The present invention relates to improved polypropylene fibers and methods for producing the same as well as uses of such polypropylene fibers for the production of fiber cement products. The present invention further relates to fiber cement products, such as flat or corrugated fiber cement sheets, comprising the polypropylene fibers of the present invention. The fiber cement products of the present invention have an improved impact resistance as compared to fiber cement products not containing the polypropylene fibers of the present invention.

Processes for preparing ultra-high molecular weight polyethylene (UHMW PE) filaments and multi-filament yarns, and the yarns and articles produced therefrom. Each process produces UHMW PE yarns having tenacities of 45 g/denier to 60 g/denier or more at commercially viable throughput rates.

Disclosed herein is a biodegradable polyolefin fiber comprising a core formed of polyolefin and an oxide layer formed outside the core according to an embodiment of the present invention. According to the present invention, the polyolefin fiber is capable of having biodegradable properties by mixing raw materials and the biodegradable additive in a specific condition. In addition, the oxide layer is formed on the surface of the polyolefin fiber, thereby improving the initial oxo-biodegradation rate and reducing the biodegradation time.

Disclosed herein is a biodegradable polyolefin fiber comprising a core formed of polyolefin and an oxide layer formed outside the core according to an embodiment of the present invention. According to the present invention, the polyolefin fiber is capable of having biodegradable properties by mixing raw materials and the biodegradable additive in a specific condition. In addition, the oxide layer is formed on the surface of the polyolefin fiber, thereby improving the initial oxo-biodegradation rate and reducing the biodegradation time.

A process for producing a nonwoven fabric comprises the steps of a spinneret extruding a plurality of filaments, cooling the filaments with one or more cooling elements arranged below the spinneret, drawing the filaments in a drawing duct and laying the filaments on a movable support to form a nonwoven fabric. The process further comprises suctioning gas in a first suction device, heating the nonwoven fabric using a heated calender downstream of the first suction device to consolidate the filaments of the nonwoven fabric and to cause an increase in volume of the nonwoven fabric, suctioning gas below the movable support with a higher second suction speed, in a second suction device downstream of the heated calender, and suctioning gas below the movable support in a third suction region with a third suction speed lower than the second suction speed, by a shutter with one or more adjustable openings.

A method of making nonwoven webs comprising providing a spinneret including a pattern of conduits forming an extrusion region; directing only a first stream of molten propylene polymer into a region adjacent the first side of the spinneret, directing only a second stream of molten propylene polymer into a region distal to the first side of the spinneret, extruding only the first stream propylene polymer through the exit openings in a first zone where the exit opening comprises exit ports in the first zone having a first density; extruding only the second stream propylene polymer through the exit openings of a second zone where the exit opening comprises exit ports in the second zone having a second density less than the first density; and the second zone is distal to the first side with the first zone being between the second zone and the first side.

A method of making nonwoven webs comprising providing a spinneret including a pattern of conduits forming an extrusion region; directing only a first stream of molten propylene polymer into a region adjacent the first side of the spinneret, directing only a second stream of molten propylene polymer into a region distal to the first side of the spinneret, extruding only the first stream propylene polymer through the exit openings in a first zone where the exit opening comprises exit ports in the first zone having a first density; extruding only the second stream propylene polymer through the exit openings of a second zone where the exit opening comprises exit ports in the second zone having a second density less than the first density; and the second zone is distal to the first side with the first zone being between the second zone and the first side.

A nonwoven fabric comprises a first surface, a second surface, and a visually discernible pattern on at least one of the first and second surfaces. The visually discernible pattern has a regular, repeating pattern of three-dimensional features. Each of the three-dimensional features define a microzone comprising a first region and a second region. The first and second regions having a difference in values for an intensive property. The first surface has a TS7 value in the range of about 1 dB V.sup.2 rms to about 15 dB V.sup.2 rms. The second surface has a TS7 value in the range of about 1 dB V.sup.2 rms to about 15 dB V.sup.2 rms. A ratio of the TS7 value of the first surface to the TS7 value of the second surface is in the range of about 1 to about 3.

A nonwoven fabric comprises a first surface, a second surface, and a visually discernible pattern on at least one of the first and second surfaces. The visually discernible pattern has a regular, repeating pattern of three-dimensional features. Each of the three-dimensional features define a microzone comprising a first region and a second region. The first and second regions having a difference in values for an intensive property. The first surface has a TS7 value in the range of about 1 dB V.sup.2 rms to about 15 dB V.sup.2 rms. The second surface has a TS7 value in the range of about 1 dB V.sup.2 rms to about 15 dB V.sup.2 rms. A ratio of the TS7 value of the first surface to the TS7 value of the second surface is in the range of about 1 to about 3.

A method is provided for producing solid cellulose filaments or films from a solution of cellulose, NMMO (N-methylmorpholine-N-oxide) and water, including pressure-extruding the solution by one or more extrusion openings and by solidifying the filaments or films in a precipitation bath. The solution is guided between the extrusion opening and the precipitation bath by an air gap, the temperature of the solution on the extrusion opening being lower than 105 C. and the pressure difference in the air gap between the pressure of the solution immediately prior to extrusion and after extrusion is between 8 and 40 bar.