A multi-laminar electrospun nanofiber scaffold for use in repairing a defect in a tissue substrate is provided. The scaffold includes a first layer formed by a first plurality of electrospun polymeric fibers, and a second layer formed by a second plurality of electrospun polymeric fibers. The second layer is combined with the first layer. A first portion of the scaffold includes a higher density of fibers than a second portion of the scaffold, and the first portion has a higher tensile strength than the second portion. The scaffold is configured to degrade via hydrolysis after at least one of a predetermined time or an environmental condition. The scaffold is configured to be applied to the tissue substrate containing the defect, and is sufficiently flexible to facilitate application of the scaffold to uneven surfaces of the tissue substrate, and to enable movement of the scaffold by the tissue substrate.

A multi-laminar electrospun nanofiber scaffold for use in repairing a defect in a tissue substrate is provided. The scaffold includes a first layer formed by a first plurality of electrospun polymeric fibers, and a second layer formed by a second plurality of electrospun polymeric fibers. The second layer is combined with the first layer. A first portion of the scaffold includes a higher density of fibers than a second portion of the scaffold, and the first portion has a higher tensile strength than the second portion. The scaffold is configured to degrade via hydrolysis after at least one of a predetermined time or an environmental condition. The scaffold is configured to be applied to the tissue substrate containing the defect, and is sufficiently flexible to facilitate application of the scaffold to uneven surfaces of the tissue substrate, and to enable movement of the scaffold by the tissue substrate.

The present invention relates to a cleanable 3D filter medium, a method for manufacturing said filter and the use of the filter.

The filter medium according to the present invention comprises at least one textile layer being a non-woven of synthetic, organic polymer fibers. The nonwoven having an embossed pattern in which the nonwoven having at the non-embossed area a thickness D and at the embossed area a thickness d and the ratio d/D is the compression factor CF, said compression factor CF being in the range 0.2FC0.5.

The filter medium according to the present invention can be cleaned and are used in filter systems for air/gas and liquid filtration, particularly in the motor vehicle industry, in air conditioning systems, passenger compartment filters, pollen filters, clean room filters, domestic filters, and as oil filters and hydraulic filters, thus removing solids from air/gas and liquids.

A sheet material for extraction with excellent transparency and extraction properties, is less likely to cause powder leakage, and has high modulus and excellent machine adaptability; an extraction filter; and an extraction bag. The sheet material having a first layer of a spunbonded nonwoven fabric formed from polyester-based fibers having an average diameter of 18 to 28 m, the fabric having a basis weight of 8 to 19 g/m.sup.2; and a second layer of a meltblown nonwoven fabric formed from polyester-based fibers having an average diameter of 16 to 28 m, the fabric having a basis weight of 2 to 8 g/m.sup.2, wherein the sum of the lengths of all fibers included in 1 cm.sup.2 of the sheet material for extraction is 3.3 to 4.8 m, and the 3% modulus is 5.5 N or higher; and an extraction filter and an extraction bag formed by this sheet material for extraction.

A sheet material for extraction with excellent transparency and extraction properties, is less likely to cause powder leakage, and has high modulus and excellent machine adaptability; an extraction filter; and an extraction bag. The sheet material having a first layer of a spunbonded nonwoven fabric formed from polyester-based fibers having an average diameter of 18 to 28 m, the fabric having a basis weight of 8 to 19 g/m.sup.2; and a second layer of a meltblown nonwoven fabric formed from polyester-based fibers having an average diameter of 16 to 28 m, the fabric having a basis weight of 2 to 8 g/m.sup.2, wherein the sum of the lengths of all fibers included in 1 cm.sup.2 of the sheet material for extraction is 3.3 to 4.8 m, and the 3% modulus is 5.5 N or higher; and an extraction filter and an extraction bag formed by this sheet material for extraction.

A spunbonded nonwoven fabric includes thermoplastic fibers, wherein the thermoplastic fibers are conjugate fibers in which a low-melting polymer having a melting point lower by 10 to 140 C. than that of a high-melting polymer is provided around the high-melting polymer, the spunbonded nonwoven fabric has a non-pressure bonding portion having an apparent density of 0.20 to 0.60 g/cm.sup.3, when a long axis length of a fiber cross section of the non-pressure bonding portion is a and a short axis length thereof is b, a fiber flatness a/b is 1.5 to 5, and an air permeability satisfies formula (1):

[air permeability (cc/cm.sup.2.Math.sec)]520exp(0.0236[basis weight (g/m.sup.2)]2.85[apparent density (g/cm.sup.3)])(1).

A silt fence includes a plurality of spaced stakes and a silt fence fabric coupled to the stakes wherein the silt fence fabric is a nonwoven needle punched fabric having a thickness of at least 5.25 mm, a denier size of 10-25 and a weight of 9-24 oz/square yard. The silt fence fabric may be asymmetrical dual sided needle punched wherein the downstream side of the fabric is punched 2-6 times more than the upstream side. The silt fence fabric may have a transverse direction orientation of fibers forming the fabric. The fence may include two independent tensioning members. The silt fence may include at least one vertical transverstivity cutoff element that prevents water from migrating from above the cutoff element within the fabric to below the cutoff element.

Nanofiber filter media ribbons are flexible elongate strips of polymeric material having a surface on which is formed an array of nanofibers. Ribbons are formable into woven or non-woven mats. The array of nanofibers can be configured to filter a predetermined contaminant from a fluid stream passing through the mats. Filter ribbons are formable by applying a moldable polymer to a first angular location of a rotating cylindrical roll having an array of nanoholes formed in a circumferential surface thereof so that the polymer covers the surface of the roll and infiltrates the nanoholes; cooling the polymer while rotating the polymer-covered roll to a second angular position; and removing the cooled polymer from the roll as an elongate film having an array of nanofibers formed on a surface thereof by the polymer that infiltrated the nanoholes.

Nanofiber filter media ribbons are flexible elongate strips of polymeric material having a surface on which is formed an array of nanofibers. Ribbons are formable into woven or non-woven mats. The array of nanofibers can be configured to filter a predetermined contaminant from a fluid stream passing through the mats. Filter ribbons are formable by applying a moldable polymer to a first angular location of a rotating cylindrical roll having an array of nanoholes formed in a circumferential surface thereof so that the polymer covers the surface of the roll and infiltrates the nanoholes; cooling the polymer while rotating the polymer-covered roll to a second angular position; and removing the cooled polymer from the roll as an elongate film having an array of nanofibers formed on a surface thereof by the polymer that infiltrated the nanoholes.

Nanofiber filter media ribbons are flexible elongate strips of polymeric material having a surface on which is formed an array of nanofibers. Ribbons are formable into woven or non-woven mats. The array of nanofibers can be configured to filter a predetermined contaminant from a fluid stream passing through the mats. Filter ribbons are formable by applying a moldable polymer to a first angular location of a rotating cylindrical roll having an array of nanoholes formed in a circumferential surface thereof so that the polymer covers the surface of the roll and infiltrates the nanoholes; cooling the polymer while rotating the polymer-covered roll to a second angular position; and removing the cooled polymer from the roll as an elongate film having an array of nanofibers formed on a surface thereof by the polymer that infiltrated the nanoholes.