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 and the ratio of the tip radius to the stalk radius 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 and the ratio of the tip radius to the stalk radius 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.

Innovation suggests methods and installations for productions of viscose filament rayon with cyclically varying linear density. According to the method of the invention, constantly synchronizated viscose solution supplying and spinning devices actuation is interrupted, as first (27) and second (28) spinning devices and arranging freshly spun yam in centrifuge system 39-5 are actuated by the use of existing power feeding installation (40-4), motors 40-1 and 40-2 and reduction gear groups 39-1 and 39-2 named as the first power feeding and actuating installation. According to the method of the invention new power feeding 40-7 and actuating; 40-3 installation is added to the same spinning machine named second power feeding and actuating installation which work runs under unit 42 control. According to the invention power shaft 21 actuation do not depends on other spinning devices actuation anymore and quantity of viscose dozed to the spinning could be changed independently of other devices work.

When to the spinning machine one or two individual installations for dying are joined suggested method allows production of dyed in one or two colours filament rayon with cyclically varying linear density.

Innovation suggests methods and installations for productions of viscose filament rayon with cyclically varying linear density. According to the method of the invention, constantly synchronizated viscose solution supplying and spinning devices actuation is interrupted, as first (27) and second (28) spinning devices and arranging freshly spun yam in centrifuge system 39-5 are actuated by the use of existing power feeding installation (40-4), motors 40-1 and 40-2 and reduction gear groups 39-1 and 39-2 named as the first power feeding and actuating installation. According to the method of the invention new power feeding 40-7 and actuating; 40-3 installation is added to the same spinning machine named second power feeding and actuating installation which work runs under unit 42 control. According to the invention power shaft 21 actuation do not depends on other spinning devices actuation anymore and quantity of viscose dozed to the spinning could be changed independently of other devices work.

When to the spinning machine one or two individual installations for dying are joined suggested method allows production of dyed in one or two colours filament rayon with cyclically varying linear density.

Provided is a nonwoven fabric structure containing an odd-shaped fiber. The odd-shaped fiber has bubbles inside and has a cross-sectional shape that is an irregular, non-circular cross-section. Further, it is preferable that the cross-sectional shape of the odd-shaped fiber changes in the fiber length direction, the odd-shaped fiber has a crystallinity of 40% or less, and the odd-shaped fiber is made of at least two kinds of thermoplastic resins. It is also preferable that that the nonwoven fabric structure contains a heat fusible fiber, the odd-shaped fiber is present in the form of a net-like fiber sheet, and the odd-shaped fiber is in the form of short fibers. In addition, a method for producing such a nonwoven fabric structure is a method in which a thermoplastic resin containing a foaming agent is extruded through a slit die to give an odd-shaped fiber having bubbles inside, followed by three-dimensional shaping.

Provided is a nonwoven fabric structure containing an odd-shaped fiber. The odd-shaped fiber has bubbles inside and has a cross-sectional shape that is an irregular, non-circular cross-section. Further, it is preferable that the cross-sectional shape of the odd-shaped fiber changes in the fiber length direction, the odd-shaped fiber has a crystallinity of 40% or less, and the odd-shaped fiber is made of at least two kinds of thermoplastic resins. It is also preferable that that the nonwoven fabric structure contains a heat fusible fiber, the odd-shaped fiber is present in the form of a net-like fiber sheet, and the odd-shaped fiber is in the form of short fibers. In addition, a method for producing such a nonwoven fabric structure is a method in which a thermoplastic resin containing a foaming agent is extruded through a slit die to give an odd-shaped fiber having bubbles inside, followed by three-dimensional shaping.

A method for making a fiber reinforcement with variations in transverse cross section is disclosed. The method includes forming a fiber comprising polymeric material and exposing the fiber to a heat treatment, such that at least a portion of the polymeric material at or near said surface of said fiber is at or above the melting point temperature and substantially all of the polymeric material at or near the core is below the melting point temperature. The method further includes cooling the fiber to a temperature below the melting point temperature.

A method for making a fiber reinforcement with variations in transverse cross section is disclosed. The method includes forming a fiber comprising polymeric material and exposing the fiber to a heat treatment, such that at least a portion of the polymeric material at or near said surface of said fiber is at or above the melting point temperature and substantially all of the polymeric material at or near the core is below the melting point temperature. The method further includes cooling the fiber to a temperature below the melting point temperature.

The invention relates to a nonwoven as well as to a wipe, a face mask, and a dryer sheet including the nonwoven, which includes a network of molded bodies, the nonwoven, in the dry state, having a specific opacity of greater than or equal to 1.0%.Math.m.sup.2/g. In order to create a nonwoven of low basis weight, which is easy to produce and has, without special modifications, a high specific opacity, it is proposed that the molded bodies are regenerated cellulosic molded bodies and are materially interconnected via node points to form the network, and the regenerated cellulosic molded bodies comprising monofilament sections extending between node points, whose diameter varies along their lengthwise extension and which have a diameter of less than or equal to 15 m for at least 90% of their lengthwise extension.

The invention relates to a nonwoven as well as to a wipe, a face mask, and a dryer sheet including the nonwoven, which includes a network of molded bodies, the nonwoven, in the dry state, having a specific opacity of greater than or equal to 1.0%.Math.m.sup.2/g. In order to create a nonwoven of low basis weight, which is easy to produce and has, without special modifications, a high specific opacity, it is proposed that the molded bodies are regenerated cellulosic molded bodies and are materially interconnected via node points to form the network, and the regenerated cellulosic molded bodies comprising monofilament sections extending between node points, whose diameter varies along their lengthwise extension and which have a diameter of less than or equal to 15 m for at least 90% of their lengthwise extension.