Reinforced silt retention sheet

Abstract

A reinforced silt retention sheet and systems for silt retention are provided. The reinforced silt retention sheet includes a non-woven fabric having a series of entangled polymer fibers with a reinforcing material secured within the fabric. The resultant reinforced silt retention sheet further can have openings of a desired size to enable filtering of a flow of fluid passing through the reinforced silt retention sheet.

1. A reinforced silt retention sheet arranged above ground, for use in a silt management application, comprising:
 a flexible, water permeable, nonwoven fabric comprising a plurality of entangled polymer fibers and having a thickness of about 0.1 mm to about 5mm; and 
 a reinforcing material or element extending along the nonwoven fabric and adapted to support and prevent ripping or tearing of the silt retention sheet secured within with the entangled polymer fibers without substantially being bonded thereto, the reinforcing material or element being arranged spaced in non-overlapping intervals in the warp and/or fill direction of the nonwoven fabric, 
 wherein the silt retention sheet has a maximum apparent opening size of less than about 0.6 millimeters as measured by ASTM D-4751. 
 
     
     
       2. The silt retention sheet of  claim 1 , wherein the nonwoven fabric comprises a spunbond polyester having a basis weight of from about 1 to about 8 ounces per square yard. 
     
     
       3. The silt retention sheet of  claim 1 , wherein the nonwoven fabric comprises a spunbond polypropylene fabric, a spunbond polyester fabric, spunbond polyethylene terephthalate fabric, a needle punched polyester fabric, a needlepunched polyethylene terephthalate fabric, a needlepunched spunbond polyethylene terephthalate fabric, or any combination thereof. 
     
     
       4. The silt retention sheet of  claim 1 , wherein the reinforcing material comprises a fiberglass scrim having a mesh size of from about 0.1 inches to about 0.5 inches. 
     
     
       5. The silt retention sheet of  claim 1 , having a tensile strength of at least about 75 lbs, as measured according to ASTM D-4632. 
     
     
       6. The silt retention sheet of  claim 1 , having a standard concentration reduction in turbidity of at least about 58% as measured according to ASTM D-5141-96(2004). 
     
     
       7. The silt retention sheet of  claim 1 , having a double concentration reduction in turbidity of at least about 55% as measured according to ASTM D-5141-96(2004). 
     
     
       8. The silt retention sheet of  claim 1 , having a standard concentration filtering efficiency of at least about 90% as measured according to modified ASTM D-5141-96(2004). 
     
     
       9. The silt retention sheet of  claim 1 , having a double concentration filtering efficiency of at least about 92% as measured according to modified ASTM D-5141-96(2004). 
     
     
       10. The silt retention sheet of  claim 1 , formed by the process comprising:
 (a) forming a layer of the entangled polymeric fibers; 
 (b) overlying the entangled polymeric fibers with the reinforcing material; and 
 (c) overlying the reinforcing material with additional entangled polymeric fibers. 
 
     
     
       11. The silt retention sheet of  claim 10 , formed by the process further comprising:
 (d) heating the sheet to form bonds between the entangled polymeric fibers without substantially bonding the entangled polymeric fibers to the reinforcing material. 
 
     
     
       12. The silt retention sheet of  claim 10 , formed by the process further comprising:
 (d) selecting the polymeric fibers to have a lower softening point than a softening point of the reinforcing material; and 
 (e) heating the sheet to a temperature above the softening point of the entangled polymeric fibers but below the softening point of the reinforcing material. 
 
     
     
       13. The silt retention sheet of  claim 1 , wherein the reinforcing material comprises a plurality of strands formed from at least one of polypropylene, polyester, nylon 6, 6, yarn, cord material, fiberglass, aramid fibers, and combinations thereof. 
     
     
       14. The silt retention sheet of  claim 1  and wherein the reinforcing material or element comprises a series of strands aligned in proximity so as to form reinforcing elements at spaced locations along the non-woven fabric. 
     
     
       15. The silt retention sheet of  claim 1  and further comprising ground supports attached to the reinforcing material or element. 
     
     
       16. The reinforced silt retention sheet as claimed in  claim 15 , further comprising an attachment means for attaching the ground supports to the reinforcing material wherein the reinforcing material further functions as an attachment point for the ground supports. 
     
     
       17. The silt retention sheet as claimed in  claim 16 , wherein the attachment means are selected from the group consisting of staples, pins, nails, rings, clips, adhesives, hook and loop fasteners, and combinations thereof. 
     
     
       18. The silt retention sheet of  claim 1  and wherein the reinforcing material comprises a polymer material entangled within the polymer fibers of the non-woven fabric. 
     
     
       19. The silt retention sheet as claimed in  claim 1 , wherein the reinforcing element is comprised of a plurality of reinforcing strands or strips that form a band. 
     
