Temporary Degradable Plastic Erosion Control Blanket

Abstract

A temporary all plastic erosion control blanket is configured to slow water runoff, to provide sediment and erosion control, and to enhance re-vegetation. The temporary all plastic erosion control blanket is fully degradable within less than one year. The temporary all plastic erosion control blanket is a warp knitted structure formed from polyolefin or polyamide materials and includes integral visual stake placement indicia.

Claims

1. A temporary all plastic erosion control blanket which is configured to slow water runoff, to provide sediment and erosion control, and to enhance re-vegetation, wherein the blanket is fully degradable within less than one year, wherein the blanket is a warp knitted structure formed from polyolefin or polyamide materials and includes integral visual stake placement indicia.

2. The temporary all plastic erosion control blanket according to claim 1 wherein the blanket is a warp knitted structure formed from polyolefin materials including polypropylene (PP) and polyethylene (PE) materials.

3. The temporary all plastic erosion control blanket according to claim 1 wherein the polyolefin or polyamide materials additionally include oxi-degradable plastic additives configured to assure complete degradation of the blanket via oxo-degradation within 12 months.

4. The temporary all plastic erosion control blanket according to claim 1 wherein the blanket is configured for formation via warp knitting technology on a RASCHELL Warp Knitted Double Needle Bar Machine.

5. The temporary all plastic erosion control blanket according to claim 1 wherein the blanket has a width of between 8 and 16.

6. The temporary all plastic erosion control blanket according to claim 1 wherein the blanket includes mesh opening sizes having an effective diameter of at least 3/16 and no greater than .

7. The temporary all plastic erosion control blanket according to claim 1 wherein the blanket includes mesh opening sizes having an effective diameter of at least and no greater than .

8. The temporary all plastic erosion control blanket according to claim 1 wherein the blanket includes a warp knitted structure which yields an elongated triangle for openings that are about long, about 3/16 wide at the wider end and tapering to about wide at a narrow end.

9. The temporary all plastic erosion control blanket according to claim 1 wherein the integrated visible stake placement indicia in the blanket is formed by a distinctly colored thread that follows a warp thread and then inlays back and forth between two adjacent warp threads at the appropriate intervals to form the indicia.

10. The temporary all plastic erosion control blanket according to claim 1 wherein the integrated visible stake placement indicia are evenly spaced such that they also serve as a blanket length measurement tool.

11. The temporary all plastic erosion control blanket according to claim 1 wherein the blanket is configured to be degraded to be mulched after three months when the blanket is engaged by a mower.

12. The temporary all plastic erosion control blanket according to claim 1 wherein the blanket yields a RUSLE C factor which is less than or equal to the RUSLE C factor of conventional Straw Double Synthetic Erosion Control Blankets.

13. A temporary all plastic erosion control blanket which is configured to slow water runoff, to provide sediment and erosion control, and to enhance re-vegetation, wherein the blanket is a warp knitted structure formed from polyolefin or polyamide materials and wherein the polyolefin or polyamide materials additionally include oxi-degradable plastic additives configured to assure complete degradation of the blanket via oxo-degradation within 12 months.

14. The temporary all plastic erosion control blanket according to claim 13 wherein the blanket is configured to be degraded to be mulched after three months when the blanket is engaged by a mower.

15. The temporary all plastic erosion control blanket according to claim 13 further including integrated visible stake placement indicia, wherein the integrated visible stake placement indicia in the blanket is formed by a distinctly colored thread that follows a warp thread and then inlays back and forth between two adjacent warp threads at the appropriate intervals to form the indicia.

16. The temporary all plastic erosion control blanket according to claim 15 wherein the integrated visible stake placement indicia are evenly spaced such that they also serve as a blanket length measurement tool.

17. The temporary all plastic erosion control blanket according to claim 13 wherein the blanket includes a warp knitted structure which yields an elongated triangle for openings that are about long, about 3/16 wide at the wider end and tapering to about wide at a narrow end.

18. The temporary all plastic erosion control blanket according to claim 13 wherein the blanket is a warp knitted structure formed from polyolefin materials including polypropylene (PP) and polyethylene (PE) materials.

19. The temporary all plastic erosion control blanket according to claim 13 wherein the blanket has a width of between 8 and 16.

