Tufted nonwoven low mass high frictional interface ground cover

Abstract

A ground cover of an elongated nonwoven matting of a plurality of fibers defining open voids throughout the matting and tufted with a plurality of spaced-apart tufts as simulated blades of grass, the space-apart fibers and open voids having a respective lower asperity extent defining a frictional contact interface surface, and overlying a surface and receiving a granular infill in the interstices and at lease some of the voids, for reducing infill migration and the frictional contact interface surface resists slippage movement of the ground cover relative to the ground surface.

Description

TUFTED NONWOVEN LOW MASSHIGH FRICTIONAL INTERFACE GROUND COVERTechnical Field

[0001] The present invention relates to cover systems for covering land sites, waste disposal sites, and other environmental closures. More particularly, the present invention relates to improved cover systems for reduced cover system costs while enhancing operational performance features for increased ground cover service life.Background Of The Invention

[0001] Large-area landfills and waste sites typically remain open for a number of years for receiving waste materials, mining spoils or power plant wastes and ash, landfill trash and municipal solids and liquids wastes. Such waste sites typically have elevational slopes rising from a toe or base to an upper elevated upper deposit surface at an apex or peak as the additional deposits of waste materials are placed over previously deposited materials in the landfill. The elevation of landfills may typically reach several hundred feet above the toe with accumulated deposits of waste fill materials. While steep slopes allow geometrically increased storage volume, slopes and particularly steep slopes experience significantly high shear forces. These shear forces occur in response to the waste fill materials loaded within a vertical portion of the area allocated for the landfill and also arise from dry shear (wind) and hydraulic shear (ambient precipitation and water flow such as from rainfall on the waste site) from high volumes of water flowing downwardly over the ground cover. Steep slopes often experience large hydraulic shear forces from rapid water flow run-off.4898-1981-295 Ivl2171320-00018008 / 11 / 2025

[0002] When a portion of the landfill approaches capacity, other areas are opened for depositing of water material. The portion however may be overlaid with a short-term cap. Also, upon reaching an appropriate capacity for the particular site, the site is closed to receiving additional waste materials. Closure involves overlaying the site with a ground cover. In some prior instances, the ground cover comprises an overburden of soil covering. However, such soil covering has drawbacks, and in recent years, synthetic ground covers have been used for both short-term and long-term closures. A synthetic ground cover comprises panels of tufted geosynthetic sheets made of a backing and spaced-apart tufts of yam extending as simulated blades of grass. The blades shade the backing but often the tufted geosynthetic ground cover includes an infill distribution of sand (or particles) that fill-in the interstices between the tufts and the backing as a covering layer to block UV light from reaching the backing. The backing typically is made from a woven polypropylene material that has a lower tolerance to UV degradation that the tufts that are typically made from polyethylene yarns. UV light degrades the polypropylene backing and may lead to ground cover failure with tears or rips in the backing. Ground cover design and installation needs to consider cover stability and integrity during the closure period.

[0003] For example, the ground cover during operational use experiences a thermodynamic loading arising from daily thermal expansion and contraction as well as shear loading forces. The thermodynamics in operational use causes movement of the closure system relative to the ground, and over time, the ground cover forms wavey portions having ripples (heights of about 16 inch or less), wrinkles (higher upstanding folding of portions with heights of U inch to 1 inch), or bunching as compactions of tight folds or groups of multiple or enlarged wrinkles.

[0004] The dry and hydraulic shear forces proximate the ripples and wrinkles cause migration of the covering infill sand that shields the backing from UV. Migration of the infill develops4898-1981-2951vl2171320-00018008 / 11 / 2025openings between the tufts that exposes the backing of the ground cover to UV light. It has been found that landsites covered with tufted geosynthetic ground covers develop a number of small areas of exposed underlying textiles (backing). It is exceptionally impractical to eliminate ripples and wrinkles and thus over time more areas of the tufted geosynthetic ground cover are exposed to degradation from UV.

