34results about How to "Small denier" patented technology

The invention relates to a preparation method of a high-performance polyacrylonitrile-based carbon fiber precursor. The method provided by the invention comprises the following steps of: (1) dissolving less high-performance polyacrylonitrile resin into a diluted polyacrylonitrile solution; (2) dissolving certain amount of polyacrylonitrile with conventional molecular weight into the diluted polyacrylonitrile solution with super-high molecular weight to obtain a polyacrylonitrile spinning solution; (3) obtaining a polyacrylonitrile carbon fiber precursor through utilizing a dry-wet spinning method; and (4) washing the primary precursor by water, stretching, carrying out a second-grade stretching by hot water, drying and densifying, and stretching by saturated steam to obtain the high-performance polyacrylonitrile-based carbon fiber precursor. Compared with the prior art, the method provided by the invention can prepare the good-quality polyacrylonitrile-based carbon fiber precursor with high strength, high modulus, high orientation degree and small fineness.

The invention relates to a superfine dacron low stretch yarn and a preparation method thereof. Modified polyester fusant is subjected to metering, extrusion, cooling, oiling and winding to prepare POYyarns; the POY yarns are subjected to yarn guide tube passing, networking, heating stretching, false twisting, heat setting and winding formation to prepare DTY yarns, i.e., the superfine dacron lowstretch yarn is obtained. During cooling, the longitudinal height is kept unchanged; the cross section area of a slow cooling chamber is increased; meanwhile, the slow cooling chamber maintains the plate surface temperature of a spinneret plate in a heat insulation mode; an oil agent for oiling contains crown ether; the content of the crown ether is 67.30 to 85.58 weight percent; the dihydric alcohol chain segment with branched chain is introduced into modified polyester; the prepared superfine dacron low stretch yarn has the filament number being smaller than 0.3dtex; the crimp shrinkage is 8.0+ / -1.0 percent; the crimp stability is greater than or equal to 75 percent. The method is simple and reasonable; the prepared superfine dacron low stretch yarn has the advantage of low fiber number.

The invention discloses a method for preparing a high-strength polyacrylonitrile-based carbon fiber precursor. The method comprises the steps of: using azodiisobutyronitrile to trigger acrylonitrile and a comonomer to perform homogeneous solution polymerization in dimethyl sulfoxide to obtain spinning solution, and controlling the temperature of the spinning solution to be between 40 and 70 DEG C and the solid content to be between 18 and 24 percent; performing monomer removal on the spinning solution under the pressure of between -60 and -78KPa, and performing deaeration treatment under the pressure of between -78 and -97KPa; then extruding the spinning solution into a spin duct in a coagulation bath with a temperature of between 35 and 65 DEG C and a dimethyl sulfoxide concentration of between 50 and 70 percent for molding through a spinneret, and obtaining PAN-based as-spun fiber through 45 to 75 percent of minus stretch in the coagulation bath; then molding and stretching through a secondary coagulation bath, a third coagulation bath, a fourth coagulation bath and a fifth coagulation bath; and obtaining the high-strength polyacrylonitrile-based carbon fiber precursor through solvent removal by water scrubbing, hot water stretch, oiling, drying and densification, steam stretch, and hot air setting. The tensile strength of the high-strength polyacrylonitrile-based carbon fiber precursor reaches 10.2cN / dtex.

The present invention relates to a high shrinkage side-by-side type composite filament, wherein two kinds of thermoplastic polymers are arranged side by side type and a boiling water shrinkage (Sr2) measured by the method (initial load = notified denier x 1 / 10g, static load = notified denier x 20 / 10g) of clause 5.10 of JIS L 1090 is 20 to 75% of a boiling water shrinkage (Sr1) measured by the method (initial load = notified denier x 1 / 30g, static load = notified denier x 40 / 30g) of clause 7.15 of JIS L 1013. The side-by-side type composite filament. is made of two kinds of thermoplastic polymers having a number average molecular weight difference (Mn) of 5,000 to 15,000 upon spinning and the composite filament is drawn and heat-treated so as to satisfy the following physical properties: Temperature area exhibiting 95% of maximum thermal stress (Tmax, 95%): 120 to 230 DEG C Range of maximum thermal stress per denier : 0.1 to 0.4g / denier.