20. The temporary all plastic erosion control blanket according to claim 13 wherein the blanket yields a RUSLE C factor which is less than or equal to the RUSLE C factor of conventional Straw Double Synthetic Erosion Control Blankets.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0032] FIG. 1 is a schematic plan view of a Temporary Degradable Plastic Erosion Control Blanket formed according to one aspect of the present invention;

[0033] FIG. 2 is a schematic plan view of a Temporary Degradable Plastic Erosion Control Blanket formed according to one aspect of the present invention; and

[0034] FIG. 3 is a perspective view of a Temporary Degradable Plastic Erosion Control Blanket formed according to one aspect of the present invention;

[0035] FIG. 4 is a plan view of a portion of a conventional Jute Netting Erosion Control Blanket known in the prior art;

[0036] FIG. 5 is a plan view of a portion of a conventional Fabrijute Netting Erosion Control Blanket known in the prior art;

[0037] FIG. 6 is a plan view of a portion of a conventional Straw Single Synthetic Erosion Control Blanket known in the prior art;

[0038] FIG. 7 is a plan view of a portion of a conventional Straw double jute net Erosion Control Blanket known in the prior art;

[0039] FIG. 8 is a plan view of a portion of a conventional Coir Double Jute Erosion Control Blanket known in the prior art;

[0040] FIG. 9 is a plan view of a portion of a conventional Coir Double Synthetic Erosion Control Blanket known in the prior art;

[0041] FIG. 10 is a plan view of a portion of a conventional Excelsior (Aspen fiber) Single Synthetic Erosion Control Blanket known in the prior art; and

[0042] FIG. 11 is a plan view of a portion of a conventional Excelsior (Aspen fiber) Double Synthetic Erosion Control Blanket known in the prior art.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] The present invention is temporary all plastic erosion control blanket 100 which is effective to slow water runoff, to provide effective sediment and erosion control, and to enhance re-vegetation which is fully degradable within less than one year. Fully degraded is a known term in the erosion control art relating to blankets and effectively defines that the blanket 100 will no longer be an integrated unit and generally only trace components or remnants of the blanket 100 would be found, if any, after a year. The blanket 100 of the present invention shown in FIGS. 1-3 is preferably a warp knitted structure formed from plastic yarns or materials, such as polyolefin or polyamide materials. Acceptable polyolefin materials include polypropylene (PP) and polyethylene (PE) materials. The polyolefin or polyamide materials, commonly polypropylene, will additionally include oxi-degradable plastic additives, such as those sold by EPI under the TDPA brand, sufficient to assure complete degradation of the blanket via oxo-degradation within 12 months. The oxidegradable plastic additives sold by EPI under the TDPA brand are suitable for PE and PP materials. FIG. 1 is a schematic top plan view of the Temporary Degradable Plastic Erosion Control Blanket 100 according to the present invention. Specifically, the Temporary Degradable Plastic Erosion Control Blanket according to the present invention will appear as shown in FIG. 3.

[0044] The warp knitted structure of the blanket of the present invention include warp 102 and weft threads 104 wherein the warp threads 102 extend substantially longitudinally along a longitudinal axis of the blanket 100 while the weft threads 104 extend generally perpendicular to the longitudinal axis of the blanket 100. The arrangement of the warp and weft threads is analogous to the arrangement found in the DIAMOND SOCK brand compost filter sock sold by MKB, and the range of variation of the warp threads 102 from being parallel with the longitudinal axis (substantially longitudinally) or of the weft threads 104 extending generally perpendicular to the longitudinal axis of the blanket within the meaning of the present invention are defined and known in this filter sock netting forming technology. The structure may be effectively formed using warp knitting technology on a RASCHELL Warp Knitted Double Needle Bar Machine. The use of warp knitting technology on a RASCHELL Warp Knitted Double Needle Bar Machine allows effective widths of the blanket 100 of the present invention to be between 4 and 54. Preferably the effective widths of the blanket will be 8 and 16. As noted above, larger areas can easily have two blankets 100 adjacent each other with one overlapping the other at the edges.

