise relation with respect to each other, forming alternating upper and lower crests (e.g., ridges and valleys in at least one of the warp and/or weft filament patterns) in the machine and cross-machine directions. Provision of a plurality of fill filaments 26 at the crests provides increased resistance to compression of the material in use. In the depicted embodiment, three crest filaments 26 are utilized, but in alternate embodiments, one, two or more than three crest filaments are provided. Also, while the depicted embodiment provides multiple crest filaments 26 in the fill direction, alternate embodiments may comprise multiple crest filaments in the warp direction or in both the warp and fill directions at the peak and/or valley boundaries of each cell 12 of the turf reinforcement material 10. Two horizontal filaments are then set on top of the vertical filament on either side of the central horizontal filament and each parallel to the central horizontal filament. Two vertical filaments are then set on top of the horizontal filaments on either side of the central horizontal filaments and parallel to the central horizontal filament. This process is repeated with further horizontal filaments extending further from, and parallel to, the central horizontal filament and with further vertical filaments extending further from, and parallel to, the central vertical filament, until the height 24 from the center 16 to each corner is at least about 0.25 inches as shown in
In the example embodiment, each filament has the same tensioning level and warp level, and the same yarn stiffness and denier. In alternate embodiments, varying tensioning, warp level and/or yarn characteristics are within the scope of the invention. The harness operation is preferably automatically controlled, for example by electronic or punch card programming.
In further example embodiments, a flame retardant material optionally can be incorporated into the fabric. Preferably, the treated fabric can pass the NFPA (i.e., National Fire Protection Association) 701 testing procedure and still meet an 80% tensile retention at at least about 2500 hours, or more preferably at about 3000 hours, per ASTM D4355 xenon arc UV exposure (a test by the American Society for Testing and Materials that covers the determination of the deterioration in tensile strength of geotextiles by exposure to xenon arc radiation, moisture, and heat), and meet a strength specification, for example, of 4000 lbs.×3000 lbs. Alternatively or additionally, the treated material meets the requirements of one or more flame retardant testing standards such as for example Federal MIL STD 191A Method 5903.1 Vertical flame test; NFPA 701 Vertical Flame Test; and/or ASTM D6413 Vertical Flame Test of Textiles (Test Method D6413 has been adopted from Federal Test Standard No. 191A method 5903.1). In one form, a brominated flame retardant (i.e., organobromide compounds) is added to the yarn during the extrusion process. For example, in example embodiments, about 3-9% of the fibers' material content comprises the flame retardant. In alternate embodiments, other flame retardant additives may be incorporated, in greater or lesser percentage of fiber content, such as for example a combination flame retardant and hindered amine light stabilizer (HALS) such as BASF Flamestab™ NOR 116 (a monomeric N-alkoxy hindered amine), or a bromine-based flame retardant, optionally in combination with a HALS UV stabilizer.
In further embodiments, the material additionally or alternatively comprises a UV (ultraviolet) stabilizer to provide the mat with resistance to UV degradation from sunlight exposure. For example, some or all of the fibers of the mat can be extruded from a polypropylene base material and include a carbon black additive having a particle size of about 19 nanometers. Alternatively or additionally, a hindered amine light stabilizer (HALS) may be used for UV stabilization.
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.
This application is a continuation-in-part of U.S. Non-Provisional patent application Ser. No. 12/845,234 filed Jul. 28, 2010, which in turn claims priority benefit to U.S. Provisional Patent Application Ser. No. 61/229,962 filed Jul. 30, 2009, which applications are hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61229962 | Jul 2009 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12845234 | Jul 2010 | US |
| Child | 13693574 | US |