[0005] While synthetic grass cover systems have been long used for ground cover closures, there is a need in the trade for a lower-cost ground cover system but featuring a high-friction interface surface for securing the cover system to a surface for ground covering purposes with improved resistance to downslope slippage and increased retention of granular infill for ambient environmental water flow filtering and UV protection, for increased service life during long term ground covering purposes. It is to such that the present invention is directed.Summary of the Invention

[0006] The present invention meets a need in the art for an improved ground cover that has a lower manufacturing cost yet features a high-friction interface surface for securing the cover system to a surface for ground covering purposes. The present invention provides a ground cover of an elongated nonwoven matting of a plurality of fibers and having opposing upper and lower asperity extents, said plurality of fibers defining open voids among the plurality of fibers throughout the matting between the opposing upper and lower asperity extents, which said lower asperity extents of the spaced-apart fibers and open voids defining a frictional contact interface surface. The nonwoven matting receives a plurality of spaced-apart tuft rows, each tuft row formed in the matting of a synthetic yarn and defining a plurality of spaced-apart tufts extending from the upper asperity extents as simulated blades of grass and a plurality of interstices between the4898-1981-2951vl2171320-00018008 / 11 / 2025adjacent tufts. A granular infill is received in the interstices and at least some of the voids of matting. The ground cover, being overlaid on a surface and receiving the granular infill, covers a ground surface while reducing infill migration and the frictional contact interface surface resists slippage movement of the ground cover relative to the ground surface.

[0007] In another aspect, the present invention provides a ground cover of an elongated nonwoven matting of a plurality of fibers and having opposing upper and lower extents, said plurality of fibers defining open voids among the plurality of fibers throughout the matting between the opposing upper and lower extents, said lower extents of the spaced-apart fibers and open voids defining a frictional contact interface. The matting is tufted with a plurality of spaced- apart tuft rows, each tuft row formed in the matting of a synthetic yarn and defining a plurality of spaced-apart tufts extending from the upper extents as simulated blades of grass and interstices between the adjacent tufts. A granular infill received in the interstices for overlying the upper extents and a portion received in at least some of the open voids of the matting. The ground cover provides a lower cost low-mass matting with a high-frictional interface for securing to a ground surface for land site covering purposes with resistance to downslope slippage and retention of granular infill for ambient environmental water flow filtering and UV protection with extended service life of ground covering purposes.

[0008] In yet another aspect, the present invention provides a ground cover system for overlying a land site, with a synthetic grass comprising an elongated nonwoven matting of a plurality of fibers randomly disposed and defining a plurality of orifices within the nonwoven matting, said nonwoven matting having opposing upper and lower asperity extents, tufted with a plurality of spaced-apart tuft rows, each tuft row tufted with a synthetic yam to form a plurality of spaced- apart tufts of simulated grass blades extending from the upper asperity extents of the nonwoven 4898-1981-2951vl 2171320-00018008 / 11 / 2025matting, said tufts defining interstices therebetween. A geomembrane for overlying a surface of a land site. The lower asperity extents and the orifices proximate thereto defining a frictional interface between the nonwoven matting and the geomembrane. A granular infill received within the interstices and a portion of the granular infill within at least some of the orifices of the nonwoven matting. The ground cover provides a lower cost low-mass matting with a high- frictional interface securing through the geomembrane to a ground surface for land site covering purposes with resistance to downslope slippage and retention of granular infill for ambient environmental water flow filtering and UV protection with extended service life of ground covering purposes.

[0009] Objects, advantages, and features of the present invention will become apparent upon a reading of the following detailed description in conjunction with reference to the drawings.Brief Description Of The Drawings

[0010] Fig. 1 illustrates in side elevational view a ground cover according to the present invention.

[0011] Fig. 2 illustrates in side elevational view the ground cover illustrated in Fig. 1 with an underlying elongated geomembrane for covering a land site according to the present invention.

[0012] Fig. 3 illustrates in side elevational view the ground cover illustrated in Fig. 1 overlying a surface of a land site according to the present invention.Detailed Description

[0013] With reference to the drawings in which like parts have like identifiers, Fig. 1 illustrates in side elevational view a ground cover 10 according to the present invention for overlying a land4898-1981-2951vl2171320-00018008 / 11 / 2025site such as a land fill, waste containment land site, or other environmental land surface with an ornamentally attractive simulated grass field to reduce site maintenance costs. The ground cover 10 features a low mass ground cover (compared to woven backing tufted geosynthetic ground covers) yet with a high frictional interface between the ground cover and the ground being covered to resist movement thereon during covering use.