[0045] The mesh opening size 106 is significant for a proper erosion control blanket allowing revegetation, as if the openings 106 are too small, namely less than 3/16 in diameter, the vegetation cannot grow; and if the openings 106 are too big, namely greater than in diameter, then there may be insufficient erosion control and heat and moisture retention. Mesh openings 106 can take many shapes, and thus the true measurement of opening size 106 should be in area terms (i.e. square inches or the like), however custom has been to define openings in mesh with a length measurement which can be considered as an effective diameter. The mesh opening size 106 of the blanket 100 of the present invention have an effective diameter of at least 3/16 and no greater than , preferably - effective diameter. The warp knitted structure described and shown above yields an elongated triangle for openings that are about long, about 3/16 wide at the wider end and tapering to about wide at a narrow end of the opening 106 and is quite effective openings for the erosion control blanket 100.

[0046] The Temporary Degradable Plastic Erosion Control Blanket 100 according to the present invention can be utilized and placed in a conventional fashion and operate as substantially conventional Temporary Degradable Plastic Erosion Control Blanket 100. The Temporary Degradable Plastic Erosion Control Blanket 100 may be staked in position with stakes driven through the Temporary Degradable Plastic Erosion Control Blanket 100 at spaced locations along the blanket 100 to secure the blanket 100 at a desired location. As described below the blanket of the present invention may have visible indicia 108 integrated into the blanket 108 to indicate the desired location of the stakes and this is schematically in FIG. 2.

[0047] FIG. 2 schematically illustrates the integrated visible stake placement indicia 108, also called pinning indicia, in the Temporary Degradable Plastic Erosion Control Blanket 108 according to the present invention. Each integrated visible stake placement indicia in the blanket is formed by a distinctly colored thread 110 (e.g., an orange thread) that follows a warp thread 102 and then inlays back and forth between two adjacent warp threads 102 at the appropriate intervals to form the indicia 108. FIG. 1 shows the indicating thread 110 as thicker solely for illustrative purposes, as in practice a visibly distinct thread 110 of the same general thickness as the warp thread 102 and/or the weft thread 104 can easily form the indicia 108. Warp knitting technology can easily and effectively add distinct visible threads 110 at any location in the netting forming the blanket as known in the art to form the indicia.

[0048] The indicia 108 are evenly spaced such that they also serve as a blanket 100 length measurement tool for users and inspectors, separate from stake placement. This allows for inspectors to easily measure the length of an installation without the need to measure on the slope, which can be difficult. Similarly for the users during installation is allows them to quickly measure out the length of blanket 100 needed for a given installation.

[0049] The color of the blanket 100, namely the color of the warp 102 and weft threads 104 other than the ones 110 forming the stake indicia 108, can be an important aspect of the invention. The color of the stake indicia 108 threads is also important in that this color must be sufficiently different from the remaining color(s) of the blanket 100 so as to be easily viewable, however the stake indicia 108 color is not the dominant color of the blanket.

[0050] The color of the blanket 100 may, in one embodiment, be a green as color match for the grass for aesthetic look minimizing the visibility of the blanket 100 to the public while grass is starting. An alternative color for the blanket 100 is one in which reflected light is of a color to promote the selected vegetation. It is known that certain colors of light will promote certain plant growth. For example blue lights have been found to increase the growth rate of stalks and leaves of certain plants, while red light (possibly combined with blue) has been found to promote the flowering of certain plants. Thus a blue color for the warp and weft threads 102 and 104 may increase the effectiveness of the blanket to stimulate vegetation in certain applications.

[0051] The temporary fully degradable, all plastic erosion control blanket 100 according to the present invention is a replacement for existing temporary Rolled Erosion Control Blanketing (RECB). The temporary fully degradable, all plastic erosion control blanket 100 according to the present invention will retain as much moisture in the soil as a Straw Double Synthetic Erosion Control Blanket. Further, the temporary fully degradable, all plastic erosion control blanket 100 according to the present invention will deflect rill cutting energy and prevent rills from flowing water at least as effective as a Straw Double Synthetic Erosion Control Blanket. Further, the temporary fully degradable, all plastic erosion control blanket 100 according to the present invention will deflect heat in sun, and retain heat in cold at least as effective as a Straw Double Synthetic Erosion Control Blanket.

