The present disclosure is directed toward an improved nanofibrous electret filtration media of which the stand-alone electret nanofibrous web comprises a single source randomly intermingled fiber network that yields high breathability due to the high porosity and improved filtration efficiency for use as improved filtration media for respiratory devices and face masks.

The present disclosure is directed toward an improved nanofibrous electret filtration media of which the stand-alone electret nanofibrous web comprises a single source randomly intermingled fiber network that yields high breathability due to the high porosity and improved filtration efficiency for use as improved filtration media for respiratory devices and face masks.

A fiber bundle containing a plurality of fibers that are twisted about a longitudinal axis is provided. At least a portion of the fibers are formed from a thermoplastic composition containing a continuous phase that includes a polyolefin matrix polymer and a nanoinclusion additive dispersed within the continuous phase in the form of discrete domains. A porous network is defined in the composition that includes a plurality of nanopores.

A fiber bundle containing a plurality of fibers that are twisted about a longitudinal axis is provided. At least a portion of the fibers are formed from a thermoplastic composition containing a continuous phase that includes a polyolefin matrix polymer and a nanoinclusion additive dispersed within the continuous phase in the form of discrete domains. A porous network is defined in the composition that includes a plurality of nanopores.

A method for forming filaments, wherein the method uses a die assembly suitable for spinning filaments and more particularly to a die assembly having a fluid environment around the die assembly's filament exit holes is provided.

A composite hot-melt adhesive mesh film and preparation process thereof, in particular, a composite hot-melt adhesive mesh film and preparation process thereof for bonding metal and non-polar material are disclosed. The mesh film is compounded of a polar polyamide hot-melt adhesive and a non-polar polyolefin hot-melt adhesive mesh film containing a compatibilizer. The mesh film has a high adhesive strength and a durable and stable adhesion, and is especially suitable for bonding stainless steel, aluminum, copper or other metal materials and polyethylene, polypropylene or other non-polar polymers. Additionally, the preparation process is completed in one set of production process from raw material pretreatment to the final preparation of the hot melt adhesive mesh film product, thereby greatly reducing production failures, and providing high production efficiency and low costs.

A composite hot-melt adhesive mesh film and preparation process thereof, in particular, a composite hot-melt adhesive mesh film and preparation process thereof for bonding metal and non-polar material are disclosed. The mesh film is compounded of a polar polyamide hot-melt adhesive and a non-polar polyolefin hot-melt adhesive mesh film containing a compatibilizer. The mesh film has a high adhesive strength and a durable and stable adhesion, and is especially suitable for bonding stainless steel, aluminum, copper or other metal materials and polyethylene, polypropylene or other non-polar polymers. Additionally, the preparation process is completed in one set of production process from raw material pretreatment to the final preparation of the hot melt adhesive mesh film product, thereby greatly reducing production failures, and providing high production efficiency and low costs.

A spinning beam for producing melt-spun filaments, in which liquid plastics material is conveyed via an externally arranged extruder to at least one pump, which conveys the liquid plastics material to at least one spin pack having a spinneret, at least the pump and the spin pack being heated by a heat transfer medium which is heated in a boiler. The pump, the boiler and an opening for receiving a spin pack are arranged in a modular assembly, which can be installed and fixed singly, or in a plurality one behind the other, in a frame of the spinning beam.

A spinning nozzle which has a perforated part in which ejection holes have been arranged in a density as high as 600-1,200 holes/mm.sup.2. This process for producing a fibrous bundle comprises ejecting a spinning dope having a viscosity as measured at 50° C. of 30-200 P from the ejection holes of the spinning nozzle to produce a fibrous bundle. This fibrous bundle has a single-fiber fineness of 0.005-0.01 dtex. By the wet-process direct spinning, a mass of nanofibers which are stably uniform and continuous can be produced at a high efficiency.

A spinning nozzle which has a perforated part in which ejection holes have been arranged in a density as high as 600-1,200 holes/mm.sup.2. This process for producing a fibrous bundle comprises ejecting a spinning dope having a viscosity as measured at 50° C. of 30-200 P from the ejection holes of the spinning nozzle to produce a fibrous bundle. This fibrous bundle has a single-fiber fineness of 0.005-0.01 dtex. By the wet-process direct spinning, a mass of nanofibers which are stably uniform and continuous can be produced at a high efficiency.