[0014] Embodiments of the present invention provide an ornamentally attractive simulated grass field with the nonwoven (low-mass) matting of fibers and open voids therebetween having spaced-apart tufts of simulated grass blades extending from an upper fluctuating-surface defined by the asperity extents of the fibers, for overlying a land fill, waste containment land sites, or other environmental land surfaces, for mitigation of ambient environmental water flow while a high friction interface of a bottom fluctuating-surface of the lower extents of the fibers of the matting resists downslope slippage of the cover system on sloped land surfaces. The term “fluctuating” refers to a non-smooth or variable surface with rising and falling portions. A granular infill received in interstices between the tufts and at least partially in the matting orifices resists migration for improved infill retention that cooperatively with the simulated grass blades reduces UV exposure and thereby increases service life of the ground cover. The cover system moderates flow of ambient environmental water, such as rainfall, across the land site. The matting is permeable and cooperatively with the granular infill moderates flow to facilitate blow ground seepage for water table replenishment. An illustrative alternate embodiment further includes an impermeable geomembrane for flow of ambient environmental water off of the land site to water flow channels and collection sites for remediation and discharge to local waterways, ponds, lakes, or streams.4898-1981-2951vl2171320-00018008 / 11 / 2025

[0015] With continued reference to Fig. 1, the ground cover 10 comprises an elongated nonwoven matting 12 of a plurality of fibers 14 nonwoven in overlapping and interlaced relations. The plurality of fibers 14 define a plurality of voids 20 or open cavities throughout the matting 12. The fibers 14 have asperity extents on opposing sides of the matting 12. The asperity extents of the fibers 14 and voids 20 proximate opposing sides of the matting 12 define opposing upper and lower fluctuating surfaces 16, 18 illustrated generally by dashed lines (and lower surface 18 shown in partial cut-away view). The asperity extents of the lower surface 18 of the spaced-apart fibers 14 and the open voids 20 define a frictional contact interface 22 for engaging a ground surface or other surface. The nonwoven matting 12 is preferably formed with airlaid fibers.

[0016] The nonwoven matting provides a low-mass structure compared to woven backing tufted geosynthetic ground covers. The nonwoven matting 12 has a basis weight from 2 ounces per square yard to about 10 ounces per square yard. An exemplary but not limiting embodiment uses an airlaid nonwoven matting having a basis weight of 4 oz per square yard. Another exemplary but not limiting embodiment uses an airlaid matting with a basis weight of 6 oz per square yard.

[0017] The matting 12 further includes a plurality of spaced-apart tuft rows 24. Each tuft row 24 has a plurality of spaced-part tufts 26. Fig. 1 illustrates in side view a first tuft row 24 without illustrating other of the spaced-apart tuft rows. Each tuft row 24 is formed of a synthetic yam that is tufted with underlying tuft bridges 25 to define the plurality of spaced-apart tufts 26. The tufts 26 extend from the upper surface 16 as simulated blades 28 of grass. The spaced-apart tufts 26 of simulated grass blades 28 have open interstices 30 between the adjacent tufts. The tuft bridge 25 may seat into an edge portion of the matting 12 as illustrated in a left portion of the matting depicted in Fig. 1.4898-1981-2951vl2171320-00018008 / 11 / 2025

[0018] The ground cover 10 further includes a granular infill 36 as best illustrated in Figs. 2 and 3. The interstices 30 receive the granular infill 36 for overlying the upper surface 16. The granular infill 36 and the blades 28 of the tufts 26 shade the matting 12 from UV and thereby resist matting deterioration. Further, at least some of the open voids 20 of the matting 12 receive a portion of the granular infill 36 in at least a boundary portion 37 of the matting 12 proximate the surface 16. The granular infill 36 may fill to a depth interior of the matting 12. The depth varies across the matting 12 based on clumping of infill, infill particle size entering voids 20, blockage of infill such as by fibers below that restrict infill passage, and voids too small to allow infill passage.

[0019] The engagement of the infill 36 in the voids 20 interacts with the infill 36 in the interstices 30 for interlocking the above-surface infill with the interior infill. The infill 36 has reduced lateral migration across the matting 12 relative to the interstices. The retention of infill 36 within the interstices reduces maintenance to replenish gaps and openings in infill 36 on the surface 16 of the matting 12 in response to shear forces of wind and ambient environmental water flow over the ground cover.

[0020] The bottom fluctuating surface 18 develops a frictional interface engagement 38 relative to the ground 50 as shown in Fig. 3. The frictional interface 38 resists movement of the ground cover 10 relative to the ground 50, such as from thermal expansion caused by sun exposure and contraction after sundown and cooling during the night darkness.