[0052] The temporary fully degradable, all plastic erosion control blanket 100 according to the present invention will degrade completely in 12 months via Oxo degradation. Further, the blanket 100 of the present invention will avoid unwanted cross contamination (i.e. it will bring along no extraneous seeds, bacteria, fungus, etc.unlike straw, coconut, or excelsior blankets). The later treatment of an unwanted weed, bacteria or fungus is time consuming and can set back, or in worst case completely undue, the vegetation efforts.

[0053] The blanket 100 of the present invention is degraded or broken down enough to mulch into grown grass, if the area is mowed, after three months when the blanket 100 is engaged by the mower. A blanket 100 may be engaged by a mower because the growing vegetation can sometimes lift the blanket to the height of the mower deck. The failure of prior art plastic netting from being capable of being mulched (i.e. defined herein as capable of being sheared by the rotating blades of a conventional mower deckas opposed to wrapping around the rotor of the mower and possibly clogging the mower) has limited the use of such netting in applications that are subject to mowing during the netting life.

[0054] The blanket of the present invention costs less than conventional a Straw Double Synthetic Erosion Control Blankets of the same size, and the present invention is not be caught up in straw shortages and the components making the blanket 100 of the present invention are viewed as a more stable commodity than straw. The blanket 100 of the present invention is 4-5 denser packaging than conventional Straw Double Synthetic Erosion Control Blankets of the same size, yielding a large shipping advantage to the present invention (and thus lower final cost).

[0055] The blanket 100 of the present invention yields a favorable RUSLE C factor, which requires some explanation. The Revised Universal Soil Loss Equation (now RUSLE2) estimates soil loss from rill and interrill (sheet and rill) erosion caused by rainfall and its associated overland flow. RUSLE2 uses six factors including climatic erosivity, soil erodibility, slope length, slope steepness, cover management, and support practices to compute soil loss. The USDA-Agricultural Research Service (ARS) is the lead research agency that developed RUSLE2. The structure of the revised universal soil loss equation RUSLE2 is based on the Universal Soil Loss Equation (USLE), which is given by: A=R K L S C P where A=average annual soil loss from rill and interrill erosion caused by rainfall and its associated overland flow (tons ac-1 yr-1), R=the factor for climatic erosivity, K=the factor for soil erodibility measured under a standard condition, L=the factor for slope length, S=the factor for slope steepness, C=the factor for cover-management, and P=the factor for support practices. A value for soil loss A is computed by selecting values for each factor and multiplying them. These factors represent the effect of climate, soil, topography, and land use on rill and interrill erosion. By assigning values to these factors based on site-specific conditions, the rule is a widely accepted computation of soil loss for specific sites, and is used to guide conservation planning tailored to individual field sites.

[0056] The RUSLE C factor is the most common factor used to assess the impact of BMPs on reducing erosion because the RUSLE C factor represents the effect of land use on soil erosion (See Renard, K. G., G. R. Foster, G. A. Weesies, D. K. McCool, and D. C. Yoder. 1997. Predicting Soil Erosion by Water: A Guide to Conservation Planning with the Revised Universal Soil Loss EquationUSDA Agric. Handb. 703. U.S. Gov. Print. Office, Washington, D.C.). Erosion control blankets and surface applied BMPs such as blown straw are represented as C factors within RUSLE. By definition, C=1 under standard fallow conditions. As surface cover is added to the soil, the C factor value approaches zero. For example, a C factor of 0.20 signifies that 20% of the amount of erosion will occur compared to continuous fallow conditions. C factors vary from region to region because they are strongly influenced by different R factors (see Wischmeier, W. H., and D. D. Smith. 1978. Predicting Rainfall Erosion Losses: A Guide For Conservation PlanningUSDA Agric. Handb. 537. U.S. Gov. Print. Office, Washington, D.C.). The blanket 100 of the present invention yields a favorable RUSLE C factor, at least as it relates to reducing soil loss. The specific C factor will vary upon soil type and other site specific issues, as discussed above, but the blanket 100 of the present invention yields a favorable RUSLE C factor, specifically one which is less than or equal to the RUSLE C factor of conventional Straw Double Synthetic Erosion Control Blankets.

[0057] While the invention has been shown in several particular embodiments it should be clear that various modifications may be made to the present invention without departing from the spirit and scope thereof. The scope of the present invention is defined by the appended claims and equivalents thereto.