The invention relates to a fibrous nonwoven, in particular for a filter medium, having a first layer, wherein at least one single-piece fiber strand of said first layer has a first fiber portion and a second fiber portion in the longitudinal direction, and wherein the fiber strand has a thickening substantially in said second fiber portion.

The invention relates to a fibrous nonwoven, in particular for a filter medium, having a first layer, wherein at least one single-piece fiber strand of said first layer has a first fiber portion and a second fiber portion in the longitudinal direction, and wherein the fiber strand has a thickening substantially in said second fiber portion.

This invention identifies important geometric parameters of an adhesive microfiber with mushroom-shaped tip for improving and optimizing adhesive ability. The magnitude of pull-off stress is dependent on a wedge angle γ and the ratio of the tip radius to the stalk radius β of the mushroom-shaped fiber. Pull-off stress is also found to depend on a dimensionless parameter x, the ratio of the fiber radius to a length-scale related to the dominance of adhesive stress. Finally, the shape of edge tip, where the surface and sides of the mushroom-shaped tip join, is a factor that impacts strength of adhesion. Optimizing ranges for these parameters are identified.

This invention identifies important geometric parameters of an adhesive microfiber with mushroom-shaped tip for improving and optimizing adhesive ability. The magnitude of pull-off stress is dependent on a wedge angle γ and the ratio of the tip radius to the stalk radius β of the mushroom-shaped fiber. Pull-off stress is also found to depend on a dimensionless parameter x, the ratio of the fiber radius to a length-scale related to the dominance of adhesive stress. Finally, the shape of edge tip, where the surface and sides of the mushroom-shaped tip join, is a factor that impacts strength of adhesion. Optimizing ranges for these parameters are identified.

Bi— or multicomponent fibre (3) comprising a reinforcing core (1) of a first material and at least one sheath (2) of a second, thermoplastic or pre-polymerized thermoset material, for the manufacturing of composite parts, the matrix of which composite parts consists of the material of said sheath (2), wherein said first material has a degradation temperature, ignition temperature, glass transition temperature, melting temperature or liquidus temperature which is higher than the melting temperature, flowing temperature, r softening temperature of said second, thermoplastic or pre-polymerized thermoset material, wherein said reinforcing core (1) has a core volume fraction (v.sub.f) defined as the volume fraction of the reinforcing core (1) in the bi- or multicomponent fibre (3), which is in the range of 0.3-0.8, and wherein along a longitudinal axis (Z) of the bi- or multicomponent fibre outer surface (4) of the sheath (2) has a corrugated, preferably irregular corrugated shape.

Methods, systems, and devices for changing cross-sectional sizes and/or shapes of flat braided sutures and the resulting constructs are disclosed. The flat braided sutures can have a textile first cross-sectional shape that can be changed to a textile second cross-sectional shape. The systems can have a heater and a die. The flat braided sutures can be movable through the heater and the die. When the flat braided sutures are in the heater, the flat braided sutures can be heatable from a textile first temperature to a textile second temperature greater than the textile first temperature. When the flat braided sutures are at the textile second temperature, the textile first cross-sectional shape can be changeable to the textile second cross-sectional shape.

A method for providing a multifilament bundle of melt spun polymer filaments, the that includes providing a spinning device including at least M extruders for melting M polymers, M groups of spinning stations, each group comprising N spinning stations, each spinning station comprising and a spin pack coupled to a spin pump which receives molten polymer from one of the M extruders and spins a strand of filaments by pushing said polymer through the coupled spin pack, and N transformation stations for bundling M strands of filaments. The method further includes spinning N*M strands of filaments from the spinning stations at a given spin pump output and bundling the strands into N multifilament bundles via the N transformation stations whereby the spin pump outputs are varied over time.

There is provided herein a preform for drawing fibres therefrom, the preform formed of east first material and having a non-uniform structure in the longitudinal direction and a method of forming the same.

There is provided herein a preform for drawing fibres therefrom, the preform formed of east first material and having a non-uniform structure in the longitudinal direction and a method of forming the same.

Nonwoven fabrics suitable for a wide variety of applications (e.g., healthcare, filtration, industrial, packaging, etc.) are provided. In one aspect, the nonwoven fabric includes a plurality of segmented fibers. Each of the plurality of segmented fibers may comprise a fiber axis and a plurality of alternating larger diameter and smaller diameter segments along the fiber axis. The plurality of segmented fibers may be substantially aligned in a first direction.