[0021] Fig. 2 illustrates in side elevational view the ground cover 10 illustrated in Fig. 1 with an underlying elongated geomembrane 40 for covering a land site 41. The geomembrane 40 comprises a polymeric material impermeable to water flow. The geomembrane 40 in the illustrated embodiment has a field of extending projections 42. In the illustrative embodiment, the4898-1981-2951vl2171320-00018008 / 11 / 2025geomembrane 40 has a first field of projections 42 extending from atop surface and a second field of projections 43 extending from a bottom surface. The geomembrane 40 may have both projections 42 and 43, or in an alternate embodiment have the projections 42 and an opposing planar bottom surface that may be smooth or textured. An alternate embodiment has the projections 43 and an opposing planar top surface that may be smooth or textured. The projections 42, 43 may thus be formed on the top surface, the bottom surface, or both top and bottom surfaces as illustrated.

[0022] The bottom surface 18 and the geomembrane 40 define a drainage component generally 44 with a flow path gap 46 therebetween. The bottom surface 18 of the matting 12 has a frictional interface 48 by contact with the geomembrane 40. The frictional interface 48 resists movement of the ground cover 10 relative to the geomembrane 40, such as from thermal expansion caused by sun exposure and contraction after sundown and cooling during the night darkness.

[0023] The geomembrane in the illustrated embodiment is impermeable, such that ambient water flow seeping through the matting 12 and the infill 36 flow along the flow path 48 of the drainage component 44, such as to collection ponds or treatment facilities. In an alternate embodiment (not illustrated), the geomembrane includes spaced-apart through openings, whereby ambient environmental water flows in the flow path 48 but a volume seeps through the openings below ground such as into below grade water tables for aquifer replenishment.

[0024] The ground cover 10 within a covering system with the geomembrane experiences reduced downslope movement in response to thermal expansion and contraction from daylight and night time temperature changes while resisting infill migration arising from hydraulic or wind shear forces over the ground cover for long term operational life covering a land site while reducing maintenance needs.4898-1981-2951vl2171320-00018008 / 11 / 2025

[0025] Fig. 3 illustrates in side elevational view the ground cover 10 illustrated in Fig. 1 overlying a ground surface 50 of a land site 52. The ground cover 10 moderates ambient environmental water flow across the land site, and with increased dwell, the water flow seeps though the matting 12 and the infill 36 below grade for passage to below ground water tables. The moderated flow reduces migration of the infill. Particularly, the seepage directs infill migration downwardly into and though the orifice voids 20 of the matting 12. The engagement of the infill 36 in the voids 20 interacts with the infill 36 in the interstices 30 for interlocking the above surface infill with the interior infill. The infill 36 has reduced lateral migration relative to the interstices 30. The retention of infill 36 within the interstices 30 reduces maintenance to replenish gaps and openings in infill on the surface 16 of the matting 12.

[0026] The bottom -surface 18 develops the frictional interface engagement 38 relative to the ground 50 as shown in Fig. 3. The frictional interface 38 resists movement of the ground cover 10 relative to the ground 50, such as from thermal expansion caused by sun exposure and contraction after sundown and cooling during the night darkness.

[0027] The cover system of the present invention provides various benefits and features for land covering systems:

[0028] - Lower cost - elongated nonwoven matting rather than woven backing cover systems.Lower basis mass per unit coverage reduces material cost but does not sacrifice resistance to movement slippage relative to the covered surface and reduces infill migration.

[0029] - Bottom surface of the matting provides high interface friction contact with surfaces of ground or geomembrane, for resisting relative downslope slippage in response to thermal expansion and contraction movements.4898-1981-2951vl2171320-00018008 / 11 / 2025

[0030] -Mating fibers define orifices or open voids in the matting, in which an orifice is an opening through which something may pass. The open voids at least partially receive portions of the granular infill and cooperatively interlock with infill received in interstices between adjacent tufts of the simulated grass blades.

[0031] - Matting provided with tufts of simulated grass blades for ornamental appearance of large area land sites

[0032] - Interstices between adjacent tufts

[0033] - Granular infill received in the interstices and at least partially into the voids or orifices of the matting, for interlocking the infill and resisting migration arising from hydraulic or dry flow shear forces

[0034] - Granular infill in the voids inter-engage and interlock with infill in the interstices

[0035] - Matting permeable even with granular infill.