The invention belongs to the technical field of melt-blowing and particularly relates to a composite wadding sheet and a preparation method and application thereof. The composite wadding sheet comprises a melt-blown fiber layer consisting melt-blown fiber and staple fiber; the diameter of the melt-blown fiber ranges from 200 nanometer and 2000 nanometer, and the mass percent content of the melt-blown fiber within the range of the diameter is greater than or equal to 80%. The composite wadding sheet has excellent resilience rate and voidage, its filtering effect, heat insulation, flame resistance, oil absorbency and noise reduction effect is increased by 10-60% as compared with that of the wadding sheet prepared of the general melt-blown fiber, and besides, the composite wadding sheet is poisonless and harmless.

The invention relates to a method of preparing ultrahigh molecular weight polyethylene fiber through gel spinning method. The method comprises the following steps: (1) preparing gel protofilament of ultrahigh molecular weight polyethylene; and (2) processing the gel protofilament through extracting, drying and hot drawing to obtain the ultrahigh molecular weight polyethylene fiber. The method is characterized in that the method also comprises the step of pre-drawing the gel protofilament obtained in the step (1) before the step (2), wherein the pre-drawing time is 2.2-24 times and the total hot drawing time in the step (2) is 30-45 times. The method of the invention can be used to obtain ultrahigh molecular weight polyethylene fiber product with low size and high breaking strength and theproduction cost is low.

The invention relates to a method for preparing ultrahigh-molecular-weight polyethylene fine denier fibers by a jelly spinning process, which comprises: (1) preparing jelly protofilaments of ultrahigh-molecular-weight polyethylene; and (2) subjecting the jelly protofilaments to pre-stretching, extraction, drying and hot stretching to obtain ultrahigh-molecular-weight polyethylene fine denier fibers, wherein the pre-stretching is performed for many times till the jelly protofilaments are stretched by 15 to 35 times totally, the many times of stretching are all performed in a stretching medium at 30 to 50 DEG C, the stretching medium is air, water or oil, and the jelly protofilaments are hotly stretched by 35 to 50 times totally. And after the step (1) and before the step (2), the method also comprises a step of standing the jelly protofilaments at a constant temperature of 20 to 40 DEG C and a constant humidity of 30 to 60 percent for 48 to 72 hours. When the method is used, low-titre and high-breaking-strength ultrahigh-molecular-weight polyethylene fine denier fiber products can be obtained, and the production cost is low.

The invention provides a method for preparing polyacrylonitrile-based carbon fiber precursors without a skin-core structure and belongs to the technical field of carbon fiber precursors. The method comprises the followings steps of: evenly mixing water or alcohol compounds and an organic solvent, adding polyacrylonitrile resin in the mixed solution, performing the heated swelling dissolution treatment, and filtering the mixed solution to obtain polyacrylonitrile spinning solution; and ageing the polyacrylonitrile spinning solution, performing spraying and extrusion to obtain primary precursors, and performing water-washing stretching, second-level hot water stretching, drying densification and saturated steam stretching of the primary precursors in sequence to obtain the polyacrylonitrile-based carbon fiber precursors. By the method, the good-quality polyacrylonitrile-based carbon fiber precursors having the advantages of no skin-core structure, less defects, small fiber number and high strength can be mass produced in large scale in the conventional industrialized spinning equipment, and the production cost can be effectively lowered.

The invention relates to a preparation method of a binary polyacrylonitrile carbon fiber precursor. The method comprises the following steps: mixing acrylonitrile, a second comonomer beta-itaconic acid ester amide and a solvent in the presence of nitrogen, and adding an initiator; reacting for 22-38 hours under the condition of 35-75 DEG C, so as to obtain an acrylonitrile polymer; then filtering, taking off and defoaming, so as to prepare a spinning solution; spinning the spinning solution by virtue of a dry-jet wet process, stretching, oiling, drying, densifying, drawing by hot steam, and thermoforming, so as to obtain the binary polyacrylonitrile carbon fiber precursor. By adopting the preparation method, double functional group beta-itaconic acid ester amide is adopted as a comonomer, and a polyacrylonitrile macromolecule for the carbon fiber precursor is prepared by binary copolymerization and substituted ternary copolymerization. Thus, the dosage of the comonomer is reduced, meanwhile, the structural regularity of the polyacrylonitrile macromolecule is improved, and the prepared carbon fiber precursor is even in structure, small in fineness and high in strength.