     
       20. A reinforced silt retention sheet comprising a flexible, water permeable non-woven fabric sheet material having a thickness of about 0.1 mm to about 5 mm and including a plurality of non-woven polymer fibers and reinforcing elements formed from a resilient, tear resistant material and interspersed along said fabric sheet material to provide said fabric sheet material with enhanced strength and resistance to tearing, wherein the reinforced silt retention sheet has an apparent sieve opening size of less than approximately 0.6 mm as measured according to ASTM D-4751 to provide filtering efficiency for sediment control applications, and has an ultimate tensile strength ranging from about 100 lbs to 350 lbs in the warp direction and an ultimate tensile strength ranging from about 75 lbs to 450 lbs in the fill direction. 
     
     
       21. The reinforced silt retention sheet of  claim 20 , and wherein said fabric sheet comprises a spin bond material having a denier of approximately 1 dpf to approximately 10 dpf. 
     
     
       22. The reinforced silt retention sheet of  claim 20 , wherein the silt retention sheet is a silt retention fence. 
     
     
       23. A reinforced silt retention sheet arranged above ground, for use in a silt management application, comprising:
 a flexible, water permeable, nonwoven geotextile fabric filter material having a thickness of less than about 5 mm and comprising a plurality of entangled polymer fibers; and 
 a reinforcing material secured within to the entangled polymer fibers without being bonded thereto, the reinforcing material being spaced in discontinuous and non-overlapping intervals in the warp and and/or fill direction directions, 
 wherein the silt retention sheet has a maximum apparent opening size of less than about 0.6 millimeters as measured by ASTM D-4751. 
 
     
     
       24. The reinforced silt retention sheet as claimed in  claim 23 , wherein the reinforced silt retention sheet has an ultimate tensile strength ranging from about 100 lbs to 350 lbs in the warp direction and an ultimate tensile strength ranging from about 75 lbs to 450 lbs in the fill direction. 
     
     
       25. The silt retention sheet of claim 1, wherein the fabric comprises a non-woven fabric. 
     
     
       26. The silt retention sheet of claim 1, wherein the reinforcing elements comprise an array. 
     
     
       27. The reinforced silt retention sheet as claimed in claim 23, wherein the reinforcing material is secured within the entangled polymer fibers. 
     
     
       28. A reinforced silt retention sheet comprising a flexible, water permeable fabric sheet material having a thickness of about 0.1 mm to about 5 mm and including a plurality of reinforcing elements, said reinforcing elements formed from a resilient, tear resistant material and interspersed along said fabric sheet material to provide said fabric sheet material with enhanced strength and resistance to tearing, wherein said reinforced silt retention sheet has an apparent sieve opening size of less than approximately 0.6 mm as measured according to ASTM D-4751 to provide filtering efficiency for sediment control applications, and has an ultimate tensile strength ranging from about 100 lbs to 350 lbs in the warp direction and an ultimate tensile strength ranging from about 75 lbs to 450 lbs in the fill direction. 
     
     
       29. The reinforced silt retention sheet as claimed in claim 28, wherein said reinforcing elements are attached to said polymer fibers by an attachment means selected from the group consisting of stitching, adhesion, felting, heat fusion, and weaving. 
     
     
       30. The reinforced silt retention sheet as claimed in claim 29, wherein said reinforcing elements are interspersed along said fabric sheet such that said reinforcing elements form an array. 
     
     
       31. A reinforced silt retention sheet comprising:
 a flexible, water permeable fabric sheet material comprising a plurality of polymer fibers; and   a plurality of reinforcing elements that provide reinforcing points at which at least one fastener can be attached, said reinforcing elements formed from a resilient, tear resistant material and attached to said fabric sheet material to provide a reinforced fabric sheet material with enhanced strength and resistance to tearing,   wherein said fabric sheet material comprises a geotextile fabric filter material having an apparent sieve opening size of less than approximately 0.6 mm as measured according to ASTM D-4751 to provide filtering efficiency for sediment control applications, and   wherein said reinforced silt retention sheet has:
 an ultimate tensile strength ranging from about 100 lbs to 350 lbs in a warp direction, 
 an ultimate tensile strength ranging from about 75 lbs to 450 lbs in a fill direction, 
 a mullen burst strength ranging from about 150 to 450 pounds per square inch, 
 a flow rate ranging from about 35 to 160 gallons/minute/square foot, and 
   wherein said reinforcing elements are applied as strands, cords, arrays, strips, patches, or lengths of material attached along the web of said flexible, water permeable fabric sheet material.   
     
     
       32. The reinforced silt retention sheet of claim 31 and further comprising ground supports attached to the reinforcing material. 
     
     
       33. The reinforced silt retention sheet as claimed in claim 32, further comprising an attachment means for attaching the ground supports to the reinforcing material wherein the reinforcing material further functions as an attachment point for the ground supports.  
     
     
       34. The reinforced silt retention sheet as claimed in claim 33, wherein the attachment means are selected from the group consisting of staples, pins, nails, rings, clips, adhesives, hook and loop fasteners, and combinations thereof.