[0036] - Fibers of matting and tufts moderate flow of ambient environmental water across the ground cover

[0037] - Moderated flow of ambient environmental water increases dwell and seepage through the nonwoven matting and infill to the surface below

[0038] - In an illustrative embodiment of the ground cover overlying a ground surface, the moderated seepage flows below grade and into undersurface water tables

[0039] - In an illustrative embodiment of the ground cover and geomembrane system overlying a ground surface, the moderated seepage flows below the matting and along a flow drainage component defined by the matting and the overlaid geomembrane, for flow off of the sloped ground and to water channels for flow to holding ponds, water treatment systems, and discharge to water supplies or below ground water tables.4898-1981-2951vl2171320-00018008 / 11 / 2025

[0040] - Reduced infill migration contributes to increased infill retention and reduced maintenance

[0041] - Increased UV protection as the tufts and the infill shield the matting from UV exposure, and providing an increased system life.

[0042] While the foregoing discloses the invention in illustrative embodiments of a tufted nonwoven ground cover of reduced costs while featuring a high-friction interface surface for securing the cover system to a surface for ground covering purposes with improved resistance to downslope slippage and increased retention of granular infill for ambient environmental water flow filtering and UV protection, for increased service life during long term ground covering purposes, it will be apparent to those skilled in the art that many modifications can be made therein without departing from the invention as defined by the appended claims.4898-1981-2951vl2171320-00018008 / 11 / 2025

Claims

CLAIMSWhat is claimed is:

1. A ground cover, comprising: an elongated nonwoven matting of a plurality of fibers and having opposing upper and lower asperity extents, said plurality of fibers defining open voids among the plurality of fibers throughout the matting between the opposing upper and lower asperity extents; said lower asperity extents of the spaced-apart fibers and open voids defining a frictional contact interface surface; a plurality of spaced-apart tuft rows, each tuft row formed in the matting of a synthetic yarn and defining a plurality of spaced-apart tufts extending from the upper asperity extents as simulated blades of grass and a plurality of interstices between the adjacent tufts; and a granular infill, whereby the ground cover, being overlaid on a surface and receiving the granular infill in the interstices and at least some of the voids, covers a ground surface while reducing infill migration and the frictional contact interface surface resists slippage movement of the ground cover relative to the ground surface.

2. The ground cover as recited in claim 1, further comprising a geomembrane for overlying a ground surface and receiving thereon the elongated nonwoven matting.

3. The ground cover as recited in claim 1, wherein the upper asperity extents of the fibers define an upper fluctuating surface.4898-1981-2951vl2171320-00018008 / 11 / 20254. The ground cover as recited in claim 3, further comprising an infdl of granular material received into the interstices and a portion of the infdl passing through the upper fluctuating-surface inwardly of a proximate portion of the matting.

5. A ground cover, comprising: an elongated nonwoven matting of a plurality of fibers and having opposing upper and lower extents, said plurality of fibers defining open voids among the plurality of fibers throughout the matting between the opposing upper and lower extents; said lower extents of the spaced-apart fibers and open voids defining a frictional contact interface; a plurality of spaced-apart tuft rows, each tuft row formed in the matting of a synthetic yarn and defining a plurality of spaced-apart tufts extending from the upper extents as simulated blades of grass and interstices between the adjacent tufts; and a granular infill received in the interstices for overlying the upper extents and a portion received in at least some of the open voids of the matting, whereby the ground cover provides a lower cost low-mass matting with a high-frictional interface for securing to a ground surface for land site covering purposes with resistance to downslope slippage and retention of granular infill for ambient environmental water flow filtering and UV protection with extended service life of ground covering purposes.

6. A ground cover system for overlying a land site, comprising: a synthetic grass comprising an elongated nonwoven matting of a plurality of fibers randomly disposed and defining a plurality of orifices within the nonwoven matting, said4898-1981-2951vl2171320-00018008 / 11 / 2025nonwoven matting having opposing upper and lower asperity extents, tufted with a plurality of spaced-apart tuft rows, each tuft row tufted with a synthetic yam to form a plurality of spacedapart tufts of simulated grass blades extending from the upper asperity extents of the nonwoven matting, said tufts defining interstices therebetween; a geomembrane for overlying a surface of a land site; the lower asperity extents and the orifices proximate thereto defining a frictional interface between the nonwoven matting and the geomembrane; and a granular infill received within the interstices and a portion of the granular infill within at least some of the orifices of the nonwoven matting, whereby the ground cover provides a lower cost low-mass matting with a high-frictional interface securing through the geomembrane to a ground surface for land site covering purposes with resistance to downslope slippage and retention of granular infill for ambient environmental water flow filtering and UV protection with extended service life of ground covering purposes.4898-1981-2951vl2171320-00018008 / 11 / 2025

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