4results about "Spinning solution filtering" patented technology

The application discloses a preparation method of low-grain-size polyacrylonitrile precursor. The method comprises the following steps: drying and densifying the fiber after hot water drawing and oiling through 10-25 hot rollers, wherein the hot roller pressure is 0.45-0.55 MPa, the temperature interval is 146-167 DEG C, the temperature gradient between the hot rollers is 3-5 DEG C, and then the fiber after the drying and densifying treatment is subjected to steam drawing under the steam pressure of 0.30-0.60 MPa, and the drawing ratio is 4.0-4.5 times, so as to obtain the low-grain-size polyacrylonitrile precursor. The application uses steam as the heating medium, and realizes the effective regulation of the grain size of the precursor by the low-temperature long-time drying and densifying technology and the high-multiple steam drawing technology, the regulation of the drying temperature and time of the precursor bundle, the gradual removal of the water molecules in the bundle by the outward diffusion, and the crystal rupture of the grains under the high stress by the high-multiple steam drawing.

This invention relates to the field of filter membrane preparation technology, specifically disclosing an equipment and process for preparing polyvinylidene fluoride (PVDF) membranes via phase inversion. The equipment includes a stirring and dissolving tank, a spinning tank, a core liquid tank, a spinneret, a first gel bath, a second gel bath, a winding device, and a control system. The stirring and dissolving tank and the spinning tank are connected via a first conveying assembly. Before spinning, this invention eliminates all air bubbles in the casting solution through the combined action of a mechanical stirring defoaming mechanism and a vibration defoaming mechanism in the spinning tank. This not only improves the quality of the subsequent spinning castings but also eliminates the need for a vacuum system. When the casting spinning traction speed changes, the fork-type telescopic adjustment frame can be adjusted via a telescopic drive component, thereby regulating the traction distance of the casting in the non-solvent or non-solvent mixture during traction. This ensures that the exchange rate between solvent and non-solvent in the casting remains the same, guaranteeing consistent product quality and performance.

A method of manufacturing bulked continuous carpet filament that includes providing a polymer melt and separating the polymer melt from the extruder into at least eight streams. The multiple streams are exposed to a chamber pressure within a chamber that is below approximately 25 millibars, or another predetermined pressure. The streams are recombined into a single polymer stream. Polymer from the polymer stream is then formed into bulked continuous carpet filament.

Systems and processes for producing short carbon fibers from an asphaltene-rich feedstock are disclosed. The asphaltene-rich feedstock are melted, filtered, and / or degassed before spinning into fibers. The molten feed may be spun using melt blowing or centrifugal spinning, to form random mats of discontinuous green fibers. These random mats of discontinuous fibers are suitable for transporting and processing using low-cost, standard bulk solids handling methods. In the methods discussed herein, the green fibers are first exposed within a reactor to a gas containing nitrogen dioxide (NO2) which infuses the fibers, thereby adding nitrogen oxide functional groups to the green fibers. The infused fibers are heated during which the infused fibers undergo oxidation leading to stabilization at low temperatures, allowing low softening point asphaltene-rich feeds to be successfully stabilized. The stabilized fibers are further heated in a substantially oxygen-free environment to carbonize the fibers to produce a random mat, discontinuous carbon fiber product. The produced random fiber material is suitable for blending into polymers or other matrices to produce random short carbon fiber reinforced products.