Strong Nonwoven Fabrics for Use in Silt Control Systems
Strong nonwoven fabrics can be used as a sheet in a silt screen fence or other temporary silt screen barrier. The fabrics can be without reinforcements. Enhanced features of these strong nonwoven fabrics can enable them to be used as a sheet in a silt screen fence or other temporary silt screen barrier without adding additional processing steps. A strong nonwoven fabric without internal or external reinforcement that does not tear easily and has excellent light stability can be used.
1 . A containment system, comprising a nonwoven fabric having no reinforcement, wherein the nonwoven fabric has an average filter efficiency of at least 93% as measured by ASTM D5141, and a tensile strength of at least 20 pounds force (lb f ) as measured by ASTM D4632.
2 . The containment system according to claim 1 , wherein the nonwoven fabric is adapted to separate oil from an oil and water emulsion.
3 . The containment system according to claim 1 , wherein the nonwoven fabric is adapted to separate at least 95% of 320 centipoise (cp) oil from an oil and water emulsion that contains about 4.5% of 320 cp oil as measured according to test method 1664A HEM (n-Hexane Extractable Material) (Oil and Grease).
4 . The containment system according to claim 1 , wherein the nonwoven fabric comprises nylon, polyester, polypropylene, or a combination thereof.
5 . The containment system according to claim 1 , wherein the nonwoven fabric comprises nylon 6 or nylon 6,6.
6 . The containment system according to claim 1 , wherein the nonwoven fabric comprises an engraved pattern.
7 . The containment system according to claim 1 , wherein the nonwoven fabric is a bonded nonwoven fabric and_comprises a bond area of 17% to 25% of the nonwoven fabric.
8 . The containment system according to claim 1 , wherein the nonwoven fabric has a filter efficiency of at least 93% for a flux rate of at least 0.9 gallons per minute per square foot as measured by ASTM D5141.
9 . The containment system according to claim 1 , wherein the nonwoven fabric has a basis weight in a range of from 1 ounce per square yard (osy) to 12 osy,
wherein the nonwoven fabric has an air permeability of no more than 250 cubic feet per minute per square foot (ft 3 /minute/ft 2 ), and
wherein the nonwoven fabric has a thickness of at least 18 mils and a fabric density of at least 0.18 grams per cubic centimeter (g/cc).
10 . The containment system according to claim 1 , wherein the nonwoven fabric has a mean pore size of no more than 65 microns.
11 . The containment system according to claim 1 , wherein the nonwoven fabric comprises a UV stabilizer, and wherein the nonwoven fabric is adapted to have, after 500 hours of exposure to a xenon light source and water spray according to the protocol described in ASTM D5534 07, a machine direction grab tensile strength of at least 44 lb f as measured by ASTM D5034, a cross direction grab tensile strength of at least 33 lb f as measured by ASTM D5034, a machine direction grab elongation of at least 42% as measured by ASTM D5034, and a cross direction grab elongation of at least 56% as measured by ASTM D5034.
12 . The containment system according to claim 11 , wherein the nonwoven fabric has an orange shade that is at least as dark as a Pantone 472C after 500 hours of exposure to a xenon light source and water spray according to the protocol described in ASTM D4355 07.
13 . The containment system according to claim 1 , further comprising a post to which the nonwoven fabric is attached.
14 . The containment system according to claim 13 , wherein the nonwoven fabric passes the criteria for United States Environmental Protection Agency (EPA) SW-846, Third Edition.
15 . The containment system according to claim 13 , wherein the nonwoven fabric passes the criteria for NSF/ANSI Standard 61-2007a.
16 . The containment system according to claim 2 , further comprising a post to which the nonwoven fabric is attached.
17 . The containment system according to claim 16 , wherein the nonwoven fabric passes the criteria for United States Environmental Protection Agency (EPA) SW-846, Third Edition.
18 . The containment system according to claim 16 , wherein the nonwoven fabric passes the criteria for NSF/ANSI Standard 61-2007a.
19 . A method of fabricating a containment system, comprising:
forming a nonwoven fabric; and
attaching the nonwoven fabric to a supporting structure to form the containment system,
wherein forming the nonwoven fabric comprises:
forming, in an extruder, a master batch comprising at least one polymer;
extruding the master batch in the form of a plurality of filaments,
depositing the filaments onto a collection surface to form a web, and
thermally bonding the filaments of the web to form the nonwoven fabric,
wherein the nonwoven fabric has an average filter efficiency of at least 93% as measured by ASTM D5141, and a tensile strength of at least about 20 lb f as measured by ASTM D4632.
20 . The method according to claim 19 , wherein the nonwoven fabric is adapted to separate oil from an oil and water emulsion.
21 . The containment system according to claim 2 , wherein the oil is crude oil.