Disclosed are polymer nanofiber sensors for detecting gas, which generates visible color change although a specific gas having a concentration of less than 1 ppm is exposed to the sensor in a short time, in which it is impossible to detect the gas using existing colorimetric sensors, through securing high surface area and porosity, and a method of the same.

Disclosed are polymer nanofiber sensors for detecting gas, which generates visible color change although a specific gas having a concentration of less than 1 ppm is exposed to the sensor in a short time, in which it is impossible to detect the gas using existing colorimetric sensors, through securing high surface area and porosity, and a method of the same.

A method of forming color change fiber, comprises preparing polymer base material and preparing a plurality of warp yarns and a plurality of weft yarns , wherein the plurality of warp yarns are made by mixing a polymer base material with a color changeable material with a weight percentage ratio and the plurality of weft yarns are made of a polymer base material or natural fiber; forming a polymer fiber by spinning, weaving process for the warp yarns and the weft yarns, wherein the polymer fiber is color changeable when sunlight irradiates on the polymer fiber.

A method for controlling fiber cross-alignment in a nanofiber membrane, comprising: providing a multiple segment collector in an electrospinning device including a first and second segment electrically isolated from an intermediate segment positioned between the first and second segment, collectively presenting a cylindrical structure, rotating the cylindrical structure around a longitudinal axis proximate to an electrically charged fiber emitter; electrically grounding or charging edge conductors circumferentially resident on the first and second segment, maintaining intermediate collector electrically neutral; dispensing electrospun fiber toward the collector, the fiber attaching to edge conductors and spanning the separation space between edge conductors; attracting electrospun fiber attached to the edge conductors to the surface of the cylindrical structure, forming a first fiber layer; increasing or decreasing rotation speed of the cylindrical structure to alter the angular cross-alignment relationship between aligned nanofibers in adjacent layers, the rotation speed being altered to achieve a target relational angle.

Systems for producing M yarns, wherein M≥1, include N extruders, M spin stations, and a processor, wherein N>1. Each extruder includes a thermoplastic polymer having a color, hue, and/or dyability characteristic, which are different from each other. Each spin station produces one yarn comprising at least one bundle of filaments. Each spin station comprises at least one spinneret through which filaments are spun from at least two molten thermoplastic polymer streams received by the respective spin station and N spin pumps upstream of the spinneret for the respective spin station. Each spin pump is paired with one of the N extruders. The processor is in electrical communication with the N*M spin pumps and is configured to adjust the volumetric flow rate of the polymers pumped from each spin pump to achieve a ratio of the polymers to be included in each M yarn.

Fibrous structures, for example sanitary tissue products, containing a plurality of filaments that employ one or more filament-forming materials, such as one or more hydroxyl polymers, and one or more hueing agents, present within the filaments such that the fibrous structures exhibit a Whiteness Index of greater than 72 as measured according to the Whiteness Index Test Method described herein.

Fibrous structures, for example sanitary tissue products, containing a plurality of filaments that employ one or more filament-forming materials, such as one or more hydroxyl polymers, and one or more hueing agents, present within the filaments such that the fibrous structures exhibit a Whiteness Index of greater than 72 as measured according to the Whiteness Index Test Method described herein.

A polypropylene composition for a dyeable polypropylene filament yarn includes a polypropylene having a melt flow rate ranging from 30 g/10 min to 40 g/10 min, a polyester serving to modify the polypropylene and having a melt flow rate ranging from 40 g/10 min to 50 g/10 min, and a compatibilizer serving to improve compatibility between the polypropylene and the polyester. The polypropylene composition has a melt flow rate ranging from 30 g/10 min to 40 g/10 min.

A polypropylene composition for a dyeable polypropylene filament yarn includes a polypropylene having a melt flow rate ranging from 30 g/10 min to 40 g/10 min, a polyester serving to modify the polypropylene and having a melt flow rate ranging from 40 g/10 min to 50 g/10 min, and a compatibilizer serving to improve compatibility between the polypropylene and the polyester. The polypropylene composition has a melt flow rate ranging from 30 g/10 min to 40 g/10 min.

Methods of manufacturing bulked continuous carpet filament which, in various embodiments, comprise: (A) grinding recycled PET bottles into a group of flakes; (B) washing the flakes; (C) identifying and removing impurities, including impure flakes, from the group of flakes; (D) adding one or more color concentrates to the flakes; (E) passing the group of flakes through an MRS extruder (400) while maintaining the pressure within the MRS portion (420) of the MRS extruder (400) below about 25 millibars; (F) passing the resulting polymer melt through at least one filter (450) having a micron rating of less than about 50 microns; and (G) forming the recycled polymer into bulked continuous carpet filament that consists essentially of recycled PET.